FAB RESEARCH COMMENT:
As this article explains, vegetarians and vegans (along with anyone else who does not eat fish and seafood) tend to have much lower blood levels of long-chain omega-3 (EPA and DHA) - and this is associated with higher risks for heart disease and many other health problems.
As the author points out, however, other aspects of many vegetarian diets (such as an increased intake of vegetables, fruits and whole grains) can provide advantages that may help to offset the potential health risks of insufficient long-chain omega-3 intakes.
Conversion of the shorter chain omega-3 found in some nut and seed oils (such as flax, chia, walnut etc) into EPA/DHA is not reliable in humans (see
Brenna et al, 2009), so although these can generally make a healthy contribution to the diet, they will NOT ensure adequate DHA status in particular.
Instead, for vegetarians wishing to improve their long-chain omega-3 status, vegan-friendly sources of these long-chain omega-3 derived from algae are now available (as supplements, or added to some foods) - although these are more expensive than fish oils.
For more details of this research review, see:
While this news item and the review focus on cardiovascular health only, there is an abundance of evidence that Omega -3 fatty acids play a major role in neurodevelopment and mental health.
For some recent news and research in this area please see:
Furthermore, lack of Omega -3 fatty acids in the diet has also been associated with antisocial behaviour:
The EFSA research panel has published the following reccomendations in July:
The Panel concluded that consumption of about 1‑2 servings of seafood per week and up to 3‑4 servings per week during pregnancy has been associated with better functional outcomes of neurodevelopment in children compared to no consumption of seafood.