When it comes to brain health, nothing is more important than DHA – docosahexaenoic acid – an omega-3 fatty acid.
Forty percent of all the polyunsaturated fatty acids (PUFAs) in the brain consist of DHA. DHA is so essential to brain development that it makes up nearly 50 percent of breast milk. Perhaps no other brain nutrient is receiving as much attention lately as DHA. Scientists have been aggressively studying this critical brain fat for the past several decades for at least three reasons.
First, more than two-thirds of the dry weight of the human brain is fat, and one quarter of that fat is DHA. From a structural point of view, DHA is an important building block for the membranes that surround brain cells. These membranes include the areas where one brain cell connects to another – the synapses. This means that DHA is involved in the transmission of information from one neuron to the next, and thus is fundamental for efficient brain function.
Second, DHA is one of nature’s important regulators of inflammation. Inflammation is responsible for a large number of brain maladies, including Alzheimer’s, Parkinson’s, attention deficit hyperactivity disorder (ADHD), and multiple sclerosis. DHA naturally reduces the activity of the CX-2 enzyme, which turns on the production of damaging chemical mediators of inflammation. In other words, by inhibiting this enzyme, DHA helps put out the fire in our brains.
The third and perhaps most compelling reason for studying DHA is its role in modulating gene expression for the production of Brain-derived neurotrophic factor, or BDNF. BDNF is a protein that plays a key role in creating new neurons. It is important not only in neurogenesis and neuroplasticity but also in protecting delicate neurons from being damaged by a variety of insults, including trauma, transient reduction in blood supply, and perhaps most important, environmental toxins. Thus, DHA helps orchestrate the production, synaptic connection, and viability of brain cells while enhancing functionality.
In a double-blind interventional trial called the Memory Improvement with DHA (MIDAS), some members of a group of 485 healthy individuals with an average age of 70 and mild memory problems were given a supplement that contained DHA made from marine algae, and some were given a placebo. After six months, not only did blood DHA levels double in the group that received DHA, but the effects on brain function, compared with those who received the placebo, were outstanding. The lead project researcher, Karin Yurko-Mauro, commented, “In our study, healthy people with memory complaints who took algal DHA capsules for six months had almost double the reduction of errors on a test that measures learning and memory performance, versus those who took a placebo. …The benefit is roughly equivalent to having the memory skills of someone three years younger.”
Humans are able to synthesize DHA from a common dietary omega-3 fat, alpha-linolenic acid. But so little DHA is produced by this chemical pathway that many researchers in human nutrition now consider DHA to be an essential fatty acid, meaning that health maintenance requires a dietary source of this key nutrient. Data also shows that most Americans typically consume an average of only 60 to 80 milligrams of DHA daily, less than 25 percent of what researchers consider to be an adequate intake of 200 to 300 milligrams each day.
Fish is a natural source of the omega-3 essential fatty acid DHA. While fish is superior brain food, take care to avoid farmed fish, which are often pumped full of antibiotics and supplements to enhance color, and fed soybeans and grain that they would never eat in the wild. Wild varieties – especially cold-water fish like Alaskan wild salmon, sardines, and herring – are lower in toxins, but bear in mind that the larger the fish, the more likely it is to be contaminated with mercury, so avoid tuna and swordfish.
It’s interesting to note that DHA-rich fish oil was so highly prized by North American Indians from the Pacific Northwest, that it was traded like currency. The “grease” (or extract) produced from the so-called candle-fish was so rich in oil that you could simply stick a wick in the mouth of one of the dried fish, and it would burn like a candle!
DHA works closely with another omega-3 fatty acid, EPA, eicosapentaenoic acid. Both are found in fish, nuts, seeds, and certain oils. Since the body doesn’t make DHA-EPA, it’s recommended that you take three grams daily as fish oil or an algae derivative. The best DHA comes from krill. Researchers have noted an 85 percent reduction in the risk for Alzheimer’s among people with high levels of DHA in their diet.
You can read more about this in Power Up Your Brain.