By Tony Vendryes
WHEN GRANDMA told you that fish was brain food she was right. Fish oils are high in special essential fatty acids (EFA) called the omega-3 fats. The main EFA's in fish oil have long scientific names abbreviated to EPA and DHA.
While EPA has many important functions particularly for inflammation, the circulation and mental health, DHA is vital to brain health. They seem to have complementary benefits. DHA is literally a brain food and modern research has made the following interesting discoveries.
This key fatty acid, DHA, plays critical roles in all the cells of the body and is a major component of the brain, the retina of the eye, and human sperm. However, the brain contains the highest levels of DHA in the body, and within the brain itself, regions most closely related to memory show the greatest DHA concentrations.
Individuals with a DHA deficiency often show cognitive deficiencies and an increased risk for mental disorders like Alzheimer's disease. As we age, DHA levels normally drop, especially in an important region of the brain, the hippocampus, that is critical for memory.
Children with high levels of DHA often perform better in school examinations. In a landmark study of school children in Canada, higher DHA levels correlate well with improved performance on tests of memory and learning.
Scientists believe that DHA influences how the brain develops and functions in several ways. It helps to determine brain structure, and it protects brain tissue from damage. This protective effect comes from three different actions.
DHA protects the brain from inflammation.
It does this by its anti-inflammatory properties while suppressing the creation of other inflammatory chemicals in brain cells. That action alone offers powerful protection against the various stresses that cause ageing of the brain. Brain inflammation is now considered to be an underlying cause of Alzheimer's disease.
DHA encourages the brain cells to growth new neurites, the tiny projections that create the connections between cells as memories are formed. DHA promotes the movement of chemical messages from brain cell to brain cell and helps the membranes maintain their function, the conditions required for the creation and storage of memory.
DHA helps brain healing after injury
Immediately after any injury to the brain, be it a head injury, a stroke or seizure or a lack of oxygen, the brain cell membranes release DHA in massive amounts for conversion into substances called protectins.
Protectins begin to form at the very first sign of damage to brain cells. Scientists believe that protectins derived from DHA in sufficient quantities may stop widespread brain degeneration, and slowing neurodegenerative diseases like mild cognitive decline, and even Azheimer's and Parkinson's diseases.
Get enough DHA
Some individuals, in their efforts to eat healthier, may be at particular risk of a deficiency in omega-3 fatty acids. For example, those who follow a vegan diet run the danger of a serious DHA deficiency because their diets provide little or no DHA at all. Even a vegetarian diet with dairy and eggs may only supply about 20mg/day of DHA.
The usual plant sources of omega-3 fats like flax seed (linseed) provide another fatty acid called ALA. The body must then convert it into DHA via EPA. This conversion may be below five per cent in men, and a bit higher in women. Consequently, vegetarians are at risk of a DHA deficiency as are children, the elderly and many on the modern fast-food diet.
Fish oil has been the best dietary source of omega-3 fats in general and DHA in particular. But fish do not make DHA. Predatory fatty ocean fish consume smaller fish and crustaceans that, in turn, feed on algae. Algae powered by solar energy, produce the DHA (and EPA) that we need.
As a result, all of the DHA we get from fish originates from algae - tiny one-celled plants in the seas. For the strict vegan, algae-derived DHA supplements are now being produced by supplement manufacturers.
Eating fatty fish provides a useful source of DNA, but optimal therapeutic dosages necessary for the brain protection mentioned above may require supplementing with the omega-3 fatty acids. Most of the studies report benefits when taking over 1000mg of DHA daily.
It is best to use a product that combines both DHA and EPA as they both complement each other. Choose a very pure omega-3 product free from contaminants like mercury and other harmful chemicals. These fats are extremely sensitive to heat and light, so packaging and storage is important. I recommend nontransparent containers, preferably white, that you may store in the refrigerator if not being used quickly.
Unfortunately, DHA supplementation, like any other treatment, is much less effective when diseases like Alzheimer's disease is advanced, probable because so much damage has already been done. Still, supplementation may control some of the troubling features of the disease.
Alzheimer's patients typically lose weight as a result of lost sense of smell and taste, and a general disinterest in food. But supplementation with DHA at 1.7g/day improved weight gain and well-being in patients with mild to moderate Alzheimer's.
It is never too early to start supplementing with the omega-3 fats. Pregnant mothers who take them are providing optimal nutrition to their unborn baby's brain and nervous system. Children who take them learn more and behave better. Adults need not wait for memory loss or other sighs of mental deterioration to start. Prevention is better than cure.
You may email Dr Tony Vendryes at firstname.lastname@example.org or listen to 'An Ounce of Prevention' on POWER 106FM on Fridays at 8 p.m. His new book 'An Ounce of Prevention, Especially for Women' is available locally and on the Internet.