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OBITUARY Philip Lawley and the
discovery that DNA damage
can cause cancer p.36
LITERATURE How Charles
Dickens drew on science, but
left room for wonder p.32
NEUROSCIENCE The source of the
self is in the brain’s wiring,
not individual neurons p.3
ECOLOGY Komodo dragons and
elephants could reduce fire
risk in Australia p.30
The toxic truth about sugar
Added sweeteners pose dangers to health that justify controlling them like alcohol,
argue Robert H. Lustig, Laura A. Schmidt and Claire D. Brindis.
susceptible to non-communicable diseases;
80% of deaths attributable to them occur in
these countries.
Many people think that obesity is the
root cause of these diseases. But 20% of
obese people have normal metabolism and
L
ast September, the United Nations
declared that, for the first time in
human history, chronic non-commu-
nicable diseases such as heart disease, cancer
and diabetes pose a greater health burden
worldwide than do infectious diseases,
contributing to 35million deaths annually.
This is not just a problem of the developed
world. Every country that has adopted the
Western diet — one dominated by low-cost,
highly processed food — has witnessed rising
rates of obesity and related diseases. There
are now 30% more people who are obese
than who are undernourished. Economic
development means that the populations
of low- and middle-income countries
are living longer, and therefore are more
will have a normal lifespan. Conversely, up
to 40% of normal-weight people manifest
the diseases that constitute the meta-
bolic syndrome: diabetes, hypertension,
lipid problems, cardio vascular disease,
non-alcoholic fatty liver disease, cancer and
dementia. Obesity is not the cause; rather,
it is a marker for metabolic dysfunction,
which is even more prevalent.
The UN announcement targets tobacco,
alcohol and diet as the central risk factors
in non-communicable disease. Two of these
three — tobacco and alcohol — are regulated
by governments to protect public health,
leaving one of the primary culprits behind
this worldwide health crisis unchecked.
Of course, regulating food is more
SUMMARY
● Sugar consumption is linked to a rise
in non-communicable disease
● Sugar’s effects on the body can be
similar to those of alcohol
● Regulation could include tax, limiting
sales during school hours, and placing
age limits on purchasing
ILLUSTRATION BY MARK SMITH
2 FEBRUARY 2012 | VOL 482 | NATURE | 27
COMMENT
complicated — food is required, whereas
tobacco and alcohol are non-essential con-
sumables. The key question is: what aspects
of the Western diet should be the focus of
intervention?
Denmark first chose, in October 2011,
to tax foods high in saturated fat, despite
the fact that most medical professionals no
longer believe that fat is the primary culprit.
But now, the country is considering taxing
sugar as well — a more plausible and defen-
sible step. Indeed, rather than focusing on fat
and salt — the current dietary ‘bogeymen’ of
the US Department of Agriculture (USDA)
and the European Food Safety Authority —
we believe that attention should be turned to
‘added sugar’, defined as any sweetener con-
taining the molecule fructose that is added
to food in processing.
Over the past 50 years, consumption of
sugar has tripled worldwide. In the United
States, there is fierce controversy over the
pervasive use of one particular added sugar —
high-fructose corn syrup (HFCS). It is manu-
factured from corn syrup (glucose), processed
to yield a roughly equal mixture of glucose
and fructose. Most other developed countries
eschew HFCS, relying on naturally occurring
sucrose as an added sugar, which also consists
of equal parts glucose and fructose.
Authorities consider sugar as ‘empty cal-
ories’ — but there is nothing empty about
these calories. A growing body of scientific
evidence shows that fructose can trigger
processes that lead to liver toxicity and a
host of other chronic diseases1. A little is
not a problem, but a lot kills — slowly (see
‘Deadly effect’). If international bodies are
truly concerned about public health, they
must consider limiting fructose — and its
main delivery vehicles, the added sugars
HFCS and sucrose — which pose dangers
to individuals and to society as a whole.
