21 Foods that Fight Disease

Ward off disease and ailments with these nutrient packed foods.

By: Leslie Beck, R.D.


July/August 2017

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Healthy fats such as avocados and nuts can help prevent alzheimer's disease.

Photo by StephanieFrey; iStock

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Double up on these 21 amazing foods packed with the types of nutrients that may help ward off some of the world’s most common and harmful chronic diseases

Since ancient times, humans have understood the connection between eating well and being healthy. Today, overwhelming evidence supports our innate understanding that when it comes to longevity, eating a healthy diet that includes plenty of nutrient-packed plant foods and minimizes processed foods high in trans fats, added sugars and sodium is what counts. Of course, when it comes to health, there are no silver bullets. No single food will prevent chronic disease. Yet, study after study confirms the healthful properties of foods found in nature. Getting more of our calories from these foods can help us live longer lives, feel better and look better, too. When it comes to living healthfully and eating to reduce risk of chronic illness, the following foods deserve a regular spot on your menu.

Breast Cancer

Breast cancer is the most commonly diagnosed cancer in women, and one in eight U.S. women will be diagnosed in her lifetime. The good news is that breast cancer incidence rates among women older than 50 have been on a slow decline, possibly related to the decline in prescriptive hormone replacement therapy after menopause, which can increase breast cancer risk. What’s more, death rates from breast cancer have been on the decline since the 1990s, likely due to a combination of better screening, early detection and improved treatment options. Although genetics play a role in our risk of breast cancer, lifestyle factors may also increase risk. These include a lack of physical activity; being overweight or obese; alcohol consumption; and eating a poor diet lacking in fruits and vegetables. When it comes to the last one, consider the foods that follow among your best dietary allies to help reduce your risk.

Blackberries: Increasing fiber intake is a smart strategy to help guard against breast cancer, and blackberries serve up 8 grams a cup. A large 2016 study revealed that women who consumed the most fiber (versus the least) as teens and young adults had significantly lower future risk of developing breast cancer. Plant fiber was especially beneficial.

A high-fiber diet helps lower circulating levels of estrogen; extended exposure to estrogen is thought to increase breast cancer risk. Fiber also helps control blood sugar, insulin and insulin-like growth factors, which may be implicated in breast cancer.

Also Eat: Raspberries, kiwifruit, green peas, beans and lentils, sweet potato, bran cereals, whole grains.

Edamame: These fresh green soybeans are packed with isoflavones, phytochemicals linked with a lower risk of breast cancer recurrence and improved survival after breast cancer.

Studies conducted in breast cancer patients and survivors suggest that soy’s protective effect is most apparent for women with aggressive forms of breast cancer that can’t be treated with hormones. Found in grocery store freezers, edamame also delivers plant protein, fiber and a decent amount of calcium, magnesium and potassium

Add shelled edamame to a stir-fry or soup near the end of cooking. Toss them into salads or grain bowls. Or, steam or boil edamame in their pods and enjoy as a snack.

Also Eat: Soy flour, soy nuts, soy milk, tempeh, tofu

Broccoli: Growing evidence suggests that eating vegetables guards against breast cancer, especially aggressive hormone-receptor negative breast cancers.

It’s possible that antioxidants such as vitamins C and E, folate, phytochemicals and fiber in vegetables have a synergistic effect when it comes to protecting against breast cancer.

While all types of vegetables are beneficial, cruciferous veggies, such as broccoli, also supply anti-cancer isothiocyanates, phytochemicals that fend off harmful free radicals, quell inflammation and help the liver eliminate carcinogens.

Add chopped broccoli to stir-fries, omelets and frittatas. Top a baked potato or pizza with broccoli florets. Or, serve it roasted or steamed as a side dish.

Also Eat: Bok choy, Brussels sprouts, cabbage, cauliflower, kale, turnip

Flaxseed: These seeds are a rich source of lignans, phytochemicals that appear to alter estrogen metabolism in ways that may guard against breast cancer. Short-term studies in women have demonstrated that consuming one to two tablespoons of flaxseed daily significantly lowered circulating estrogen levels.

Flaxseeds also serve up fiber and more than a day’s worth of alpha linolenic acid, an anti-inflammatory omega-3 fatty acid.

