What to Eat to Fend Off Alzheimer's by Annie Fenn, MD
Updated: Nov 14, 2019
I first suspected my mother’s dementia when she got lost driving to the mall in the city where she’s lived for 30 years. Then I took notice of other behavioral changes: rapidly forgetting things, retelling stories over and over, confusion over her medications and difficulty managing her personal finances. When I took her to see a cognitive health specialist, I was shocked to learn that she did not know the year, thought George W. Bush was still president and could not correctly draw the hands on a clock.
Like many women, my mom was able to hide her cognitive deficits from her adult children until they became glaringly obvious. (Women are less likely than men to be diagnosed in the early stages of dementia by standard testing, possibly because of their advanced verbal skills.) Once I realized that she had mild cognitive impairment, the first stage of Alzheimer’s, I was able to work with her doctor to try to slow down the deterioration of her memory, and her brain. The most promising intervention we have is changing the way she eats.
Preventing Alzheimer’s Just a few years ago, this idea seemed far-fetched. We used to think that Alzheimer’s just happened to the brains of people when they got old. Now we know that this type of dementia is a process that begins at mid-life. It takes decades of insults to the brain—through deposition of toxic proteins and exposure to oxidative stress—to reach a tipping point of impaired cognitive function.
It may be disheartening to learn that our brains are continuously accumulating the plaques and tangled proteins that lead to Alzheimer’s later in life. But there’s a flip side. Our lifestyle habits can have a positive impact on brain aging, too. There is solid scientific data to support that managing stress, getting good-quality sleep, exercising, keeping our brains active and eating a brain-healthy diet can all slow down the rate of cognitive decline as we age. Some experts believe we have the power to reduce 90% of all Alzheimer’s cases by addressing modifiable risk factors. The most conservative estimates, such as those by the Lancet Commission, determined we could eliminate at least 35% of the world’s Alzheimer’s burden by paying attention to these factors.
The case for preventing Alzheimer’s with food is far stronger if the modifications are started early, before the brain spirals into decline. Certain dietary patterns have been shown to accelerate brain aging. (Hello Standard American Diet!) And others, like the Mediterranean and MIND diets, have been proven to slow decline. That’s why I founded Brain Health Kitchen, a cooking school that teaches people how to cook and eat with the most neuroprotective foods.
Fending off cognitive decline and slashing Alzheimer’s risk is important for everyone, not just those of us with a family history of the disease. As our population ages, experts are predicting an epidemic of Alzheimer’s in the coming decades.
If you are a woman, your risk is even greater:
Two-thirds of all Alzheimer’s victims are female.
At the age of 65, a woman’s lifetime risk of Alzheimer’s (1 in 5) is greater than a man’s (1 in 11) and far surpasses her risk of breast cancer (1 in 29).
So, what should we eat to keep our memories strong and our brains healthy? The Mediterranean diet and its close cousin the MIND diet have the best scientific data to show they significantly reduce Alzheimer’s risk. MIND stands for the Mediterranean-DASH Intervention for Neurodegenerative Delay. It’s a combination of the Mediterranean and DASH (for high blood pressure) diets, tweaked to be more specifically healthy for the brain.
In a population of healthy, dementia-free people between the ages of 45 and 85, those who followed the MIND diet most closely reduced their Alzheimer’s risk by 53% after just four and a half years. And those who followed the diet sometimes (because, let’s face it, most people cheat on diets) had 37% less Alzheimer’s risk.
Put another way, those who followed the MIND diet most closely reduced the rate at which their brains aged by seven and a half years! No drug, supplement or lifestyle intervention has ever been proven to slow down brain aging to the degree of the MIND diet.
The premise of the MIND diet is simple: Eat more brain-healthy foods. Eat fewer brain-unhealthy foods. First, let’s take a look at the MIND diet’s 10 brain-healthy food groups.