NO ORDINARY COMMODITY
In 2003, social psychologist Thomas Babor
and his colleagues published a landmark
book called Alcohol: No Ordinary Commod-
ity, in which they established four criteria,
now largely accepted by the public-health
community, that justify the regulation of
alcohol — unavoidability (or pervasiveness
throughout society), toxicity, potential for
abuse and negative impact on society
2
. Sugar
meets the same criteria, and we believe that
it similarly warrants some form of societal
intervention.
First, consider unavoidability. Evolu-
tionarily, sugar as fruit was available to
our ancestors for only a few months a year
(at harvest time), or as honey, which was
guarded by bees. But in recent years, sugar
has been added to virtually every processed
food, limiting consumer choice3. Nature
made sugar hard to get; man made it easy.
In many parts of the world, people are
consuming an average of more than 500cal-
ories per day from added sugar alone (see
‘The global sugar glut’).
Now, let’s consider toxicity. A growing
body of epidemiological and mechanistic
evidence argues that excessive sugar con-
sumption affects human health beyond
simply adding calories
4
. Importantly, sugar
induces all of the diseases associated with
metabolic syndrome
1,5
. This includes: hyper-
tension (fructose increases uric acid, which
raises blood pressure); high triglycerides
and insulin resistance through synthesis of
fat in the liver; diabetes from increased liver
glucose production
combined with insu-
lin resistance; and
the ageing process,
caused by damage to
lipids, proteins and
DNA through non-
enzymatic bind ing
of fructose to these
molecules. It can also
be argued that fructose exerts toxic effects on
the liver similar to those of alcohol
1
. This is
no surprise, because alcohol is derived from
the fermentation of sugar. Some early stud-
ies have also linked sugar consumption to
human cancer and cognitive decline.
Sugar also has a clear potential for abuse.
Like tobacco and alcohol, it acts on the
brain to encourage subsequent intake.
There are now numerous studies examin-
ing the dependence-producing properties
of sugar in humans6. Specifically, sugar
dampens the suppression of the hormone
ghrelin, which signals hunger to the brain.
It also interferes with the normal transport
and signalling of the hormone leptin, which
helps to produce the feeling of satiety. And
it reduces dopamine signalling in the brain’s
reward centre, thereby decreasing the pleas-
ure derived from food and compelling
the individual to consume more1,6.
Finally, consider the negative effects
of sugar on society. Passive smoking and
drink-driving fatalities provided strong
arguments for tobacco and alcohol con-
trol, respectively. The long-term economic,
health-care and human costs of metabolic
syndrome place sugar overconsumption in
the same category
7
. The United States spends
$65 billion in lost productivity and $150 bil-
lion on health-care resources annually for
co-morbidities associated with metabolic
syndrome. Seventy-five per cent of all US
health-care dollars are now spent on treat-
ing these diseases and resultant disabilities.
Because 75% of military applicants are now
rejected for obesity-related reasons, the past
three US surgeons general and the chairman
of the US Joint Chiefs of Staff have declared
obesity a “threat to national security”.
HOW TO INTERVENE
How can we reduce sugar consumption?
After all, sugar is natural. Sugar is a nutri-
ent. Sugar is pleasure. So is alcohol, but in
both cases, too much of a good thing is toxic.
It may be helpful to look to the many genera-
tions of international experience with alcohol
and tobacco to find models that work8,9. So
far, evidence shows that individually focused
approaches, such as school-based interven-
tions that teach children about diet and exer-
cise, demonstrate little efficacy. Conversely,
for both alcohol and tobacco, there is robust
evidence that gentle ‘supply side’ control
strategies which stop far short of all-out pro-
hibition — taxation, distribution controls,
age limits — lower both consumption of the
product and accompanying health harms.
Successful interventions all share a common
end-point: curbing availability2,8,9.
