July 15, 2012
Study Confirms Cardioprotective Effect of Chia Seeds
Consumption of chia seeds, rich in ALA, may increase blood levels of the long chain omega-3 EPA by 30%, says a new study from the Appalachian State University and the University of North Carolina.
Twenty-five grams per day of milled chia seed for seven weeks were associated with 138% increases in levels of alpha-linolenic acid (ALA) and 30% increases in eicosapentaenoic acid (EPA) levels, according to data presented in Plant Foods for Human Nutrition.
However, there was significant variation between the women in the study. The study does support previous findings about the conversion of ALA to EPA, said the researchers.
"The health implications of increasing plasma ALA through milled chia seeds or other plant sources are still being debated, but two randomized studies (10--12 weeks) by our research team have failed to show changes in disease risk factors including blood lipids, blood pressure, inflammation, oxidative stress, and arterial stiffness," they wrote.
"A cardioprotective effect of high, long-term ALA intake has been suggested by a number of epidemiological studies, and an additive effect of ALA with n-3 long-chain PUFA from fish and fish oil has been observed."
ALA omega-3 is an essential fatty acid that the body cannot make, and therefore must be consumed in the diet. Good sources of ALA include: flaxseed, soybeans, walnuts, chia, and olive oil. The U.S Institute of Medicine recommends an ALA intake of 1.6 grams per day for men and 1.1 grams per day for women.
The health benefits associated with ALA consumption include cardiovascular effects, neuro-protection, a counter to the inflammation response, and benefits against autoimmune disease.
However, the longer-chain EPA and docosahexaenoic acid (DHA) have received more study from scientists and more attention from the consumers.
Much attention has been paid to the conversion of ALA to the longer chain EPA, with many stating that this conversion is very small. According to an article in Nutrition Reviews (Vol. 66, pp. 326-332), between eight and 20 per cent of ALA is converted to EPA in humans, and between 0.5 and nine percent of ALA is converted to DHA.
In addition, the gender plays an important role with women of reproductive age reportedly converting ALA to EPA at a 2.5-fold greater rate than healthy men.
This conversion obviously contributes to the body's pool of EPA and DHA, which play a key role in, amongst other things, maintaining cardiovascular health.
The North Carolina-based scientists recruited 10 postmenopausal women with an average of 55.6 and an average BMI of 24.6 kg/m2 and assigned them to consume 25 grams per day of milled chia seed (Chia Farms, Inc., Orlando, FL) for seven weeks.
While ALA and EPA levels increased, no significant increases in blood levels of docosapentaenoic acid (DPA) were recorded.
There was a slight decrease in blood levels of DHA, said the researchers.
"Plasma EPA increased 30% above baseline levels in the present study, but individuals varied widely both pre-study and in response to milled chia seed supplementation.
"The 30 % increase in plasma EPA in our subjects (postmenopausal women) following seven weeks of chia seed ALA supplementation (4.1 g/day) is comparable to other similar studies."
Plant Foods for Human Nutrition