ArticlePDF Available

Caloric restriction and human longevity: What can we learn from the Okinawans?

Authors:

Abstract

Caloric (or dietary) restriction (CR) extends lifespan and lowers risk for age associated diseases in a phylogenetically diverse group of species. Whether prolonged CR increases average or maximum lifespan or promotes a more youthful physiology in humans at advanced ages is not yet known. However, available epidemiological evidence indicates that CR may already have contributed to an extension of average and maximum life span in one human population and appears to have lowered risk for age associated chronic diseases in other human populations. We review the human studies in the context of a special human population, older Okinawans, who appear to have undergone a mild form of prolonged CR for about half their adult lives.
Abstract Caloric (or dietary) restriction (CR)
extends lifespan and lowers risk for age associated
diseases in a phylogenetically diverse group of
species. Whether prolonged CR increases average or
maximum lifespan or promotes a more youthful
physiology in humans at advanced ages is not yet
known. However, available epidemiological evi-
dence indicates that CR may already have contrib-
uted to an extension of average and maximum life
span in one human population and appears to have
lowered risk for age associated chronic diseases in
other human populations. We review the human
studies in the context of a special human population,
older Okinawans, who appear to have undergone a
mild form of prolonged CR for about half their adult
lives.
Keywords Caloric restriction Æ Okinawa Æ
Maximum life span Æ Healthy aging Æ Diet Æ
Longevity
Introduction
Caloric (or dietary) restriction (CR) is the only con-
sistently reproducible experimental means of
extending mean and maximum lifespan and markedly
decreasing morbidity in a phylogenetically diverse
group of short lived laboratory mammals. Studies
underway with longer-lived species such as non-
human primates are also showing promising early
results regarding the life-extending physiological
effects seen in rodents and other animals (Roth et al.
2001; Mattison et al. 2003; Lane et al. 2004). The
question of whether or not CR would work in humans
may be one of the most significant unanswered
questions in biogerontology.
We take the position that CR not only will work
but in fact available epidemiological evidence indi-
cates that CR may already have contributed to an
extension of average and maximum life span in one
human population and appears to have lowered risk
D. C. Willcox (&)
College of Nursing, Okinawa Prefectural University,
1-24-1 Yogi, Naha, Okinawa 902-0076, Japan
e-mail: willcox@okinawa-nurs.ac.jp
B. J. Willcox Æ J. D. Curb Æ D. C. Willcox
Pacific Health Research Institute, 846 South Hotel Street,
Suite 301, Honolulu, HI 96813, USA
B. J. Willcox Æ J. D. Curb
Departments of Geriatric Medicine and Medicine, John A.
Burns School of Medicine, University of Hawaii, 1356
Lusitana Street, 7F, Honolulu, HI 96813, USA
H. Todoriki
Faculty of Medicine, University of the Ryukyus,
Department of Environmental and Preventive Medicine,
207 Vehara, Nishihara, Okinawa 903-0215, Japan
M. Suzuki
Professor Emeritis, University of the Ryukyus, 207
Uehara, 903-0215, Nishihara-Cho, Okinawa, Japan
Biogerontology (2006) 7: 173–177
DOI 10.1007/s10522-006-9008-z
123
OPINION
Caloric restriction and human longevity: what can we learn
from the Okinawans?
D. Craig Willcox Æ Bradley J. Willcox Æ
Hidemi Todoriki Æ J. David Curb Æ
Makoto Suzuki
Received: 20 January 2006 / Accepted: 20 January 2006 / Published online: 30 June 2006
Ó Springer Science+Business Media B.V. 2006
for age associated chronic diseases in other human
populations. We review the human studies in the
context of a special human population that we believe
has undergone prolonged CR while also maintaining
a high quality diet—a necessary condition for CR to
manifest its beneficial effects.
CR studies and effects in humans
Short-term studies of humans under various CR par-
adigms have shown dramatic changes in biology
similar to prior studies in other animals. While some
effects appear partly mediated by reduction of fat
mass, multiple mechanisms have been proposed
including altered insulin signaling, reduced free rad-
ical damage, and hormesis, among others. This evi-
dence has been reviewed elsewhere and we will
concentrate on long term human studies (Heilbronn
and Ravussin 2003; Masoro 2005; Dirks and
Leeuwenburgh 2006).
Recent data from individuals (18 subjects) under-
taking a voluntary long-term CR regimen supports
what would be expected by the short term studies.
Long term caloric restriction for periods of 3–15 years
(average of 6 years) has shown it to be highly effec-
tive in reducing the risk for atherosclerotic arterial
disease, the leading cause of morbidity and mortality
in Western societies, by changing key biochemical,
hormonal and metabolic parameters (Fontana et al.
2004). CR also appears to ameliorate the decline in
diastolic heart function that occurs with human aging
(Meyer et al. 2006). A key question is whether or not
these systemic changes are reflective of a more
youthful physiology and will enhance health and
lifespan if continued over a longer time period.
A recently published 25 years follow-up report
from the Baltimore Longitudinal Study of Aging
(BLSA) suggests that this might indeed be the case.
