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Abstract

Mainstream dietary recommendations now commonly advise people to minimize the intake of red meat for health and environmental reasons. Most recently, a major report issued by the EAT-Lancet Commission recommended a planetary reference diet mostly based on plants and with no or very low (14 g/d) consumption of red meat. We argue that claims about the health dangers of red meat are not only improbable in the light of our evolutionary history, they are far from being supported by robust scientific evidence. OPEN ACCESS here: https://www.tandfonline.com/doi/full/10.1080/10408398.2019.1657063?
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Should dietary guidelines recommend low red
meat intake?
Frédéric Leroy & Nathan Cofnas
To cite this article: Frédéric Leroy & Nathan Cofnas (2019): Should dietary guidelines
recommend low red meat intake?, Critical Reviews in Food Science and Nutrition, DOI:
10.1080/10408398.2019.1657063
To link to this article: https://doi.org/10.1080/10408398.2019.1657063
© 2019 The Author(s). Published with
license by Taylor & Francis Group, LLC.
Published online: 05 Sep 2019.
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REVIEW
Should dietary guidelines recommend low red meat intake?
Fr
ed
eric Leroy
a
and Nathan Cofnas
b
a
Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bioengineering Sciences, Vrije
Universiteit Brussel, Pleinlaan 2, Brussels, B-1050, Belgium;
b
Balliol College, University of Oxford, Oxford, OX1 3BJ, UK
ABSTRACT
Mainstream dietary recommendations now commonly advise people to minimize the intake of red
meat for health and environmental reasons. Most recently, a major report issued by the EAT-
Lancet Commission recommended a planetary reference diet mostly based on plants and with no
or very low (14 g/d) consumption of red meat. We argue that claims about the health dangers of
red meat are not only improbable in the light of our evolutionary history, they are far from being
supported by robust scientific evidence.
KEYWORDS
red meat; health;
vegetarianism; veganism;
dietary guidelines; disease
1. Introduction
On January 16
th
, 2019, the EAT-Lancet Commission for-
mally expressed its desire for a Great Food Transformation
toward a predominantly plant-based diet for the planet
(Willett et al., 2019). The proposed reference diet includes
minute daily doses of beef (7 g), pork (7 g), and eggs (13 g),
with somewhat larger amounts of poultry (29 g) and fish
(28 g). Despite heavy restrictions on other animal source
foods, it allows for 250 g of dairy products per day, with a
limit of 153 kcal. Stricter vegetarian and even vegan diets
were sanctioned as valid options too, provided that vitamin
B12 supplements are taken in the case of veganism. In the
words of the Commission: This healthy reference diet
includes a low to moderate amount of seafood and
poultry, and includes no or a low quantity of red meat,
processed meat(Willett et al., 2019). One of the key
messagesis that Healthy diets consist of a diversity of
plant-based foods, low amounts of animal source foods.
Red meat is specifically labeled as an unhealthy food.
While the authors acknowledge that livestock products can
offer benefits for those who are nutritionally deficient, a
strong reduction of animal products was said to be benefi-
cial for both health and the environment. Soon after the
release of this EAT-Lancet report, a similar argument was
made by yet another Lancet Commission, classifying meat as
a driver of the Global Syndemica system of interconnected
global crises related to health and the environmentand
arguing for an interventionist approach through mass-mar-
keting campaigns and legal measures, including the manda-
tory use of warning labels and the application of taxes
(Swinburn et al., 2019). Previously, other groups associated
with the EAT-Lancet Commission have made similar recom-
mendations. A study whose first author belongs to the EAT-
Lancet Commission recently called for taxes on meat
consumption (Springmann et al., 2018). The World
Research Institute, a direct partner of the EAT-Lancet net-
work, considers various interventions to reduce meat eating
with varying degrees of compulsion (e.g., influencing nutri-
tional labeling and dietary guidelines, stimulating 30-day
diet challenges, imposing taxes, and banning meat from
menus) (Ranganathan et al., 2016).
Contemporary arguments against meat eating appeal
mostly to nutritional, environmental, and ethical considera-
tions (Leroy, 2019). The present review focuses on nutrition.
Although the environmental and ethical arguments should
certainly not be overlooked, these require separate analyses.
Furthermore, the nutritional debate has its own complexities
and controversies, for instance with respect to the potential
health implications of shifts in macronutrient ratios toward
elevated levels of carbohydrates (e.g., Deghan et al., 2017)or
the reliance on ample amounts of cereals (e.g., Antvorskov
et al., 2018), soy (e.g., Siepmann et al., 2011), and plant oils
(e.g., DiNicolantonio, 2014). The present overview, therefore,
will be dedicated to the specific topic of severe meat restric-
tion or avoidance and the potential impact of such dietary
restriction on health. Ultimately, the conclusions will have
to be integrated into a more holistic evaluation that balances
nutrition, sustainability, and ethics.
2. Meat and health: a shifting paradigm?
Humans are biologically adapted to a diet that includes
meat. Archeological findings suggest that hominins were
butchering animals with stone tools 2.5 million years ago
(de Heinzelin et al., 1999). At some point we lost the ability
to absorb vitamin B12 in the large intestine, where it is pro-
duced by gut bacteria, making man dependent on dietary
sources of the vitamin (Schjønsby, 1989). Presumably our
ancestors were able to survive losing this ability because
CONTACT Nathan Cofnas nathan.cofnas@balliol.ox.ac.uk Balliol College, University of Oxford, Oxford, UK.
ß2019 The Author(s). Published with license by Taylor & Francis Group, LLC
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION
https://doi.org/10.1080/10408398.2019.1657063
they were regularly consuming B12-rich meat (Lents, 2018).
Hominin skeletal remains from 1.5 million years ago show
signs of porotic hyperostosis, which is generally linked to
B12 deficiency and is virtually absent in chimpanzees who
still obtain B12 from gut bacteria (Dom
ınguez-Rodrigo
et al., 2012). This provides some evidence that by at least
the early Pleistocene meat had become so essential to proper
hominin functioning that its paucity or lack led to deleteri-
ous pathological conditions(Dom
ınguez-Rodrigo et al.,
2012). Over time our capacity to convert the omega-3 fatty
acid alpha-linolenic acid (ALA), found in plants, to the bio-
logically important eicosapentaenoic acid (EPA) and docosa-
hexaenoic acid (DHA) forms (found primarily in seafood,
but also in meat, eggs, and dairy; Tur et al., 2012) became
greatly reduced in comparison to other primates (Stark
et al., 2016). The shift to energy-dense meat caused our
guts, particularly our large intestines, to shrink significantly
compared to those of apes. Gut proportions in humans are
also adapted to meat eating. Our small intestine (in which
most nutrients are extracted) comprises 56% of total gut vol-
ume, while the large intestine comprises about 20%these
proportions are reversed in apes (Milton, 2003). Meat eating,
and the concomitant reduction in size of the energy-con-
suming gut, is believed to have played an essential role in
the increase of brain size in the hominin lineage. Because
the brain and gut compete for energy, the former was able
to increase in size when the latter became smaller (Aiello &
Wheeler, 1995). Gupta (2016) expounds: To build and
maintain a more complex brain, our ancestors used ingre-
dients found primarily in meat, including iron, zinc, vitamin
B12 and fatty acids. Although plants contain many of the
same nutrients, they occur in lower quantities and often in a
form that humans cannot readily use.
The fact that we are biologically adapted to diets that
include substantial amounts of meat does not by itself prove
that low-meat diets cannot be healthy. However, when it
comes to virtually every other species, we generally take it for
granted that it will flourish best on a diet that roughly resem-
bles the one to which it was adapted. It would be, though not
impossible, somewhat surprising if Homo sapiens turned out
to be such a spectacular exception to this principle.
Nevertheless, mainstream nutrition discourse often portrays
meat as a health disaster (see Leroy, 2019), suggesting that it
can be readily replaced with legumes and B12 supplements,
and whereby additional confusion is generated by sensational-
ist misrepresentations of the scientific evidence in mass media
(Leroy et al., 2018a). Nonetheless, the anti-meat discourse is
able to refer to a large set of international and peer-reviewed
scientific data that have been institutionalized in dietary
advice from various health authorities worldwide (e.g., WHO,
2015; NHS, 2018). These data are, for the largest part, gener-
ated from observational studies within the domain of nutri-
tional epidemiology, the limitations of which will be discussed
below. Taken together, it is repeatedly stated in academic lit-
erature that high meat intake is associated with higher mortal-
ity (Sinha et al., 2009; Pan et al., 2012; Larsson & Orsini, 2014;
Etemadi et al., 2017), cardiometabolic illnesses (Pan et al.,
2011; Chen et al., 2013; Feskens et al., 2013; Abete et al., 2014;
Yang et al., 2016; Kim & Je, 2018), diverse types of cancer
(Huang et al., 2013; Farvid et al., 2015; Carr et al., 2016), and
intestinal disorders (Cao et al., 2018). The above-mentioned
Lancet reports (Swinburn et al., 2019; Willett et al., 2019)
make recommendations based on this research, assuming
causal relationships between meat intake and morbidity
and mortality.
3. Meat eating and chronic disease: evaluation of
the evidence
3.1. Evidence from observational studies needs to be
interpreted with care
Despite the merits of epidemiology as a scientific discipline,
an overwhelming corpus of often non-robust and overstated
observational findings has been amassing over the last deca-
des in the field of nutrition (Ioannidis, 2018). Naïve inter-
pretations of these findings are often promoted by the
media and influence nutritional guidelines. Ioannidis illus-
trates the absurdity of taking them at face value:
Assuming the meta-analyzed evidence from cohort studies
represents life span-long causal associations, for a baseline life
expectancy of 80 years, eating 12 hazelnuts daily (1 oz) would
prolong life by 12 years (i.e., 1 year per hazelnut), drinking 3
cups of coffee daily would achieve a similar gain of 12 extra
years, and eating a single mandarin orange daily (80 g) would
add 5 years of life. Conversely, consuming 1 egg daily would
reduce life expectancy by 6 years, and eating 2 slices of bacon
(30 g) daily would shorten life by a decade, an effect worse than
smoking. (Ioannidis, 2018)
Schoenfeld and Ioannidis (2013) found that, among 50 com-
mon ingredients used in a cookbook, 40 had been associated
with cancer risk or benefit based on observational studies.
As a first point of concern, the input data obtained from
food frequency questionnaires should be interpreted pru-
dently as they can be problematic for a variety of reasons
(Schatzkin et al., 2003; Archer et al., 2018; Feinman, 2018).
Social desirability bias in food reporting is just one example,
as reported consumption can be affected by the perceived
health status of certain foods. Not all self-defined vegetarians
avoid meat, which is suggestive of a considerable risk for
underreported intake in health-conscious groups (Haddad &
Tanzman, 2003).
Secondly, diets are difficult to disentangle from other life-
style factors. It has been shown that Western-style meat eat-
ing is closely associated with nutrient-poor diets, obesity,
smoking, and limited physical activity (Alexander et al.,
2015; Fogelholm et al., 2015; Grosso et al., 2017; Turner &
Lloyd, 2017). Given the fact that health authorities have
been intensely promoting the view that meat is unhealthy,
health-conscious people may be inclined to reduce intake.
Typically, the associations between meat eating and disease
tend to be higher in North American than in European or
Asian cohort studies, indicating the presence of lifestyle bias
and the need for cross-cultural assessments (Wang et al.,
2016; Grosso et al., 2017; Hur et al., 2018). A pooled ana-
lysis of prospective cohort studies in Asian countries even
indicated that red meat intake was associated with lower
2 F. LEROY AND N. COFNAS
cardiovascular mortality in men and cancer mortality in
women (Lee et al., 2013). Likewise, when omitting Seventh-
Day Adventist studies from meta-analyses, the beneficial
associations with cardiovascular health for vegetarian diets
are either less pronounced or absent indicating the specific
effects of health-conscious lifestyle rather than low meat
consumption as such (Kwok et al., 2014; FCN, 2018). This is
important, as Seventh-Day Adventism has had considerable
influence on dietary advice worldwide (Banta et al., 2018).
As a third point, the relative risks (RRs) obtained from
observational studies are generally low, i.e., much below 2.