Taxing alcohol and tobacco products — in
the form of special excise duties, value added
taxes and sales taxes — are the most popular
DEADLY EFFECT
Excessive consumption of fructose can cause many of the same health problems as alcohol.
Chronic ethanol exposure Chronic fructose exposure
Hematologic disorders
Electrolyte abnormalities
Hypertension Hypertension (uric acid)
Cardiac dilatation
Cardiomyopathy Myocardial infarction (dyslipidemia, insulin
resistance)
Dyslipidemia Dyslipidemia (de novo lipogenesis)
Pancreatitis Pancreatitis (hypertriglyceridemia)
Obesity (insulin resistance) Obesity (insulin resistance)
Malnutrition Malnutrition (obesity)
Hepatic dysfunction (alcoholic steatohepatitis) Hepatic dysfunction (non-alcoholic steatohepatitis)
Fetal alcohol syndrome
Addiction Habituation, if not addiction
Source: ref. 1
“Sugar is
cheap, sugar
tastes good,
and sugar sells,
so companies
have little
incentive to
change.”
28 | NATURE | VOL 482 | 2 FEBRUARY 2012
COMMENT
and effective ways to reduce smoking and
drinking, and in turn, substance abuse and
related harms2. Consequently, we propose
adding taxes to processed foods that contain
any form of added sugars, such as HFCS and
sucrose. This would include sweetened fizzy
drinks (soda) and other sugar-sweetened
beverages (for example, juice, sports drinks
and chocolate milk), and also sugared cereal.
Already, Canada and some European coun-
tries impose small additional taxes on some
sweetened foods. The United States is cur-
rently considering a penny-per-ounce soda
tax (about 34cents per litre), which would
raise the price of a can of soda by 10–12
cents. Currently, each US citizen consumes
an average of 216 litres of soda per year, of
which 58% contains sugar; taxing at a penny
an ounce could provide annual revenues in
excess of $45 per capita (roughly $14 billion
per year); however, this would be unlikely
to reduce total consumption. Statistical
modelling suggests that the price would
have to double to significantly reduce soda
consumption — so a $1 can of soda should
cost $2 (ref. 10).
Other successful tobacco- and alcohol-
control strategies limit availability, such as
reducing the hours that retailers are open,
controlling the location and density of retail
markets and limiting who can legally pur-
chase the products2,9. A reasonable parallel
for sugar would tighten licensing require-
ments on vending machines and snack bars
that sell sugary products in schools and
workplaces. Many schools have removed
soda and candy from vending machines, but
often replaced them with juice and sports
drinks, which also contain added sugar.
States could apply zoning ordinances to
control the number of fast-food outlets and
convenience stores in low-income commu-
nities, and especially around schools, while
providing incentives for the establishment of
grocery stores and farmer’s markets.
Another option would be to limit sales
during school operation, or to designate
an age limit (such as 17) for the purchase of
drinks with added sugar, particularly soda.
Indeed, parents in South Philadelphia, Penn-
sylvania, recently took this upon themselves
by lining up outside convenience stores and
blocking children from entering them after
school. Why couldn’t a public-health direc-
tive do the same?
THE POSSIBLE DREAM
Government-imposed regulations on
the marketing of alcohol to young people
have been quite effective, but there is no such
approach to sugar-laden products. Even so,
the city of San Francisco, California, recently
instituted a ban on including toys with
unhealthy meals such as some types of fast
food. A limit — or, ideally, ban — on televi-
sion commercials for products with added
sugars could further protect children’s health.
Reduced fructose consumption could
also be fostered through changes in sub-
sidization. Promotion of healthy foods in
US low-income programmes, such as the
Special Supplemental Nutrition Program
for Women, Infants and Children and the
Supplemental Nutrition Assistance Pro-
gram (also known as the food-stamps
programme) is an obvious place to start.
Unfortunately, the petition by New York City
to remove soft drinks from the food-stamp
programme was denied by the USDA.
