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Omega-3 Linked to Younger
Biological Age Reports A New Study
High Bood Levels of Omega-3 Fatty Acids May Slow Cellular
Aging in People With Coronary Heart Disease...
Researchers from the University of California, San Francisco looked
at the length of telomeres, DNA sequences at the end of chromosomes
that shorten as cells replicate and age.
The ageing and lifespan of normal, healthy cells are linked to the
so-called telomerase shortening mechanism, which limits cells to
a fixed number of divisions. During cell replication, the telomeres
function by ensuring the cell's chromosomes do not fuse with each
other or rearrange, which can lead to cancer. A simple analogy is
comparing telomeres to the ends of shoelaces, without which the
lace would unravel.
With each replication the telomeres shorten, and when the telomeres
are totally consumed, the cells are destroyed (apoptosis). Previous
studies have also reported that telomeres are highly susceptible to
oxidative stress. Some experts have noted that telomere length may
actually be a marker of biological aging.
"Among patients with stable coronary artery disease, there was
an inverse relationship between baseline blood levels of marine
omega-3 fatty acids and the rate of telomere shortening over
5 years," wrote the researchers.
"These findings raise the possibility that omega-3 fatty acids
may protect against cellular aging in patients with coronary heart
disease," they added.
The research adds to a large body of science supporting the
potential health benefits of omega-3 fatty acids, particularly in
relation to heart health.
Several studies have shown increased survival rates among
individuals with high dietary intake of fish oil omega-3 fatty acids
and established cardiovascular disease.
The mechanisms underlying this protective effect are not well
understood, according to background information in the article.
The UCSF researchers looked at telomere length in blood cells of
608 outpatients with stable coronary artery disease. The length of
telomeres was measured in leukocytes at the start of the study and
again after 5 years.
Comparing levels of omega-3 fatty acids, EPA (eicosapentaenoic
acid) and DHA (docosahexaenoic acid) with subsequent change in
telomere length, the researchers found that individuals with the lowest
average levels of DHA and EPA experienced the most rapid rate of
telomere shortening, while people with the highest average blood
levels experienced the slowest rate of telomere shortening.
"Each 1-standard deviation increase in DHA plus EPA levels was
associated with a 32 per cent reduction in the odds of telomere
shortening," wrote the authors.
Commenting on the potential mechanism, they noted that this may
be linked to oxidative stress, known to drive telomere shortening.
Omega-3 fatty acids have been shown to reduce levels of
F2-isoprostanes, a marker of systemic oxidative stress, as well as
increasing levels of the antioxidant enzymes catalase and superoxide
dismutase, thereby reducing oxidative stress.
Another possible mechanism may involve the enzyme telomerase.
The enzyme works to maintain telomere length, and omega-3 may
increase its activity.
Multivitamins and Green Tea, too...
The work of the UCSF scientists was limited to people with CHD,
thereby limiting how general the results may be. Other studies in
healthy people have already linked specific nutrients to telomere
length, and subsequently a younger 'biological age'.
Recently, researchers from the US National Institute of Environmental
|Health Sciences reported that telomere length was longer in regular
multivitamin users in their cohort of 586 women aged between 35
and 74. The subjects did not have coronary heart disease.
Writing in the American Journal of Clinical Nutrition, the researchers
noted that theirs was the first epidemiologic study of multivitamin use
and telomere length.
"Regular multivitamin users tend to follow a healthy lifestyle and have
a higher intake of micronutrients, which sometimes makes it difficult
to interpret epidemiologic observations on multivitamin use," they
said.
An association between Green Tea drinkers and telomere length
was also reported by scientists from the Chinese University of
Hong Kong last year. The telomeres of people who drank an
average of three cups of tea per day were about 4.6 kilobases
longer than people who drank an average of a quarter of a cup
a day, reported the researchers in the British Journal of Nutrition.
This average difference in the telomere length corresponds to
"approximately a difference of 5 years of life", wrote the researchers
in China. "Our data showed that majority of Chinese tea consumed
by our subjects were of green tea" they added.
Source: Journal of the American Medical Association
2010, Volume 303, Issue 3, Pages 250-257
"Association of Marine Omega-3 Fatty Acid Levels With Telomeric
Aging in Patients With Coronary Heart Disease"
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