In view of the profusion of false-positive findings and the
large uncertainty and bias in the data due to the problems
mentioned above (Boffetta et al., 2008; Young & Karr,
2011), such low RR levels in isolation would not be treated
as strong evidence in most epidemiological research outside
nutrition (Shapiro, 2004; Klurfeld, 2015). Relationships with
RRs below 2, which are susceptible to confounding, can be
indicative but should always be validated by other means,
such as randomized controlled trials (RCTs) (Gerstein et al.,
2019). The association between meat eating and colorectal
cancer, for instance, leads to an RR estimate below 1.2,
whereas for the association between visceral fat and colorec-
tal neoplasia this value equals 5.9 (Yamamoto et al., 2010).
The latter provides a robust case that is much more deserv-
ing of priority treatment in health policy development.
To sum up, the case propagated by the EAT-Lancet
Commission (Willett et al., 2019) has essentially been based
on observational studies with RRs much below 2 (e.g., Sinha
et al., 2009; Pan et al., 2011,2012; Chen et al., 2013; Feskens
et al., 2013; Lee et al., 2013; Abete et al., 2014; Farvid et al.,
2015; Etemadi et al., 2017). We find this particularly prob-
lematic, as it is not good practice to infer a causal connec-
tion to meat eating from such weak and confounded
associational data (McAfee et al., 2010; Alexander et al.,
2015; Klurfeld, 2015; Feinman, 2018; Leroy et al., 2018b).
Moreover, the science used to incorporate the data from
meat studies into dietary policy making is all-too often par-
tial and inaccurate (Truswell, 2009). This concern is under-
lined by the fact that claims from observational
epidemiology very often fail to hold up when tested in
RCTs (Young & Karr, 2011). Nutritional epidemiology is a
useful tool for the generation of hypotheses, but its findings
as such do not provide a robust basis for the implementa-
tion of health policies in the absence of further substanti-
ation. Or, as stated by Gerstein et al. (2019), analyses of
most observational data from the real world, regardless of
their sophistication, can only be viewed as hypothesis gener-
ating. This is especially so when the results are counterin-
tuitive, as is the case for meat eating given its long record as
an essential food within our species-adapted diet.
3.2. Intervention studies have not been able to indicate
unambiguous detrimental effects
As stated by Abete et al. (2014), epidemiological findings on
meat eating should be interpreted with caution due to the
high heterogeneity observed in most of the analyses as well
as the possibility of residual confounding. The interactions
between meat, overall diet, human physiology (including the
gut microbiome), and health outcomes are highly intricate.
Within this web of complexity, and in contrast to what is
commonly stated in the public domain (Leroy et al., 2018a),
the current epidemiological and mechanistic data have not
been able to demonstrate a consistent causal link between
red meat intake and chronic diseases, such as colorectal can-
cer (Oostindjer et al., 2014; Turner & Lloyd, 2017).
RCTs can play an important role in establishing causal
relationships, and generally provide much stronger evidence
than that provided by observational data. However, even
RCTs are not fail-safe and can also be prone to a range of
serious flaws (Krauss, 2018). Intervention studies that over-
look the normal dietary context or use non-robust bio-
markers should be interpreted with caution, and do not
justify claims that there is a clear link between meat and
negative health outcomes (see Turner & Lloyd, 2017; Kruger
& Zhou, 2018). The available evidence generally suggests
that interventions with red meat do not lead to an elevation
of in vivo oxidative stress and inflammation, which are usu-
ally cited as being part of the underlying mechanisms trig-
gering chronic diseases (Mann et al., 1997; Hodgson et al.,
2007; Turner et al., 2017). Even in an epidemiological cohort
study that was suggestive of an inflammatory response based
on an increased CRP level, this effect became non-significant
upon adjustment for obesity (Montonen et al., 2013).
Moreover, a meta-analysis of RCTs has shown that meat
eating does not lead to deterioration of cardiovascular risk
markers (OConnor et al., 2017). The highest category of
meat eating even paralleled a potentially beneficial increase
in HDL-C level. Whereas plant-based diets indeed seem to
lower total cholesterol and LDL-C in intervention studies,
they also increase triglyceride levels and decrease HDL-C
(Yokoyama et al., 2017), which are now often regarded as
superior markers of cardiovascular risk (Jeppesen
et al., 2001).
Based on the above, we conclude that there is a lack of
robust evidence to confirm an unambiguous mechanistic
link between meat eating as part of a healthy diet and the
development of Western diseases. It is paramount that the
available evidence is graded prior to developing policies and
guidelines, making use of quality systems such as GRADE
(Grading of Recommendations Assessment, Development
and Evaluation; Guyatt et al., 2008). One of the founders of
the GRADE system has issued a public warning that the sci-
entific case against red meat by the IARC panel of the
WHO has been overstated, doing the public a disservice
(Guyatt, 2015). The IARCs(2015) claim that red meat is
probably carcinogenichas never been substantiated. In
fact, a risk assessment by Kruger and Zhou (2018) con-
cluded that this is not the case. Such hazard classification
systems have been heavily criticized, even by one of the
members of the IARC working group on red meat and can-
cer (Klurfeld, 2018). They are accused of being outmoded
and leading to avoidable health scares, public funding of
unnecessary research and nutritional programs, loss of
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 3
beneficial foods, and potentially increased health costs
(Boyle et al., 2008; Anonymous, 2016; Boobis et al., 2016).
3.3. A scientific assessment should not overlook
conflicting data
Dietary advice that identifies meat as an intrinsic cause of
chronic diseases often seems to suffer from cherry-picking
(Feinman, 2018). One example of a fact that is typically
ignored is that hunter-gatherers are mostly free of cardiome-
tabolic disease although animal products provide the domin-
ant energy source (about two-thirds of caloric intake on
average, with some hunter-gatherers obtaining more than
85% of their calories from animal products; Cordain et al.,
2000,2002). In comparison, contemporary Americans obtain
only about 30% of calories from animal foods
(Rehkamp, 2016).
Whereas per capita consumption of meat has been drop-
ping over the last decades in the US, cardiometabolic dis-
eases such as type-2 diabetes have been rapidly increasing.
Although this observation does not resolve the question of
causality one way or the other, it should generate some
skepticism that meat is the culprit (Feinman, 2018).
Moreover, several studies have found either that meat intake
has no association with mortality/morbidity, or that meat
restriction is association with various negative health out-
comes (e.g., Key et al., 2009; Burkert et al., 2014; Kwok
et al., 2014; Lippi et al., 2015; Hur et al., 2018; Iguacel et al.,
2018; Yen et al., 2018). As another example of conflicting
information, the epidemiological association pointing to a
potential role of the meat nutrient L-carnitine in atheroscler-
osis via trimethylamine N-oxide (TMAO) formation (Koeth
et al., 2013), is contradicted by intervention studies
(Samulak et al., 2019) and epidemiological data showing
that fish intake, being by orders of magnitude the largest
supplier of TMAO (Zhang et al., 1999), improves triglycer-
ides and HDL levels (Alhassan et al., 2017).
Although all of the aforementioned studiesparticularly
the observational onesclearly have their limitations, they
equally deserve to be incorporated in the scientific analysis
and health debates.
4. The nutritional benefits of meat
Throughout human history, meat has delivered a wide range
of valuable nutrients that are not always easily obtained (or
obtainable) from plant materials (Williams, 2007; McAfee
et al., 2010; Pereira & Vicente, 2013; Young et al., 2013;
McNeill, 2014; Leroy et al., 2018b). A major asset of meat is
of course its high protein value (Burd et al., 2019), with
especially lysine, threonine, and methionine being in short
supply in plant-derived diets. It brings in B vitamins (with
vitamin B12 being restricted to animal sources only), vita-
mins A, D, and K2 (particularly via organ meats), and vari-
ous minerals with iron, zinc, and selenium being of
particular importance. Also, the long-chain omega-3 fatty
acids EPA and DHA present in animal sources are only
poorly obtained in vivo from a-linolenic acid conversion
(Cholewski et al., 2018), making plants a suboptimal source.
Despite being overlooked in most nutritional evaluations,
meat also contains various bioactive components as taurine
(Laidlaw et al., 1988), creatine (Rae et al., 2003; Benton &
Donohoe, 2011), carnosine (Everaert et al., 2011), as well as
conjugated linoleic acid, carnitine, choline, ubiquinone, and
glutathione (Williams, 2007). These components can offer
important nutritional benefits, for instance with respect to
the optimal development of cognitive functions.
Sufficient intake of animal products is therefore particu-
larly advisable for population groups with enhanced nutri-
tional needs and is helpful to offer nutritional robustness
during various stages of life. As such, it contributes to the
physical and cognitive development of infants and children
(Neumann et al., 2007; Hulett et al., 2014; Tang & Krebs,
2014; Cofnas, 2019) and prevents deficiencies in young
females (Fayet et al., 2014; Hall et al., 2017). In the elderly,
sufficient meat intake can prevent or improve malnutrition
and sarcopenia, also improving health-related quality of life
(Pannemans et al., 1998; Shibata, 2001; Phillips, 2012;
Rondanelli et al., 2015; Torres et al., 2017).
5. Meat avoidance leads to a loss of
nutritional robustness
Diets poor in animal source foods can lead to various nutri-
tional deficiencies, as already described more than a century
ago for the case of pellagra (Morabia, 2008), a condition
which remains relevant today for poorly planned vegan diets
(Ng & Neff, 2018). Advocates of vegetarian/vegan diets usu-
ally admit that these diets must indeed be well-plannedin
order to be successful, which involves regular supplementa-
tion with nutrients such as B12. However, realistically, many
people are not diligent about supplementation, and will
often dip into deficient or borderline-deficient ranges if they
do not obtain nutrients from their regular diet. In such
cases, general malnutrition (Ingenbleek & McCully, 2012),
poorer health (Burkert et al., 2014), and nutrient limitations
(Kim et al., 2018) may be the result, as found in various
countries, such as Denmark (Kristensen et al., 2015),
Finland (Elorinne et al., 2016), Sweden (Larsson &
Johansson, 2002), and Switzerland (Sch
upbach et al., 2017).
For example, a substantial number of vegetarians and vegans
are in the deficient or borderline-deficient range for B12
(Herrmann & Geisel, 2002; Herrmann et al., 2003), despite
the fact that the need for B12 supplementation is well-publi-
cized (see also Herbert, 1994; Hokin & Butler, 1999;
Donaldson, 2000; Elmadfa & Singer, 2009; Gilsing et al.,
2010; Obersby et al., 2013; Pawlak et al. 2013,2014; Pawlak,
2015; Woo et al., 2014; Naik et al., 2018). B12 deficiency is
particularly dangerous during pregnancy (Specker et al.,
1988,1990; Bjørke Monsen et al., 2001; Koebnick et al.,
2004), childhood (Rogers et al., 2003) and adolescence (van
Dusseldorp et al., 1999; Louwman et al., 2000).
Other potentially challenging micronutrients for people
on plant-based diets include (but are not limited to) iodine
(Krajcovicov
a-Kudl
ackov
a et al., 2008; Leung et al., 2011;
Brantsaeter et al., 2018), iron (Wilson & Ball, 1999;
4 F. LEROY AND N. COFNAS
Wongprachum et al., 2012; Awidi et al., 2018), selenium
(Schultz & Leklem, 1983; Kadrabov
a et al., 1995), and zinc
(Foster et al., 2013). Even if plant-based diets contain alpha
linolenic acid, this may not (as noted) prevent deficiencies
in the long-chain omega-3 fatty acids EPA and DHA (Rosell
et al., 2005), which can pose serious risks in pregnancy and
for growing children (Burdge et al., 2017; Cofnas, 2019).
Risks of nutritional deficiency are also documented by an
extensive list of clinical case reports in the medical literature,
with serious and sometimes irreversible pathological symp-
toms being reported for infants (e.g., Shinwell & Gorodisher,
1982; Zengin et al., 2009; Guez et al., 2012; Bravo et al.,
2014; Kocaoglu et al., 2014; Goraya et al., 2015), children
(e.g., Colev et al., 2004; Crawford & Say, 2013), adolescents
(e.g., Chiron et al., 2001; Licht et al., 2001;OGorman et al.,
2002), and adults (e.g., Milea et al., 2000; Brocadello et al.,
2007; De Rosa et al., 2012; Førland & Lindberg, 2015). The
latter reports commonly refer to failure to thrive, hyperpara-
thyroidism, macrocytic anemia, optic and other neuropa-
thies, lethargy, degeneration of the spinal cord, cerebral
atrophy, and other serious conditions. Although the direc-
tion of causality is not clear, meat avoidance is statistically
associated with eating disorders and depression (Zhang
et al., 2017; Barthels et al., 2018; Hibbeln et al., 2018; Matta
et al., 2018; Nezlek et al., 2018) and may mirror neurological
problems (Kapoor et al., 2017).