The BLSA noted that healthy men who displayed
three ‘‘biomarkers of the CR phenotype’’—lower
insulin levels, lower body temperature and a slower
decline in levels of the hormone dehydroepiandros-
terone sulfate (DHEA-S) also had significantly longer
survival (Roth et al. 2002). Furthermore, similar
findings have also been seen in the Honolulu Heart
Program cohort where blood glucose in middle age
strongly predicts late life survival (Rodriguez et al.
1999). More human studies are needed to confirm
these preliminary findings and are currently under-
way, such as the CALERIE trials, but they do not
address longevity as an outcome (Heilbronn and
Ravussin 2003).
Only one long-term epidemiological prospective
study (>30 years) has directly addressed the issue of
caloric intake and human longevity. This 36-year
follow-up study reported a weak trend for lower all-
cause mortality in healthy non-smoking Japanese-
American men suggesting that those who consumed a
modestly low energy intake (85% of group mean) had
the lowest risk for all-cause mortality (Willcox et al.
2004). There was higher mortality risk when caloric
intake dropped below 50% of the group mean. This is
consistent with previous animal findings that show
decreased risk for mortality from age associated
diseases and increased life span under a CR regimen
of up to 50% restriction.
The Okinawa findings
Older Okinawans exhibit the CR phenotype
Low caloric intake was first reported in the Okinawan
population by Hokama et al. (1967) who showed that
Okinawan school children consumed only 62% of the
calories of other Japanese school children. Kagawa
(1978) confirmed low caloric intake (83% of Japan
average) in the Okinawa adult population from the
1972 Japan National Nutrition Survey and docu-
mented anthropometric and morbidity data from
older Okinawans that were consistent with CR.
Kagawa (1978) hypothesized that this may have been
partly responsible for the long and healthy lives of
Okinawans. Death rates from heart disease, cancer
and cerebral vascular disease were found to be only
60 to 70% of that of the Japan average and the all-
cause mortality rate for 60–64 year olds was only half
that of other Japanese. A later study published by
Chan et al. (1997) also reported dietary and pheno-
typic data in Okinawan septuagenarians and cente-
narians consistent with CR.
Our recent analysis of long-term trends in whole
population caloric intake and energy balance for the
years beginning in 1949 demonstrates that the
Okinawan septuagenarian population appeared to be
in a relative ‘‘energy deficit’’ consistent with CR
until the late 1960s, eating approximately 11% fewer
174 Biogerontology (2006) 7: 173–177
123
calories (approximately 1,785 kcal per day) than
would normally be recommended for maintenance of
body weight according to the Harris-Benedict equa-
tion (Willcox et al. Unpublished data). The body
mass index (BMI) of adult Okinawans also remained
stable at a very lean 21 kg/m
2
and peak body weight
was reached in young adulthood and appeared rela-
tively stable until elderly ages (Willcox et al.
Unpublished data). These dietary and anthropometric
data are consistent with adaptation to a long-term
energy deficit and fit proposed epidemiologic defini-
tions by a recent US National Institutes of Health
panel (see Lee et al. 2001) of the human CR pheno-
type (i.e. no weight gain after early adulthood).
Moreover, nutritional studies suggest that the tra-
ditional Okinawan diet, with its high intake of green
leafy and yellow root vegetables, sweet potatoes as a
dietary staple, and soy as a principle protein supple-
mented by small amounts of fish and meat, was
adequate in most nutrients and particularly high in
antioxidant vitamins (Sho 2001; Suzuki et al. 2001;
Todoriki et al. 2004; Willcox 2005).
Was there a CR effect?
If a CR phenomenon occurred for the current gen-
eration of elderly Okinawans then there should be
biomarker evidence of CR-linked delayed physio-
logical aging. Thus, it is of keen interest that recent
findings from our ongoing study of Okinawa’s elderly
population show that Okinawan septuagenarians, who
would have undergone CR until at least middle age
according to the previous population data, exhibit
higher DHEA levels when compared to age-matched
Americans not subjected to CR (Willcox et al.
Unpublished data). In addition, if delayed aging oc-
curred in Okinawans, then there should be a right-
ward shift in the survival curve, with increases in
both average lifespan and maximum lifespan. Indeed,
survival curves for Okinawan, Japanese and U.S.
populations calculated based on life table data for the
year 1995 do show increases in both average and
maximum lifespan in the Okinawan population
compared to Japanese and American populations,
consistent with CR. Average lifespan (measured as
50th percentile survival) and maximum lifespan
(measured as 99th percentile survival) in the Okina-
wan, Japanese and U.S. populations were 83.8 and
104.9 years, 82.3 and 101.1 years, and 78.9 and
101.3 years, respectively (Willcox et al. Unpublished
data).
Finally, age-adjusted mortality for specific age-
related diseases (especially cardiovascular diseases)
is extremely low in elderly Okinawans compared to
other age-matched Japanese or Americans (Kagawa
1978; Suzuki et al. 2001).Thus, life expectancy at
older ages is extremely long in Okinawa. For the
septuagenarian cohort, life expectancy from age 65 is
the longest in Japan, and possibly the world, at
24.1 years for females and 18.5 years for males (Ja-
pan Ministry of Health, Labor and Welfare, 2005).
