A fish a day keeps the doctor away?

Most people, whether healthy or having cardiovascular disease (CVD), would benefit from regular consumption of oily fish, concluded speakers at the EuroPRevent 2012 meeting. While eating whole fish undoubtedly offers the optimum approach for increasing omega-3 intakes in both primary and secondary prevention, delegates heard, supplements have a major role to play in increasing omega-3 intakes for people who do not like fish. The EuroPRevent 2012 meeting, held 3 May to 5 May 2012 in Dublin, Ireland, was organised by the European Association for Cardiovascular Prevention and Rehabilitation (EACPR), a registered branch of the European Society of Cardiology (ESC).

The symposium " A fish a day keeps the doctor away" (1) centred on the cardiovascular disease (CVD) benefits of the long chain highly unsaturated omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in the flesh of oily fish, such as salmon, mackerel, herring, trout and sardines. In the round table debate speakers attempted to unravel the current confusion where initial studies showed eating fish/taking omega 3 supplements delivered CVD benefits, but more recent studies with supplements failed to reproduce these effects.

"Omega-3 fatty acids are really important to human health, whether you're talking about CVD, brain or immune health. Heath professionals have a key role to play in educating the public about the beneficial effects of including fish in their diets," said Philip Calder, a metabolic biochemist and nutritionist from the University of Southampton, UK.

The latest European Guidelines on Cardiovascular Disease Prevention in Clinical Practice, also launched at the EuroPRevent 2012 meeting, recommend that people should eat fish at least twice a week, one meal of which should be oily fish (2). For people opting for supplements, warned Calder, it is best to take pharmaceutical grade preparations of omega-3 oils since not all over the counter preparations contain the same dose of the fatty acids. "It's important that health professionals give clear guidance around the need for patients to take 1g of omega-3 a day to achieve any beneficial effects.

With over the counter brands containing different concentrations there's a danger people may not be receiving sufficient intakes," said Calder.

Eating oily fish may prove more beneficial than taking capsules of omega-3. "This is because fish contain all sorts of other nutrients like vitamin D, selenium and iodine that may also be beneficial against CVD. And we don't have the final proof that the benefits from eating fish come from the omega-3," said Daan Kromhout, from Wageningen University, The Netherlands. "Fish, it needs to be remembered, don't provide a total panacea against CVD. As well as consuming fish, people need to eat healthy diets, not smoke and be physically active."

Conflicting trials of omega-3

The first association between omega-3 consumption and incidence of CVD was found in epidemiological studies in the late 1970s when Danish investigators Bang and Dyerberg discovered the incidence of myocardial infarction (MI) was ten times higher among the Danish population than Greenland Inuits. "At the time the Greenland Inuits ate diets of whale and seal meat that were exceptionally high in omega-3 fatty acids," said Erik Berg Schmidt, from Aalborg University Hospital, Aarhus, Denmark. "The findings went contrary to the dogma of the time that animal fats were harmful and led to the hypothesis that omega-3 fatty acids reduce vascular disease."