Our main concern is that avoiding or minimizing meat
consumption too strictly may compromise the delivery of
nutrients, especially in children and other vulnerable popula-
tions. Evidently, health effects of plant-based approaches
depend largely on the dietary composition (Satija et al.,
2016). Yet, the more restricted the diet and the younger the
age, the more this will be a point of attention (Van Winckel
et al., 2011). According to Cofnas (2019), however, even
realistic vegetarian diets that include diligent supplementa-
tion can put children at risk for deficiencies and thereby
compromise health in both the short and long term. There
is some direct and indirect evidence that the elevated phyto-
estrogen intake associated with low-meat diets may pose
risks for the development of the brain and reproductive sys-
tem (Cofnas, 2019). Moreover, attempts to introduce dietary
modifications that are also compatible with vegan philoso-
phy often pose a medicosocial challenge (Shinwell &
Gorodischer, 1982). In our opinion, the official endorsement
of diets that avoid animal products as healthy options is
posing a risk that policy makers should not be taking. As
stated by Giannini et al. (2006): It is alarming in a devel-
oped country to find situations in which a childs health is
put at risk by malnutrition, not through economic problems
but because of the ideological choices of the parents.
6. Conclusions
Although meat has been a central component of the diet of
our lineage for millions of years, some nutrition author-
itieswho often have close connections to animal rights
activists or other forms of ideological vegetarianism, such as
Seventh-Day Adventism (Banta et al., 2018)are promoting
the view that meat causes a host of health problems and has
no redeeming value. We contend that a large part of the
case against meat is based on cherry-picked evidence and
low-quality observational studies. The bald claim that red
meat is an unhealthy food(Willett et al., 2019) is wildly
unsupported.
Based on misrepresentations of the state of the science,
some organizations are attempting to influence policy mak-
ers to take action to reduce meat consumption.
Simplification of complex science increases persuasive power
but may also serve ideological purposes and lead to scientis-
tic approaches. According to Mayes and Thompson (2015),
manifestations of nutritional scientism in the context of bio-
politics can have various ethical implications for individual
responsibility and freedom, concerning iatrogenic harm, and
for well-being. Well-meaning yet overemphasized and pre-
mature recommendations may eventually cause more dam-
age than benefit, not only physiologically but also by
unjustifiably holding individuals accountable for their health
outcomes. We believe that a large reduction in meat con-
sumption, such as has been advocated by the EAT-Lancet
Commission (Willett et al., 2019), could produce serious
harm. Meat has long been, and continues to be, a primary
source of high-quality nutrition. The theory that it can be
replaced with legumes and supplements is mere speculation.
While diets high in meat have proved successful over the
long history of our species, the benefits of vegetarian diets
are far from being established, and its dangers have been
largely ignored by those who have endorsed it prematurely
on the basis of questionable evidence.
Acknowledgements
FL acknowledges financial support of the Research Council of the Vrije
Universiteit Brussel, including the SRP7 and IOF342 projects, and in
particular the Interdisciplinary Research Program Tradition and natur-
alness of animal products within a societal context of change(IRP11).
References
Abete, I., D. Romaguera, A. R. Vieira, A. Lopez de Munain, and T.
Norat. 2014. Association between total, processed, red and white
meat consumption and all-cause, CVD and IHD mortality: a meta-
analysis of cohort studies. British Journal of Nutrition 112 (5):
76275. doi: 10.1017/S000711451400124X.
Aiello, L. C., and P. Wheeler. 1995. The expensive-tissue hypothesis:
the brain and the digestive system in human and primate evolution.
Current Anthropology 36 (2):199221. doi: 10.1086/204350.
Alexander, D. D., D. L. Weed, P. E. Miller, and M. A. Mohamed. 2015.
Red meat and colorectal cancer: a quantitative update on the state
of the epidemiologic science. Journal of the American College of
Nutrition 34 (6):52143. doi: 10.1080/07315724.2014.992553.
Alhassan, A.,. J. Young, M. E. J. Lean, and J. Lara. 2017. Consumption
of fish and vascular risk factors: a systematic review and meta-ana-
lysis of intervention studies. Atherosclerosis 266:8794. doi: 10.1016/
j.atherosclerosis.2017.09.028.
Anonymous 2016. Editorial: when is a carcinogen not a carcinogen?
Lancet Oncology 17:681.
Antvorskov, Julie C., Thorhallur I. Halldorsson, Knud Josefsen, Jannet
Svensson, Charlotta Granstr
om, Bart O. Roep, Trine H. Olesen,
Laufey Hrolfsdottir, Karsten Buschard, and Sjudur F. Olsen. 2018.
Association between maternal gluten intake and type 1 diabetes in
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 5
offspring: national prospective cohort study in Denmark. BMJ 362:
k3547. doi: 10.1136/bmj.k3547.
Archer, E., M. L. Marlow, and C. J. Lavie. 2018. Controversy and
debate: memory based methods paper 1: the fatal flaws of food fre-
quency questionnaires and other memory-based dietary assessment
methods. Journal of Clinical Epidemiology 104:11324. doi: 10.1016/
j.jclinepi.2018.08.003.
Awidi, M., H. Bawaneh, H. Zureigat, M. AlHusban, and A. Awidi.
2018. Contributing factors to iron deficiency anemia in women in
Jordan: a single-center cross-sectional study. PLOS ONE 13 (11):
e0205868. doi: 10.1371/journal.pone.0205868.
Banta, J. E., J. W. Lee, G. Hodgkin, Z. Yi, A. Fanica, and J. Sabate.
2018. The global influence of the Seventh-day Adventist Church on
diet. Religions 9 (9):251. doi: 10.3390/rel9090251.
Barthels, F., F. Meyer, and R. Pietrowsky. 2018. Orthorexic and
restrained eating behaviour in vegans, vegetarians, and individuals
on a diet. Eating and Weight Disorders -Studies on Anorexia,
Bulimia and Obesity 23 (2):15966. doi: 10.1007/s40519-018-0479-0.
Benton, D., and R. Donohoe. 2011. The influence of creatine supple-
mentation on the cognitive functioning of vegetarians and omni-
vores. British Journal of Nutrition 105 (7):11005. doi: 10.1017/
S0007114510004733.
Bjørke Monsen, A. L., P. M. Ueland, S. E. Vollset, A. B. Guttormsen,
T. Markestad, E. Solheim, and H. Refsum. 2001. Determinants of
cobalamin status in newborns. Pediatrics 108 (3):62430. doi: 10.
1542/peds.108.3.624.
Boffetta, P., J. K. McLaughlin, C. La Vecchia, R. E. Tarone, L.
Lipworth, and W. J. Blot. 2008. False-positive results in cancer epi-
demiology: a plea for epistemological modesty. Journal of the
National Cancer Institute 100 (14):98895. doi: 10.1093/jnci/djn191.
Boobis, Alan R., Samuel M. Cohen, Vicki L. Dellarco, John E. Doe,
Penelope A. Fenner-Crisp, Angelo Moretto, Timothy P. Pastoor,
Rita S. Schoeny, Jennifer G. Seed, and Douglas C. Wolf. 2016.
Classification schemes for carcinogenicity based on hazard-identifi-
cation have become outmoded and serve neither science nor society.
Regulatory Toxicology and Pharmacology 82:15866. doi: 10.1016/j.
yrtph.2016.10.014.
Boyle, P., P. Boffetta, and P. Autier. 2008. Diet, nutrition and cancer:
public, media and scientific confusion. Annals of Oncology 19 (10):
16657. doi: 10.1093/annonc/mdn561.
Brantsaeter, Anne, Helle Knutsen, Nina Johansen, Kristine Nyheim,
Iris Erlund, Helle Meltzer, and Sigrun Henjum. 2018. Inadequate
iodine intake in population groups defined by age, life stage and
vegetarian dietary practice in a norwegian convenience sample.
Nutrients 10 (2):230. doi: 10.3390/nu10020230.
Bravo, J. P., C. J. Ibarra, and M. M. Paredes. 2014. Hematological and
neurological compromise due to vitamin B12 deficit in infant of a
vegetarian mother: case report. Revista Chilena de Pediatr
ıa85:
33743.
Brocadello, F., G. Levedianos, F. Piccione, R. Manara, and F. F.
Pesenti. 2007. Irreversible subacute sclerotic combined degeneration
of the spinal cord in a vegan subject. Nutrition 23 (7-8):6224. doi:
10.1016/j.nut.2007.05.006.
Burd, N. A., J. W. Beals, I. G. Martinez, A. F. Salvador, and S. K.
Skinner. 2019. Food-first approach to enhance the regulation of
post-exercise skeletal muscle protein synthesis and remodeling.
Sports Medicine 49 (S1):5968. doi: 10.1007/s40279-018-1009-y.
Burdge, G. C., S.-Y. Tan, and C. J. Henry. 2017. Long-chain n-3 PUFA
in vegetarian women: a metabolic perspective. Journal of Nutritional
Science 6:e58. doi: 10.1017/jns.2017.62.
Burkert, N. T., J. Muckenhuber, F. Großsch
adl, E. R
asky, and W.
Freidl. 2014. Nutrition and health the association between eating
behavior and various health parameters: a matched sample study.
PLOS ONE 9 (2):e88278. doi: 10.1371/journal.pone.0088278.
Cao, Y., L. L. Strate, B. R. Keeley, I. Tam, K. Wu, E. L. Giovannucci,
and A. T. Chan. 2018. Meat intake and risk of diverticulitis among
men. Gut 67 (3):46672. doi: 10.1136/gutjnl-2016-313082.
Carr, P. R., V. Walter, H. Brenner, and M. Hoffmeister. 2016. Meat
subtypes and their association with colorectal cancer: systematic
review and meta-analysis. International Journal of Cancer 138 (2):
293302. doi: 10.1002/ijc.29423.
Chen, G. C., D. B. Lv, Z. Pang, and Q. F. Liu. 2013. Red and processed
meat consumption and risk of stroke: a meta-analysis of prospective
cohort studies. European Journal of Clinical Nutrition 67 (1):915.
doi: 10.1038/ejcn.2012.180.
Chiron, R., A. Dabadie, V. Gandemer-Delignieres, M. Balenc¸on, E.
Legall, and M. Roussey. 2001. Anemia and limping in a vegetarian
adolescent. Archives de P
ediatrie 8 (1):625. doi: 10.1016/S0929-
693X(00)00168-8.
Cholewski, M., M. Tomczykowa, and M. Tomczyk. 2018. A compre-
hensive review of chemistry, sources and bioavailability of omega-3
fatty acids. Nutrients 10 (11):1662. doi: 10.3390/nu10111662.
Cofnas, N. 2019. Is vegetarianism healthy for children? Critical Reviews
in Food Science and Nutrition 59 (13):205260. doi: 10.1080/
10408398.2018.1437024.
Colev, M., H. Engel, M. Mayers, M. Markowitz, and L. Cahill. 2004.
Vegan diet and vitamin a deficiency. Clinical Pediatrics 43 (1):
1079. doi: 10.1177/000992280404300116.
Cordain, L., J. Brand Miller, S. Boyd Eaton, N. Mann, S. H. A. Holt,
and J. D. Speth. 2000. Plant-animal subsistence ratios and macronu-
trient energy estimations in worldwide hunter-gatherer diets. The
American Journal of Clinical Nutrition 71 (3):68292. doi: 10.1093/
ajcn/71.3.682.
Cordain, L., S. B. Eaton, J. Brand Miller, N. Mann, and K. Hill. 2002.
The paradoxical nature of hunter-gatherer diets: meat-based, yet
non-atherogenic. European Journal of Clinical Nutrition 56 (S1):
S42S52. doi: 10.1038/sj.ejcn.1601353.
Crawford, J. R., and D. Say. 2013. Vitamin B12 deficiency presenting
as acute ataxia. Case Reports 2013:bcr2013008840.
