Omega-3 science review criticized for bias

26-Mar-2009 - Last updated on 02-Apr-2009 at 15:47 GMT

The International Society for the Study of Fatty Acids and Lipids (ISSFAL) statement that ALA only converts to DHA in the body at negligible levels, has drawn criticism for bias toward marine sources.

Much criticism has flowed in from those sympathetic to the flax industry and other crop growers, from which the majority of ALA (Alpha-linolenic acid) found in the food supply is sourced.

They questioned the study review that also found ALA did not match DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) in terms of its health benefits – with infant cognitive health being singled out.

ALA alarm

“True, the best sources of functional EPA and DHA are marine or fish oils,” said Pennsylvania-based Sciproserv consultant, and former Pfizer and Becton Dickinson researcher and developer, Herman Rutner, adding, “Narrowly focusing on the shortcomings of plant omega-3s in conversions to DHA ignores benefits of flaxseed.”

Rutner observed that consuming omega-3s from plant sources compete with dominant omega-6 sources to promote digestive, intestinal and cardiac health and thus, “supplement and do not interfere with the beneficial effects of EPA and DHA.”

But a Martek spokesperson told NutraIngredients-USA.com the review had used independent criteria that scrutinized a wide range of omega-3 science.

“This statement is based on independent research,” she said. “It just so happens that much of the recent research has been conducted in the area of DHA and brain health.”

“This statement goes a long way to clearing industry and consumer confusion about the role omega-3s play in the body. Of course the ALA camp is not going to be happy but this is what the research demonstrates.”

Some of the studies pointed to the fact ALA-DHA conversion rates were higher in women and pregnant women, she said.

ISSFAL statement

ISSFAL stated: “…conversion of ALA to EPA is very low, and to DHA is even less – essentially negligible. These very low conversion rates mean that ALA cannot meet the body’s need for DHA.”

ISSFAL chair, Tom Brenna, professor of nutritional sciences at Cornell University in Ithaca in New York state added: “Each type of omega-3 has distinct nutritional functions. Nevertheless, seafood/algal omega-3s – also known as long-chain omega-3s – are more potent than terrestrial plant sources of omega-3s and boast certain critical functions that terrestrial plant-based omega-3s simply cannot perform.”

ISSFAL, which counts many major marine-sourced suppliers as members, along with academics, referenced a study, co-authored by Brenna and published in a recent edition of the journal, Prostaglandins, Leukotrienes and Essential Fatty Acids, that stated:

“With no other changes in diet, improvement of blood DHA status can be achieved with dietary supplements of preformed DHA, but not with supplementation of ALA, EPA, or other precursors.”