To get their benefits, flaxseeds must be ground; whole flaxseeds pass through our digestive tracts undigested.

Blend ground flaxseeds into smoothies and muffin batters. Sprinkle them over salads, hot cereal and yogurt. Or, mix ground flax into mashed avocado for a healthy sandwich spread.


Alzheimer’s Disease

Deaths from Alzheimer’s disease have increased by 89 percent since 2000. Alzheimer’s disease is the sixth leading cause of death in the United States, and one in 10 people age 65 and older is living with Alzheimer’s dementia. As with so many diseases, the most promising research-backed prevention methods focus on diet and exercise. Several conditions known to increase risk of cardiovascular disease, including high blood pressure and diabetes, also increase risk of developing Alzheimer’s disease, and autopsies show as many as 80 percent of those who die of Alzheimer’s also have cardiovascular disease. Research suggests heart-healthy eating habits — more fruits, vegetables and whole grains, and less sugar and unhealthy fats — may reduce risk. Within that framework, consider putting these anti-Alzheimer’s heavy hitters into regular rotation at your dinner table.

Strawberries: The MIND diet, developed by researchers from Rush University Medical Center in Chicago, is an eating pattern found to significantly reduce the risk of developing Alzheimer’s disease. It advises eating berries, including strawberries, at least twice a week.

Berries are rich in polyphenols, phytochemicals that protect brain cells by fighting free radical damage, reducing inflammation and removing toxic proteins that accumulate as we age.

All berries are packed with polyphenols, but research suggests strawberries and blueberries are most potent for brain health.

Also Eat: Acai berries, blackberries, blueberries, cherries, cranberries, plums, pomegranate seeds, prunes, grapes

Avocado: One medium avocado delivers 30 grams of fat, two-thirds of it monounsaturated, the type that helps reduce inflammation and is thought to improve brain function.

A study published in the Annals of Neurology found that, among 6,183 women aged 65 and older, those who consumed the most monounsaturated fat had better cognitive scores than women who consumed more of their fat as saturated fat.

One avocado also delivers 40 percent of a day’s recommended dose of folate, a B vitamin that’s crucial for proper brain function and may play a role in guarding against Alzheimer’s disease.

Also Eat: Olive oil, olives, peanut butter, peanuts, almond butter, cashews, cashew butter, pecans and pistachios

Romaine Lettuce: Eating plenty of leafy green vegetables, especially salad greens, has been linked with a slower rate of cognitive decline in older adults. The brain-healthy MIND diet recommends eating leafy green vegetables six times a week (a serving is 1/2 cup cooked or 1 cup raw).

Leafy greens are excellent sources of vitamin K, folate, beta-carotene and lutein, nutrients thought to help preserve brain functioning. (Note: You’ll get more beta-carotene and lutein if you eat greens cooked rather than raw.)

Romaine, green leaf, butterhead (also called Boston or bibb) and red leaf lettuces have more vitamins, minerals and antioxidants than iceberg lettuce.

Also Eat: Arugula, beet greens, collard greens, dandelion, kale, mustard greens, leaf lettuce, rapini, spinach, Swiss chard, turnip greens and watercress

Grapeseed Oil: This healthy cooking oil is an excellent source of vitamin E, an antioxidant that protects brain cells from damage caused by free radicals. Evidence suggests that adults who have higher intakes of vitamin E from foods have a lower risk of Alzheimer’s disease.

One tablespoon of grapeseed oil supplies 6 international units (IU) of vitamin E, almost one-third of a day’s worth for adults. That’s impressive. Grapeseed oil also has a moderately high smoke point, making it well-suited for high-heat cooking.

Also Eat: Almonds, hazelnuts, avocado oil, wheat germ oil, sunflower oil, safflower oil, peanut butter, frozen spinach


Type 2 Diabetes

The most common form of diabetes, type 2 diabetes occurs when the body does not use insulin properly, which is known as insulin resistance. Type 2 diabetes is increasing in prevalence; 29.1 million people in the U.S. have the disease, and another 8.1 million may be undiagnosed. What’s more, research suggests one in three adults has prediabetes, and that nine of 10 of these people are unaware they have it. Type 2 diabetes is largely preventable and sometimes manageable with lifestyle changes, including maintaining a healthy weight, getting regular exercise and eating well. If you’re working to ward off diabetes, eliminate prediabetes or manage diagnosed type 2 diabetes, focus on adding the foods that follow to your meals.