This compares to 22.5 years and 17.6 years for the
same birth cohort in mainland Japan (Japan Ministry
of Health, Labor and Welfare 2000) and 19.3 years
and 16.2 years for corresponding U.S. birth cohorts
of females and males respectively (U.S. Centers for
Disease Control and Prevention 2003). Also consis-
tent with a longer life expectancy at older ages is the
high numbers of centenarians at approximately 50 per
100,000 or about 4–5 times the average for most
industrialized countries (Japan Ministry of Health,
Labor and Welfare 2005).
Other factors may also be contributing to the
exceptional longevity of the Okinawans such as ge-
netic factors, specific nutritional components of the
diet (high anti-oxidants), social support and/or health
care (Takata et al. 1987; Goto et al. 2003; Todoriki
et al. 2004; Suzuki et al. 2001, 2004; Willcox 2005;
Willcox et al. 2006). However, the forces of mor-
bidity and mortality act most strongly at older ages
and it is at these ages one would expect to see the
most marked phenotypic differences and the most
marked survival advantage, had CR occurred in the
Okinawans, and indeed this is the case.
Should we restrict our calories?
Some scientists who study the mechanisms of aging
suggest that it is unlikely that the maximum lifespan
of humans can be extended by any intervention,
including caloric restriction (Hayflick 2004). It has
also been argued that while CR is likely to be almost
universal in its beneficial effects on longevity, the
benefit to humans is likely to be small, even if hu-
mans restrict their caloric intake substantially and
over long periods of time (Phelan and Rose 2005).
The latter argument derives from observations of
Biogerontology (2006) 7: 173–177 175
123
complex differences between species (such as amount
of energy allocated to reproduction) and the fact that
underlying physiological mechanisms that determine
longevity are not necessarily the same between spe-
cies. Furthermore, there are potential health concerns,
particularly if practiced incorrectly (too severe) or at
vulnerable (too young, too old, pregnancy) life stages
(Le Bourg 2005; Dirks and Leeuwenburgh 2006).
While fully acknowledging that the nature of the
life-extending action of CR may differ among spe-
cies, we believe these views to be overly pessimistic
and not reflective of the available evidence. However,
we believe that people should not attempt to restrict
calories to the extreme levels seen in animal studies
(up to 60%) because human studies, although prom-
ising, have not fully addressed issues such as quality
of life and other potential side effects. With that
caveat in mind, cautious approaches to lowering
calories (mild CR) among adults while maintaining
optimal nutrient intakes would still likely result in
significant health benefits. In fact, recent findings
show that even 8% CR has beneficial effects on
specific biochemical and inflammatory biomarkers
(Dirks and Leeuwenburgh 2006).
We cite the following reasons for a more optimistic
view of the potential benefits of the CR lifestyle for
human beings: First, the accumulated evidence of
70 years of CR studies suggests that CR is an ex-
tremely ancient and very important survival mecha-
nism which appeared early in the evolution of
eukaryotes. Therefore it appears to be strongly con-
served throughout the phylogenetic scale (from yeast
to mammals). As such, it would be unusual if it did not
work in some positive capacity in humans as well.
Second, studies in progress with non-human primates
(who share over 95% of our genes and have similar
reproductive physiology) on a CR regimen, while not
yet conclusive, are showing early results consistent
with previous animal data. Third, short-term and
longer-term studies of humans under a true CR para-
digm have shown dramatic changes in physiology and
metabolic shifts similar to other animals. Fourth, our
research shows that older Okinawans (ages-65 plus)
exhibit a CR-like phenotype and ate a low calorie diet
over a prolonged period of time. Calories in the
Okinawan population were approximately 11% fewer
than what would usually be recommended for their
body weight and activity levels (based on the Harris-
Benedict equation) but only for half their adult lives.
Yet, even with this mild CR-like regimen older
Okinawans have gained an additional 6% survival
time from age 65 (1.3 years) versus other Japanese
and an additional 20% survival time (3.6 years) ver-
sus Americans. Given the large number of factors that
influence human lifespan, this is also surprisingly
similar to the gain in lifespan observed in prior ani-
mal studies (i.e. 10–20% calorie reduction leads to a
10–20% increase in lifespan). Most importantly, the
Okinawans appear to have gained an increased health
span, with almost a decade of disability-free life
expectancy beyond what typical Western populations
experience.
Lastly, while Okinawans were not consciously
practicing CR, they did develop cultural habits that
led to the kind of prudent food choices that maximize
nutritional properties of foods while minimizing
caloric density as would be the favored strategy for
anyone who attempts a CR regimen. Simply avoiding
calorie-dense refined sugars, saturated fats and pro-
cessed foods and replacing them with nutrient-dense
but calorie poor vegetables, fruits and legumes will
not only likely lead to spontaneous weight loss
through lower caloric intake but would also result in a
vastly increased intake of health-enhancing phytonu-
trients, including key vitamins and minerals, antioxi-
dants and flavonoids. Practicing a little restraint at the
dinner table may also have its benefits. ‘‘Eat until you
are 80% full’’ (or hara hachi-bu) is the advice that
Okinawan grandmothers have given for years and the
science of CR appears to be proving that the wisdom
of the elders still rings as true as ever.