Deghan, M., A. Mente, X. Zhang, S. Swaminathan, W. Li, V. Mohan.,
et al. 2017. Associations of fats and carbohydrate intake with cardio-
vascular disease and mortality in 18 countries from five continents
(PURE): a prospective cohort study. Lancet 39:205062.
de Heinzelin, J., J. D. Clark, T. White, W. Hart, P. Renne, G.
WoldeGabriel, Y. Beyene, and E. Vrba. 1999. Environment and
behavior of 2.5-million-year-old bouri hominids. Science 284 (5414):
6259. doi: 10.1126/science.284.5414.625.
De Rosa, Anna, Fabiana Rossi, Maria Lieto, Roberto Bruno, Amalia De
Renzo, Vincenzo Palma, Mario Quarantelli, and Giuseppe De
Michele. 2012. Subacute combined degeneration of the spinal cord
in a vegan. Clinical Neurology and Neurosurgery 114 (7):10002. doi:
10.1016/j.clineuro.2012.01.008.
DiNicolantonio, J. J. 2014. The cardiometabolic consequences of replac-
ing saturated fats with carbohydrates or X-6 polyunsaturated fats:
do the dietary guidelines have it wrong? Open Heart 1 (1):
e000032doi: 10.1136/openhrt-2013-000032.
Dom
ınguez-Rodrigo, Manuel, Travis Rayne Pickering, Fernando Diez-
Mart
ın, Audax Mabulla, Charles Musiba, Gonzalo Trancho, Enrique
Baquedano, Henry T. Bunn, Doris Barboni, Manuel Santonja., et al.
2012. Earliest porotic hyperostosis on a 1.5-million-year-old homi-
nin, olduvai gorge, tanzania. PLOS ONE 7 (10):e46414. doi: 10.1371/
journal.pone.0046414.
Donaldson, M. S. 2000. Metabolic vitamin B12 status on a mostly raw
vegan diet with follow-up using tablets, nutritional yeast, or pro-
biotic supplements. Annals of Nutrition & Metabolism 44 (5-6):
22934. doi: 10.1159/000046689.
Elorinne, Anna-Liisa, Georg Alfthan, Iris Erlund, Hanna Kivim
aki,
Annukka Paju, Irma Salminen, Ursula Turpeinen, Sari Voutilainen,
and Juha Laakso. 2016. Food and nutrient intake and nutritional
status of finnish vegans and non-vegetarians. PLOS ONE 11 (2):
e0148235. doi: 10.1371/journal.pone.0148235.
Elmadfa, I., and I. Singer. 2009. Vitamin B-12 and homocysteine status
among vegetarians: a global perspective. The American Journal of
Clinical Nutrition 89 (5):1693S8S. doi: 10.3945/ajcn.2009.26736Y.
Etemadi, A., R. Sinha, M. H. Ward, B. I. Graubard, M. Inoue-Choi,
S. M. Dawsey, and C. C. Abnet. 2017. Mortality from different
causes associated with meat, heme iron, nitrates, and nitrites in the
NIH-AARP diet and health study: population based cohort study.
BMJ 357:j1957. doi: 10.1136/bmj.j1957
6 F. LEROY AND N. COFNAS
Everaert, Inge, Antien Mooyaart, Audrey Baguet, Ana Zutinic, Hans
Baelde, Eric Achten, Youri Taes, Emile De Heer, and Wim Derave.
2011. Vegetarianism, female gender and increasing age, but not
CNDP1 genotype, are associated with reduced muscle carnosine lev-
els in humans. Amino Acids 40 (4):12219. doi: 10.1007/s00726-010-
0749-2.
Farvid, M. S., E. Cho, W. Y. Chen, A. H. Eliassen, and W. C. Willett.
2015. Adolescent meat intake and breast cancer risk. International
Journal of Cancer 136 (8):190920. doi: 10.1002/ijc.29218.
Fayet, F.,. V. Flood, P. Petocz, and S. Samman. 2014. Avoidance of
meat and poultry decreases intakes of omega-3 fatty acids, vitamin
B12, selenium and zinc in young women. Journal of Human
Nutrition and Dietetics 27:13542.
FCN 2018. Vegan diets: review of nutritional benefits and risks. Expert
report of the federal commission for nutrition. Bern: Federal Food
Safety and Veterinary Office.
Feinman, R. 2018. Whats really wrong with medical research and how
to fix it. Journal of Evolution and Health 2 (3):10. doi: 10.15310/
2334-3591.1069.
Feskens, E. J., D. Sluik, and G. J. van Woudenbergh. 2013. Meat con-
sumption, diabetes, and its complications. Current Diabetes Reports
13 (2):298306. doi: 10.1007/s11892-013-0365-0.
Fogelholm, M., N. Kanerva, and S. M
annist
o. 2015. Association
between red and processed meat consumption and chronic diseases:
the confounding role of other dietary factors. European Journal of
Clinical Nutrition 69 (9):10605. doi: 10.1038/ejcn.2015.63.
Førland, E. S., and M. J. Lindberg. 2015. Severe macrocytic anaemia
and secondary hyperparathyroidism in a vegan. Ugeskriftet Laeger
177:V02150167.
Foster, M., A. Chu, P. Petocz, and S. Samman. 2013. Effect of vegetar-
ian diets on zinc status: a systematic review and meta-analysis of
studies in humans. Journal of the Science of Food and Agriculture 93
(10):236271. doi: 10.1002/jsfa.6179.
Gerstein, H. C., J. McMurray, and R. R. Holman. 2019. Real-world
studies no substitute for RCTs in establishing efficacy. Lancet 393
(10168):2101. doi: 10.1016/S0140-6736(18)32840-X.
Giannini, A., N. Mirra, and M. F. Patria. 2006. Health risks for chil-
dren raised on vegan or vegetarian diets. Pediatric Critical Care
Medicine 7 (2):188. doi: 10.1097/01.PCC.0000200965.44972.8F.
Gilsing, A. M. J., F. L. Crowe, Z. Lloyd-Wright, T. A. B. Sanders, P. N.
Appleby, N. E. Allen, and T. J. Key. 2010. Serum concentrations of
vitamin B12 and folate in british male omnivores, vegetarians, and
vegans: results from a cross-sectional analysis of the EPIC-Oxford
cohort study. European Journal of Clinical Nutrition 64 (9):9339.
doi: 10.1038/ejcn.2010.142.
Goraya, J. S., S. Kaur, and B. Mehra. 2015. Neurology of nutritional
vitamin B12 deficiency in infants: case series from India and litera-
ture review. Journal of Child Neurology 30 (13):18317. doi: 10.1177/
0883073815583688.
Grosso, G., A. Micek, J. Godos, A. Pajak, S. Sciacca, F. Galvano, and P.
Boffetta. 2017. Health risk factors associated with meat, fruit and
vegetable consumption in cohort studies: a comprehensive meta-
analysis. PLOS ONE 12 (8):e0183787. doi: 10.1371/journal.pone.
0183787.
Guez, S., G. Chiarelli, F. Menni, S. Salera, N. Principi, and S. Esposito.
2012. Severe vitamin B12 deficiency in an exclusively breastfed 5-
month-old italian infant born to a mother receiving multivitamin
supplementation during pregnancy. BMC Pediatrics 12 (1):85. doi:
10.1186/1471-2431-12-85.
Gupta, S. 2016. Brain food: clever eating. Nature 531 (7592):S12S13.
doi: 10.1038/531S12a.
Guyatt, G.H. 2015. A false alarm on red meat and cancer. The
Financial Times.https://www.ft.com/content/42259e20-92b5-11e5-
bd82-c1fb87bef7af
Guyatt, Gordon H., Andrew D. Oxman, Gunn E. Vist, Regina Kunz,
Yngve Falck-Ytter, Pablo Alonso-Coello, and Holger J. Sch
unemann.
2008. GRADE: an emerging consensus on rating quality of evidence
and strength of recommendations. BMJ 336 (7650):9246. doi: 10.
1136/bmj.39489.470347.AD.
Haddad, E. H., and J. S. Tanzman. 2003. What do vegetarians in the
United States eat? The American Journal of Clinical Nutrition 78 (3):
626S32S. doi: 10.1093/ajcn/78.3.626S.
Hall, A. G., T. Ngu, H. T. Nga, P. N. Quyen, P. T. Hong Anh, and
J. C. King. 2017. An animal-source food supplement increases
micronutrient intakes and iron status among reproductive-age
women in rural vietnam. The Journal of Nutrition 147 (6):12007.
doi: 10.3945/jn.116.241968.
Herbert, V. 1994. Staging vitamin B-12 (cobalamin) status in vegeta-
rians. The American Journal of Clinical Nutrition 59 (5):1213S22S.
doi: 10.1093/ajcn/59.5.1213S.
Herrmann, W., and J. Geisel. 2002. Vegetarian lifestyle and monitoring
of vitamin B-12 status. Clinica Chimica Acta 326 (1-2):4759. doi:
10.1016/S0009-8981(02)00307-8.
Herrmann, W., H. Schorr, R. Obeid, and J. Geisel. 2003. Vitamin B-12
status, particularly holotranscobalamin II and methylmalonic acid
concentrations, and hyperhomocysteinemia in vegetarians. The
American Journal of Clinical Nutrition 78 (1):1316. doi: 10.1093/
ajcn/78.1.131.
Hibbeln, J. R., K. Northstone, J. Evans, and J. Golding. 2018.
Vegetarian diets and depressive symptoms among men. Journal of
Affective Disorders 225:137. doi: 10.1016/j.jad.2017.07.051.
Hodgson, J. M., N. C. Ward, V. Burke, L. J. Beilin, and I. B. Puddey.
2007. Increased lean red meat intake does not elevate markers of
oxidative stress and inflammation in humans. The Journal of
Nutrition 137 (2):3637. doi: 10.1093/jn/137.2.363.
Hokin, B. D., and T. Butler. 1999. Cyanocobalamin (vitamin B-12) sta-
tus in Seventh-day Adventist ministers in Australia. The American
Journal of Clinical Nutrition 70 (3):576s8s. doi: 10.1093/ajcn/70.3.
576s.
Huang, W., Y. Han, J. Xu, W. Zhu, and Z. Li. 2013. Red and processed
meat intake and risk of esophageal adenocarcinoma: a meta-analysis
of observational studies. Cancer Causes & Control 24 (1):193201.
doi: 10.1007/s10552-012-0105-9.
Hulett, J. L., R. E. Weiss, N. O. Bwibo, O. M. Galal, N. Drorbaugh,
and C. G. Neumann. 2014. Animal source foods have a positive
impact on the primary school test scores of kenyan schoolchildren
in a cluster-randomised, controlled feeding intervention trial. British
Journal of Nutrition 111 (5):87586. doi: 10.1017/
S0007114513003310.
Hur, S. J., C. Jo, Y. Yoon, J. Y. Jeong, and K. T. Lee. 2018. Controversy
on the correlation of red and processed meat consumption with
colorectal cancer risk: an asian perspective. Critical Reviews in Food
Science and Nutrition. doi: 10.1080/10408398.2018.1495615.
IARC 2015. IARC Monographs evaluate consumption of red meat and
processed meat. Press release n240, https://www.iarc.fr/en/media-
centre/pr/2015/pdfs/pr240_E.pdf
Iguacel, I.,. M. L. Miguel-Berges, A. G
omez-Bruton, L. A. Moreno, and
C. Juli
an. 2018. Veganism, vegetarianism, bone mineral density, and
fracture risk: a systematic review and meta-analysis. Nutrition
Reviews 77 (1):18. doi: 10.1093/nutrit/nuy045.
Ingenbleek, Y., and K. S. McCully. 2012. Vegetarianism produces sub-
clinical malnutrition, hyperhomocysteinemia and atherogenesis.
Nutrition 28 (2):14853. doi: 10.1016/j.nut.2011.04.009.
Ioannidis, J. P. A. 2018. The challenge of reforming nutritional epide-
miologic research. JAMA 320 (10):96970. doi: 10.1001/jama.2018.
11025.
Jeppesen, J.,. H. Ole Hein, P. Suadicani, and F. Gyntelberg. 2001. Low
triglycerideshigh high-density lipoprotein cholesterol and risk of
ischemic heart disease. Archives of Internal Medicine 161 (3):3616.
doi: 10.1001/archinte.161.3.361.
