Very high omega-3 intakes linked to big health benefits

Intakes of omega-3 exceeding levels consumed by the general US population may significantly reduce the risk of chronic disease, suggests a new study with Yup’ik Eskimos.

High levels of the omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA(docosahexaenoic acid) were associated with lower levels of triglycerides, as well as higher levels of HDL cholesterol, according to data from 357 Yup’ik Eskimos published in the American Journal of Clinical Nutrition.

Raised levels of the fatty acids were also associated with decreased levels of markers of inflammation, such as C-reactive protein (CRP), which is produced in the liver and is a known marker for inflammation. Increased levels of CRP are a good predictor for the onset of both type-2 diabetes and cardiovascular disease.CVD causes almost 50 per cent of deaths in Europe, and is reported to cost the EU economy an estimated €169 billion ($202 billion) per year.

The study of omega-3 intakes in inuits is nothing new. The first reports of the heart health benefits of the marine fatty acids were reported in the early 1970s by Jørn Dyerberg and his co-workers in The Lancet and The American Journal of Clinical Nutrition. The young Danes sought to understand how the Greenland Eskimos, or Inuit as they prefer to be called, could eat a high fat diet and still have one of the lowest death rates from cardiovascular disease on the planet.

Despite the precedent of study in these populations, the new research, led by Zeina Makhoul from Fred Hutchinson Cancer Research Center in Seattle, claims that: “Few studies have examined the associations of with biomarkers of chronic disease risk in populations with high intakes”.

In an attempt to fill this knowledge gap, they analysed blood levels of EPA and DHA in red blood cells of in a cross-section of 357 Yup’ik Eskimos.

Data showed EPA and DHA represented an average 2.8 and 6.8 percent, respectively, of the total fatty acid content of red blood cells.

In addition to the links between EPA and DHA levels and triglycerides and HDL, increased levels of DHA were positively with levels of LDL and total cholesterol, said the researchers.

While a link between EPA/DHA and CRP were reported, Makhoul and her co-workers noted that the link was stronger when EPA concentrations excessed 3 percent of fatty acids in the cells, and when DHA levels exceeded 7 percent.

“Increasing EPA and DHA intakes to amounts well above those consumed by the general US population may have strong beneficial effects on chronic disease risk,” they concluded.

Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.2009.28820
“Associations of very high intakes of eicosapentaenoic and docosahexaenoic acids with biomarkers of chronic disease risk among Yup’ik Eskimos”
Authros: Z. Makhoul, A.R. Kristal, R. Gulati, B. Luick, A. Bersamin, B. Boyer, G.V. Mohatt

Fish oil during pregnancy may slash infant allergy

Supplements of omega-3-rich fish oils during pregnancy may reduce the risk of food allergy and eczema in children, according to a new study from Sweden.

The occurrence of eczema and food allergies was 16 and 13 per cent lower, respectively, in infants of mothers receiving the fish oil supplements during pregnancy and the early months of breast-feeding, compared to placebo, according to findings published in the journal Acta Paediatrica.
“This randomized placebo-controlled double-blind study shows that omega-3 supplementation during pregnancy and lactation may reduce the risk of developing allergic sensitization to egg, IgE-associated eczema and food allergy during the first year of life,” wrote the authors, led by Catrin Furuhjelm from Linkoping University.
Immunoglobulin E (IgE) is the predominant antibody associated with an allergic response.
The new study adds to the ever-growing list of studies supporting the potential health benefits of omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA. Much of its healthy reputation that is seeping into consumer consciousness is based largely on evidence that it can aid cognitive function and may help protect the heart against cardiovascular disease.
From mother to child
Furuhjelm and her co-workers recruited 145 pregnant women with allergies, or with partners or other children with allergies. Starting at the 25th week of their pregnancy, and continuing for between three and four months of breastfeeding, the women were randomly assigned to receive either daily fish oil supplements providing 1.6 g of EPA and 1.1 g of DHA (Bio Marin capsules from Pharma Nord, Denmark), or placebo.
Using a range of tests, including clinical examination, skin prick tests, and blood tests for IgE, the researchers observed a 2 per cent prevalence of food allergy in the omega-3 group, compared to 15 per cent in the placebo group.
Furthermore, the incidence of IgE-associated eczema was only 8 per cent in the omega-3 group, compared to 24 per cent in the placebo group.
“Our findings suggest that the mechanisms leading to sustained IgE antibody production early in life may be inhibited by the omega-3 fatty acids EPA and DHA,” wrote Furuhjelm.
What’s happening?
Commenting on the mechanism, the Linkoping-based scientists proposed several possibilities. Both DHA and EPA may produce changes in the fluidity of the membranes of immune cells, and reduce the levels of the omega-6 fatty acid arachidonic acid (AA). By inhibiting the metabolism of AA, the formation of the less inflammatory eicosanoids is favoured, which may be linked to lower allergic sensitization in the children, said the researchers.
“Additional anti-inflammatory effects of EPA andDHA in early immune development through bioactive lipids, lipoxins, neuroprotectines and resolvins, have been discussed but it is not clear whether those are plausible explanatory mechanisms regarding our findings,” they said.
Food allergy rises
The number of allergic disease has also been rising, with an estimated eight per cent of children in the EU suffering from food allergies, according to the European Federation of Allergy and Airways Diseases Patients’ Associations.
The most common food allergen ingredients and their derivatives are cereals containing gluten, fish, crustaceans, egg, peanut, soybeans, milk and dairy products including lactose, nuts, celery, mustard, sesame seed, and sulphites.
Source: Acta Paediatrica
Published online ahead of print, doi: 10.1111/j.1651-2227.2009.01355.x
“Fish oil supplementation in pregnancy and lactation may decrease the risk of infant allergy”
Authors: C. Furuhjelm, K. Warstedt, J. Larsson, M. Fredriksson, M. Fageras Bottcher, K. Falth-Magnusson, K. Duchen

The danger with many Omega-3 fish oils available on the retail shelves is the risk of mercury and other heavy metal contamination. Make sure that you purchase a pharmaceutical grade fish oil supplement which is guaranteed to be mercury free.