References
Chan YC, Suzuki M, Yamamoto S (1997) Dietary, anthropo-
metric, hematological and biochemical assessment of the
nutritional status of centenarians and elderly people in
Okinawa, Japan. J Am Coll Nutr 16: 229–235
Centers for Disease Control and Prevention, National Center
for Health Statistics (2003) National Vital Statistics Sys-
tem. NCHS, Hyattsville, MD. Available at http://
www.cdc.gov/nchs/
Dirks AJ, Leeuwenburgh C (2006) Calorie restriction in
humans: potential pitfalls and health concerns. Mech
Ageing Dev 127:1–7
Fontana L, Meyer TE, Klein S, Holloszy JO (2004) Long-term
calorie restriction is highly effective in reducing the risk
for atherosclerosis in humans. Proc Natl Acad Sci
101:6659–6663
Goto A, Yasumura S, Nishise Y, Sakihara S (2003) Association
of health behavior and social role with total mortality
176 Biogerontology (2006) 7: 173–177
123
among Japanese elders in Okinawa, Japan. Aging Clin
Exp Res 15:443–450
Hayflick L (2004) The not-so-close relationship between bio-
logical aging and age-associated pathologies in humans. J
Gerontol Bio Sci 59:547–550
Heilbronn LK, Ravussin E (2003) Calorie restriction and
aging: review of the literature and implications for studies
in humans. Am J Clin Nutr 78:361–369
Hokama T, Arakaki H, Sho H, Inafuku M (1967) Nutrition
survey of school children in Okinawa. Sci B Coll Agr
Univ Ryukyus 14:1–15
Japan Ministry of Health, Labor and Welfare (2000) Prefec-
tural Life Tables. Statistics and Information Department.
Health and Welfare Statistics Association
Japan Ministry of Health, Labor and Welfare (2005) Journal of
Health and Welfare Statistics. Health and Welfare Sta-
tistics Association, Tokyo
Kagawa Y (1978) Impact of Westernization on the nutrition of
Japanese: changes in physique, cancer, longevity and
centenarians. Prev Med 7:205–217
Lane MA, Mattison JA, Roth GS, Brant LJ, Ingram DK (2004)
Effects of long-term diet restriction on aging and lon-
gevity in primates remain uncertain. J Gerontol Biol Sci
59:405–407
Le Bourg E (2005) Is caloric restriction a means of delaying
ageing and increasing longevity? Presse Med 34:121–
127
Lee IM, Blair SN, Allison DB, Folsom AR, Harris TB, Manson
JE, Wing RR (2001) Epidemiologic data on the relation-
ships of caloric intake, energy balance, and weight gain
over the life span with longevity and morbidity. J Ger-
ontol Biol Sci 56:7–19
Mattison JA, Lane MA, Roth GS, Ingram DK (2003) Caloric
restriction in rhesus monkeys. Exp Gerontol 38:35–46
Masoro EJ (2005) Overview of caloric restriction and ageing.
Mech Ageing Dev 126:913–922
Meyer TE, Kovacs SJ, Ehsani AA, Klein S, Holloszy JO,
Fontana L (2006) Long-term caloric restriction amelio-
rates the decline in diastolic function in humans. J Am
Coll Cardiol 47:398–402
Phelan JP, Rose MR (2005) Why dietary restriction sub-
stantially increases longevity in animal models but won’t
in humans. Ageing Res Rev 4: 339–350
Rodriguez BL, Lau N, Burchfiel CM, Abbott RD, Sharp DS,
Yano K, Curb JD (1999) Glucose intolerance and 23-year
risk of coronary heart disease and total mortality: the
Honolulu Heart Program. Diabetes Care 22:1262–1265
Roth GS, Ingram DK, Lane MA (2001) Caloric restriction in
primates and relevance to humans. Ann N Y Acad Sci
928:305–315
Roth GS, Lane MA, Ingram DK, Mattison JA, Elahi D, Tobin
JD, Muller D, Metter EJ (2002) Biomarkers of caloric
restriction may predict longevity in humans. Science
297:811
Suzuki M, Willcox BJ, Willcox DC (2001) Implications from
and for food cultures for cardiovascular disease: longev-
ity. Asia Pac J Clin Nutr 10:165–171
Suzuki M, Willcox BJ, Willcox DC (2004) Successful aging:
secrets of Okinawan longevity. Geriatr Gerontol Int.
