Several studies have demonstrated that vegetarians and vegans have much lower plasma concentrations of omega-3 fatty acids (DHA and EPA) when compared to those who eat fish. A recent study published in Clinical Nutrition showed low blood omega-3 levels in vegans and the fatty acid analysis data was presented on more than 160 vegans who were not supplementing with DHA and EPA (1). The result of the study showed the average omega-3 index of the vegans in the study was 3.7% with a total of 64% of the vegans having levels lower than 4%; 27 percent had levels lower than 3%; and a small number (about 1%) had very low levels (lower than 2%). It is also important to note that omega-3 index of lower than 4% has been known as a risk factor for heart disease.
As you may already know, omega-3 fatty acids are crucial components of cell membranes in the human brain (2) and I have highlighted in my previous posts that it could even potentially reverse ageing by affecting the telomere lengths.
It is understood that many vegans probably consume a huge amount of flax seeds, walnuts, chia seeds etc to try and boost their omega-3 fatty acid levels. However, what they are actually consuming is actually ALA (Alpha-lipoic-acid) which is the plant based omega-3 fatty acids which then converts to EPA and DHA. This conversion actually varies with different individuals and factors involved includes genetic factors (3). So eating plenty of ALA-rich foods is simply not enough for many people to achieve sufficient DHA and EPA levels—supplementation is often necessary.
In conclusion, if you are vegan (which means you are more prone to omega-3 fatty acid deficiency), please check your levels with a blood test to assure that you are sufficient, or take the supplement as a preventative measure.
1: Sarter B, Kelsey KS, Schwartz TA, Harris WS. Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: Associations with age and gender and effects of an algal-derived omega-3 fatty acid supplement. Clin Nutr. 2015 Apr;34(2):212-8.
2. Higdon J: Essential Fatty Acids. In An Evidence-Based Approach to Dietary Phytochemicals. New York, NY: Thieme; 2006: 78-99
3. Davis BC, Kris-Etherton PM. Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications. Am J Clin Nutr. 2003 Sep;78(3 Suppl):640S-646S. Review.
Dr Nicole Ng (MBBS) is a medical doctor with a passion in women's health and medical research