An adequate daily intake for adults of alpha-linolenic acid
has been established by the U.
Eicosapentaenoic and Docosapentaenoic Acids are the Principal Products of Alpha-Linolenic Acid
Metabolism in Young Men," British Journal of Nutrition 88(4), 355-363 (2002).
This suggests that conversion rates of alpha-linolenic acid
to DHA and EPA may be higher than would be predicted from earlier studies.
Back in 1994, the scientific community was stunned by a study that linked high blood levels of alpha-linolenic acid
with an increased risk of prostate cancer.
The best sources of omega 3 alpha-linolenic acid
include flaxseed (linseed) oil, rapeseed oil, chia seeds, walnuts and walnut oil, the Mediterranean plant purslane, grass-reared meat and dark-green leafy vegetables.
There are 20 different types of essential fatty acids (EFAs) that the human body requires for optimum health; humans manufacture all but two: Omega-3 alpha-linolenic acid
(ALA) and Omega-6 linolenic acid, the sources of which come from nutrients in our foods.
They are also high in healthy polyunsaturated fats such as omega-3 alpha-linolenic acid
Careful evaluation of recent evidence, however, suggests that allowing a health claim for vegetable oils rich in omega-6 linoleic acid but relatively poor in omega-3 alpha-linolenic acid
may not be warranted," Drs.
While the good news about omega-3s is widespread, what many people don't realize is that there are two major types: the long chain omega-3s eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found in fish and fish oil; and the short-chain form alpha-linolenic acid
(ALA), found in walnuts, flax, and some vegetable oils.
Blood samples collected between 1999 and 2001 were analyzed for plasma alpha-linolenic acid
and the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA).
In addition, high linoleic acid intake might result in decreased conversion of alpha-linolenic acid
(an omega-3 fatty acid) to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), due to competition for the enzyme, delta-6 desaturase.
Neither low doses of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which are found in fish oil, nor of alpha-linolenic acid
(ALA), derived from nuts and several vegetable oils, provided any benefit to the vast majority of heart patients.