Lipids or fats include various fatty acids.
Most vegetable oils are high in omega-6, and vegans and non-vegans alike tend to get plenty in their diets.1 In the following we will concentrate on omega-3 fatty acids, which are especially important for good health, and in which vegans and non-vegans alike can become deficient.
Some studies have found evidence that consumption of adequate amounts of omega-3 fatty acids can reduce the risk of suffering from cardiovascular problems, though other studies have found no evidence of such a connection. Based on the current state of the information on omega-3, nothing conclusive can be said, but it is generally considered important for overall health and it is considered especially important for pregnant and lactating women, children and the elderly.2
Among the omega-3 fatty acids are ALA, EPA and DHA. Our bodies need all three types. ALA is an essential fatty acid necessary to survival,3 easily obtained in the the diet, and our bodies can convert ALA into the other two. Some algae produce DHA and EPA, and they can be taken as a supplement. It’s important to remember that our bodies need ALA itself, and it is not just useful because it can be converted into DHA and EPA.4
High levels of omega-6 fatty acids, found in high amounts in some oils (sunflower, corn, sesame, soy and safflower) and margarine, can inhibit the conversion of ALA into DHA and EPA. Alcohol and tobacco consumption and high blood cholesterol levels can also affect conversion rates.
Current recommended amounts are 1.1 grams of ALA daily for women and 1.6 grams daily for men. The total amount needed by men and about 1.3 times the amount needed by women can be found in one tablespoon of chia seeds, one teaspoon of flax seed oil, four teaspoons of ground flax seeds, or four whole walnuts. We must grind the seeds for a good absorption. One cup of firm tofu contains a quarter of this amount. Oregano and cloves also contain small amounts of omega-3.5
As mentioned above, there are some vegan DHA supplements derived from algae, and there are some studies that have shown that taking these supplements can increase DHA levels in vegans up to 50%.6 However, there is no evidence that such supplementation is necessary for vegans. Taking all of this into consideration, some nutritionists recommend that vegans can take a DHA supplement although nothing conclusive can be said.7
We can get ALA from walnuts, seeds (flax or chia) and firm tofu. Grinding the seeds improves absorption.
1 Sanders, T. A. & Younger, K. M. (1981) “The effect of dietary supplements of omega 3 polyunsaturated fatty acids on the fatty acid composition of platelets and plasma choline phosphoglycerides”, British Journal of Nutrition, 45, pp. 613-616. Sanders, T. A. & Roshanai, F. (1992) “Platelet phospholipid fatty acid composition and function in vegans compared with age- and sex-matched omnivore controls”, European Journal of Clinical Nutrition, 46, pp. 823-831. Fokkema, M. R.; Brouwer, D. A.; Hasperhoven, M. B.; Martini, I. A. & Muskiet, F. A. (2000) “Short-term supplementation of low-dose γ-linolenic acid (GLA), α-linolenic acid (ALA), or GLA plus ALA does not augment LCP ω 3 status of Dutch vegans to an appreciable extent”, Prostaglandins Leukot Essent Fatty Acids, 63, pp. 287-292.
2 Mangels, A. R. & Messina, V. (2001) “Considerations in planning vegan diets: Infants”, Journal of the American Dietetic Association, 101, pp. 670-677.
3 Davis, B. & Melina, V. (2014) Becoming vegan, comprehensive ed., Summertown: Book Publishing, p. 117.
4 Brouwer, I. A.; Katan, M. B. & Zock. P. L. (2004) “Dietary α-linolenic acid is associated with reduced risk of fatal coronary heart disease, but increased prostate cancer risk: A meta-analysis”, Journal of Nutrition, 134, pp. 919-922 [accessed on 31 January 2021]
5 Muskiet, F. A.; Fokkema, M. R.; Schaafsma, A.; Boersma, E. R. & Crawford, M. A. (2004) “Is docosahexaenoic acid (DHA) essential? Lessons from DHA status regulation, our ancient diet, epidemiology and randomized controlled trials”, Journal of Nutrition, 134, pp. 183-186 [accessed on 17 September 2016]. Geppert, J. (2006) “Microalgal docosahexaenoic acid decreases plasma triacylglycerol in normolipidaemic vegetarians: A randomised trial”, British Journal of Nutrition, 95, p. 779-786. Hooper, L. (2006) “Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: Systematic review”, British Medical Journal, 332 [accessed on 14 April 2018]. Wang, C.; Harris, W. S.; Chung, M.; Lichtenstein, A. H.; Balk, E. M.; Kupelnick, B.; Jordan, H. S. & Lau, J. (2006) “n-3 Fatty acids from fish or fish-oil supplements, but not α-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: A systematic review”, The American Journal of Clinical Nutrition, 84, pp. 5-17 [accessed on 22 January 2021]. Williams, C. M. & Burdge, G. (2006) “Long-chain n-3 PUFA: Plant v. marine sources”, Proceedings of the Nutrition Society, 65, pp. 42-50 [accessed on 10 January 2018]. Kornsteiner, M.; Singer, I. & Elmadfa, I. (2008) “Very low n-3 long-chain polyunsaturated fatty acid status in Austrian vegetarians and vegans”, Annals of Nutrition and Metabolism, 52, pp. 37-47. Kris-Etherton, P. M.; Hill, A. M. (2008) “N-3 fatty acids: Food or supplements?”, Journal of the American Dietetic Association, 108, pp. 1125-1130. Mangat I. (2009) “Do vegetarians have to eat fish for optimal cardiovascular protection?”, American Journal of Clinical Nutrition, 89, pp. 1597S-1601S. Norris, J. & Messina, V. (2011) Vegan for life, Philadelphia: Da Capo, pp. 51-60. Davis, B. & Melina, V. (2014) Becoming vegan, op. cit., p. 129.
6 Conquer, J. A. & Holub, B. J. (1996) “Supplementation with an algae source of docosahexaenoic acid increases (n-3) fatty acid status and alters selected risk factors for heart disease in vegetarian subjects”, Journal of Nutrition, 126, pp. 3032-3039 [accessed on 31 January 2021]. Lloyd-Wright, Z.; Preston, R.; Gray, R.; Key, T. J. A. & Sander, J. A. B. (2003) “Randomized placebo controlled trial of a daily intake of 200 mg docasahexanoic acid in vegans”, Proceedings of the Nutrition Society, 62, p. 42a.
7 Messina, G. (2020 ) “Do omega-3 fats in vegan diets: A quick primer”, The Vegan RD, 9/3/2020 [accessed on 14 July 2020]. Norris, J. (2014) “Omega-3 fatty acid recommendations for vegetarians”, Vegan Health, April [accessed on 22 July 2015]. Gould, J. F.; Roberts, R. M. & Makrides, M. (2021) “The influence of Omega-3 long-chain polyunsaturated fatty acid, docosahexaenoic acid, on child behavioral functioning: A review of randomized controlled trials of DHA supplementation in pregnancy, the neonatal period and infancy”, Nutrients, 13 (2) [accessed on 30 April 2021].