February 1, 2013
Eating the right foods may cut your dementia risk by 40%
Can you really prevent Alzheimer’s disease by eating certain foods? Research is not yet definitive, but there is mounting evidence that certain foods can indeed reduce dementia risk or delay the onset of symptoms.New finding: In a recent analysis published in Annals of Neurology, researchers who reviewed the diets of more than 2,000 older adults discovered that those who ate ample amounts of fatty fish and certain vegetables, such as leafy greens, were about 40% less likely to develop Alzheimer’s or some other type of dementia than those who ate less of those brain-healthy foods.
The sooner you start eating a brain-healthy diet, the better—Alzheimer’s is believed to develop over decades. But even if you’re an older adult, I firmly believe that eating the foods described in this article is one of the best ways to improve your odds of staying mentally sharp.
THE “ORAC” POWERHOUSES
Alzheimer’s disease seems to be caused, in part, by oxidative stress—the disease-causing cellular process triggered by unstable molecules known as free radicals. One way to decrease oxidative stress is to eat antioxidant-rich foods.
In laboratory studies, animals that have been genetically engineered to develop Alzheimer’s disease show lower rates of cognitive decline when they consume more antioxidants. It is likely that humans get the same benefits.
For overall health, researchers recommend a daily diet that includes 3,000 to 5,000 oxygen radical absorbance capacity (ORAC) units (a measure of antioxidant activity). Where to start…
Load up on the right kind of vegetables. The Chicago Health and Aging Project, a study of aging and dementia that involved more than 6,000 participants, found that those who ate two to four servings of leafy green, yellow or cruciferous vegetables daily were significantly less likely to suffer from cognitive declines than those who ate less.
Best: Kale is an ORAC powerhouse with 1,770 units per one-and-a-half-cup serving. Spinach has 1,260 units. In general, the darker-colored vegetables—such as Brussels sprouts, broccoli and acorn squash—have the most antioxidants. You should have at least three servings each day.
Important: Many of the nutrients and antioxidants contained in vegetables are destroyed by high-heat cooking (such as boiling and lengthy steaming). Therefore, I recommend lightly sautéing vegetables in a little olive oil. The oil provides additional antioxidants and improves the body’s absorption of fat-soluble antioxidants, such as beta-carotene.
Use more spices. Believe it or not, spices are the most concentrated sources of antioxidants in the kitchen. In fact, just one teaspoon of cinnamon has more antioxidants than a serving of vegetables.
Another very high antioxidant spice is turmeric, which gets a lot of attention for its brain-protective effects.
Important fact: In India, where curries and other dishes seasoned with turmeric are eaten almost every day, the rate of Alzheimer’s disease is among the lowest in the world. However, other high-antioxidant spices, such as cloves, oregano, thyme and rosemary, are also worth adding to your diet. Although there’s no definitive research showing how much of these spices you need to consume for brain health, it’s reasonable to add as much as your taste buds permit in as many dishes as possible.
Be choosy about the fruit you eat. Fruit consumption, in general, does not appear to lower the incidence of cognitive decline or Alzheimer’s disease. That’s probably because most fruits have a much lower concentration of antioxidants than vegetables.
Blueberries are a well-known exception to this rule. But there are other antioxidant powerhouse fruits, such as cherries and acai fruit (a slightly tart berry), that are often overlooked. So for an excellent antioxidant boost, have one cup of any type of fresh or frozen berries (including raspberries and blackberries).
Helpful: Juice (with no added sugar) is a good way to include more berry antioxidants in your diet. Pomegranate, blueberry, grape and acai juices are all high in brain-protective polyphenols. Orange and pineapple juices are high in vitamin C but don’t seem to protect against Alzheimer’s—the high sugar levels of these juices aren’t offset by enough benefits to justify drinking them.
My approach: I drink a six-ounce glass of unsweetened pomegranate juice every day. That’s because studies suggest that pomegranate juice, in particular, reduces levels of beta-amyloid, the protein that accumulates in the brains of Alzheimer’s patients. Apple and cherry juices also have been shown to reduce beta-amyloid levels. Grape juice is another good choice. Along with red wine, it contains resveratrol, a compound believed to break down the amyloid protein.
Don’t forget tea. Tea is possibly the most effective beverage for brain health. A study that looked at more than 1,000 elderly Japanese participants found that those who drank two cups of green tea daily had far lower rates of cognitive decline than those who drank three or fewer cups a week.
Green tea has epigallocatechin-3-gallate (EGCG), an antioxidant that seems to be particularly effective for neurodegenerative diseases, including Alzheimer’s. If you don’t like green tea, drink black tea—it also contains significant levels of EGCG—or coffee. Both lower risk for Alzheimer’s to a somewhat lesser extent than green tea.
Put fatty fish on your menu. By now, most people have gotten the message that eating fish is good for your brain. But not all types have this effect. Lean fish, such as cod, flounder, halibut, sole and haddock, are not the best choices.
That’s because it’s the high levels of omega-3 fatty acids in cold-water fish (such as herring, mackerel and sardines) that offer brain protection. These healthful fats are so beneficial that you should buy the fattiest fish you can find.
Herring, mackerel and sardines are the fattiest. Salmon, another fatty fish, is also an excellent source of docosahexaenoic acid (DHA). Brain cells require DHA, a type of omega-3, to maintain their integrity—a breakdown of these cells is the hallmark of Alzheimer’s disease.
Important: I advise patients to eat a three-ounce (or larger) serving of fatty fish at least three times a week—just lightly sauté the fish in olive oil, bake or broil.
At the same time, I suggest decreasing one’s intake of saturated fat and processed foods (which tend to be high in soybean oil and other unhealthy fats, including omega-6s).
People who do this can achieve the recommended ratio of one part omega-3s for every three parts of omega-6s—optimal for preventing Alzheimer’s and other forms of dementia.
Source: Marwan Sabbagh, MD, a neurologist and director of Banner Sun Health Research Institute in Sun City, Arizona. He is associate director of the Arizona Alzheimer’s Disease Core Center, a clinical instructor in the Banner Family Medicine Geriatrics Fellowship Program and a visiting scientist in the department of neurology at Mayo Clinic in Scottsdale, Arizona. He is the author, with professional chef Beau MacMillan, of The Alzheimer’s Prevention Cookbook (Ten Speed).
The Ultimate Alzheimer’s-Fighting Diet