1. Berries: Two or more half-cup servings each week. All purple/red, blue and black berries possess potent brain-friendly antioxidants. Before the MIND diet study was published, researchers had already determined that healthy elderly women who ate at least two servings of berries a week had better memories than those who ate berries only a few times a month. Just eating berries delayed cognitive aging by two and a half years!
2. Leafy Green Vegetables: Six or more servings each week. Leafy greens are their own food group here, separate from other vegetables, and that’s because they are the most important of all the veggies to protect the brain from cognitive decline. Besides being a food group in the MIND diet, another study showed that eating leafy greens delayed cognitive aging by 11 years. Many of the brain-boosting phytonutrients in leafy greens are fat soluble and are best absorbed in the presence of healthy fats. (See #10.) Shoot for one cup raw or ½ cup cooked leafy greens each day.
3. Other Vegetables: One or more servings each day. Certain vegetables possess more cognitive-enhancing nutrients than others. Cruciferous veggies —broccoli, bok choy, Brussels sprouts, cabbage and cauliflower—are top choices for brain health. Colorful veggies—purple carrots, beets, eggplant, sweet peppers—are packed with plant pigments that double as antioxidant powerhouses. And mushrooms, although technically fungi, are brain health superstars. Eating two servings of mushrooms each week, in a recent study, was associated with lower dementia rates in healthy seniors in Singapore. Shoot for one cup raw or ½ cup cooked servings of vegetables each day.
4. Whole Grains: Three half-cup servings each day. Think grains are bad for the brain? That’s not what the data supports. But there’s an important distinction here between whole grains and processed ones. Processed grains are industrially treated to be shelf stable, which strips them of any nutritional value. With a high glycemic index, the body metabolizes them just like sugar. (Ninety-eight percent of the grain in Americans’ diets is from all-purpose white flour.) Whole grains (oats, brown rice, farro, spelt, etc.), however, are rich in brain-healthy minerals and B vitamins. They are an important source of fiber and vitamin E and they are proven to protect from cardiovascular diseases, a major risk factor for Alzheimer’s.
5. Nuts: More than five one-ounce servings each week. The most brain-healthy nuts are high in monounsaturated fats and vitamins E and B: almonds, cashews, walnuts, Brazil nuts, pecans and pistachios. Look for raw (not roasted), unsalted nuts. Toast and season them yourself for snacking and keep your portion size to one small handful.
6. Fish and Seafood: At least one serving each week. The MIND diet was associated with 53% less Alzheimer’s with just one fish meal a week, far less than what has been recommended by the Mediterranean diet. If you have access to high-quality seafood, feel free to eat more; fish is an excellent source of lean protein and omega-3 fatty acids. Look for wild-caught salmon from Alaska, scallops, shrimp, tuna (fresh ahi or light canned tuna), squid, oysters, lake trout and mackerel. Sardines and anchovies are especially high in omega-3s. Avoid marlin, shark, swordfish, tilefish, bluefin tuna and orange roughy due to high levels of mercury exposure. And be sure to avoid fried fish—high-heat cooking methods destroy the brain-friendly nutrients and fats. (I’ll discuss cooking methods in more detail in a future newsletter.)
7. Poultry: Up to four servings each week. Limit your serving size to three to five ounces. A diet with moderate poultry intake is proven to reduce cardiovascular and Alzheimer’s disease. As with fish, poultry cooking methods are key: avoid high heat (especially frying) and remove the skin to reduce saturated fat content. There’s no study that looks at the quality of poultry and Alzheimer’s risk. But I recommend seeking out natural poultry, free of antibiotics and hormones, that is raised on a farm not in a factory.
8. Beans: More than three half-cup servings each week. Legumes—beans, split peas and lentils—are a staple in every diet that is associated with dementia-free longevity. The most nutrient-dense legumes include black beans, chickpeas, white beans, edamame, lentils and lima beans.