Kadrabov
a, J., A. Madaric, Z. Kov
acikov
a, and E. Ginter. 1995.
Selenium status, plasma zinc, copper, and magnesium in vegetarians.
Biological Trace Element Research 50 (1):1324. doi: 10.1007/
BF02789145.
Kapoor, A., M. Baig, S. A. Tunio, A. S. Memon, and H. Karmani.
2017. Neuropsychiatric and neurological problems among vitamin
B12 deficient young vegetarians. Neurosciences 22 (3):22832. doi:
10.17712/nsj.2017.3.20160445.
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 7
Key, T. J., P. N. Appleby, E. A. Spencer, R. C. Travis, A. W. Roddam,
and N. E. Allen. 2009. Mortality in british vegetarians: results from
the european prospective investigation into cancer and nutrition
(EPIC-Oxford). The American Journal of Clinical Nutrition 89 (5):
1613S9S. doi: 10.3945/ajcn.2009.26736L.
Kim, Y., and Y. Je. 2018. Meat consumption and risk of metabolic syn-
drome: results from the korean population and a Meta-analysis of
observational studies. Nutrients 10 (4):390. doi: 10.3390/nu10040390.
Kim, S., M. F. Fenech, and P.-J R. Kim. 2018. Nutritionally recom-
mended food for semi- to strict vegetarian diets based on large-scale
nutrient composition data. Scientific Reports 8 (1):4344. doi: 10.
1038/s41598-018-22691-1.
Klurfeld, D. M. 2015. Research gaps in evaluating the relationship of
meat and health. Meat Science 109:8695. doi: 10.1016/j.meatsci.
2015.05.022.
Klurfeld, D. M. 2018. What is the role of meat in a healthy diet?.
Animal Frontiers 8 (3):510. doi: 10.1093/af/vfy009.
Kocaoglu, C., F. Akin, H. Caksen, S. B. B
oke, S. Arslan, and S. Ayg
un.
2014. Cerebral atrophy in a vitamin B12-deficient infant of a vege-
tarian mother. Journal of Health, Population and Nutrition 32(2):
36771.
Koebnick, Corinna, Ingrid Hoffmann, Pieter C. Dagnelie, Ulrike A.
Heins, Sunitha N. Wickramasinghe, Indrika D. Ratnayaka, Sindy
Gruendel, Jan Lindemans, and Claus Leitzmann. 2004. Long-term
ovo-lacto vegetarian diet impairs vitamin B-12 status in pregnant
women. The Journal of Nutrition 134 (12):331926. doi: 10.1093/jn/
134.12.3319.
Koeth, Robert A., Zeneng Wang, Bruce S. Levison, Jennifer A. Buffa,
Elin Org, Brendan T. Sheehy, Earl B. Britt, Xiaoming Fu, Yuping
Wu, Lin Li., et al. 2013. Intestinal microbiota metabolism of l-carni-
tine, a nutrient in red meat, promotes atherosclerosis. Nature
Medicine 19 (5):57685. doi: 10.1038/nm.3145.
Krajcovicov
a-Kudl
ackov
a, M., K. Buckov
a, I. Klimes, and E. Sebokov
a.
2008. Iodine deficiency in vegetarians and vegans. Annals of
Nutrition and Metabolism 47:1835.
Krauss, A. 2018. Why all randomised controlled trials produce biased
results. Annals of Medicine 50 (4):31222. doi: 10.1080/07853890.
2018.1453233.
Kristensen, Nadja B., Mia L. Madsen, Tue H. Hansen, Kristine H.
Allin, Camilla Hoppe, Sisse Fagt, Mia S. Lausten, Rikke J. Gøbel,
Henrik Vestergaard, Torben Hansen., et al. 2015. Intake of macro-
and micronutrients in danish vegans. Nutrition Journal 14 (1):115.
doi: 10.1186/s12937-015-0103-3.
Kruger, C., and Y. Zhou. 2018. Red meat and Colon cancer: a review
of mechanistic evidence for heme in the context of risk assessment
methodology. Food and Chemical Toxicology 118:13153. doi: 10.
1016/j.fct.2018.04.048.
Kwok, C. S., S. Umar, P. K. Myint, M. A. Mamas, and Y. K. Loke.
2014. Vegetarian diet, seventh day adventists and risk of cardiovas-
cular mortality: a systematic review and meta-analysis. International
Journal of Cardiology 176 (3):6806. doi: 10.1016/j.ijcard.2014.07.
080.
Laidlaw, S. A., T. D. Shultz, J. T. Cecchino, and J. D. Kopple. 1988.
Plasma and urine taurine levels in vegans. The American Journal of
Clinical Nutrition 47 (4):6603. doi: 10.1093/ajcn/47.4.660.
Larsson, C. L., and G. K. Johansson. 2002. Dietary intake and nutri-
tional status of young vegans and omnivores in Sweden. The
American Journal of Clinical Nutrition 76 (1):1006. doi: 10.1093/
ajcn/76.1.100.
Larsson, S. C., and N. Orsini. 2014. Red meat and processed meat con-
sumption and all-cause mortality: a meta-analysis. American Journal
of Epidemiology 179 (3):2829. doi: 10.1093/aje/kwt261.
Lee, Jung Eun., Dale F. McLerran, Betsy Rolland, Yu Chen, Eric J.
Grant, Rajesh Vedanthan, Manami Inoue, Shoichiro Tsugane, Yu-
Tang Gao, Ichiro Tsuji., et al. 2013. Meat intake and cause-specific
mortality: a pooled analysis of asian prospective cohort studies. The
American Journal of Clinical Nutrition 98 (4):103241. doi: 10.3945/
ajcn.113.062638.
Lents, N.H. 2018. The evolutionary quirk that made vitamin B12 part
of our diet. Discover.http://blogs.discovermagazine.com/crux/2018/
08/13/vitamin-b12-essential/#.XUMXUOgzY2w.
Leroy, F. 2019. Meat as a pharmakon: an exploration of the biosocial
complexities of meat consumption. Advances in Food and Nutrition
Research 87:40946.
Leroy, F., M. Brengman, W. Ryckbosch, and P. Scholliers. 2018. Meat
in the post-truth era: mass media discourses on health and disease
in the attention economy. Appetite 125:34555. doi: 10.1016/j.appet.
2018.02.028.
Leroy, Fr
ed
eric, Teresa Aymerich, Marie-Christine Champomier-
Verg
es, Luca Cocolin, Luc De Vuyst, M
onica Flores, Franc¸oise
Leroi, Sabine Leroy, R
egine Talon, Rudi F. Vogel., et al. 2018.
Fermented meats (and the symptomatic case of the flemish food
pyramid): are we heading towards the vilification of a valuable food
group?. International Journal of Food Microbiology 274:6770. doi:
10.1016/j.ijfoodmicro.2018.02.006.
Leung, A. M., A. Lamar, X. He, L. E. Braverman, and E. N. Pearce.
2011. Iodine status and thyroid function of boston-area vegetarians
and vegans. The Journal of Clinical Endocrinology &Metabolism 96
(8):e13037. doi: 10.1210/jc.2011-0256.
Licht, D. J., G. T. Berry, D. G. Brooks, and D. P. Younkin. 2001.
Reversible subacute combined degeneration of the spinal cord in a
14-year-old due to a strict vegan diet. Clinical Pediatrics 40 (7):
4135. doi: 10.1177/000992280104000710.
Lippi, G., C. Mattiuzzi, and F. Sanchis-Gomar. 2015. Red meat con-
sumption and ischemic heart disease. A systematic literature review.
Meat Science 108:326. doi: 10.1016/j.meatsci.2015.05.019.
Louwman, Marieke W. J., Marijke van Dusseldorp, Fons J. R. van de
Vijver, Chris M. G. Thomas, Jørn Schneede, Per M. Ueland, Helga
Refsum, and Wija A. van Staveren. 2000. Signs of impaired cognitive
function in adolescents with marginal cobalamin status. The
American Journal of Clinical Nutrition 72 (3):7629. doi: 10.1093/
ajcn/72.3.762.
Mann, N., A. Sinclair, M. Pille, L. Johnson, G. Warrick, E. Reder, and
R. Lorenz. 1997. The effect of short-term diets rich in fish, red
meat, or white meat on thromboxane and prostacyclin synthesis in
humans. Lipids 32 (6):63544. doi: 10.1007/s11745-997-0081-5.
Matta, Joane, S
ebastien Czernichow, Emmanuelle Kesse-Guyot, Nicolas
Hoertel, Fr
ed
eric Limosin, Marcel Goldberg, Marie Zins, and Cedric
Lemogne. 2018. Depressive symptoms and vegetarian diets: results
from the constances cohort. Nutrients 10 (11):1695. doi: 10.3390/
nu10111695.
Mayes, C. R., and D. B. Thompson. 2015. What should we eat? biopo-
litics, ethics, and nutritional scientism. Journal of Bioethical Inquiry
12 (4):58799. doi: 10.1007/s11673-015-9670-4.
McAfee, A. J., E. M. McSorley, G. J. Cuskelly, B. W. Moss, J. M.
Wallace, M. P. Bonham, and A. M. Fearon. 2010. Red meat con-
sumption: an overview of the risks and benefits. Meat Science 84
(1):113. doi: 10.1016/j.meatsci.2009.08.029.
McNeill, S. H. 2014. Inclusion of red meat in healthful dietary patterns.
Meat Science 98 (3):45260. doi: 10.1016/j.meatsci.2014.06.028.
Milea, D., N. Cassoux, and P. LeHoang. 2000. Blindness in a strict
vegan. The New England Journal of Medicine 342 (12):8978. doi:
10.1056/NEJM200003233421217.
Milton, K. 2003. The critical role played by animal source foods in
human (Homo) evolution. The Journal of Nutrition 133 (11 Suppl
2):3886S92S. doi: 10.1093/jn/133.11.3886S.
Montonen, J., H. Boeing, A. Fritsche, E. Schleicher, H.-G. Joost, M. B.
Schulze, A. Steffen, and T. Pischon. 2013. Consumption of red meat
and whole-grain bread in relation to biomarkers of obesity, inflam-
mation, glucose metabolism and oxidative stress. European Journal
of Nutrition 52 (1):33745. doi: 10.1007/s00394-012-0340-6.
Morabia, A. 2008. Joseph goldbergers research on the prevention of
pellagra. Journal of the Royal Society of Medicine 101 (11):5668.
doi: 10.1258/jrsm.2008.08k010.
Naik, S., N. Mahalle, and V. Bhide. 2018. Identification of vitamin B12
deficiency in vegetarian indians. The British Journal of Nutrition 119
(6):62935. doi: 10.1017/S0007114518000090.
8 F. LEROY AND N. COFNAS
Neumann, C. G., S. P. Murphy, C. Gewa, M. Grillenberger, and N. O.
Bwibo. 2007. Meat supplementation improves growth, cognitive, and
behavioral outcomes in Kenyan children. The Journal of Nutrition
137 (4):111923. doi: 10.1093/jn/137.4.1119.
Nezlek, J. B., C. A. Forestell, and D. B. Newman. 2018. Relationships
between vegetarian dietary habits and daily well-being. Ecology of
Food and Nutrition 57 (5):42538. doi: 10.1080/03670244.2018.
1536657.
Ng, E., and M. Neff. 2018. Recognising the return of nutritional defi-
ciencies: a modern pellagra puzzle. BMJ Case Reports 11 (1):
e227454. doi: 10.1136/bcr-2018-227454.
NHS 2018. Red meat and the risk of bowel cancer. https://www.nhs.uk/
live-well/eat-well/red-meat-and-the-risk-of-bowel-cancer
Obersby, D., D. C. Chappell, A. Dunnett, and A. A. Tsiami. 2013.
Plasma total homocysteine status of vegetarians compared with
omnivores: a systematic review and Meta-analysis. British Journal of
Nutrition 109 (5):78594. doi: 10.1017/S000711451200520X.
OConnor, L. E., J. E. Kim, and W. W. Campbell. 2017. Total red meat
intake of 0.5 servings/d does not negatively influence cardiovascu-
lar disease risk factors: a systemically searched meta-analysis of
randomized controlled trials. The American Journal of Clinical
Nutrition 105(1):5769. doi: 10.3945/ajcn.116.142521.
