The issue is one in the forefront of the minds of omega-3 researchers, Holub said, with the widely publicized release last year of a study linking higher omega-3 intakes with an increased risk of prostate cancer in men. That study was roundly criticized on a number of grounds, including that the higher levels of omega-3s mentioned in the study were very modest, and if the connection inferred in the paper were true, higher levels of prostate cancer would be observed in those countries where omega-3 intake is high. Which is not the case.
Nevertheless, the paper has had an effect. The Global Organization of EPA and DHA Omega 3s (GOED) has observed a flattening of sales for the ingredient in North America, an effect which it attributes in large part to the paper. Many experts have opined that the strong underlying demand for the ingredient means that this effect will be temporary, but it is not clear yet if the demand curve has returned to its pre-paper slope.
You don't win every game
“When you compare omega-3s to other ingredients, the science we have is extremely strong, but we seem to get attacked if a study comes out where there is no effect or a possible negative effect,” Holub told NutraIngredients-USA. "I come from Canada, so I think of it in terms of hockey. And as a hockey guy, I like to say that you don’t win all the games. So I like to base it on a record that looks like 12 wins, one loss and one tie.
“Unfortunately, the press doesn’t look at it that way. They look at the most recent negative study and that’s the one that gets heavily publicized. We are under attack and that’s just the way the media seems to work. Omega-3s are are the top of the heap and with the large number of positive studies, it can almost seem like it is too good to be true,” he said.
“But we can rest in some confidence that there are numerous studies going on almost every day in various parts of the world,” Holub said.
Getting the word out
Holub said the only recourse for scientists in the field is to keep doing what they are doing, and the truth will out. To that end, he has been involved with putting together a meeting to update experts in the field on the latest science in the sector. Titled DHA / EPA Omega3 for Health Symposium: Update 2014, the one-day meeting is set for May 22 in Toronto, and brings together experts from the US, Canada and the UK to present their latest findings in the field.
Holub, who is the chair of the meeting, will present a paper in which his team looked at actual intake of EPA and DHA among various groups when compared to reported intakes based on a food questionnaire approach.
Holub makes the point that the food questionnaire approach contains some potential built-in inaccuracies, because it relies on USDA tables that give standard reference amounts of the essential fatty acid content of various foods. But as the ways in which these foods are produced changes, who can say if their precise chemical composition remains the same?
“Over half the fish now are farmed. When you buy salmon in the store, is it wild or is it farmed? If it is farmed, how much EPA and DHA does it have? We don’t know. It depends on what the farmers fed the fish. The numbers can differ by as much as tenfold,” Holub said.
Not surprisingly, Holub found that the food questionnaire approach seems to significantly over report the EPA and DHA intakes for various groups, such as children and pregnant and nursing mothers. But physically analyzing the food intakes of groups is time consuming and expensive, so one avenue of future research could be to better quantify how much those intakes are over reported and apply a ‘correction’ factor to the reporting of intakes via food questionnaires, Holub said.
Among the other reseachers who will present papers at the conference are Capt. Joseph Hibblen, MD, of the National Institutes of Health who will report on the latest research on omega-3s and mental disorders, including depression and violent behaviors, and Elizabeth Kerling, a research associate at the University of Kansas Medical Center, who will report her striking findings of the positive effects of prenatal DHA supplementation.
For more information on the symposium or to register, click here.