4:180–181
Sho H (2001) History and characteristics of Okinawan lon-
gevity food. Asia Pac J Clin Nutr 10:159–164
Takata H, Suzuki M, Ishii T, Sekiguchi S, Iri H (1987) Influ-
ence of major histocompatibility complex region genes on
human longevity among Okinawan-Japanese centenarians
and nonagenarians. Lancet 2:824–826
Todoriki H, Willcox DC, Willcox BJ (2004) The effects of
post-war dietary change on longevity and health in
Okinawa. Okinawa J Amer Studies 1:52–61
Willcox BJ, Yano K, Chen R, Willcox DC, Rodriguez BL,
Masaki KH, Donlon T, Tanaka B, Curb JD (2004) How
much should we eat? The association between energy
intake and mortality in a 36-year follow-up study of
Japanese American men. J Gerontol Biol Sci 59:789–
795
Willcox DC (2005) Okinawan longevity: where do we go from
here? Nutr Diet 8:9–17
Willcox BJ, Willcox DC, He Q, Curb JD,Suzuki M (2006)
Siblings of Okinawan centenarians share lifelong mor-
tality advantages. J Gerontol Biol Sci [in Press]
Biogerontology (2006) 7: 173–177 177
123
... By 2050, the proportion of adults aged ≥ 80 yrs is expected to exceed 15% [1]. Although knowledge regarding dietary intake and energy and nutrient requirements among adults aged ≥ 95 yrs is limited, caloric restriction, dairy product consumption, and healthy plantbased dietary patterns are gaining attention in relation to longevity [2]. Centenarians residing in the western region of Sicily tend to consume a Mediterranean-based diet [3], while the dietary behaviors of the oldest-old in Okinawa are unique in that energy intake is low and sweet potatoes and legumes are frequently consumed [4]. ...
... To address intake differences between adults aged ≥ 95 yrs and those aged ≥ 80 yrs living in similar times, intakes of adults 95 yrs and older were compared with those of KNHANES participants. Compared with KNHANES participants, the surveyed adults 95 yrs and older yielded lower BMI and energy intakes, aligning with caloric restrictions associated with longevity [2]. In the current study, adults 95 yrs and older consumed a mean of 316 kcal per meal, similar to centenarians in Tokyo and Okinawa who consumed approximately 1,100 kcal per day, accounting for snacks [25,26]. ...
... A further study investigated who the Okinawans are in terms of ancestry and genome diversity and analysed implications for the genetic study of human longevity from a geographically isolated population [45]. After the 'shock 26', a large part of research interest still focused on the traditional diet of Okinawan centenarians and more specifically on the impact of calorie restriction [46] that people in Okinawain a mild form but prolonged over about half of their adult lives -have undergone [47]. Considering the longer life expectancy, and the higher prevalence of centenarians in Okinawa, these arguments have been used to support the hypothesis of the positive effect of calorie restriction for increasing lifespan in humans. ...
... Clearly, according to the literature, the main factor that could have favoured longevity in Okinawa is calorie restriction -a hypothesis that has been largely investigated [46,47,58] -but there are still arguments against the fact that calorie restriction may really be beneficial for the lifespan of human beings [59,60]. Incidentally, if calorie restriction can be considered a factor in longevity, it is important to consider that the nutrition pathway of the Okinawa population included some significant famines. ...
Article
Demographers have studied the Japanese mortality pattern since Japan became the most longevous population worldwide, half a century ago. Nutrition and lifestyle were considered by epidemiologists, gerontologists and other scientists as the most important reasons explaining the Japanese superiority. In Okinawa, the mortality pattern is even more exceptional, but few demographers have pointed out this exception. Other scientists proposed different explanations – for example some genetic characteristics, less salt and more animal protein in the food, a mild climate, a higher level of activity, a better consideration of the oldest in the population and, globally speaking, a more traditional lifestyle. At the end of the 1980s, lower improvements of mortality among young adults were identified in Okinawa. In 2002, Okinawa fell from the 4th to the 26th place in the ranking of the 47 Japanese prefectures by male life expectancy. This has been considered by the population of Okinawa as a ‘shock’. Our in‐depth analysis of available life tables and associated mortality rates proves that the population of Okinawa is divided into two groups of generations: those born before World War II and those born after. The older generations clearly experience a highly favourable mortality pattern, whereas the younger generations show mortality levels that are definitively higher compared to mainland Japan. This contribution considers which factors may explain such a situation, including the plausible invalidation of the age of some oldest in the population. We plea for in‐depth demographic age validation that will enhance all scientific findings so far and boost the exceptional longevity in Okinawa.
... Additionally, improved insulin sensitivity enhances the body's ability to manage blood sugar levels, reducing the risk of type 2 diabetes. Interestingly, people of the island of Okinawa have reduced incidence of diabetes and obesity which is being associated to their fasting habits (Willcox et al., 2006). ...
Article
Fasting is a practice with deep cultural and religious significance, which has been a part of living for thousands of years across various civilizations and religions. Fasting during the Islamic month of Ramadan is a deeply spiritual and communal activity, promoting self-discipline, reflection and unity. Beyond its religious importance, fasting has gained attention for its potential therapeutic and health benefits, including increased longevity, enhanced metabolic health and improved organ function. At cellular level, fasting triggers autophagy and alters gene expression related to longevity. Fasting's influence extends to vital organs facilitating metabolic shifts, improving insulin sensitivity and promoting neurogenesis. Physiologically, fasting has been associated with weight loss, reduced inflammation and a lower risk of chronic diseases. Psychologically, fasting fosters resilience, self-discipline and spiritual growth. The communal aspects further enhance social cohesion. Furthermore, traditional practices, such as breaking the fast with dates, water or salt, hold both spiritual and nutritional significance. Despite its benefits, fasting requires careful consideration, particularly for vulnerable populations such as pregnant women, elderly and individuals with illnesses. In conclusion, fasting during Ramadan exemplifies a multifaceted approach to health and well-being, encompassing physical, psychological and social dimensions and warrants further scientific exploration to fully understand its wide-ranging impacts.
