Feed Your Brain
How to eat to sharpen your memory today, and protect against Alzheimer's for the long haul
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My mother’s father was a small-town doctor. Back in the days when there was no health insurance, he delivered babies, took care of children and adults, and helped people through serious illnesses. When he was about 60, he suffered a heart attack. Soon, it became clear that something else was wrong. He became forgetful and confused. Sometimes he left the house without knowing where he was going. Once in a while, a patient would pick him up and bring him back home. No one knew what was wrong, but he went steadily downhill and died in his mid 60s.
My grandmother lived much longer, but she suffered from memory problems too. “By the time I get to the end of a magazine article,” she told me, “I can’t remember the beginning.”
As her dementia worsened, she lost her ability to remember even simple things and no longer recognized her family members. My father’s parents suffered the same devastating memory loss; so did my father. Alzheimer’s disease attacks half of us by age 85. In dollars and cents, the disease is a disaster—a person with Alzheimer’s now averages nearly $45,000 a year in medical costs, which can get to almost $70,000 if residential care is needed. But the personal cost—the loss of everything that ever mattered to us—is incalculable. In case these terms are mysterious, dementia is a general term referring to a loss of cognitive function. Alzheimer’s disease is one type of dementia marked by the presence of specific abnormalities in the brain.
Memory problems are not just an issue for older folks. They can hit at any age. How often have you said to yourself, “It’s on the tip of my tongue”? Or you see a familiar face, but you can’t come up with the name?
Researchers have been working hard to understand what causes memory to sputter and fail. A genetic trait, called the APOE epsilon 4 allele, is strongly linked to Alzheimer’s risk. Yet some people with this gene stay free of the disease, while others with no apparent genetic risk succumb to Alzheimer’s. As research studies tease apart the contributors to memory problems, more and more evidence is pointing to foods. Some foods are memory boosters, while others increase the risk of memory lapses.
Clues From Chicago
In 1993, Martha Clare Morris and her team of researchers with the Chicago Health and Aging Project began studying thousands of people in three Chicago neighborhoods, examining their diets, exercise patterns, and overall health. The researchers then waited to see who stayed mentally clear and who did not.
Ten years later, the study identified two key culprits for heightened Alzheimer’s risk. First, saturated fat—the solid fat found in bacon, butter, and other animal-derived foods. Specifically, a person eating 25 grams of saturated fat per day was three times more likely to develop the disease, compared with people eating about half that much.
Culprit No. 2: trans fats, the hydrogenated oils often found in doughnuts, cupcakes, and other snack foods, had an even stronger link to Alzheimer’s disease than did saturated fat.
Research teams in New York and Finland found much the same thing. “Bad fats” that had already been known to increase the risk of heart problems appeared to be linked to Alzheimer’s disease too. They also played a role in a condition called mild cognitive impairment, which applies to a person whose day-to-day life is more or less normal but whose memory has slipped a notch or two. Researchers with Finland’s Cardiovascular Risk Factors, Aging and Dementia study found that a high intake of saturated fat more than doubled the risk of mild cognitive impairment. Among people with the APOE epsilon 4 allele, a fatty diet increased the risk five-fold.
What Is Fat Doing to Your Brain?
How does this happen? For starters, “bad fats” tend to increase your cholesterol levels. And that can spell blocked arteries, slowing the flow of blood and oxygen to the brain. Indeed, California researchers following a group of 9,844 people for three decades found that cholesterol levels measured in a person’s 40s predicted Alzheimer’s risk in their 70s.
High cholesterol levels don’t just block arteries. They also appear to encourage the formation of microscopic collections of protein and cholesterol in the brain—called beta-amyloid plaques—that are the hallmarks of Alzheimer’s. Looking like tiny meatballs through a microscope, these plaques are believed to damage brain cells.
The take-home message is clear enough. It pays to minimize the saturated fats that are abundant in animal products and scarce in typical grains, beans, vegetables, and fruits, and to steer clear of the trans fats in highly processed snack foods—you’ll see them on labels listed as partially hydrogenated oil.
Bad fats are not the only problem. As researchers examine plaques, they find more than just beta-amyloid protein. They have also found certain metals. Iron, for starters. Yes, your body needs iron. It is a key part of the hemoglobin that your red blood cells use to carry oxygen in your blood stream. But excess iron is hazardous. In the same way that a cast-iron pan rusts—that is, oxidizes—iron can oxidize in your body. In the process, it encourages the production of free radicals—unstable molecules that attack your cell membranes, your DNA, and even your brain connections.
So when it comes to brain health, iron is a balancing act. You want to get enough so that your red blood cells can carry oxygen. But you want to avoid excesses that can harm your brain. In a study published in 2011, Chicago researchers found what might be the iron sweet spot: People most likely to preserve their mental functioning had hemoglobin levels just below 14 grams per deciliter. People who were much lower or much higher tended to lose brain function as the years passed.
