Are vegans Omega-3 deficient?

Omega-3 is a healthy fat that is typically found in oily fish and fish oil supplements. It obviously presents a problem for vegans because they don’t eat fish. So does that remain a sticking point in a vegan diet? To find out more, we put in a call to Philip Calder, professor of nutritional immunology at the University of Southampton. Philip is a leading expert on Omega-3…

Philip - Omega-3s are a type of fat that we get from the diet. Now people probably assume that fat is bad for us. In fact, there are some fats that are healthy, there are some essential fats and Omega-3 are among these healthy fats.

Chris - Why are they essential? What does that actually mean?

Philip - So essential usually in a nutritional sense means we can't make that nutrient ourselves and we have to get it from the diet. So there are two essential fats. One of them is called linoleic acid, that's an Omega-6 fat. And the other is called alpha-linolenic acid. That's an Omega-3 fat. Both of those essential fats are actually made in plants. So we get plenty of those from plant foods. But the really important Omega-3 fats, we call them EPA and DHA. We can actually get those from fish. We don't get them from plants. EPA and DHA are really important to supporting how our cells work in the body. Our brain cells, our heart cells, our immune cells. And that means they're associated with better health and over a long time period, reduced risk of many diseases.

Chris - And if we don't have them, what sorts of diseases are the deficiencies of these things associated with? How might a person who's running low on these things see this manifest in their health?

Philip - So a long-term consequence of not getting enough Omega-3s would be increased risk of heart disease. Also inflammatory conditions, things like arthritis for example.

Chris - What about brain health? Because I read a report from a celebrity commentator who said that she had embraced a vegan diet and then found that she couldn't think straight a number of months later, but then went and met a salmon steak and it was like someone had injected her with 50 million IQ points literally overnight. I mean does that sound plausible and why might that be?

Philip - Well I think it might be an exaggeration, but it is true that one of these important Omega-3s I mentioned, DHA, is really important in brain function. And there are experiments and data from research showing that if babies get more DHA early in life, they have better cognitive function. Maybe they have improved learning abilities, improved behaviour and so on. It's a small difference, but it does seem to be a consistent finding. Now later on in life it's believed, although it's been difficult to demonstrate, that having more DHA in the brain, which we'll be getting from our diet of course, helps with our cognitive function. Of course, you can get Omega-3 supplements that sometimes we call fish oils. These obviously come from fish, but now there are supplements on the market which are algal oils. And these are for all intents and purposes, these are equivalent to fish oils that are suitable for people who choose not to eat fish or take fish oil supplements.

Chris - So have people actually looked at, say, vegan diet consumers and compared their levels of these Omega-3s with people who are not eating that diet, do they tend to be on average deficient in these oils?

Philip - One of the problems is we can't define deficiency of Omega-3s with a number unlike some of the vitamins and minerals where there's a clear cutoff for deficiency. But we do know that vegans particularly have a lower intake of EPA and DHA. I think that's obvious because the main source is fish. And they also have lower levels of EPA and DHA in their blood than vegetarians. And vegetarians have lower levels than omnivores. But having said that, it's not that the levels are extremely low, that's actually been quite well described now. So they're lower but they're not totally absent, let's say. So that asks some other questions about our body's ability to make those important Omega-3s if we're not getting them from the diet.

Chris - And if a person is chronically low in them, do we have documented evidence then that there is an association with an increase in inflammatory states, heart problems, and possibly cognitive problems?

Philip - So we know that from two types of science. One is what we call observation and that's where you look at people's intake or the levels of these fatty acids in their blood at a point in time. And then you find out what happens to them maybe in 10, 15, 20 years time. So we know that people who start with a higher intake of EPA and DHA or who have more EPA and DHA in their blood, they have a lower risk of all of the things I mentioned, particularly heart disease. So I think that's a relationship. The other is in trials where people have been given EPA and DHA usually through supplements because that's easier to do in a human trial. There are beneficial health impacts. So I think that's quite clear. But I think we also have to keep in mind that there is an Omega-3 that I mentioned earlier on that we get from plants like rape seed oil for example. Flax seeds and flax seed oils are very good sources and we do have the capability to convert a little bit of that alpha-linolenic acid into these, I'm going to call them fish-type Omega-3s in our own body. So we are able to make our own EPA particularly in small amounts.

Chris - Do you think it's an advisory, like a healthy vegan diet or is it better to be vegetarian?

Philip - That's a really difficult question to answer. Many diets can be healthy and many diets can be unhealthy. So you know, an omnivorous diet can be an extremely unhealthy omnivorous diet or it can be a very healthy omnivorous diet. And I think with vegans it's roughly the same. So I think it's possible to have a healthy vegan diet so long as people are attentive to the things they're not getting enough of and maybe seek out ways which might be supplements to make sure they're getting enough of those nutrients.