On Nutrition

I don’t know about you, but when I think of Alzheimer’s disease, what strikes fear in my heart is the idea of losing my memories and my independence. It’s easy to forget that Alzheimer’s is also the fifth-leading cause of disease-related death in the United States. Currently, 6.2 million people in the U.S. have Alzheimer’s disease, with someone new diagnosed every 64 seconds — and those numbers are growing.

Dr. Ayesha Sherzai, neurologist and co-director of the Brain Health and Alzheimer’s Prevention Program at Loma Linda University, called these numbers a “tsunami” when she spoke at the annual conference of the Academy of Nutrition and Dietetics last month. She said current numbers may be underestimated because of the false assumption that cognitive impairment and memory problems are a normal part of aging.

“Typically, as we age, we all lose some of our mental sharpness, but that decline is very minimal,” said Dr. Christy Tangney, professor of clinical nutrition and preventive medicine at Rush University Medical Center, who also spoke at the conference. “When we move into mild cognitive impairment, we are really starting to lose certain capabilities to function in our environment.” As this cognitive impairment gets progressively worse, it can become Alzheimer’s.

According to the Alzheimer’s Association, at age 65, women are more likely than men to develop Alzheimer’s in their lifetimes. It’s unclear why women have higher risk, but Sherzai said higher rates of atherosclerosis (buildup of plaque in the arteries) among women, changing hormone levels after menopause, and a variety of social factors — including stress — may play roles.

Genetics matter, to a point

While several genes can increase Alzheimer’s risk, that’s not the main driver. “We always say that genes don’t determine destiny, they give us essentially a range of when the disease can manifest itself,” Sherzai said. She said adopting habits that reduce or manage cardiovascular risk factors can affect whether these genes become activated or not.

In fact, newer research is pointing to prevention as the new treatment. In 2019, the big news was that lifestyle factors are the best — and only — bet for reducing Alzheimer’s risk at this time. “For the first time, there was hope,” Sherzai said. “Until then, for decades and decades we were only looking at medication for treatment and management of this devastating disease.” She said when we eventually have medications for Alzheimer’s, it probably won’t be one medication, but instead a combination of different treatments.

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Sherzai said research is clear that people who have genetic risk of developing Alzheimer’s have a much higher risk if they also have an unhealthy lifestyle, but that they can potentially cut their risk in half with a healthy lifestyle. And a healthy lifestyle isn’t an all-or-nothing venture — she said having two or three healthy lifestyle habits reduces risk, while having four or five healthy habits reduces risk even further. These habits have the handy — and appropriate — acronym NEURO (Nutrition, Exercise, Unwind, Restorative sleep, Optimize mental and social activity).

Exercise includes both aerobic and leg-strengthening exercises, as well as simply moving throughout the day. And that restorative sleep? “It’s not the type of sleep where people take a sleeping pill, but the kind of sleep that allows us to go through the deeper stages of sleep that allows for the brain to cleanse itself and for the memories to get consolidated,” Sherzai said.

Feeding a healthy brain

For nutrition, research points to the MIND diet, which takes the best of the Mediterranean and the DASH (Dietary Approaches to Stop Hypertension) diets and optimizes them for brain health. The MIND diet is based on nine foods to eat regularly, and five foods to limit.

Nine foods to eat

  • Leafy, dark green vegetables: At least one serving per day (1 cup raw or 1⁄2 cup cooked) of spinach, kale, collards, Swiss chard, mustard greens, turnip greens, dandelion greens, arugula, endive or romaine lettuce.
  • Other vegetables: At least one serving per day (1⁄2 cup).
  • Nuts: Five servings per week (1 ounce each) of nuts or nut butter.
  • Berries: At least five servings per week (1⁄2 cup each) of blueberries, strawberries, raspberries or blackberries.
  • Beans and legumes: At least three servings per week (1⁄2 cup each) of beans, chickpeas, lentils, hummus or soy (tofu, edamame or soy yogurt).
  • Whole grains: Three servings per day (1⁄2 cup or 1 slice each) of dark or whole grain bread, brown rice, whole grain pasta, wild rice, quinoa, barley, bulgur, farro, oats or whole grain cereal.
  • Fish: At least one serving per week (3 to 5 ounces), not fried. Good choices include salmon, tuna, tilapia, cod, mahi mahi and halibut.
  • Poultry: At least two servings per week (3 to 5 ounces each) of skinless chicken or turkey breast.
  • Extra-virgin olive oil: 2 tablespoons per day.

Five foods to limit

  • Red meat and processed meat: No more than three servings per week (3 to 5 ounces each) of beef, lamb, pork, ham, hamburger, hot dogs, sausages, bacon, roast beef or salami.
  • Butter and stick margarine: Less than 1 teaspoon per day. Smart Balance and Earth Balance are exceptions.
  • Regular (full-fat) cheese: No more than 2 ounces per week.
  • Pastries and other sweets. No more than four per week.
  • Fried and fast foods. No more than one meal per week from fast-food or fast-casual restaurants, or one serving of any fried food.

Tangney points to a 2015 MIND diet study among participants ages 58-98, 75% of whom were women. She said that while participants who followed MIND very closely had the best protection from cognitive decline, people who followed the diet “moderately well” still saw some slowed decline. She said this is unique from similar studies focusing on the Mediterranean or the DASH diets, in which only those who followed the diets closely saw improvement. “This is offering great hope for people, because they don’t have to be perfect eaters,” she said.