Hemp Seeds: Three tablespoons of these nutritious seeds deliver 210 milligrams of magnesium, two-thirds of a day’s worth for women and half a day’s worth for men. Magnesium, a mineral many Americans don’t get enough of, is required for proper release of insulin, the hormone that removes glucose (sugar) from the bloodstream.

Getting too little magnesium can cause insulin resistance, a precursor for type 2 diabetes. With insulin resistance, the body’s cells don’t respond properly to insulin and, as a result, can’t easily absorb glucose from the bloodstream.

A 2016 review of 40 studies conducted in countries including the United States, the United Kingdom, Australia, China and Japan revealed that people who consumed the most — versus the least — magnesium from foods had a significantly lower risk of type 2 diabetes. A high-magnesium diet has also been found to cut the risk of pre-diabetes progressing to type 2 diabetes.

Also Eat: Pumpkin seeds, almonds, cashews, walnuts, sunflower seeds, Swiss chard, black beans, teff and acorn squash

Sweet Potato: Thanks to its low glycemic index value, eating this nutrient-rich potato helps slow the rise in blood sugar after eating. That’s a good thing, as carbohydrate foods that score high on the glycemic index scale — such as white bread, white rice, sugar and some varieties of white potato — are broken down and absorbed quickly, causing blood sugar and insulin to rise quickly. A diet based on high-glycemic foods is thought to contribute to insulin resistance, a precursor to type 2 diabetes.

• Also Eat: Steel-cut/large-flake oats, brown rice, wild rice, quinoa, whole-grain rye bread, beans, lentils, apples, berries, oranges, pears

Walnuts: Unlike other nuts, walnuts contain alpha linolenic acid (ALA), a plant-based omega-3 acid that helps improve how the body uses insulin. A 2011 study published in The American Journal of Clinical Nutrition, conducted among 44,000 adults, concluded that higher ALA intake was strongly protective from diabetes.

Bonus: Walnuts also provide heart-healthy unsaturated fats and a decent amount of magnesium.

• Also Eat: Chia seeds, flax seeds, hemp seeds, walnut oil and soybeans

Coffee: Numerous published studies have revealed that drinking coffee — as much as four to six cups a day — reduces the risk of developing type 2 diabetes.

Antioxidants found naturally in caffeinated and decaffeinated coffee are thought to dampen inflammation in the body and improve how the body uses insulin. Coffee also contains magnesium and chromium, minerals linked to blood sugar regulation.

Not everyone should start drinking coffee, though. If you are pregnant, experience insomnia or have osteoporosis, it’s important to limit caffeine intake. And if you suffer from gastroesophageal reflux disease (GERD), coffee with and without caffeine can trigger symptoms.


High Blood Pressure

High blood pressure affects about 75 million Americans — nearly one in three has high blood pressure, while another one in three has prehypertension (higher than normal blood pressure). High blood pressure can increase risk for several dangerous health conditions including heart attack, stroke, chronic heart failure and kidney disease. Ways to reduce risk include not smoking, getting adequate physical activity, maintaining a healthy weight, and not drinking too much alcohol. Of course, eating a healthful diet also plays a role. The foods below are especially equipped to help maintain healthy blood pressure levels and reduce your risk of other serious disease.

Cantaloupe: This tasty fruit is packed with potassium, a mineral that relaxes blood vessel walls and helps the kidneys excrete excess sodium. Most North Americans get only half the daily recommended 4,700 mg of potassium. One cup of cantaloupe supplies 427 mg, the same as a medium banana. Its high water content makes cantaloupe low in calories (54 calories a cup), making it a good choice if you’re trying to lose weight to lower blood pressure.

Top fish and shrimp tacos with salsa made of diced cantaloupe, minced onion and cilantro. Try a fruit pizza made with slices of cantaloupe, ricotta cheese, toasted pine nuts and baby arugula. Or, enjoy half a cantaloupe filled with a big spoonful of Greek yogurt.

