There is another alarming way fat can harm your brain: overeating one type fat and skimping on another type, thus ignoring evolutionary wisdom. Most Americans are filling their brain cells full of the wrong kind of fat and ignoring the right type fat, creating a very destructive imbalance.
Among so-called polyunsaturated fatty acids, there are two basic types of fat, one called omega-6 fat and the other omega-3 fat. They have distinctly different chemical makeups. During prehistoric days when our brains evolved, our ancestors ate equal amounts of omega-3 and omega-6.
Omega-3 is found in seafood; our bodies also made some from other fatty acids found in nuts, greens, and lean meat.
The omega-6s at that time came mostly from fruits and vegetables, nuts and legumes. (Today omega-6s come primarily from processed vegetable oils.)
This ideal fat ratio prevailed for about four million years until the 1800s. The Industrial Revolution brought drastic changes, including the processing of high omega-6 vegetable oils. Wild, lean game was replaced with high-fat cattle and pigs. In the last one hundred and fifty years, intakes of saturated fat and omega-6s skyrocketed while consumption of omega-3s plunged to pathetic lows. Today, Americans, feasting on processed oil and Big Macs, eat from fifteen to twenty times more omega-6 fats than omega-3 fats. This ratio is wildly out of sync with our genetic origins, and we are paying a high price in accelerated aging and sky-high rates of chronic disease.
Your brain, because it is made up mostly of fat—fat you feed it—is the prime target of this dangerous fat imbalance. Excesses of bad fats and shortages of good fats can eventually lead to brain cell dysfunction and death, deteriorating mental faculties in people of all ages, notably in the young and the old.
ALARMING FACT: Even though we eat a lot of fat, it is not the right type for optimal brain functioning.
Americans typically eat fifteen times more potentially brain-destructive type oils than we do brain-building omega-3 fish-type fats.
When Bad Omega-6s Rule Your Brain
It’s amazing how the landscape of your brain changes when
you eat too much polyunsaturated fat, chemically classified as omega-6s. Your brain literally becomes a battlefield where omega-3 fatty acids (in fish) and omega-6s (in vegetable oils and dressings) fight for control of your cells. And because of their huge numbers, due to our prodigious intakes, the omega-6s usually win, establishing tyrannical rule over neuronal activity. These constant omega-6 victories create havoc in the brain.
One of the most fearful potential consequences of omega-6 dominance in brain cells is persistent inflammation of brain tissue. Such inflammation can injure cerebral blood vessels, set up processes that kill brain cells, warp nerve cell membranes disrupting normal functioning, interfere with neuronal message transmission, and promote strokes, Alzheimer’s disease, and probably all degenerative brain diseases. In new 1999 findings, evidence of chronic inflammation increased the odds of thromboembolic stroke by nearly 500 percent in a large group of men observed for twenty years as part of the Honolulu Heart Study.