OGorman, P., D. Holmes, A. V. Ramanan, B. Bose-Haider, M. J.
Lewis, and A. Will. 2002. Dietary vitamin B12 deficiency in an ado-
lescent white boy. Journal of Clinical Pathology 55(6):4756. doi: 10.
1136/jcp.55.6.475.
Oostindjer, Marije, Jan Alexander, Gro V. Amdam, Grethe Andersen,
Nathan S. Bryan, Duan Chen, Denis E. Corpet, Stefaan De Smet,
Lars Ove Dragsted, Anna Haug., et al. 2014. The role of red and
processed meat in colorectal cancer development: a perspective.
Meat Science 97 (4):58396. doi: 10.1016/j.meatsci.2014.02.011.
Pan, A., Q. Sun, A. M. Bernstein, M. B. Schulze, J. E. Manson, W. C.
Willett, and F. B. Hu. 2011. Red meat consumption and risk of type
2 diabetes: 3 cohorts of US adults and an updated meta-analysis.
The American Journal of Clinical Nutrition 94 (4):108896. doi: 10.
3945/ajcn.111.018978.
Pan, A., Q. Sun, A. M. Bernstein, M. B. Schulze, J. E. Manson, M. J.
Stampfer., et al. 2012. Red meat consumption and mortality: results
from 2 prospective cohort studies. Archives of Internal Medicine 172:
55563. doi: 10.1001/archinternmed.2011.2287.
Pannemans, D. L., A. J. Wagenmakers, K. R. Westerterp, G. Schaafsma,
and D. Halliday. 1998. Effect of protein source and quantity on pro-
tein metabolism in elderly women. The American Journal of Clinical
Nutrition 68 (6):122835. doi: 10.1093/ajcn/68.6.1228.
Pawlak, R. 2015. Is vitamin B12 deficiency a risk factor for cardiovas-
cular disease in vegetarians? American Journal of Preventive
Medicine 48 (6):e1126. doi: 10.1016/j.amepre.2015.02.009.
Pawlak, Roman, Scott James Parrott, Sudha Raj, Diana Cullum-Dugan,
and Debbie Lucus. 2013. How prevalent is vitamin B
12
deficiency
among vegetarians? Nutrition Reviews 71 (2):1107. doi: 10.1111/
nure.12001.
Pawlak, R., S. E. Lester, and T. Babatunde. 2014. The prevalence of
cobalamin deficiency among vegetarians assessed by serum vitamin
B12: a review of literature. European Journal of Clinical Nutrition 68
(5):5418. doi: 10.1038/ejcn.2014.46.
Pereira, P. M., and A. F. Vicente. 2013. Meat nutritional composition
and nutritive role in the human diet. Meat Science 93 (3):58692.
doi: 10.1016/j.meatsci.2012.09.018.
Phillips, S. M. 2012. Nutrient-rich meat proteins in offsetting age-
related muscle loss. Meat Science 92 (3):1748. doi: 10.1016/j.
meatsci.2012.04.027.
Rae, C., A. L. Digney, S. R. McEwan, and T. C. Bates. 2003. Oral creat-
ine monohydrate supplementation improves brain performance: a
double-blind, placebo-controlled, cross-over trial. Proceedings of the
Royal Society B: Biological Sciences 270 (1529):214750. doi: 10.1098/
rspb.2003.2492.
Ranganathan, J., D. Vennard, R. Waite, B. Lipinski, T. Searchinger, and
P. Dumas. 2016. Shifting diets for a sustainable food future. https://
wriorg.s3.amazonaws.com/s3fs-public/Shifting_Diets_for_a_
Sustainable_Food_Future_1.pdf?_ga=2.114696014.831878447.
1548317259-387216062.1543582872.
Rehkamp, S. 2016. A look at calorie sources in the American diet.
Unites States Department of Agriculture, Economic Research
Service, https://www.ers.usda.gov/amber-waves/2016/december/a-
look-at-calorie-sources-in-the-american-diet.
Rogers, L. M., E. Boy, J. W. Miller, R. Green, J. C. Sabel, and L. H.
Allen. 2003. High prevalence of cobalamin deficiency in guatemalan
schoolchildren: associations with low plasma holotranscobalamin II
and elevated serum methylmalonic acid and plasma homocysteine
concentrations. The American Journal of Clinical Nutrition 77 (2):
43340. doi: 10.1093/ajcn/77.2.433.
Rondanelli, M., S. Perna, M. A. Faliva, G. Peroni, V. Infantino, and R.
Pozzi. 2015. Novel insights on intake of meat and prevention of sar-
copenia: all reasons for an adequate consumption. Nutricion
Hospitalaria 32 (5):213614. 23.
Rosell, M. S., Z. Lloyd-Wright, P. N. Appleby, T. A. Sanders, N. E.
Allen, and T. J. Key. 2005. Long-chain n-3 polyunsaturated fatty
acids in plasma in british meat-eating, vegetarian, and vegan men.
The American Journal of Clinical Nutrition 82 (2):32734. doi: 10.
1093/ajcn.82.2.327.
Samulak, J. J., A. K. Sawicka, D. Hartmane, S. Grinberga, O. Pugovics,
W. Lysiak-Szydlowska, and R. A. Olek. 2019. L-Carnitine supple-
mentation increases trimethylamine-N-oxide but not markers of ath-
erosclerosis in healthy aged women. Annals of Nutrition and
Metabolism 74 (1):117. doi: 10.1159/000495037.
Satija, Ambika, Shilpa N. Bhupathiraju, Eric B. Rimm, Donna
Spiegelman, Stephanie E. Chiuve, Lea Borgi, Walter C. Willett,
JoAnn E. Manson, Qi Sun, Frank B. Hu., et al. 2016. Plant-based
dietary patterns and incidence of type 2 diabetes in US men and
women: results from three prospective cohort studies. PLOS
Medicine 13 (6):e1002039. doi: 10.1371/journal.pmed.1002039.
Schatzkin, Arthur, Victor Kipnis, Raymond J. Carroll, Douglas
Midthune, Amy F. Subar, Sheila Bingham, Dale A. Schoeller,
Richard P. Troiano, and Laurence S. Freedman. 2003. A comparison
of a food frequency questionnaire with a 24-hour recall for use in
an epidemiological cohort study: results from the biomarker-based
observing protein and energy nutrition (OPEN) study. International
Journal of Epidemiology 32 (6):105462. doi: 10.1093/ije/dyg264.
Schjønsby, H. 1989. Vitamin B12 absorption and malabsorption. Gut
30 (12):168691. doi: 10.1136/gut.30.12.1686.
Schoenfeld, J. D., and J. P. A. Ioannidis. 2013. Is everything we eat
associated with cancer? a systematic cookbook review. The American
Journal of Clinical Nutrition 97 (1):12734. doi: 10.3945/ajcn.112.
047142.
Schultz, T. D., and J. E. Leklem. 1983. Selenium status of vegetarians,
nonvegetarians, and hormone-dependent cancer subjects. The
American Journal of Clinical Nutrition 37:1148. doi: 10.1093/ajcn/
37.1.114.
Sch
upbach, R., R. Wegm
uller, C. Berguerand, M. Bui, and I. Herter-
Aeberli. 2017. Micronutrient status and intake in omnivores, vegeta-
rians and vegans in Switzerland. European Journal of Nutrition 56
(1):28393. doi: 10.1007/s00394-015-1079-7.
Shapiro, S. 2004. Looking to the 21st century: have we learned from
our mistakes, or are we doomed to compound them?.
Pharmacoepidemiology and Drug Safety 13 (4):25765. doi: 10.1002/
pds.903.
Shibata, H. 2001. Nutritional factors on longevity and quality of life in
Japan. Journal of Nutrition, Health and Aging 5 (2):97102.
Shinwell, E. D., and R. Gorodischer. 1982. Totally vegetarian diets and
infant nutrition. Pediatrics 70 (4):5826.
Siepmann, T., J. Roofeh, F. W. Kiefer, and D. G. Edelson. 2011.
Hypogonadism and erectile dysfunction associated with soy product
consumption. Nutrition 27 (7-8):85962.
Sinha, R., A. J. Cross, B. I. Graubard, M. F. Leitzmann, and A.
Schatzkin. 2009. Meat intake and mortality: a prospective study of
over half a million people. Archives of Internal Medicine 169 (6):
56271. doi: 10.1001/archinternmed.2009.6.
Specker, B. L., D. Miller, E. J. Norman, H. Greene, and K. C. Hayes.
1988. Increased urinary methylmalonic acid excretion in breast-fed
CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 9
infants of vegetarian mothers and identification of an acceptable
dietary source of vitamin B-12. The American Journal of Clinical
Nutrition 47 (1):8992. doi: 10.1093/ajcn/47.1.89.
Specker, B. L., A. Black, L. Allen, and F. Morrow. 1990. Vitamin B-12:
low milk concentrations are related to low serum concentrations in
vegetarian women and to methylmalonic aciduria in their infants.
The American Journal of Clinical Nutrition 52 (6):10736. doi: 10.
1093/ajcn/52.6.1073.
Springmann, Marco, Daniel Mason-DCroz, Sherman Robinson, Keith
Wiebe, H. Charles J. Godfray, Mike Rayner, and Peter Scarborough.
2018. Health-motivated taxes on red and processed meat: a model-
ling study on optimal tax levels and associated health impacts. PLOS
ONE 13 (11):e0204139. doi: 10.1371/journal.pone.0204139.
Stark, A. H., R. Reifen, and M. A. Crawford. 2016. Past and present
insights on alpha-linolenic acid and the omega-3 fatty acid family.
Critical Reviews in Food Science and Nutrition 56 (14):22617. doi:
10.1080/10408398.2013.828678
Swinburn, Boyd A., Vivica I. Kraak, Steven Allender, Vincent J. Atkins,
Phillip I. Baker, Jessica R. Bogard, Hannah Brinsden, Alejandro
Calvillo, Olivier De Schutter, Raji Devarajan., et al. 2019. The global
syndemic of obesity, undernutrition, and climate change: the Lancet
Commission report. Lancet 393 (10173):791846. doi: 10.1016/
S0140-6736(18)32822-8.
Tang, M., and N. F. Krebs. 2014. High protein intake from meats as
complementary food increases growth but not adiposity in breastfed
infants: a randomized trial. The American Journal of Clinical
Nutrition 100 (5):13228. doi: 10.3945/ajcn.114.088807.
Torres, Susan J., Sian Robinson, Liliana Orellana, Stella L. OConnell,
Carley A. Grimes, Niamh L. Mundell, David W. Dunstan, Caryl A.
Nowson, and Robin M. Daly. 2017. Effects of progressive resistance
training combined with a protein-enriched lean red meat diet on
health-related quality of life in elderly women: secondary analysis of
a 4-month cluster randomised controlled trial. British Journal of
Nutrition 117 (11):15509. doi: 10.1017/S0007114517001507.
Truswell, A. S. 2009. Problems with red meat in the WCRF2. The
American Journal of Clinical Nutrition 89 (4):12745. doi: 10.3945/
ajcn.2008.27201.
Tur, J. A., M. M. Bibiloni, A. Sureda, and A. Pons. 2012. Dietary sour-
ces of omega 3 fatty acids: public health risks and benefits. British
Journal of Nutrition 107 (S2):S23S52. doi: 10.1017/
S0007114512001456.
Turner, N. D., and S. K. Lloyd. 2017. Association between red meat
consumption and colon cancer: a systematic review of experimental
results. Experimental Biology and Medicine 242 (8):81339. doi: 10.
1177/1535370217693117.
Turner, K. M., J. B. Keogh, and P. M. Clifton. 2015. Red meat, dairy,
and insulin sensitivity: a randomized crossover intervention study.
The American Journal of Clinical Nutrition 101 (6):11739. doi: 10.
3945/ajcn.114.104976.
Turner, K. M., J. B. Keogh, P. J. Meikle, and P. M. Clifton. 2017.
Changes in lipids and inflammatory markers after consuming diets
high in red meat or dairy for four weeks. Nutrients 9 (8):886. doi:
10.3390/nu9080886.
van Dusseldorp, M., J. Schneede, H. Refsum, P. M. Ueland, C. M.
