foodconsumer.org: Genes help centenarians, healthy diet helps you to live longer

Genes help centenarians, healthy diet helps you to live longer
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admin on 07/03/2010 20:17:00
 
Genetic patterns found in centenarians
A new study of more than 1000 centenarians led by Tom Perls at Boston Medical
Center and colleagues suggests that a set of 150 genes may largely determine a
person's longevity or how long a person can live.
The researchers pubulished in Thursday's online edition of the journal Science
saying that a math model based on gene variants identified in The New England
Centenarian Study may be enlisted to predict whether a person can live over 100
years and the accuracy can be up to 77 percent.
The 150 newly identified genetic markers may be used soon in genetic testing
kits, some expert said.
Genetics may be the foundation of longevity. But Winifred Rossi, of the National
Institute on Aging's Division of Geriatrics and Clinical Gerontology, which
funded the study, said that the genetic influence is complex and a person's life
span is also determined by environmental factors.
Those who do not carry the longevity genes may still benefit from following a
healthy lifestyle even though they may be able to live long enough to be a
centenarian.
Caloric restriction
Researchers have been studying since 1930s how caloric restriction (CR) affects
the life-spans of animals and humans and found that eating less calories
generally makes animals live longer.  It is speculated that with low intake of
calories, the body shuts down many physiological functions and turns into a
conservative maintenance mode, preventing the body from suffering many adverse
effects such as inflammation induced when the energy is abundant and delaying
the aging process.
Fontana L. from Washington University School of Medicine in St. Louis MO and
colleagues reported in the April 2010 issue of Science that in rodents, both CR
can help prevent age-related loss of function and diseases, including tumors and
neurodegeneration, increases life span, protects against diabetes, cancer, and
cardiovascular disease in rhesus monkeys, and prevents age-related diseases in
humans.
Fontana and colleagues also reported in the March 2010 issue of Age that
individuals aged 28 who followed a calorie-restricted diet and engaged in
endurance exercise for an average 7 years were leaner and had higher insulin
sensitivity compared to those using Western diet.
According to the researchers, 40 percent of those who followed the CR diet had
elevated hyperglycemic response to a glucose load and this impaired glucose
tolerance is correlated with lower circulating levels of IGF-1, total
testosterone, and triiodothyronine (a thyroid hormone called T3), which actually
retard the aging process.
T3 affects almost every physiological process in the body, including growth and
development, metabolism, body temperature, and heart rate, according to previous
studies.
A recent trial led by Edward Weiss at Saint Louis University and colleagues
found in those following a CR diet reduced levels of  T3 even though their body
mass indexes were similar to those of inviduals on a regular diet, suggesting
that CR has a direct or indirect impact on the production of T3 in the
aging-retarding process.
The one-year trial involved one group of sedentary, non-smoking and
post-menopausal women aged 50 to 60 using a diet with its total energy cut by
300 to 500 calories and another group using a regular diet.
The researchers published their findings in the June 2008 issue of Rejuvenation
Research.
CR has been known to retard the aging process at genetic levels.
Leonard Guarente of Massachusetts Institute of Technology reported in the Sept
2005 issue of Mechanisms of  Ageing and Development that SIR2 genes regulate CR
in low species like yeast and Drosophila and the mammalian Sirt1 may be
responsible for physiological changes during CR.
Mediterranean diet
Pérez-López FR and colleagues of Universidad de Zaragoza in Spain found people
who followed Mediterranean diet or a similar diet tended to have a longer
lifespan and they were 10 to 20 percent less likely to die of heart disease,
cancer or any other cause.
The authors reviewed clinical and laboratory studies cited in the PubMed
database and found the Mediterranean diet helps bone metabolism, rheumatoid
arthritis, and neurodegenerative age-related diseases (cognitive deficit,
Alzheimer's disease, Parkinson's disease).
Their findings were published in the Oct 2009 issue of Maturitas.
Tyrovolas S. and colleagues from Harokopio University in Athens, Greece also
published a report in the Nov 30 2009 issue of Eur. J. Public Health saying that
Mediterranean diet was associated with the longevity people enjoy in
Mediterranean islands.
Okinawa diet
Willcox D.C. and colleagues from Okinawa International University in Japan
reported in the Aug 2009 issue of J. Am Coll Nutr. that a diet used by people
including many centenarians in Okinawa, the southernmost prefecture of Japan may
play a role in the longevity enjoyed by the people in this area.
The so called-Okinawa diet is similar to Mediterranean diet and DASH diet in
that it includes high amounts of vegetables and fruit and reduced amounts of
meat, refined grains, saturated fat, sugar, salt, and full fat dairy products.
Okinawa diet uses the lowest amounts of fat, particularly saturated fat and
highest amounts of carbohydrate,  antioxidant-rich orange-yellow root vegetables
such as sweet potatoes and green leafy vegetables.
These three diets share some features like all using low levels of saturated
fat, high antioxidant intake and low glycemic load, which help protect against
cardiovascular disease, some cancers, and other chronic diseases through
multiple mechanisms, including reduced oxidative stress.
Miscellaneous foods/nutrients
Dr. Joe Mercola, owner of mercola.com, says in one of his newsletter articles
that 7 foods may help you live a longer life.  They are whey protein - a source
of glutathione; raw organic eggs - a good source of essential amino acids,
lutein and other nutrients (cholesterol as well); leafy greens like spinach,
kale, turnip greens, collard greens - good sources of cancer-fighting
antioxidants like beta carotene, vitamin C, and sulforaphane; broccoli;
blueberries; chlorella; and garlic.
Rockenfeller P, and Madeo F. from the University of Graz in Australia reported
in the April 2010 issue of Biochim Biophys Acta that epidemiological studies
suggest that human lifespan can be extended by physical exercise, caloric
restriction and consuming certain nutrients or foods such as resveratrol,
selenium, flavonoids, zinc, omega 3 unsaturated fatty acids, vitamins E and C,
Ginkgobiloba extracts, aspirin, green tea catechins, and antioxidants.
A recent China study  published in Feb 2010 in Zhonghua Yu Fan YiXue Zaxhi finds
that the concentrations of serum selenium, manganese, iron, copper and zinc were
higher in centenarians.   The study led by Xu J.W. from the Chinese Center for
Disease Control and Prevention in Beijing involved 446 elderly people including
208 centenarians.
By David Liu