... This might also stem from CR's antioxidant properties, influenced by various factors like species, gender, CR duration, and the type of reactive oxygen species [7]. In the Okinawa region of Japan, the dietary and phenotypic data of 70-somethings and centenarians are consistent with CR, which provides evidence for the long-term application of CR in humans, and that they exhibit higher levels of dehydroepiandrosterone to slow aging, as well as lower mortality rates to minimize the incidence of age-related diseases, compared with other counterparts who don't receive CR [14]. Similarly, a two-year study in healthy elderly volunteers has found that long-term CR did not adversely affect cognition and was effective in improving memory, which might be related to lower protein intake, as protein restriction reduced protein oxidation in the brain and improved memory [15]. ...
Article
Full-text available
Purpose of Review The impact of dietary habits on cognitive function is increasingly gaining attention. The review is to discuss how caloric restriction (CR) and intermittent fasting (IF) can enhance cognitive function in healthy states through multiple pathways that interact with one another. Secondly, to explore the effects of CR and IF on cognitive function in conditions of neurodegenerative diseases, obesity diabetes and aging, as well as potential synergistic effects in combination with exercise to prevent cognitively related neurodegenerative diseases. Recent Findings With age, the human brain ages and develops corresponding neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and epilepsy, which in turn trigger cognitive impairment. Recent research indicates that the impact of diet and exercise on cognitive function is increasingly gaining attention. Summary The benefits of exercise for cognitive function and brain plasticity are numerous, and future research can examine the efficacy of particular dietary regimens during physical activity when combined with diet which can prevent cognitive decline.
... The definition of CR is reducing calories without sacrificing vital nutrition [16] and was reported in the early 1900s as a potent intervention for extending lifespan and promoting healthy aging in rodents [17]. In a variety of model species, including yeast and primates, CR has been shown to extend longevity and has comparable effects in humans [18][19][20]. A wide spectrum of age-related pathological complications, including cancer, immunosenescence, and cardiometabolic diseases, are also prevented by CR [21]. ...
Article
Full-text available
Genomic instability and epigenetic alterations are some of the prominent factors affecting aging. Age-related heterochromatin loss and decreased whole-genome DNA methylation are associated with abnormal gene expression, leading to diseases and genomic instability. Modulation of these epigenetic changes is crucial for preserving genomic integrity and controlling cellular identity is important for slowing the aging process. Numerous studies have shown that caloric restriction is the gold standard for promoting longevity and healthy aging in various species ranging from rodents to primates. It can be inferred that delaying of aging through the main effector such as calorie restriction is involved in cellular identity and epigenetic modification. Thus, an understanding of aging through calorie restriction may seek a more in-depth understanding. In this review, we discuss how caloric restriction promotes longevity and healthy aging through genomic stability and epigenetic alterations. We have also highlighted how the effectors of caloric restriction are involved in modulating the chromatin-based barriers.
Article
Medically speaking fasting could be defined as the ability of the body to meet its macro and micro nutrients requirements during either shortage or absence of food during a limited period of time. In human beings Intermittent Fasting (IF) regimens are most widely studied fasting methods with significant medical benefits. IF in humans ameliorates multiple metabolic & hormonal factors that are implicated in the pathogenesis of atherosclerosis, type II DM, obesity, cardiovascular diseases, neuro- degenerative & cancerous illnesses, which are the leading causes of morbidity, disability and mortality in human beings. These health benefits of intermittent fasting are not just the result of weight loss or reduced free radical production. Instead intermittent fasting triggers evolutionarily developed and preserved adaptive cellular responses that evolved billions of years ago in prokaryotes and allows mammals including humans in preventing and treating diseases and having favorable effects on aging, as IF improves glucose regulation, increases stress resistance, suppresses inflammation, promotes cellular autophagy and leads to cells engage in tissue specific processes of growth, repair and plasticity. G-K switch is supposed to play a major role in this process. Overall evidence suggests that IF regimens are not harmful in healthy normal weight, overweight, or obese adults.
