SDA soybean oil effective for omega-3 blood level boost

By Stephen Daniells, 01-Sep-2010 

Daily consumption of a soybean oil rich in stearidonic acid (SDA) increased levels of omega-3 in blood cells after 12 weeks, says a new study from Monsanto and Solae.

Blood cell levels of eicosapentaenoic acid (EPA) were 13 percent higher following 12 weeks of supplementation with 4.2 grams per day of SDA-enriched soybean oil, compared with a soybean oil control group, according to findings published in the American Journal of Clinical Nutrition.

Monsanto and Solae are leading research into genetically modified soybeans containing SDA as a source of omega-3. Soybean oil is not normally a good source of omega-3 because it contains alpha-linolenic acid (ALA), which the body coverts inefficiently to SDA.

Fish oil race

In recent years the race has been on find a way to source DHA (docosahexaenoic acid) and EPA directly from plants for human use. Solae and Monsanto teamed up in 2007 to commercialise the latter's soybean variety developed specially to be rich in SDA. The rate of conversion of SDA to EPA is understood to be comparatively efficient - between 5.5:1 and 6:1.

“SDA-enriched soybean oil is a land-based omega-3 fatty acid that is a sustainable approach to increasing tissue concentrations of long-chain polyunsaturated omega-3 fatty acids,” wrote the researchers, led by Monsanto’s Shawna Lemke.

The oil is being commercialized by Solae under the brand name Soymega. The ingredients attained GRAS status (generally recognised as safe) in 2009.

Study details

Lemke and her co-workers performed a randomized, placebo-controlled, double-blind multicenter study involving 252 overweight subjects. The participants were randomly assigned to one of three groups: The first group received 1 g encapsulated soybean oil and 14.7 grams of liquid SDA-enriched soybean oil per day, which provided a daily dose of SDA of 4.2 grams, the second group received 1 gram of encapsulated EPA and 14.7 grams of liquid soybean oil per day, while the third group received one gram of encapsulated soybean oil and 14.7 grams of liquid non-enriched soybean oil per day mixed with food (control group).

The uptake of the oil, and conversion to EPA, was assessed using a measure called the omega-3 index. The index is a measure of blood levels of omega-3 fatty acids, and is defined as the percentage of EPA plus DHA in red blood cell membranes, relative to all other fatty acids (Cardiovascular Research, 2007, Vol. 73, pp. 310-315.).

After 12 weeks of intervention, the researchers report that the index had increased to 4.69 and 4.84 percent for the SDA and EPA groups, respectively, compared with 4.15 percent for the control group.

In addition, the participants did not report any adverse effects relating to the SDA-enriched soybean oil.

Moving into food

At the recent IFT Annual Meeting and Expo in Chicago, Solae marketing and sales director, Al Gallegos, told NutraIngredients-USA the new ingredient has been successfully tested for use in soups, sauces, yoghurts, dressings, snack bars and industrial margarines and shortenings.

Solae expects its new steariodonic acid omega-3 from genetically modified soybeans to be ready for market launch in 2012, and is now sending out samples so food manufacturers can test it in applications.

Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.2009.29072
“Dietary intake of stearidonic acid–enriched soybean oil increases the omega-3 index: randomized, double-blind clinical study of efficacy and safety”
Authors: S.L. Lemke, J.L. Vicini, H. Su, D.A. Goldstein, M.A. Nemeth, E.S. Krul, W.S. Harris