9. Red Wine: One five-ounce serving per day. Wine lovers: Before we get too excited that red wine is considered a food group in the MIND diet, there are some key points. First, the portion size here is very small—smaller than the typical restaurant pour. Second, the MIND diet included red wine specifically because it’s an important part of the Mediterranean diet. But no study has shown that drinking red wine, or any alcohol, provides brain benefits above this minimal level. In fact, the MIND diet researchers decided to drop red wine as a brain-healthy food group in its current study, a randomized trial of the MIND diet due for completion in 2021.
10. Olive Oil: Use as your primary cooking oil. Extra virgin olive oil is thought to have protective effects against dementia by providing a high ratio of unsaturated fats to saturated ones, along with polyphenols with anti-inflammatory and antioxidant properties. For everyday cooking, choose a good-quality olive oil with a harvest date printed on the label. Store in a cool place away from sunlight. Be sure not to heat above its smoke point (the temperature where a continuous bluish smoke appears when an oil or fat is burned). For olive oil, that temperature ranges between 325 and 470 F, depending on the type. In general, avoid heating high-quality olive oil; drizzle on finished dishes instead.
Next week, I’ll share which foods you should avoid: the five brain-unhealthy food groups from the MIND diet study. Until then, let’s see how many brain-healthy foods you can pack into your diet this week.
Morris et al, Alzheimer’s and Dementia, Sept 2015. MIND diet associated with reduced incidence of Alzheimer’s disease.
Scarmeas et al, Annals of Neurology, Jun 2006. Mediterranean diet and risk for Alzheimer’s disease.
Alzheimer’s Association. Alzheimer’s Disease 2018 Facts and Figures.
Morris et al, Alzheimer’s and Dementia, Sept 2015. MIND diet slows cognitive decline with aging.
Devore et al, Annals of Neurology, Apr 2012. Dietary intakes of berries and flavonoids in relation to cognitive decline.
Morris et al, Neurology, Jan 2018. Nutrients and bioactives in leafy green vegetables and cognitive decline: A prospective study.
Feng et al, Journal of Alzheimer's Disease, 2019; The Association between Mushroom Consumption and Mild Cognitive Impairment: A Community-Based Cross-Sectional Study in Singapore.
How the evidence stacks up for preventing Alzheimer’s disease. Nature, July 25, 2018.
Hosking et al, Alzheimers and Dementia, 2019; MIND not Mediterranean diet related to 12-year incidence of cognitive impairment in an Australian longitudinal cohort study.
Mosconi et al, British Medical Journal, March 2018. Lifestyle and vascular risk effects on MRI-based biomarkers of Alzheimer’s disease: a cross-sectional study of middle-aged adults from the broader New York City area.
Monterey Bay Aquarium Seafood Watch. Check their website for the latest information on purchasing sustainable seafood with the least environmental toxin exposure.
Annie Fenn, MD
Annie Fenn is a board-certified physician, culinary instructor and trained chef. She practiced obstetrics and gynecology with a specialty in menopausal health for over 20 years in Jackson, Wyoming, where she lives. Dr. Fenn switched gears in 2010 to practice medicine from a different angle—teaching her patients how to eat and cook with whole foods. After attending culinary school in Italy, Mexico and the Culinary Institute of America, she taught dozens of cooking classes in her community and wrote about food, health and sustainability for numerous media outlets. In 2017, she launched Brain Health Kitchen, the only cooking school of its kind to focus exclusively on preventing Alzheimer’s and dementia. Dr. Fenn teaches cooking and gives talks throughout the U.S. and abroad about how to cook and eat to reduce Alzheimer’s risk. Along with a team of cognitive health specialists, she offers four Brain Works Boot Camps in Jackson Hole each year—seven-day immersion experiences in cutting-edge Alzheimer’s prevention. She creates recipes based on scientific data from the Mediterranean diet, the MIND diet, the study of Blue Zones centenarians and the large body of data about how lifestyle factors impact Alzheimer’s risk. She loves showing people how easy and delicious it can be to cook for brain health.
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