STRASBOURG, FRANCE. Obesity is a growing problem among adolescents and is often accompanied by metabolic syndrome (MS). Metabolic syndrome involves a cluster of several metabolic abnormalities including overweight (specifically abdominal adiposity), insulin resistance, high triglycerides and low HDL (high-density lipoprotein) levels, and is associated with an increased risk of cardiovascular disease. Whereas several studies have explored relationships between fish oil and weight loss or gain, researchers in France have examined whether a deficiency of DHA (which is found in fish oil) is linked to obesity.
TUCSON, ARIZONA. Low-fat diets have been widely promoted for lowering cholesterol levels, for reducing body weight, and for preventing certain types of cancer. At least one study, however, has found that although a reduction in cholesterol may reduce mortality from heart disease it may increase the incidence of fatal accidents, violent deaths, suicides, and depression. Researchers at the University of Arizona now believe that they may have found an explanation for this phenomenon. They point out that fat restriction and cholesterol-lowering drugs may change the concentrations of polyunsaturated fatty acids (PUFAs) in the tissues including nerve tissue (neurons). Fat-restricting diets usually lead to a relative increase in the intake of omega-6 PUFAs and a relative decrease in the intake of omega-3 fatty acids. This can have serious consequences inasmuch as the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oils, are crucial for the proper functioning of the nervous system. Several large-scale studies have found a clear association between low blood levels of EPA and DHA and an increased risk of depression, violence and suicide; a recent study in Japan found that DHA supplementation reduced aggression among healthy Japanese students.
MINNESOTA, MINNEAPOLIS. Blood levels of fatty acids are believed to reflect the dietary intake of fatty acids. Researchers at the University of Minnesota now report that while high fat diets tend to increase the level of omega-6 acids (generally undesirable) low fat diets tend to increase the level of beneficial omega-3 acids such as EPA and DHA (eicosapentaenoic acid and docosahexaenoic acid, respectfully).