• Also Eat: Bananas, apricots, prune juice, honeydew, spinach, Swiss chard, lentils, kidney beans, milk, yogurt

Black Beans: Beans are an important part of the DASH diet, an eating plan scientifically proven to lower elevated blood pressure. That’s because they offer magnesium, potassium, calcium and fiber, nutrients linked with lower blood pressure. While all beans are exceptional sources of magnesium, black beans have the most. A cup serves up 120 mg, 35 percent of a day’s worth for women and 29 percent for men.

The DASH diet suggests four or five servings of beans a week. Add black beans to tacos, chili and nachos. Throw them into green salads or toss them with cooked shrimp, avocado and lime juice. Spread black bean “hummus” in wraps or serve it as a vegetable dip.

• Also Eat: Beans including adzuki, cannellini, kidney, navy, pinto and lima; chickpeas, lentils, split peas

Yogurt: Calcium-rich foods such as yogurt are a vital component of the DASH diet. In one trial, researchers found that adding dairy products to a diet rich in produce enhanced the blood-pressure-lowering effect. While the DASH diet recommends low-fat dairy, a study on a variation that included full-fat dairy found it yielded the same blood pressure- and LDL-lowering effects, and also modestly reduced triglycerides (the higher fat consumption group reduced sugar intake to balance the increased calories).

Calcium helps blood vessels constrict and relax properly. Adults aged 19 to 50 need 1,000 mg of calcium a day; older women and men over 70 require 1,200 mg.

A cup of plain yogurt delivers 448 mg of calcium, 573 mg of potassium and 42 mg of magnesium.

Also Eat: Milk, kefir and high-quality cheese

Beets: Crimson-hued beet roots are one of the top plant sources of nitrates, compounds that may help keep blood pressure in check. A 2013 meta-analysis of randomized, placebo-controlled clinical trials published in The Journal of Nutrition found beetroot juice supplementation was associated with a significant reduction in systolic blood pressure. Beets also provide potassium — 518 mg per cooked cup.

Puree chopped, pre-cooked beets into a fruit or green smoothie. Serve sliced roasted or grilled beets over a bed of greens with orange slices and toasted walnuts. Or, enjoy a bowl of borscht, a traditional Russian soup made with beets.

• Also Eat: Lettuce, carrots, green beans, spinach, parsley, cabbage, radishes, celery, collard greens


Coronary Heart Disease

Heart disease remains the No. 1 killer in the United States for both men and women — one in every four deaths is attributable to heart disease. Coronary heart disease is the most common type of heart disease and kills more than 370,000 people each year. Three key risk factors for heart disease include high blood pressure, high LDL cholesterol and smoking, and about half of Americans have at least one of these risk factors. Other medical conditions and lifestyle choices that increase risk of heart disease include having diabetes, being overweight or obese, physical inactivity and excessive alcohol use. A poor diet is also a risk factor. These foods are particularly beneficial for heart health.

Cashews: Eating nuts regularly can help lower LDL (bad) cholesterol, reduce blood pressure and guard against type 2 diabetes, all risk factors for heart disease. In 2016, a review of studies involving more than 800,000 participants concluded that, compared with people who didn’t eat nuts, those who ate one serving a day cut their risk of coronary heart disease by nearly 30 percent.

Nuts are an excellent source of heart-healthy polyunsaturated and monounsaturated fats. Cashews, though, contain mainly monounsaturated fat, the type tied to lowering blood cholesterol and benefitting insulin and blood sugar levels. One downside: Thanks to their high fat content, eating more than a handful of cashews each day could lead to weight gain. Limit portion sizes to 18 cashews (1 ounce). Substitute nuts for less-healthy foods such as processed foods.

• Also Eat: Avocado, hazelnuts, almonds, almond butter, pecans, cashews, peanuts, peanut butter, olives, olive oil

Salmon: Gram for gram, salmon delivers more beneficial omega-3 fatty acids than most fish. The two omega-3 fatty acids in salmon — DHA and EPA — are tied to a lower risk of coronary heart disease, heart attack and cardiovascular death. DHA and EPA help slow the growth of fatty plaques on artery walls; reduce blood clotting; dampen inflammation and (modestly) lower blood pressure.

