DHA is the nutrient everyone needs but many of us have never heard of. What is DHA? Also known by its chemical name decosahexaenoic acid, DHA is one of the two major omega-3 essential fatty acids that everyone needs to fight inflammation. But DHA has an additional role in human health. It's a brain food.
Calling you a fat-head isn't necessarily an insult. You might be surprised that sixty percent of brain and nerve tissue is made of fat, with about 1/3 of that fat in the form of cholesterol. DHA is especially important to young, growing brains.
Why is fat so important to the central nervous system. It's helpful to think of your brain as a master gland as well as some kind of computer. The brain sends not just nerve messages but also chemical messages to every organ in the body, telling it how to work.
One of the most important of these chemical messengers is a group of hormones called the prostaglandins (so called because they were first discovered in the prostate gland).
Prostaglandins tell the body how to repair itself, whether to tear down tissues with inflammation or to build up tissues by turning off inflammation. Omega-6 fatty acids, found in safflower, sunflower, corn, and sesame oils, encourage the creation of inflammatory hormones. Omega-3 fatty acids, found in DHA sources such fish, microalgae, flax, and pumpkin seeds, encourage the creation of anti-inflammatory hormones. DHA is the omega-3 fatty acid your brain can't function without.
Since most of us eat a high-fat diet, why aren't we all geniuses? Most of us get plenty of omega-6 fatty acids, and plenty of other forms of fat, but not enough omega-3 fatty acids, especially DHA. When our brains don't get the DHA they need, they try to make hormones without them.
The problem is that, without DHA, the hormones the brain makes don't quite perform the functions for which they are designed in the body. Hormones act like a key that goes into a lock. Sometimes a master key will open a lock even if it is not exactly the same shape as the lock. But most keys that aren't made exactly right just jam the lock, keeping the door from being opened. That's analogous to what happens in the brain that doesn't get enough DHA.
The eyes have it. There's probably no better example of the importance of getting the right kind of fat than the human eye. The retina, the cells in the back of the eye that produce electrical impulses when they are stimulated by light, contains a very high concentration of DHA.
The more DHA in the diet, the better the eye can function. And since most people learn through vision, better eyes make better brains.
The most important times to be getting enough DHA are the first two years of life and the last two decades, during infancy, and as a senior citizen. Both aging and growing brains and nervous systems need lots of nutritious, omega-3 fats.
The most rapid growth of the brain occurs during the first twelve months of life. A baby's brain triples in size by his or her first birthday. All kinds of healthy fat, including cholesterol, are needed to make the brain cell membranes and the protective myelin sheath around each nerve. Breast-fed infants receive 50 per cent of their calories from fat, and up to about 2 grams of DHA every day.
Just say no to "moo." Cow's milk provides a different fat profile from human milk. The human brain is comparatively large for the size of the body. A cow's brain is relatively small for the size of the whole body. Cow's milk contains much less of the brain-building DHA than human mother's milk. Babies who are breastfed develop better brains more easily than babies who are fed formula, unless the formula is enriched with DHA.
How important is DHA to a growing brain? Consider these findings of research into DHA benefits:
- Babies who received more DHA while still in the womb grow up with greater athletic skills.
- Superior academic performance of breastfed babies has been linked to the DHA content of mother's milk.
- DHA-deficient lab animals develop smaller brains that mature more slowly.
- DHA has some usefulness as a remedy for ADD.
And DHA has similar effects in protecting adult brains from neurodegenerative diseases of aging, especially multiple sclerosis, but also Parkinson's and Alzheimer's disease.
With careful planning, you can get all the DHA you need from your diet. Most of us, however, don't have time to plan and then cook nutritious meals. That's why fish oil and microalgae supplements are a better way to get your DHA.