DHA/AA - are they important?

What is DHA?

You have heard that DHA omega-3 is good for you - but do you want to know why? Here are the facts.

Docosahexaenoic acid, or DHA, is a polyunsaturated omega-3 fatty acid found throughout the body. It is a major structural fat in the brain and retina of the eye accounting for up to 97 percent of the omega-3 fats in the brain and up to 93 percent of the omega-3 fats in the retina. It is also a key component of the heart. Numerous studies confirm that everyone, from infants to adults, benefits from an adequate supply of DHA:

For mothers-to-be, DHA can help support a healthy pregnancy
For infants, DHA is important for brain and eye development.
For children, DHA is important for ongoing brain and eye development.
For adults, DHA supports brain, eye & heart health.

Yet, despite its importance, most people do not get enough DHA from the foods they eat.

Why is DHA so important?

DHA omega-3 is naturally found throughout the body and is most abundant in the brain, eyes and heart. DHA is critical for healthy brain and eye development and function and has been shown to support heart health from infancy through adulthood. DHA serves as a primary building block for the brain and the eye. Just as calcium is essential for building strong bones, DHA ensures that the cells in the brain, retina, heart, and other parts of the nervous system develop and function properly. In order to ensure optimal development and function, we must continuously replenish the DHA in our bodies by getting enough of this important fatty acid in our diets.

DHA makes up approximately 30 percent of the structural fat in the grey matter of the brain. Studies have shown that DHA plays a major role in the mental development of infants and supports the mental function of children and adults throughout life. Beyond infancy, there may be a role for DHA in some behavioral and mood disorders affecting both children and adults, and low levels of DHA observed in the elderly may contribute to or accompany the onset of symptoms associated with age-related mental decline. More research is being conducted to further investigate these findings.

DHA is a major structural fat in the retina of the eye. DHA plays an important role in both infant visual development and visual function throughout life. Studies with both premature and full-term infants suggest that an adequate supply of DHA, provided through either breast milk or DHA-fortified formula, is associated with better visual function and more rapid visual development. Research also shows that DHA may play a role in adult eye health.

DHA is a key component of the heart, especially in the conducting tissue, and is important for heart health throughout life.

What are the best sources of DHA?1

Dietary sources of DHA include:

Algae - Certain algae are natural sources of DHA. And while most people believe that fish produce their own DHA, in fact, it’s the algae they feed on that make them a rich source of DHA.
Fatty fish including anchovies, salmon, herring, mackerel, tuna and halibut
Organ meat such as liver
Fish oil
Small amounts are found in poultry and egg yolks.
There is a common misconception that foods like walnuts, linseed oil, and flaxseed oil are dietary sources of DHA. However, these foods are actually sources of alpha-linolenic acid, ALNA, a precursor of DHA. ALNA has no known independent benefits on brain or eye development and function, as DHA does. And, although the human body can convert ALNA to DHA, the process is inefficient and variable.

What is AA?

AA, or Arachidonic acid, is a long-chain omega-6 fatty acid, is the principal omega-6 in the brain, representing about 48 percent of the omega-6 fats in the brain. It is also abundant in other cells throughout the body.

Why is it important?

Like DHA, AA is important for proper brain development in infants. It is also a precursor to a group of hormone-like substances called eicosanoids that play a role in immunity, blood clotting and other vital functions in the body.

Like DHA, AA occurs naturally in breast milk and supports the mental development of infants.

What are the best sources of AA?1

A balanced diet will supply healthy levels of AA. People obtain AA by eating foods such as meat, eggs and milk. Like DHA, AA also occurs naturally in breast milk

1 Nutrition for Expecting Moms, http://www.thriftyfoods.com/recipes/ntrtn_ntrtnf.html?THRIFTY=1f6c5d138bffdba8e61629be2c56102a. accessed 12.02.07