Thomas, E. de Boer, and W. A. van Staveren. 1999. Risk of persist-
ent cobalamin deficiency in adolescents fed a macrobiotic diet in
early life. The American Journal of Clinical Nutrition 69 (4):66471.
doi: 10.1093/ajcn/69.4.664.
Van Winckel, M., S. Vande Velde, R. De Bruyne, and S. Van Biervliet.
2011. Clinical practice: vegetarian infant and child nutrition.
European Journal of Pediatrics 170 (12):148994. doi: 10.1007/
s00431-011-1547-x.
Wang, X., X. Lin, Y. Y. Ouyang, J. Liu, G. Zhao, A. Pan, and F. B. Hu.
2016. Red and processed meat consumption and mortality: dose-
response meta-analysis of prospective cohort studies. Public Health
Nutrition 19 (5):893905. doi: 10.1017/S1368980015002062.
WHO 2015. Q&A on the carcinogenicity of the consumption of red
meat and processed meat. http://www.who.int/features/qa/cancer-
red-meat/en
Willett, Walter, Johan Rockstr
om, Brent Loken, Marco Springmann,
Tim Lang, Sonja Vermeulen, Tara Garnett, David Tilman, Fabrice
DeClerck, Amanda Wood., et al. 2019. Food in the anthropocene:
the EAT-Lancet Commission on healthy diets from sustainable food
systems. Lancet 393 (10170):44792. doi: 10.1016/S0140-
6736(18)31788-4.
Williams, P. 2007. Nutritional composition of red meat. Nutrition &
Dietetics 64 (s4):S113S119. doi: 10.1111/j.1747-0080.2007.00197.x.
Wilson, A. K., and M. J. Ball. 1999. Nutrient intake and iron status of
australian male vegetarians. European Journal of Clinical Nutrition
53 (3):18994. doi: 10.1038/sj.ejcn.1600696.
Wongprachum, K., K. Sanchaisuriya, P. Sanchaisuriya, S.
Siridamrongvattana, S. Manpeun, and F. P. Schlep. 2012. Proxy indi-
cators for identifying iron deficiency among anemic vegetarians in
an area prevalent for thalassemia and hemoglobinopathies. Acta
Haematologica 127 (4):2505. doi: 10.1159/000337032.
Woo, K. S., T. C. Kwok, and D. S. Celermajer. 2014. Vegan diet, sub-
normal vitamin B-12 status and cardiovascular health. Nutrients 6
(8):325973. doi: 10.3390/nu6083259.
Yamamoto, S., T. Nakagawa, Y. Matsushita, S. Kusano, T. Hayashi, M.
Irokawa, T. Aoki, Y. Korogi, and T. Mizoue. 2010. Visceral fat area
and markers of insulin resistance in relation to colorectal neoplasia.
Diabetes Care 33 (1):1849. doi: 10.2337/dc09-1197.
Yang, C., L. Pan, C. Sun, Y. Xi, L. Wang, and D. Li. 2016. Red meat
consumption and the risk of stroke: a dose-response Meta-analysis
of prospective cohort studies. Journal of Stroke and Cerebrovascular
Diseases 25 (5):117786. doi: 10.1016/j.jstrokecerebrovasdis.2016.01.
040.
Yen, H., W. Q. Li, A. Dhana, T. Li, A. Qureshi, and E. Cho. 2018. Red
meat and processed meat intake and risk for cutaneous melanoma
in white women and men: two prospective cohort studies. Journal of
the American Academy of Dermatology 79 (2):2527. doi: 10.1016/j.
jaad.2018.04.036.
Yokoyama, Y.,. S. M. Levin, and N. D. Barnard. 2017. Association
between plant-based diets and plasma lipids: a systematic review
and Meta-analysis. Nutrition Reviews 75 (9):68398. doi: 10.1093/
nutrit/nux030.
Young, S. S., and A. Karr. 2011. Deming, data and observational stud-
ies. Significance 8 (3):11620. doi: 10.1111/j.1740-9713.2011.00506.x.
Young, J. F., M. Therkildsen, B. Ekstrand, B. N. Che, M. K. Larsen, N.
Oksbjerg, and J. Stagsted. 2013. Novel aspects of health promoting
compounds in meat. Meat Science 95 (4):90411. doi: 10.1016/j.
meatsci.2013.04.036.
Zengin, E., N. Sarper, and S. Caki Kilic¸. 2009. Clinical manifestations
of infants with nutritional vitamin B deficiency due to maternal
dietary deficiency. Acta Paediatrica 98 (1):98102. doi: 10.1111/j.
1651-2227.2008.01059.x.
Zhang, A. Q., S. C. Mitchell, and R. L. Smith. 1999. Dietary precursors
of trimethylamine in man: a pilot study. Food and Chemical
Toxicology 37 (5):51520.
Zhang, Y., Y. Yang, M. S. Xie, X. Ding, H. Li, Z. C. Liu, and S. F.
Peng. 2017. Is meat consumption associated with depression? a
Meta-analysis of observational studies. BMC Psychiatry 17 (1):409.
doi: 10.1186/s12888-017-1540-7.
10 F. LEROY AND N. COFNAS
... Omnivorous diets supply approximately 23-135 mg/day of carnitine, whereas plantbased diets provide approximately 1 mg/day [53]. This contrast in dietary carnitine content has led to speculation that plant-based diets increase the risk of carnitine deficiency [10,55]. ...
... Omnivorous diets supply approximately 23-135 mg/day of carnitine, whereas plant-based diets provide approximately 1 mg/day [53]. This contrast in dietary carnitine content has led to speculation that plant-based diets increase the risk of carnitine deficiency [10,55]. ...
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Plant-based diets are associated with numerous health benefits, including reduced risks of chronic diseases. However, questions persist regarding the implications of lower dietary intakes of certain non-essential nutrients, such as retinol, vitamin K2, carnitine, and creatine, which are primarily found in animal-derived foods. This narrative review evaluates the roles of these nutrients in human physiology and examines whether their absence in plant-based diets is likely to impact health outcomes. Retinol requirements can be met through the consumption of provitamin A carotenoids in plant foods, even in individuals with reduced conversion efficiency. Endogenous synthesis adequately supports physiological needs for vitamin K2, and currently available evidence does not consistently demonstrate that dietary vitamin K2 provides additional benefits for bone or cardiovascular health. Carnitine and creatine levels may differ between individuals following omnivorous and plant-based diets, but these differences do not result in compromised muscle function, cognitive health, or metabolic outcomes. Current evidence does not indicate that the absence of these non-essential nutrients in plant-based diets adversely affects health or confers disadvantages compared to omnivorous diets.
... Moreover, in the contexts of pregnancy, lactation, infancy, and childhood, vegan diets require extensive medical supervision to prevent irreversible neurological damage and, in extreme cases, death. This fact is supported by a large body of evidence and comprehensive position statements of medical and public health agencies around the world (Gorodischer and Shinwell, 1980;Lemale et al., 2019;Rudloff et al., 2019;Dobersek and Archer, 2022;Dwyer, 1991;Dwyer and Loew, 1994;Cofnas, 2019;Leroy and Cofnas, 2019;Pawlak, 2017;Iguacel et al., 2018;Pawlak et al., 2018). ...
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... However, the decrease in foods of animal origin (meat, fish, dairy products, and eggs) can lead to a decrease in protein intake in terms of quality and quantity (Steenson, & Buttriss, 2020;Allison, et al., 2006). Additionally, concerns may also arise regarding certain micronutrients (e.g., zinc, vitamin B12, and fatty acids) if they are replaced with plant-based foods (Leroy, & Cofnas, 2020). ...
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... While the benefits and risks of including red meat and other ASFs in a healthy diet is a matter of an enduring discussion (Leroy & Cofnas, 2020;Leroy et al., 2023;Libera et al., 2021), there is no health authority or scientific society recommending the exclusion of red meat from a balanced diet. On the contrary, the lack of access to foods from terrestrial animals (meat, milk, eggs, and their derived products) leads to serious health problems, as stated in a recent report from the FAO (2023). ...
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... In recent years, much attention has been paid to the associations between imbalance of meat intake and gastrointestinal diseases (Xue et al., 2024;Yu et al., 2021). Excessive meat consumption, especially red and processed meats, has been epidemiologically associated with both the high incidence of colorectal cancer and potential risks to intestinal health (Farvid et al., 2021;Leroy & Cofnas, 2020). Myoglobin in diets, a heme-containing protein primarily found in muscle tissues, may affect intestinal health status. ...
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... However, most evidence points toward consistently high levels of meat consumption. In addition to the environmental harms described above, such high levels of meat consumption are linked to significant health risks (Bye et al., 2021), with research supporting the idea that reductions in rates of meat consumption would reduce negative health outcomes such as cancer (Ruan et al., 2019), although some (e.g., Leroy & Cofnas, 2020) contest claims that meat consumption constitutes a health risk. ...
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Background The consumption of red and processed meat has been associated with increased mortality from chronic diseases, and as a result, it has been classified by the World Health Organization as carcinogenic (processed meat) and probably carcinogenic (red meat) to humans. One policy response is to regulate red and processed meat consumption similar to other carcinogens and foods of public health concerns. Here we describe a market-based approach of taxing red and processed meat according to its health impacts. Methods We calculated economically optimal tax levels for 149 world regions that would account for (internalize) the health costs associated with ill-health from red and processed meat consumption, and we used a coupled modelling framework to estimate the impacts of optimal taxation on consumption, health costs, and non-communicable disease mortality. Health impacts were estimated using a global comparative risk assessment framework, and economic responses were estimated using international data on health costs, prices, and price elasticities. Findings The health-related costs to society attributable to red and processed meat consumption in 2020 amounted to USD 285 billion (sensitivity intervals based on epidemiological uncertainty (SI), 93–431), three quarters of which were due to processed meat consumption. Under optimal taxation, prices for processed meat increased by 25% on average, ranging from 1% in low-income countries to over 100% in high-income countries, and prices for red meat increased by 4%, ranging from 0.2% to over 20%. Consumption of processed meat decreased by 16% on average, ranging from 1% to 25%, whilst red meat consumption remained stable as substitution for processed meat compensated price-related reductions. The number of deaths attributable to red and processed meat consumption decreased by 9% (222,000; SI, 38,000–357,000), and attributable health costs decreased by 14% (USD 41 billion; SI, 10–57) globally, in each case with greatest reductions in high and middle-income countries. Interpretation Including the social health cost of red and processed meat consumption in the price of red and processed meat could lead to significant health and environmental benefits, in particular in high and middle-income countries. The optimal tax levels estimated in this study are context-specific and can complement the simple rules of thumb currently used for setting health-motivated tax levels.