Ultimately, food producers and dis-
tributors must reduce the amount of sugar
added to foods. But sugar is cheap, sugar
tastes good, and sugar sells, so companies
have little incentive to change. Although
one institution alone can’t turn this jug-
gernaut around, the US Food and Drug
Administration could “set the table” for
change
8
. To start, it should consider remov-
ing fructose from the Generally Regarded
as Safe (GRAS) list, which allows food
manufacturers to add unlimited amounts to
any food. Opponents will argue that other
nutrients on the GRAS list, such as iron and
vitamins A and D, can also be toxic when
over-consumed. However, unlike sugar,
these substances have no abuse potential.
Removal from the GRAS list would send a
powerful signal to the European Food Safety
Authority and the rest of the world.
Regulating sugar will not be easy —
particularly in the ‘emerging markets’ of
developing countries where soft drinks
are often cheaper than potable water or
milk. We recognize that societal interven-
tion to reduce the supply and demand for
sugar faces an uphill political battle against
a powerful sugar lobby, and will require
active engagement from all stakeholders.
Still, the food industry knows that it has
a problem — even vigorous lobbying by
fast-food companies couldn’t defeat the
toy ban in San Francisco. With enough
clamour for change, tectonic shifts in
policy become possible. Take, for instance,
bans on smoking in public places and the
use of designated drivers, not to mention
airbags in cars and condom dispensers in
public bathrooms. These simple measures
— which have all been on the battleground
of American politics — are now taken for
granted as essential tools for our public
health and wellbeing. It’s time to turn our
attention to sugar. ■
Robert H. Lustig is in the Department
of Pediatrics and the Center for Obesity
Assessment, Study and Treatment at the
University of California, San Francisco,
California 94143, USA. Laura A. Schmidt
and Claire D. Brindis are at the Clinical
and Translational Science Institute and
the Philip R. Lee Institute for Health Policy
Studies, University of California, San
Francisco, California 94118, USA.
e-mail: rlustig@peds.ucsf.edu
1. Lustig, R. H. J. Am. Diet. Assoc. 110, 1307–1321
(2010).
2. Babor, T. et al. Alcohol: No Ordinary Commodity:
Research and Public Policy (Oxford Univ. Press,
2003).
3. Vio, F. & Uauy, R. in Food Policy for Developing
Countries: Case Studies (eds Pinstrup-Andersen,
P. & Cheng, F.) No. 9-5 (2007); available at
http://go.nature.com/prjsk4
4. Joint WHO/FAO Expert Consultation. Diet,
Nutrition and the Prevention of Chronic Diseases
WHO Technical Report Series 916 (WHO; 2003).
5. Tappy, L., Lê, K. A., Tran, C, & Paquot, N. Nutrition
26, 1044–1049 (2010).
6. Garber, A. K. & Lustig, R. H. Curr. Drug Abuse Rev.
4, 146–162 (2011).
7. Finkelstein, E. A., Fiebelkorn, I. C. & Wang, G.
Health Aff. W3 (suppl.), 219–226 (2003).
8. Engelhard, C. L., Garson, A. Jr & Dorn, S.
Reducing Obesity: Policy Strategies from the
Tobacco Wars (Urban Institute, 2009); available
at http://go.nature.com/w4o5uk
9. Room, R., Schmidt, L. A., Rehm, J. & Mäkela P. Br.
Med. J. 337, a2364 (2008).
10. Sturm, R., Powell L. M., Chriqui, J. F. & Chaloupka,
F. J. Health Aff. 29, 1052–1058 (2010).
THE GLOBAL SUGAR GLUT
Global sugar supply (in the form of sugar and sugar crops, excluding fruit
and wine) expressed as calories per person per day, for the year 2007.
>600
Calories per
person per day
500–600
400–500
300–400
200–300
100–200
<100
No data
SOURCE: FAO
2 FEBRUARY 2012 | VOL 482 | NATURE | 29
COMMENT