Which foods will get you there? The best choices are our neglected friends, beans and green leafy vegetables. They have a special form of iron called non-heme iron, which is more absorbable when your body needs iron and less absorbable when your body has enough already. The worst choice: red meat. Long revered as a source of iron, we now know that it can have too much of a good thing. The iron in meat, called heme iron, is highly absorbable whether you need it or not. Cast-iron pans can add unneeded iron too.
“Bad fats” appeared to be linked to Alzheimer’s disease. They also played a role in a condition called mild cognitive impairment, which applies to a person whose day-to-day life is more or less normal but whose memory has slipped a notch or two.
Speaking of metals, you also need a certain amount of copper in your diet—not quite 1 milligram daily—to keep various metabolic enzymes running properly. Three servings of vegetables get you the copper you need. But some people unknowingly get a lot more than that. It can come from copper pipes, and it’s packed into most multiple vitamins (although it is possible to find vitamin formulations without added copper).
Studies in Rome and in San Diego examined older people whose memory function was generally in the normal range. In both studies, people with higher levels of copper in their blood had more trouble on memory and cognition tests. In the Chicago Health and Aging Project, researchers zeroed in on people whose diets were on the fatty side—a diet pattern we now know to be linked to Alzheimer’s. Copper made everything worse. Those who got more copper in their diets tended to have exaggerated memory problems as the years went along.
Researchers are also debating the role of aluminum in memory problems. Some view it as a contributor to dementia; others don’t. While they are fighting it out, I suggest a cautious approach: avoid uncoated aluminum cookware, and check the labels on antacids, baking powder, frozen foods, and antiperspirants, some of which contain aluminum. Some municipalities have aluminum in tap water. If you’re unsure, bottled water or a reverse osmosis filter (the greener option) are good bets.
Iron, copper, and aluminum end up in the beta-amyloid plaques in the brain, so you’ll want to protect yourself. Beans, greens, fruits, and grains give you the iron and copper you need, without the risk of overdoing it. If you take a multivitamin, it’s best to choose one that’s iron-free, unless you’ve been diagnosed as iron-deficient and advised by a caregiver to take supplemental iron. However, I would go a step further. Because typical multivitamins contain copper, and most everyone gets more than enough copper from foods, it’s best to choose a multi that is labeled as “vitamins only.” It takes a little label-reading, but they are available.
If iron and copper encourage the formation of free radicals—malicious molecules that are like sparks burning holes in your brain cells—vitamin E is your fire extinguisher. It is a powerful antioxidant—it neutralizes free radicals. You’ll find it in spinach, mangoes, and sweet potatoes, and in much larger amounts in nuts and seeds.
It makes a real difference. In the Chicago study, people who ate these vitamin E–rich foods had less than half the Alzheimer’s risk, compared with people who were missing vitamin E. The amount that made a difference was 8 milligrams per day—which you’ll find in just 1 1/2 ounces of almonds.
Vitamin E should come from foods, rather than supplements. Typical supplements lack the full range of vitamin E forms available in foods.
Vitamin E isn’t the only micronutrient that has brain researchers smiling. At the University of Oxford, investigators found that a trio of B vitamins—folate, B6, and B12—helped people preserve their memories and even slowed brain shrinkage.
Related: How Vegetarians Can Get Enough Vitamin B12
The vitamins apparently work by knocking out a toxic chemical called homocysteine that can damage the heart and the brain. Your doctor can check your homocysteine level, and if it is high, these vitamins can reduce it.
Even if your homocysteine level is normal, you don’t want to miss these B vitamins. You’ll find folate in green leafy vegetables, and vitamin B6 in foods such as chickpeas, bananas, and potatoes. Vitamin B12 is supplemented in breakfast cereals and soymilk. It is also in vitamin supplements.
Grape Juice and Blueberry Juice
Several studies have shown that red wine, consumed in modest amounts, helps protect the brain. So a group of researchers at the University of Cincinnati asked the logical question: What if the benefit comes, not from alcohol, but from the grapes themselves? In a small study of people averaging 78 years of age, everyone drank two cups of Concord grape juice each day. Within a few weeks, the participants’ ability to learn and recall improved measurably. The researchers found much the same result with blueberry juice.
Neither study was very large. But they do suggest that anthocyanins, the dark pigments in these fruits, appear to have protective effects.
Your Brain Health Checklist
The processes that can lead to memory lapses over the short term and more serious problems over the long term could be at work in your brain now. Take action today to protect yourself.
- Avoid “bad fats.”
- Limit exposure to iron, copper, and aluminum.
- Eat plenty of vegetables, fruits, beans, and whole grains.
- Occasionally eat nuts and seeds for vitamin E.
- Be sure to have a reliable source of vitamin B12, such as fortified foods or a supplement.
- Get at least 40 minutes of vigorous physical activity three times per week.
- Get plenty of sleep.