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Executive summary Malnutrition in all its forms, including obesity, undernutrition, and other dietary risks, is the leading cause of poor health globally. In the near future, the health effects of climate change will considerably compound these health challenges. Climate change can be considered a pandemic because of its sweeping effects on the health of humans and the natural systems we depend on (ie, planetary health). These three pandemics—obesity, undernutrition, and climate change—represent The Global Syndemic that affects most people in every country and region worldwide. They constitute a syndemic, or synergy of epidemics, because they co-occur in time and place, interact with each other to produce complex sequelae, and share common underlying societal drivers. This Commission recommends comprehensive actions to address obesity within the context of The Global Syndemic, which represents the paramount health challenge for humans, the environment, and our planet in the 21st century. The Global Syndemic Although the Commission's mandate was to address obesity, a deliberative process led to reframing of the problem and expansion of the mandate to offer recommendations to collectively address the triple-burden challenges of The Global Syndemic. We reframed the problem of obesity as having four parts. First, the prevalence of obesity is increasing in every region of the world. No country has successfully reversed its epidemic because the systemic and institutional drivers of obesity remain largely unabated. Second, many evidence-based policy recommendations to halt and reverse obesity rates have been endorsed by Member States at successive World Health Assembly meetings over nearly three decades, but have not yet been translated into meaningful and measurable change. Such patchy progress is due to what the Commission calls policy inertia, a collective term for the combined effects of inadequate political leadership and governance to enact policies to respond to The Global Syndemic, strong opposition to those policies by powerful commercial interests, and a lack of demand for policy action by the public. Third, similar to the 2015 Paris Agreement on Climate Change, the enormous health and economic burdens caused by obesity are not seen as urgent enough to generate the public demand or political will to implement the recommendations of expert bodies for effective action. Finally, obesity has historically been considered in isolation from other major global challenges. Linking obesity with undernutrition and climate change into a single Global Syndemic framework focuses attention on the scale and urgency of addressing these combined challenges and emphasises the need for common solutions. Syndemic drivers The Commission applied a systems perspective to understand and address the underlying drivers of The Global Syndemic within the context of achieving the broad global outcomes of human health and wellbeing, ecological health and wellbeing, social equity, and economic prosperity. The major systems driving The Global Syndemic are food and agriculture, transportation, urban design, and land use. An analysis of the dynamics of these systems sheds light on the answers to some fundamental questions. Why do these systems operate the way they do? Why do they need to change? Why are they so hard to change? What leverage points (or levers) are required to overcome policy inertia and address The Global Syndemic? The Commission identified five sets of feedback loops as the dominant dynamics underlying the answers to these questions. They include: (1) governance feedback loops that determine how political power translates into the policies and economic incentives and disincentives for companies to operate within; (2) business feedback loops that determine the dynamics for creating profitable goods and services, including the externalities associated with damage to human health, the environment, and the planet; (3) supply and demand feedback loops showing the relationships that determine current consumption practices; (4) ecological feedback loops that show the unsustainable environmental damage that the food and transportation systems impose on natural ecosystems; and (5) human health feedback loops that show the positive and negative effects that these systems have on human health. These interactions need to be elucidated and methods for reorienting these feedback systems prioritised to mitigate The Global Syndemic. Double-duty or triple-duty actions The common drivers of obesity, undernutrition, and climate change indicate that many systems-level interventions could serve as double-duty or triple-duty actions to change the trajectory of all three pandemics simultaneously. Although these actions could produce win-win, or even win-win-win, results, they are difficult to achieve. A seemingly simple example shows how challenging these actions can be. National dietary guidelines serve as a basis for the development of food and nutrition policies and public education to reduce obesity and undernutrition and could be extended to include sustainability by moving populations towards consuming largely plant-based diets. However, many countries' efforts to include environmental sustainability principles within their dietary guidelines failed due to pressure from strong food industry lobbies, especially the beef, dairy, sugar, and ultra-processed food and beverage industry sectors. Only a few countries (ie, Sweden, Germany, Qatar, and Brazil) have developed dietary guidelines that promote environmentally sustainable diets and eating patterns that ensure food security, improve diet quality, human health and wellbeing, social equity, and respond to climate change challenges. The engagement of people, communities, and diverse groups is crucial for achieving these changes. Personal behaviours are heavily influenced by environments that are obesogenic, food insecure, and promote greenhouse-gas emissions. However, people can act as agents of change in their roles as elected officials, employers, parents, customers, and citizens and influence the societal norms and institutional policies of worksites, schools, food retailers, and communities to address The Global Syndemic. Across systems and institutions, people are decision makers who can vote for, advocate for, and communicate their preferences with other decision-makers about the policies and actions needed to address The Global Syndemic. Within the natural ecosystems, people travel, recreate, build, and work in ways that can preserve or restore the environment. Collective actions can generate the momentum for change. The Commission believes that the collective influence of individuals, civil society organisations, and the public can stimulate the reorientation of human systems to promote health, equity, economic prosperity, and sustainability. Changing trends in obesity, undernutrition, and climate change Historically, the most widespread form of malnutrition has been undernutrition, including wasting, stunting, and micronutrient deficiencies. The Global Hunger Index (1992–2017) showed substantial declines in under-5 child mortality in all regions of the world but less substantial declines in the prevalence of wasting and stunting among children. However, the rates of decline in undernutrition for children and adults are still too slow to meet the Sustainable Development Goal (SDG) targets by 2030. In the past 40 years, the obesity pandemic has shifted the patterns of malnutrition. Starting in the early 1980s, rapid increases in the prevalence of overweight and obesity began in high-income countries. In 2015, obesity was estimated to affect 2 billion people worldwide. Obesity and its determinants are risk factors for three of the four leading causes of non-communicable diseases (NCDs) worldwide, including cardiovascular diseases, type 2 diabetes, and certain cancers. Extensive research on the developmental origins of health and disease has shown that fetal and infant undernutrition are risk factors for obesity and its adverse consequences throughout the life course. Low-income and middle-income countries (LMICs) carry the greatest burdens of malnutrition. In LMICs, the prevalence of overweight in children less than 5 years of age is rising on the background of an already high prevalence of stunting (28%), wasting (8·8%), and underweight (17·4%). The prevalence of obesity among stunted children is 3% and is higher among children in middle-income countries than in lower-income countries. The work of the Intergovernmental Panel on Climate Change (IPCC), three previous Lancet Commissions related to climate change and planetary health (2009–15), and the current Lancet Countdown, which is tracking progress on health and climate change from 2017 to 2030, have provided extensive and compelling projections on the major human health effects related to climate change. Chief among them are increasing food insecurity and undernutrition among vulnerable populations in many LMICs due to crop failures, reduced food production, extreme weather events that produce droughts and flooding, increased food-borne and other infectious diseases, and civil unrest. Severe food insecurity and hunger are associated with lower obesity prevalence, but mild to moderate food insecurity is paradoxically associated with higher obesity prevalence among vulnerable populations. Wealthy countries already have higher burdens of obesity and larger carbon footprints compared with LMICs. Countries transitioning from lower to higher incomes experience rapid urbanisation and shifts towards motorised transportation with consequent lower physical activity, higher prevalence of obesity, and higher greenhouse-gas emissions. Changes in the dietary patterns of populations include increasing consumption of ultra-processed food and beverage products and beef and dairy products, whose production is associated with high greenhouse-gas emissions. Agricultural production is a leading source of greenhouse-gas emissions. The economic burden of The Global Syndemic The economic burden of The Global Syndemic is substantial and will have the greatest effect on the poorest of the 8·5 billion people who will inhabit the earth by 2030. The current costs of obesity are estimated at about 2trillionannuallyfromdirecthealthcarecostsandlosteconomicproductivity.Thesecostsrepresent28Economiclossesattributabletoundernutritionareequivalentto112 trillion annually from direct health-care costs and lost economic productivity. These costs represent 2·8% of the world's gross domestic product (GDP) and are roughly the equivalent of the costs of smoking or armed violence and war. Economic losses attributable to undernutrition are equivalent to 11% of the GDP in Africa and Asia, or approximately 3·5 trillion annually. The World Bank estimates that an investment of 70billionover10yearsisneededtoachieveSDGtargetsrelatedtoundernutrition,andthatachievingthemwouldcreateanestimated70 billion over 10 years is needed to achieve SDG targets related to undernutrition, and that achieving them would create an estimated 850 billion in economic return. The economic effects of climate change include, among others, the costs of environmental disasters (eg, drought and wildfires), changes in habitat (eg, biosecurity and sea-level rises), health effects (eg, hunger and diarrhoeal infections), industry stress in sectors such as agriculture and fisheries, and the costs of reducing greenhouse-gas emissions. Continued inaction towards the global mitigation of climate change is predicted to cost 5–10% of global GDP, whereas just 1% of the world's GDP could arrest the increase in climate change. Actions to address The Global Syndemic Many authoritative policy documents have proposed specific, evidence-informed policies to address each of the components of The Global Syndemic. Therefore, the Commission decided to focus on the common, enabling actions that would support the implementation of these policies across The Global Syndemic. A set of principles guided the Commission's recommendations to enable the implementation of existing recommended policies: be systemic in nature, address the underlying causes of The Global Syndemic and its policy inertia, forge synergies to promote health and equity, and create benefits through double-duty or triple-duty actions. The Commission identified multiple levers to strengthen governance at the global, regional, national, and local levels. The Commission proposed the use of international human rights law and to apply the concept of a right to wellbeing, which encompasses the rights of children and the rights of all people to health, adequate food, culture, and healthy environments. Global intergovernmental organisations, such as the World Trade Organization, the World Economic Forum, the World Bank, and large philanthropic foundations and regional platforms, such as the European Union, Association of Southeastern Nations, and the Pacific Forum, should play much stronger roles to support national policies that address The Global Syndemic. Many states and municipalities are leading efforts to reduce greenhouse-gas emissions by incentivising less motorised travel and improving urban food systems. Civil society organisations can create a greater demand for national policy actions with increases in capacity and funding. Therefore, in addition to the World Bank's call for 70billionforundernutritionandtheGreenClimateFundof70 billion for undernutrition and the Green Climate Fund of 100 billion for LMICs to address climate change, the Commission calls for 1billiontosupporttheeffortsofcivilsocietyorganisationstoadvocateforpolicyinitiativesthatmitigateTheGlobalSyndemic.Aprincipalsourceofpolicyinertiarelatedtoaddressingobesityandclimatechangeisthepowerofvestedinterestsbycommercialactorswhoseengagementinpolicyoftenconstitutesaconflictofinterestthatisatoddswiththepublicgoodandplanetaryhealth.Counteringthispowertoassureunbiaseddecisionmakingrequiresstrongprocessestomanageconflictsofinterest.Onthebusinessside,newsustainablemodelsareneededtoshiftoutcomesfromaprofitonlymodeltoasociallyandenvironmentallyviableprofitmodelthatincorporatesthehealthofpeopleandtheenvironment.ThefossilfuelandfoodindustriesthatareresponsiblefordrivingTheGlobalSyndemicreceivemorethan1 billion to support the efforts of civil society organisations to advocate for policy initiatives that mitigate The Global Syndemic. A principal source of policy inertia related to addressing obesity and climate change is the power of vested interests by commercial actors whose engagement in policy often constitutes a conflict of interest that is at odds with the public good and planetary health. Countering this power to assure unbiased decision making requires strong processes to manage conflicts of interest. On the business side, new sustainable models are needed to shift outcomes from a profit-only model to a socially and environmentally viable profit model that incorporates the health of people and the environment. The fossil fuel and food industries that are responsible for driving The Global Syndemic receive more than 5 trillion in annual subsidies from governments. The Commission recommends that governments redirect these subsidies into more sustainable energy, agricultural, and food system practices. A Framework Convention on Food Systems would provide the global legal structure and direction for countries to act on improving their food systems so that they become engines for better health, environmental sustainability, greater equity, and ongoing prosperity. Stronger accountability systems are needed to ensure that governments and private-sector actors respond adequately to The Global Syndemic. Upstream monitoring is needed to measure implementation of policies, examine the commercial, political, economic and sociocultural determinants of obesity, evaluate the impact of policies and actions, and establish mechanisms to hold governments and powerful private-sector actors to account for their actions. Similarly, platforms for stakeholders to interact and secure funding, such as that provided by the EAT Forum for global food system transformation, are needed to allow collaborations of scientists, policy makers, and practitioners to co-create policy-relevant empirical, and modelling studies of The Global Syndemic and the effects of double-duty and triple-duty actions. Bringing indigenous and traditional knowledge to this effort will also be important because this knowledge is often based on principles of environmental stewardship, collective responsibilities, and the interconnectedness of people with their environments. The challenges facing action on obesity, undernutrition, and climate change are closely aligned with each other. Bringing them together under the umbrella concept of The Global Syndemic creates the potential to strengthen the action and accountabilities for all three challenges. Our health, the health of our children and future generations, and the health of the planet will depend on the implementation of comprehensive and systems-oriented responses to The Global Syndemic.
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A 34-year-old previously well woman presented with a 4-week history of diffuse erythema and crusting of skin affecting all four limbs. Examination revealed erythematous skin plaques associated with ulceration and fissuring affecting sun-exposed areas of all four limbs primarily on the dorsal surfaces, and a body mass index of 17 kg/m ² . She was admitted under the infectious diseases unit, and an autoimmune and infective screen was performed which returned unremarkable. Dietetic consultation led to the diagnosis of severe protein-energy malnutrition, consequent to a severely restricted, primarily vegan, diet. Analysis of the patient’s reported diet with nutritional software revealed grossly suboptimal caloric intake with risk of inadequacy for most micronutrients, vitamins and minerals, including niacin. Oral thiamine, multivitamin, iron supplementation and vitamin B complex were started, and a single intramuscular vitamin B 12 dose was administered. Marked improvement was seen after 6 weeks, with near-complete resolution of skin changes. These findings supported a diagnosis of pellagra.