Chapter
Calorie restriction (CR) is characterized by a reduction in calorie intake without malnutrition. In the context of geroscience, CR is a promising nutritional strategy that targets the biology of aging and therefore has the potential to delay the onset or slow the progression of age-related diseases. Life span extension by CR has been demonstrated in a variety of species, including yeast, drosophila, worms, rodents, and dogs, providing compelling evidence for the geroprotective potential of CR. In humans, optimizing health span is arguably a more meaningful goal of CR interventions and CR lifestyles. Numerous physiological effects of CR on biomarkers of human aging and health span have been explored, both in observational studies and in well-controlled intervention trials, providing an abundance of rich data that overwhelmingly support CR as a promising strategy for attenuating biological aging. The development of novel biomarkers of aging has advanced the field of geroscience and provided new opportunities for exploring the impact of CR on biological aging. In this chapter, we discuss the influence of CR on various biomarkers of aging and health span, with the biomarkers organized in three broad categories: cellular aging, phenotypic aging, and functional aging. We present results of CR studies in humans that demonstrate typical improvements in cardiometabolic indices, as well as effects on novel epigenetic biomarkers of cellular aging and the pace of biological aging that are based on DNA methylation. Finally, the chapter closes with highlights of ongoing CR initiatives funded by the National Institute on Aging and future directions for exploring numerous unanswered but important questions about the role of CR in enhancing health span.
Article
Background The Mediterranean dietary pattern (MDP) and Japanese dietary pattern (JDP) have received increasing attention from the scientific community and media because of their contribution to longevity and health. Although similarities between the two dietary patterns are evident, a detailed comparison between the MDP and the JDP has yet to be explored. Aims This narrative review aimed to explore the similarities and differences between the MDP and JDP regarding longevity while reflecting on the adoption of these diets by other populations outside their regions of origin. Conclusions Both dietary patterns are plant-based, minimally processed, and sustainable for their respective regions and have been shown to significantly prolong life expectancy in populations. However, the dietary patterns also differ regarding macronutrient ratios, the specific foods consumed, and the individual cultural characteristics of each population. Additionally, both dietary patterns are part of broader lifestyle patterns, including other behaviors, like abstaining from smoking, engaging in regular physical activity, having low-stress levels, and a sense of community, spirituality/ religiousness, and purpose. Their promotion to other populations should be implemented after considering different perspectives, such as cultural and socioeconomical.
Article
Full-text available
Life expectancy for men in Okinawa has fallen sharply relative to other prefectures of Japan and although at present women still retain their lead in Okinawa, if present trends continue, they too will fall. The nutrition transition in Okinawa with regards to increased fat intake and increased body weight (i. e. schoolchildren population), may be related to socio-political, socio-economic and socio-cultural changes that were set in motion either directly or indirectly during U.S. administration beginning in 1945.
Article
Full-text available
The associations between glucose intolerance measured at the study entry date and the 23-year incidence of coronary heart disease (CHD), CHD mortality, and total mortality were examined at the Honolulu Heart Program. This prospective study followed a cohort of 8,006 Japanese-American men who were 45-68 years old and living on the island of Oahu, HI, in 1965. Baseline glucose was measured in a nonfasting state 1 h after a 50-g glucose load. History and use of medication for diabetes was obtained during an interview. The cohort was divided into four categories of glucose tolerance: low-normal, high-normal, asymptomatic hyperglycemia, and known diabetes. During the 23 years of follow-up, 864 incident cases of CHD, 384 deaths from CHD, and 2,166 total deaths occurred. The relative risks (RRs) were obtained using Cox proportional hazards modeling, with the low-normal category as a reference. The RRs were adjusted for age only, as well as for age, BMI, hypertension, cholesterol, triglycerides, smoking, alcohol, and a Japanese diet index. The age-adjusted and risk factor-adjusted RRs for all outcomes were significant for the asymptomatic hyperglycemic and known diabetes groups (P<0.05). The age-adjusted RRs for CHD incidence and total mortality were marginally significant in the high-normal group, but the RRs were not significant when adjusted for risk factors. These results suggest a dose-response relation of glucose intolerance at baseline with CHD incidence, CHD mortality, and total mortality, independent of other risk factors, in this cohort of middle-aged and older Japanese-American men.
Article
•Calorie restriction increases longevity in rodents, delays the onset of certain diseases and has positive effects on ageing.•Studies are ongoing in non-human primates.•Eight persons following such a diet for 2 years reacted as anticipated (loss of body weight and fat, decrease in glycaemia and body temperature, etc.).•Calorie restriction perhaps teaches us more on the means of resisting malnutrition than on ageing in normal dietary conditions.•Calorie restriction is a tool for research, but it should not be recommended by practitioners, notably in elderly patients.
Article
Okinawan food culture in the Ryukyu island is one of the world’s most interesting culture because its consumers have the longest life expectancies and low disability rates. It is a product of cultural synthesis, with a core of Chinese food culture, inputs through food trade with South-East Asia and the Pacific and strong Japanese influences in eating style and presentation. The Satsamu sweet potato provides the largest part of the energy intake (and contributes to self-sufficiency), there is a wide array of plant foods including seaweed (especially konbu) and soy, and of herbaceous plants, accompanied by fish and pork, and by green tea and kohencha tea. Infusing multiple foodstuff and drinking the broth is characteristic. Raw sugar is eaten. The concept that ‘food is medicine’ and a high regard accorded medical practice are also intrinsic of Okinawan culture. Again, food-centered and ancestral festivities keeep the health dimensions well-developed. Pork, konbu and tofu (soy bean-curd) are indispensable ingredients in festival menus, and the combination of tofu and seaweed are used everyday. Okinawan food culture is intimately linked with an enduring belief of the system and highly developed social structure and network.
