Decosahexaenoic Acid (DHA)

If you're like most people, you've probably spent the last decade counting your fat grams because of studies that linked a high-fat diet to an increased risk of heart disease and cancer. But in your zeal to eat right, you may have eliminated some good fats in the process, notably decosahexaenoic acid (DHA), an essential fatty acid that cannot be manufactured by the body. DHA is found in foods that many people have given up in the name of good health, such as organ meats (which are high in both saturated fat and toxins) and eggs (which may be too high in cholesterol for people with lipid problems). It is also abundant in fatty fish, like salmon, mackerel, sardines, and albacore tuna; why do we need DHA? DHA is found in high concentration in the gray matter of the brain and the retina of the eye. It is also instrumental in the function of brain cell membranes, which are important for the transmission of brain signals.

Essential for normal brain and eye development, DHA is passed from the mother to the fetus via the placenta. After birth, the primary source of DHA is breast milk. Over the past 50 years, the consumption of DHA has significantly declined, and this has many scientists worried. In countries where DHA consumption has remained high, depression is not as common. Low levels of DHA have also been associated with an increase in dementia, mood changes, memory loss, and visual problems. In fact, in a Swedish study, elderly patients with Alzheimer's disease were found to have lower blood levels of DHA than healthy older people. Another Japanese study showed a 65 percent improvement in dementia symptoms among patients given DHA supplements.

Scientists are also concerned about the decline of DHA in breast milk, and they fear that it may interfere with normal mental development in children. In Europe, DHA is added to infant formulas. In addition, some scientists speculate that the deficiency in DHA may be a contributing factor in postpartum depression in new mothers.