To guard against heart disease, healthy adults should consume at least 500 mg of DHA and EPA a day, equivalent to two three-ounce servings of salmon each week. (Omega-3s store in the body, so we don’t have to eat fish every day.) Salmon is also a good source of protein, vitamin D, selenium, zinc and iodine (though nutrient levels vary by salmon type and environment), nutrients that may also benefit the heart. Salmon is also low in mercury.

• Also Eat: Anchovies, herring, bluefish, mackerel, sardines, trout

Green Hot Peppers: Hot peppers contain powerful flavones, a subclass of a family of phytochemicals called flavonoids. Flavones may protect the heart in a number of ways. Flavones act as antioxidants, ease inflammation and help prevent blood clots. Scientists also believe they help relax arteries. One study from Tufts University found that, among 98,469 older adults, a higher intake of flavonoids, particularly flavones, offered substantial protection from fatal heart attack, especially in women.

Also Eat: Celery, garlic, green bell peppers; fresh parsley, thyme, mint and oregano

Oats: Plenty of evidence suggests that eating whole grains offers protection from heart disease. But unlike other whole grains, oats are an outstanding source of beta glucan, a soluble fiber that lowers LDL (bad) blood cholesterol and helps stabilize blood sugar. Eating oats has been tied to a 7 percent drop in cholesterol. Research suggests we need at least 3 grams of soluble fiber daily to lower cholesterol, the amount in 1.5 cups of oatmeal.

Choose large-flake or steel-cut oats, not instant oats. These types have a low glycemic index, whereas instant oats can cause blood sugar and insulin to spike after eating.

Also Eat: Oat bran, barley, ground flaxseed, psyllium husks


Tomatoes, Lycopene & Chronic Disease

Nothing says summer like a ripe tomato glistening on the vine. The many colorful varieties of tomato make them almost as beautiful to look at as they are delicious to eat. Yet tomatoes offer us even more benefits than their lovely looks and tantalizing taste: Lycopene, a carotenoid present in tomatoes and tomato products, is one of the most potent antioxidants among all dietary carotenoids. Dietary intake of tomatoes and tomato products has been shown to be associated with a decreased risk of chronic diseases including cancer and  heart disease, and bodily lycopene levels are inversely related to the incidence of several cancers, according to an assessment of the health research on lycopene by researchers from the University of Toronto in an article published by the Canadian Medical Association Journal. Although eating any tomatoes is good, cooked tomatoes offer substantially more bioavailable lycopene than raw.

Epidemiological evidence is abundant for tomatoes’ wide-ranging protective effects against chronic disease. Increased consumption of tomatoes is associated with a lower risk of a variety of cancers, including a 50 percent reduction in rates of death from all cancers at all sites in the elderly U.S. population. What’s more, tomatoes seem to offer unique protective benefits. For example, in the U.S. Health Professionals Follow-Up Study, which evaluated intake of various carotenoids and retinol, estimated intake of lycopene from tomato products was inversely related to prostate cancer (10 or more servings of tomato products a week yielded a 35 percent reduction in risk), and no other carotenoid offered these results. Effects were even stronger with more advanced or aggressive forms of the disease. Similarly, recent research has found unique inverse relationships between lycopene levels and cancers of the breast and prostate.

Tomatoes also seem to offer protective effects against heart disease. It’s believed that the oxidation of low-density lipoproteins may play an important role in the formation of atherosclerosis (hardening of the arteries), and antioxidants may slow this progression. In a multicenter, case-control European study, antioxidant levels in adipose tissue (better indicators of long-term exposure than blood antioxidant levels) were measured in subjects from 10 countries. After adjustment for a range of variables, only lycopene was found to offer protection against heart attack. In a study from Johns Hopkins University, smokers with low levels of circulating carotenoids were at increased risk for heart attack, and lower blood lycopene levels were found to be associated with an increased risk for death from coronary artery disease in a study using Lithuanian and Swedish subjects.

Leslie Beck is a Toronto-based Registered Dietitian, best-selling author of 12 books on nutrition and health — including Foods that Fight Disease, available at amazon.com—and weekly columnist for The Globe and Mail, Canada’s national newspaper. Visit her at Leslie Beck.