Food-aceuticals: Drink and Eat to Your Health (cont.)
In Lichtenstein's study, women whose arteries already showed evidence of atherosclerosis who ate fish twice a week or dark fish once a week had a slower progression of their disease, as shown by X-ray images.
"Probably what happens is that when people consume more fish, they're not eating as much steak and hamburgers. So they are displacing foods high in saturated fat for one high in unsaturated fat," says Lichtenstein.
In November, the FDA also approved another new qualified health claim for olive oil based on studies that show eating about two tablespoons of olive oil a day may reduce the risk of heart disease.
Olive oil contains a type of fat known as monounsaturated fat that can lower 'bad' LDL cholesterol levels when eaten instead of saturated fats. However, olive oil contains about the same amount of total fat grams and calories as other types of fat.
New research released this year also helped explain the role of antioxidants, for better and for worse.
"Some years ago, we thought that vitamin E was protective against heart disease. Now we're not so sure about that," says Melanie Polk, RD, director of nutrition education at the American Institute for Cancer Research. "We used to think that vitamin E was valuable for a whole variety of benefits, but now we're not so sure about that either."
Several studies have cast doubt on earlier health claims about vitamin E, and a study released in November showed that taking high doses of the antioxidant may actually be hazardous to your health and shorten your life span.
"There was so much excitement over vitamin E because it seemed like such an easy answer," says Lichtenstein. "Unfortunately, it wasn't upheld with studies."
But vitamin E is just one of many antioxidants that may have potentially healthy effects, and the good news about antioxidants this year is that they may be found in unexpected places, like cereal.
Researchers have long thought that fruits and vegetables were the primary sources of antioxidants in the diet. But new research presented this year suggests that a different type of antioxidant and other phytochemicals may also be found in whole grains.
"Phytochemicals seem to be in what we call the free form in fruits and vegetables, and when we looked for these in whole grains they weren't found," says Polk. "What researchers have now discovered is that they were in different form in whole grains. They are attached to cell walls of the plant and don't get absorbed into the blood until bacteria act upon them during digestion."
"We didn't know about this bound form of phytochemicals until recently, and so the benefits of whole grains are even greater than what we thought before," says Polk.
Polk says these findings may also help explain why studies that have looked at the potential anti-cancer properties of the fiber found in whole grains have produced conflicting results.
"We know diets that are high in fiber are cancer protective, but there has been some question about whether or not it is the fiber itself," Polk tells WebMD. "It may not be fiber but maybe something else in high-fiber foods."
Confused? Mix It Up
If the conflicting research about the health benefits of different foods has you confused, researchers say the best recipe is to mix it up.
Researchers say every time they try to isolate one of the components behind the potential health benefits of a food, it doesn't seem to work.
"We have been so unsuccessful in finding that perfect food or that perfect nutrient that if you just pop a supplement you're going to have decreased risk," says Lichtenstein.
In contrast, new research suggests that it may be the ways various phytochemicals and ingredients in different foods work together that produce the biggest health benefits.
For example, a recent study showed that mice with prostate cancer fed a diet rich in both broccoli and tomatoes experienced much less tumor growth than those fed either food alone.
Another study showed that people who ate "polymeals" consisting of wine, fish, dark chocolate, fruits and vegetables, almonds, and garlic on a daily basis had a lower risk of heart disease and lived longer than those who didn't. A polymeal is a combination of foods that have been individually shown to reduce the risk of heart disease.
"When you look at individual phytochemicals, it's very exiting to see that each individual phytochemical has its own function in terms of cancer prevention and health protection. But the possibilities of looking at what they can do together working as a team could be phenomenal," says Polk. "The best way to get these substances is by eating whole foods."
Lichtenstein says researchers are now coming to the realization that certain diet and lifestyle patterns are associated with a lower risk of disease, rather than any one food.
"Fortunately those are virtually the same for heart disease, cancer, and diabetes," says Lichtenstein. "It's to consume a diet high in fruits and vegetables, whole grains, low-fat and nonfat dairy products, legumes, and fish and have regular physical activity."
SOURCES: Melanie Polk, RD, director of nutrition education, American Institute for Cancer Research. John D. Folts, PhD, professor of medicine and nutritional science, University of Wisconsin Medical School. Alice H. Lichetenstein, DSc, professor of nutrition science and policy, Tufts University. WebMD Medical News: "Eating Fish = Healthy Heart in Diabetes." WebMD Medical News: "Cholesterol Control Alternatives." WebMD Medical News: "Omega-3 Fatty Acids Get New Health Claim." WebMD Medical News: "Olive Oil Cleared for Heart-Healthy Claim." WebMD Medical News: "Tangerine Peels May Lower Cholesterol." WebMD Medical News: "Purple Berries Pack Potent Antioxidant Punch." WebMD Medical News: "Antioxidant Riches Found in Unexpected Foods."
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