Food fighters - antioxidants and flavonoids eliminate free radicals - Abstract

Men's Fitness, Dec, 1998 by Mike Carlson

Your body is battling against free radicals. Time to eat your ammunition.

Nutritionists often suggest assessing your diet in terms of color - the more colorful your plate, the more nutrients you're getting. But if you look at the typical meal of a guy who's training to increase muscle mass and decrease body fat, you'll often find a chicken breast or plain tuna, some rice and a glass of water - less color than a Republican convention. If the most vibrant thing in your daily diet is a cup of coffee, it may be time to make some changes. Without adequate variety, you could wind up deficient in vitally important compounds called antioxidants and flavonoids.

Antioxidants have earned a reputation as "good guys" that get rid of free radicals, nasty little molecules that damage cell membranes and cause defects in DNA. Unchecked free radicals can lead to a rash of health concerns, including cardiovascular disease and cancer. But new research shows that compounds called flavonoids may be even more important - particularly for active guys.

Radical thinking

Free radicals are damn near impossible to escape - you can thank pollution, pesticides, cigarette smoke (secondhand and otherwise) and sun exposure, for starters. But even a subterranean organic-vegetarian monk would have plenty of the little buggers. Why? Because the breathing process itself leads to their creation. That's ironic for active guys - after all, who breathes more, a triathlete or a couch potato? Weightlifters aren't safe, either, as free radicals are produced during the breakdown of protein and fats, processes that occur in athletes much more than they do in the average couch monkey.

In essence, it comes down to a fight, and to do battle against free radicals, your body needs nutritional ammunition. Conventional wisdom has held the antioxidant vitamins C, E and A (as beta-carotene) as the best defense against free radicals. But in one study, flavonoids worked even better: Researchers exposed DNA strands to hydrogen peroxide, causing the strands to unwind or break - the first step toward the development of melanoma and certain other cancers. They then treated the damaged DNA with several different flavonoids and vitamin C. Through computer-enhanced visualization, they found that several flavonoids provided many times greater DNA protection than did vitamin C.

Don't throw Out your bottle of G just yet, though. It was also found that quercetin, the flavonoid found in the most foods, provided even greater DNA protection when combined with vitamin C.

In living color

The daily amount of flavonoids needed to fight free radicals and provide training benefits (see sidebar at right) is not yet known. The good news is that if you eat at least five servings of fruit and vegetables a day, you probably have your flavonoid bases covered. The bad news, according to the American Dietetic Association, is that only one in 10 of us consumes that amount of fruit and veggies daily.

The easiest way to get more flavonoids is to simply put more color into your diet (margaritas and Skittles don't count). Foods such as strawberries, carrots, peaches and broccoli are flavonoid-rich. According to a Norwegian study, green tea, apples and onions also contain vast amounts. This is another strong argument for eating your fruits and vegetables. Surprisingly, red wine is high in flavonoids (as are the red grapes from which the wine is made). Dark beers, such as stouts, also contain significant quantities (though light beers contain almost none).

If your diet is seriously lacking in antioxidants or flavonoid-rich foods (and if beer is your only source, it doesn't count), you may want to consider supplementing. Start out with 1,000 milligrams of vitamin C and between 400 and 1,000 IU of vitamin E each day. If you're a fitness fanatic - especially if you do a lot of cardiointense sports activities such as triathlons or marathons - you may need even more, along with an extra flavonoid boost. For serious endurance athletes, a daily dose of flavonoid supplements, taken with meals, will offer protection from the increase in free-radical production. Regardless of your diet or exercise regimen, supplementation is a good idea if you have a genetic predisposition to heart disease or cancer of the stomach, colon or rectum.

The evidence to support the health benefits of antioxidants, and especially flavonoids, as protectants against cancer, heart disease and DNA damage is intriguing, and its benefits for athletes may be even more impressive. In the meantime, it's always a good idea to put more color in your diet.

Benefits for athletes

Sure, antioxidants and flavonoids can help your body get rid of havoc-wreaking free radicals. But wait, there's more, especially for the weight-training guy: Antioxidants, and especially flavonoids, can also promote muscle growth and speed recovery after a workout.

In a Chinese study, the flavonoid quercitin caused a 21 percent increase in total protein synthesis. Along with proper nutrient intake and regular resistance training, consistent protein synthesis is one of the most important factors in muscle growth. Over the long haul, it could make a significant difference in the amount of quality pounds you pack on.