Article
The traditional Japanese diet changed dramatically between 1950 and 1975: the intake of milk (15 fold), meat, poultry and eggs (7.5 fold) and fat (6 fold) has increased, while that of barley (), potatoes () and rice (0.7) has decreased. This westernization is more pronounced in the younger generation, rich people, non-farmers and city dwellers. However, the quantities of western foods consumed in Japan are still much less than those in the U.S. or Europe. The quality of the nutrients is also very different: amylopectin, long chain polyunsaturated fatty acids and indigestible polysaccharides are abundant in the Japanese diet.During this period, Japanese became taller and heavier. Breast, colon and lung cancers increased 2–3 fold, but those of the stomach (0.6) and uterus (0.3) decreased. As life expectancy has been extended (male 12, female 14 years), the number of patients in the same age group increased. Areas of longevity containing many centenarians (888 in 1977) were studied, in order to determine beneficial effects of westernization such as a decrease in apoplexia resulting from increased fat intake. More than the average amounts of animal proteins and vegetables were consumed in these areas. Among the Japanese, those in Okinawa were found to have the lowest total energy, sugar and salt, and the smallest physique, but had healthy longevity and the highest centenarian rate.
Article
The frequencies of 80 HLA antigen phenotypes in 82 centenarians and 20 nonagenarians in Okinawa, Japan, were compared with those in other healthy adults in various age-brackets. Subjects aged over 90 had an extremely low frequency of HLA-DRw9 and an increased frequency of DR1. In this age-group the relative risk of corrected (for number of antigens) p value for HLA-DRw9 were 5.2 and 0.0001, respectively; those for HLA-DR1 were 13.3 and 0.0367, respectively. Since a high frequency of DRw9 and a low frequency of DR1 are associated with autoimmune or immune deficiency diseases, the genetic protection against these disorders may contribute to longevity.
Article
The population of old people has increased and nutritional disorders are common among them. The assessment of nutritional status and dietary intakes of this population is necessary in order to improve their nutritional status and reduce risk to infection and mortality. In the present study, data on the nutritional status of healthy elderly and centenarians is provided. Participants were free-living healthy volunteers (39 centenarians; 11 male and 28 female and 44 elderly in their 70s; 13 male and 31 female). Their nutritional status was assessed by anthropometric measurements, hematological and biochemical variables. Activities of daily living (ADL) of 11 items were scored depending upon their activities with a maximum score of 5.0. Dietary survey by food recording was done for 2 days and food models were used to obtain the best estimate of food intake. Energy and nutrient intakes were compared with Japanese recommended dietary allowances (RDAs). The elderly had complete independence of physical activities, good sensory function and cognitive abilities. The physical activities of male centenarians were between the category of completely independent and independent but slow. In female centenarian participants, their physical activities were independent but slow or independent with difficulty. The functions of auditory acuity and eyesight of the centenarians were poor but their cognitive abilities were still good. The elderly subjects had short stature whereas their body weight and body mass index (BMI) were not low, especially among the women, compelling female elderly to reduce their food intake to control the weight. Energy intake of female centenarians was low. The ADL in the female centenarians was positively related to energy, suggesting that the low energy intake of the female centenarians was mainly due to their low ADL. Anthropometric, hematological and biochemical variables of the centenarians were lower or near the lower reference limit except serum lipids. All the hematological and biochemical variables were statistically lower (p < 0.05) in the centenarians than in the elderly particularly for females with some minor exceptions. The results of the present study showed that the nutritional status assessed by ADL and anthropometric, hematological and biochemical parameters was poor in the centenarian subjects but was maintained in the elderly subjects except height and that the diet was not the major factor of their problems in the nutritional status.
Article
A healthy cardiovascular system, with minimal arteriosclerosis, good endothelial function and well-compensated ventricular function has been observed at advanced ages, and linked to a healthy lifestyle. This has consisted of a plant-based diet, low in salt and fat, with monounsaturates as the principal fat. Other healthy lifestyle factors include regular physical activity (farming and traditional dance) and minimal tobacco use. The associated negative risk factors are low homocysteine, healthy cholesterol profile (Total:HDL ratio less than 3.5) and reasonable blood pressures throughout the life cycle. Hormone-dependent cancers including breast, ovary, prostate and colon and osteoporotic complications, such as hip fracture rates, are also less frequent compared to the west. Protective factors may include high anti-oxidant consumption, mainly flavonoids and carotenoids, through a high vegetable (e.g., onions) and soy intake. Related biological observations include low lipid peroxide, high superoxide dismutase activity and high serum hydroxyproline, a marker of bone formation. Dehydroepiandrosterone (DHEA) and its hormonal byproducts testosterone and oestrogen appear to be high in Okinawan serum compared with age-matched Americans, possibly reflecting a slower age-associated decline in the sex hormone axis in Okinawans. This may be linked to better cardiovascular and overall health. Further study is needed to delineate the reasons behind the impressive cardiovascular and overall health of the Okinawans.