Antioxidants: Are they protective against dementia and stroke?

The journal Neurology recently published a study indicating that antioxidants do not reduce stroke or dementia risk. This study contradicted what other studies have shown and I want to present the opposing viewpoint.

“These results are interesting because other studies have suggested that antioxidants may help protect against stroke and dementia,” said study author Elizabeth E. Devore, ScD, of Harvard Medical School in Boston and Erasmus Medical Center in Rotterdam, Netherlands. “It’s possible that individual antioxidants, or the main foods that contribute those antioxidants—rather than the total antioxidant level in the diet—contribute to the lower risk of dementia and stroke found in earlier studies.”

Devore add that “This differed from an Italian study that found the higher total antioxidant levels were associated with a lower risk of stroke, where the variation from coffee and tea was lower, and the contribution from alcoholic beverages, fruits and vegetables was higher.”

The study followed more than 5,000 participants aged 55 years and older who provided information about their diets. Devore pointed out that most (90%) of the difference in the antioxidant levels in people’s diets was due to how much tea or coffee they consumed.

Researchers from the University of Scranton found that coffee is the number one source of antioxidants in the US diet. Study leader, Joe Vinson, Ph.D., said “Americans get more of their antioxidants from coffee than any other dietary source. Nothing else comes close.”

Sure, coffee offers some antioxidant protection. But you can get more bang for your buck with 5 to 7 servings of fruits and vegetables every day.

How many fruits and vegetables do you eat each day?

If you’re like most Americans, you’re probably not getting the recommended five to seven servings. Now more than ever we know why getting your greens, blues, reds, oranges and yellows is absolutely essential to good health and longevity.

Just like people, fruits and vegetables come in a variety of shapes, sizes and colors. And it’s the colors that identify many of the bioactive substances called phytonutrients that give us antioxidant protection and other special health benefits.

What are phytonutrients?

Phyto comes from the Greek word that means plant. Phytonutrients are the natural chemicals found in all plant foods—including grains, nuts and seeds—that help fine-tune all bodily functions and support our health. Phytonutrients contain potent antioxidants and other compounds that help slow down the aging process and prevent chronic diseases, including cardiovascular disease, diabetes and some cancers. On a day-to-day basis, phytonutrients help boost our immunity and support our overall well being, so we feel energized, uplifted and have a sparkle in our eyes.

How do phytonutrients reduce risk of disease?

  • Provide antioxidant protection
  • Support healthy immune response
  • Convert to vitamin A (from alpha- and beta-carotene)
  • Support healthy estrogen metabolism

Proven results

The scientific community has produced a large body of research showing the potential of these super nutrients. Compared with people who eat few fruits and vegetables, populations that consume a large variety and generous amounts of plant foods enjoy longevity and reduced risk of disease.

Take for example the people of Okinawa, who live on an island between Japan and Taiwan. They have a long life expectancy, numerous centenarians, and a low-risk of age-associated diseases. Their diet is low in calories, fat, sugar, salt, and meat and dairy products. Instead, Okinawans eat fish, tofu, whole grains, and lots of fruit, dark green leafy vegetables, onions, green peppers, sea vegetables and sweet potatoes—which are all dense in phytonutrients and antioxidants. These islanders are known for a low-stress, carefree and relaxed attitude. Their rates of stroke, dementia, cancer and heart disease are also the lowest in the world. For every 100,000 people in Okinawa, 30 have passed their 100th birthday, one of the highest rates in the world.

Free radicals and antioxidants

You’ve heard the terms a million times, but what exactly are they?

Free radicals are dangerous, highly reactive, unstable molecules that produce oxidative stress or cellular damage throughout the body, and play a primary role in the aging process. It’s impossible to be alive and not have some free radical damage—because free radicals are produced by normal processes in the body (like the release of adrenaline), and from environmental sources such as ultraviolet radiation, tobacco smoke, food additives and other pollutants.

You’ve seen what happens to an apple that sits on the counter for too long. It turns brown, just like the rusty nail that has been exposed to sun and rain. These are examples of oxidation. Once free radicals are released they multiply geometrically in chain reactions causing oxidative damage, unless they are stopped by antioxidants.

Antioxidants are molecules that donate an electron to the free radical. The free radical stabilizes and stops wreaking havoc in the body. Vitamins C and E are well-known antioxidant vitamins, and phytonutrients exert antioxidant protection, as well.

It’s important to get a variety of phytonutrients

Every plant contains several types of phytonutrients. These phytonutrients work synergistically with each other and with the phytonutrients in other plants to produce the beneficial effects in your body. This is why it’s important to eat a varied diet containing fruits and vegetables of all colors of the rainbow. For example, scientists are discovering that if the only vegetable you ate for dinner was carrots, the amount of antioxidant protection you’d get, and your body’s ability to convert alpha-carotene to vitamin A would be far less than if you ate carrots and kale and broccoli at the same meal.

The Okinawans enjoy their tea. But they also include plenty of vegetables and fish in their diet, which is something that is making headlines right now in regard to the benefits of the Mediterranean diet.







  1. Elizabeth E. Devore, ScD., et al. “Total antioxidant capacity of the diet and major neurologic outcomes in older adults” Neurology Feb 20th, 2013. 10.1212/WNL.0b013e3182840c8


  1. Middleton LE, Yaffe K. Targets for the prevention of dementia. J Alzheimers Dis. 2010;20(3):915-24. doi: 10.3233/JAD-2010-091657.


  1. Willcox DC, Willcox BJ, Todoriki H, Suzuki M. The Okinawan diet: health implications of a low-calorie, nutrient-dense, antioxidant-rich dietary pattern low in glycemic load. J Am Coll Nutr. 2009 Aug;28 Suppl:500S-516S.