Is fish oil the elixir of life?
Elixir? Omega-3 fatty acids may have a direct effect on extending the lifespan of cells
They say omega-3 fatty acids from fish oil may have a direct effect on extending the lifespan of cells.
Their study is the first to link the oils - either from fish or supplements - with the body's ability to resist premature ageing.
The 'elixir of life' discovery was made in heart disease patients, who are already advised to increase their fish intake to ward off repeat heart attacks.
Scientists from the University of California, San Francisco, looked at the effect of omega-3 fatty acids on 608 outpatients with heart disease.
They found higher levels of omega-3 slowed down damage to DNA contained in telomeres - tiny 'caps' on the ends of chromosomes which help protect against inflammation and other ageing processes.
Having longer telomeres is a sign of being biologically younger and also of being healthier.
As people age, their telomeres get shorter and they become more susceptible to certain illnesses.
Scientists believe this process is at the heart of many age-related diseases, and may even place a final limit on human lifespan.
Nutritionist Dr Carrie Ruxton, speaking on behalf of the Health Supplements Information Service, said: 'If this link between high omega-3 fatty acid levels and reduced ageing is confirmed in other studies, this has important implications for intakes of omega 3 fatty acids.'
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The tests were carried out again after five years, and showed a clear link with omega-3 intake, says a report in the Journal of the American Medical Association.
Patients consuming the least omega-3 had the fastest rate of telomere shortening while those in the top 25 per cent of consumption levels had the slowest rate.
Lead researcher Dr Ramin Farzaneh-Far said animal research has shown that rodents live a third longer when given a diet enriched with fish-derived omega-3.
He said the latest study demonstrated 'a potentially novel pathway for the anti-ageing effects of omega-3 fatty acids'.
Omega-3 fatty acids are found in oily fish such as mackerel, herring, salmon, sardines or trout - and fish oil supplements - as well as soya beans, rapeseed oil, flaxseed, pumpkin seeds and walnuts.
White fish is also a healthy food although it contains lower levels of essential fatty acids.
But, said Dr Ruxton, Britons fail to consume recommended minimum levels of two fish portions each week, one of which must be oily.