By Robert Wildman, Ph.D., R.D., L.D / April 09, 2011
Antioxidants are all the rage. These nutrients protect against free radicals, the biological bullies linked to heart disease, cancer and aging. But how much is enough? And can you overdose on vitamins and other immune-system defenders? Get the answers to your top questions...
1. How do I know if I'm getting enough antioxidants?
There's no way to know. Specific dietary recommendations don't currently exist.
Cover the bases by adding antioxidant-rich foods to your diet. Supplement with vitamins and minerals that meet DRI (Dietary Reference Intakes) recommendations. Make sure to eat a rainbow of fruits and veggies. The antioxidant lycopene turns tomatoes red; anthocyanins make blueberries blue.
2. Can I overdose on antioxidants?
Too much of a good thing can be bad, and some scientists believe excessive amounts of antioxidants can overtax the immune system, hurting the body's ability to repair itself.
But if you're following the recommended supplements doses, that risk is probably low.
Loading up on a single antioxidant or a select few can cause an imbalance in your system and reduce the potency of other antioxidants.
3. Red wine, berries and pomegranates are good sources of antioxidants. What are some lesser-known ones?
The supermarket produce section is loaded with antioxidant superstars: broccoli, tomatoes, leafy greens and citrus fruits.Broccoli is a great source of cancer-fighters called isothiocyanates. It's also rich in quercetin, which supports cancer prevention and healthy blood pressure. (You'll also find quercetin in red onions, red grapes, tomatoes, capers and citrus fruit.)
Almonds, plant oils, wheat germ, safflower, corn and soybeans are loaded with vitamin E.
Lycopene-rich tomatoes, papaya, watermelon, guava, apricots and pink grapefruit support prostate health for men.
Some antioxidants target specific organs.
For example, lutein and zeaxanthin (both found in green, leafy vegetables like spinach and kale) are important for healthy eyes; grape seed and skin extracts support circulation.
4. Do antioxidant-rich cosmetics and skin creams really work? Are the benefits better than antioxidants you eat?
Skin protection comes from inside and out, so getting your antioxidants from both diet and skin creams is best.
Antioxidants from fruit extracts and other dietary sources can reduce skin damage caused by the sun and environmental pollutants. It works the same way plants produce carotenoids to absorb harmful sun rays before they can damage leaves or other parts of the plant.
In humans, dietary antioxidants may play a significant role in protecting new skin. 5. Which fruits and veggies provide the most antioxidants?
Strawberries are the top-ranking antioxidant. They're high in vitamin C and promote collagen formation – the key protein for healthy skin – as well as folate, which supports circulation and reduces risk of birth defects.
Another all-star fruit is kiwi, which is loaded with antioxidants vitamin E and carotenoids. It's also high in fiber, potassium, magnesium, copper and phosphorous.
Broccoli, which is packed with isothiocyanates and quercetin, has vitamins A and C, folate, niacin and potassium as well.
And don't forget red, black, pinto and kidney beans. They're rich in B-vitamins (including folate) and iron, and pack a couple grams of fiber per serving.
6. How can I tell if a prepared food contains antioxidants? What should I look for on a nutritional label?
Antioxidants aren't listed on food labels under "Nutrition Facts."
Here are 3 ways to know if a product is antioxidant-worthy:
•It has fresh, frozen or dried fruits and vegetable ingredients.
•It has real juice. Often, children's fruit drinks contain more fruit flavors and sweeteners than real fruit juice.
•It's labeled "whole grain." These products have higher antioxidant value and more nutrients than refined grain products, such as white bread and rolls.
7. Is it better to get my antioxidants from food or nutritional supplements?
Food is the best source because they're in their natural state and often have other nutrients that support their stability and potency. But when availablity, cost and allergies get in the way, supplements can provide what the diet doesn't.
Onions, for example, are among the best sources of quercetin. But if they disagree with you, you're missing out on a powerful antioxidant that reduces cancer risk and maintains healthy blood pressure.
Blueberries are another wonderful source of antioxidants, primarily anthocyanin. But they can be expensive, especially out of season.
8. Do alcoholic beverages count as a source of antioxidants?
Good news for happy-hour lovers! Alcoholic beverages with antioxidants have long been recognized for their health-promoting properties.
Polyphenolics and resveratrol in wine (especially red) lower the risk of heart disease, according to many recent studies. And a pomegranate martini calls for 3-6 ounces of pomegranate juice, which can definitely apply to your total daily antioxidant score.
So, go ahead, have that wine, pomtini, or beer (especially wheat beers). They provide a solid contribution to your health and daily antioxidant dose – but only when consumed in limited amounts.
9. Some nutrition bars claim to contain antioxidants. Are they hype or help?
Packaged nutrition or meal substitute bars can be a good source of antioxidants – if they contain real fruit pieces, fruit juices, or fruit paste, such as cherry or fig.
Those made with real fig pack more antioxidant power than most. But bars fortified with vitamins C and E, green tea extract, lycopene or blueberry extract are also high in these nutrients.
10. Which antioxidant-rich products and snacks do you recommend?
•100%-fruit juices. Pure fruit juice such as POM and cranberry juice are antioxidant arsenals. Beware of beverages containing less than 10% fruit juice and those sweetened with sugar or high fructose corn syrup.
•Dried fruits. Despite their wrinkled appearance, dried fruits still pack a huge antioxidant punch, research has found.
•Canned tomato paste and sauces. Tomato products – even ketchup – are rich in lycopene, which may help prevent cancer and heart disease.
•Vegetable juices. Products such as V8 contain several different vegetable juices in one beverage. Besides antioxidants, vitamins and minerals, vegetable cocktails are a good source of fiber, often containing up to 2 grams per serving.
•Fruit yogurts. Low-calorie yogurts have about 100 calories per 6-ounce serving. The added fruit is usually one of the antioxidant all-stars: blueberries, strawberries, apples or peaches. Yogurt also contain probiotics, like lactobacillus acidophilus, which support digestive tract health, boost immunity and improve cardiovascular health.
1
2
3
4
5
6
7
7a
8
8a
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
26a
26b
27
29
30
31
32
33
34
35
36
37
38
39
No comments:
Post a Comment