Doctor’s Tip: Good and bad fats for the brain
This is the fourth column in a series about preventing Alzheimer’s, based on Dr. Neal Barnard’s book “Power Foods For The Brain.” This and the next few columns will discuss what we should and shouldn’t eat for optimal brain health.
There are fats that increase our risk of Alzheimer’s and other fats that decrease our risk. Let’s start out with the bad fats: saturated and trans. Saturated fat is present in meat, dairy products and vegetable oils (including olive and especially coconut oil). It is visible as white streaks in meat, and is what makes whole milk creamy and cheese waxy. Many studies have shown a link between saturated fat intake and risk for Alzheimer’s. For example, researchers in Chicago found that people who ate around 25 grams of saturated fat a day had more than twice the risk of developing Alzheimer’s compared with those who ate half as much. Part of the explanation for this is that saturated fat increases cholesterol levels, and high cholesterol is clearly linked to Alzheimer’s risk. If your cholesterol is even mildly elevated at 220 (normal is < 200 and arguably < 150), your Alzheimer’s risk is 25 percent higher; if your cholesterol is 250 the risk is 50 percent higher.
Trans fat is the other unhealthy fat. It is found naturally in meat and dairy products. It is also found when food manufacturers convert liquid oils into solid fats, a process called hydrogenation. These partially hydrogenated fats are found in pastries, snack food and French fries. They extend shelf life but as Dr. Barnard says, “they don’t extend your shelf life” because they are toxic for your brain as well as your blood vessels. They raise cholesterol levels and increase risk of heart disease and Alzheimer’s.
There are also good fats, and an extremely low fat diet is unhealthy. Cell walls are composed of a layer of fat sandwiched between two protein layers. Studies have shown that high blood levels of omega-3 help protect against cognitive decline and Alzheimer’s, as well as heart disease.
The chemistry of healthy fats is complicated, but here’s the simplified version: Most vegetables, fruit, seeds (especially flax seeds) and nuts (especially walnuts) contain a healthy omega-3 fat called ALA (alpha-linolenic acid), a chain of 18 carbon atoms. Your body adds two more carbon atoms to the chain, forming EPA, then two more making the 22-carbon DHA, which is what the brain needs. This critical lengthening process requires an enzyme. Omega-6 fats found in cooking oils (e.g. safflower, sunflower, corn, cottonseed) tie up these enzymes, which is one of the reasons added oils aren’t good for us. We do need small amounts of omega-6 fat, but most Americans get way too much, and the primary source is the added oil in the S.A.D. (standard American diet).
It’s possible that for genetic reasons, some people might not convert enough ALA to omega-3. Therefore, many experts recommend a daily 250 mg. supplement of algae-derived omega-3, available at Vitamin Cottage (one brand is relatively cost-effective) or on Dr. Fuhrman’s website wwwDrFuhrman.com. Fish has omega-3 but it’s best to avoid fish, because as Dr. Bernard says, “People who eat fish have more weight problems and have a higher risk of diabetes compared with people who skip animal products altogether. And excess body weight and diabetes can both put you at higher risk for Alzheimer’s disease.” Furthermore, fish these days is contaminated by industrial pollutants such as PCBs and heavy metals, and the latter increase the risk of Alzheimer’s.
What about doctors who write books and have websites discounting the harmful effects of saturated fat? These claims are not based on good science — Big Food sponsors many studies in an effort to muddy the waters and confuse people, including doctors. And many of these doctors sell supplements and are therefore biased. Dr. Barnard, founding president of PCRM (Physician Committee for Responsible Medicine), has no ties to Big Pharma or Big Food, has nothing to sell and is evidence-based. Another unbiased source for accurate information on nutrition is Michael Greger, M.D., author of “How Not to Die” and website nutritionfacts.org. He has a nonprofit, and he and his staff review all the thousands of scientific English-language scientific papers on nutrition that come out every year, toss the bad or biased studies and offer evidence-based information to the public.
And what about those anecdotes we’ve all heard, about someone’s uncle who smoked, ate bacon and eggs for breakfast every day and lived to 100, sharp as a tack? Those aberrations exist, but the rest of us want to stack the deck in our favor.
Dr. Feinsinger, who retired from Glenwood Medical Associates after 42 years as a family physician, has a nonprofit Center For Prevention and Treatment of Disease Through Nutrition. He is available for free consultations about heart attack prevention and other medical issues, and to help people with hospital or other medical bills they don’t understand or think are too high. Call 970-379-5718 for an appointment. For questions about his columns, email him at firstname.lastname@example.org.