Tea, coffee, chocolate, avocados, and fatty fish all have good-for-you qualities.
By Kathleen Zelman MPH, RD/LD
WebMD Weight Loss Clinic - Feature
Reviewed by Louise Chang, MD
We all know that spinach and carrots are good for us, but would you believe that such seeming indulgences as tea, coffee, chocolate, avocados, and fatty fish also have disease-preventing and health-enhancing properties?
It's true. Some of these five "superfoods" contain antioxidants, which are thought to fight the damage from disease-causing "free radicals" (unstable molecules that damage cells). Others have omega-3 fatty acids, which promote heart health and may even help to cheer you up when you're down in the dumps.
Here's a rundown on how these five foods can benefit your health.
Topping the list of surprising superfoods is tea -- any type that comes from the leaves of the plant Camellia sinensis, including black, green, white, and oolong.
Many studies have looked at the health benefits of tea. While the jury is still out on some of these potential benefits, there appears to be compelling evidence for tea's ability to reduce the risk of heart disease.
"There are some intriguing studies that tea may prevent cancer, reduce the risk of Alzheimer's disease, and impact halitosis [bad breath], and while these studies are more speculative, the strongest evidence is on the reduction of coronary heart disease risk," says Tufts University researcher Jeffrey Blumberg, PhD.
Tea's secret ingredient is catechins, a type of flavonoid from the family of disease-fighting antioxidant phytochemicals that is also found in fruits, vegetables, and red wine.
Not just any cup of tea will provide you with a healthy dose of flavonoids. Strong, steeped tea is richest in these phytochemicals. And the longer you steep your tea, the more of these healthy extracts your beverage will contain.
Because iced tea is typically diluted, it's not as good a source as hot tea. Bottled teas start off with low levels of flavonoids, and tend to lose potency over time. Decaffeinated tea is a good option, though it has about 10% fewer phytochemicals than tea with caffeine.
So how much tea should you drink? Some studies have suggested that drinking three cups each day can reduce your risk of heart disease.
Blumberg suggests choosing tea whenever you can. He points out that it can contribute as much antioxidants as a serving of fruit or vegetable without the calories, and is far preferable to soft drinks.
If you add sugar or full-fat milk to your tea, do so sparingly. These additions can turn naturally noncaloric tea into a high-calorie beverage.
Here's good news for chocolate lovers: dark chocolate (as opposed to milk or white chocolate) contains healthful flavonoids similar to those found in tea, red wine, fruits, and vegetables.
Studies have shown that small portions of dark chocolate can improve blood vessel flow, especially in older adults, and may improve blood sugar and insulin sensitivity to help reduce the risk of diabetes.
One study, published in the journal Hypertension, reported that the antioxidants found in dark chocolate could help reduce high blood pressure. The study participants who ate chocolate also reduced their LDL "bad" cholesterol levels, and improved insulin sensitivity. A little chocolate goes a long way, however. The study subjects were limited to a small portion of dark chocolate per day and cut calories elsewhere in their diets to avoid weight gain.
In another study, reported in The Journal of the American Medical Association, researchers found that the flavonoids in dark chocolate helped prevent stiffening of blood vessels in adults over 50. And a study published in the American Journal of Clinical Nutrition found that dark chocolate may help prevent diabetes by improving insulin sensitivity in healthy adults.
The dark chocolate used in these studies has high levels of flavonoids and somewhat of a bittersweet taste -- different from the creamy milk chocolate many Americans enjoy. The flavonoids come from extracts of the cocoa bean. By choosing dark chocolate with a high percentage (70%) of cocoa, you'll get more of these health-enhancing antioxidants. Most dry cocoa mixes don't contain these health-promoting substances.
Of course, all chocolates -- including dark chocolate -- have both positive and negative attributes. Chocolate candy has plenty of saturated fat and sugar, which can lead to weight gain. A standard-size bar of Hershey's Dark Chocolate has 531 calories.
Still, at the very least, chocolate is a satisfying treat that can be an alternative to sugary snacks that provide calories with little nutritional value, says Elisa Zeid, MS, RD, CDN, a spokeswoman for the American Dietetic Association.
So enjoy small portions of dark chocolate as part of a healthy diet (and make up for the calories with regular physical activity).
It's hard to imagine that any food called "fatty" could be good for you, but when it comes to food from the sea, the fattier the fish, the better. Coldwater fatty fish, such as salmon, trout, herring, tuna, sardines, and mackerel, are rich in omega-3 fatty acids, a type of unsaturated fat that promotes health in many ways. The real strength of omega-3s appears to be their ability to lower blood cholesterol, preventing blood clots and heart attacks.
Many studies have supported the idea that omega-3 fatty acids can lower cholesterol and triglycerides (blood fats), and reduce the inflammation associated with a risk of heart disease. The science for this effect is so compelling that the American Heart Association recommends eating two servings of fatty fish weekly.
Emerging evidence suggests that omega-3s may also affect mood. A study from the University of Pittsburgh found that low levels of omega-3s were associated with mild to moderate symptoms of depression and moodiness, while people with higher levels were found to be more content. However, researcher Sarah Conklin tells WebMD that more studies are needed to fully understand the relationship between omega-3s and mood disorders.
"Enjoying fatty fish such as salmon and trout is the easiest and best way to get a healthy dose of omega-3 fatty acids," says Blumberg. "If you don't enjoy them, you can also get it in plant foods such as flaxseed, walnuts, canola and soybean oils, but these sources are not as good as fatty fish."
But keep in mind that you can undo the health benefits of fish if you eat it fried, says Zeid.
"Fried foods add lots of extra calories, and saturated fat that is not good for your waistline or your heart," she says. So fire up the grill or put your fish under the broiler for a quick, tasty, and heart-healthy meal.
Zied also recommends keeping portions to 4 ounces. While the fat in the fish is good for you, it adds to the calorie count.
Yes, these luscious green fruits are full of fat. But most of it is the heart-healthy, monounsaturated kind that can help lower both total cholesterol and "bad" cholesterol.
Avocados contain health-promoting carotenoids. They're also rich in vitamin E and potassium, and contain some fiber to help fill you up, says Zied.
"Avocados are rich in beta-sitosterol, a natural substance that has been shown to reduce cholesterol levels," she says. The avocado "also contains plant chemicals and antioxidants, all of which contribute to good health."
While avocados are a great way to add flavor and texture to meals without too much saturated fat, portion control is critical.
"A medium avocado has 30 grams of fat and even though it is the healthy kind, it can add lots of extra calories if you don't watch your portion size and balance it with other wise food choices," Zeid says.
Her advice: slice avocados into salads; float slices or cubes of avocado on top of soups, or use avocado instead of butter, cream cheese, or mayonnaise on breads, bagels, and sandwiches.
Your morning cup of coffee not only helps wake you up, it may have health benefits. The caffeine in coffee stimulates the brain and nervous system, and may lower your risk of diabetes, Parkinson's disease, mood problems, headaches, and even cavities.
Coffee contains many beneficial substances including chlorogenic acid, a compound in the antioxidant family that may improve glucose (sugar) metabolism. Another perk is that coffee contains magnesium, a mineral that can also improve insulin sensitivity and enhance glucose tolerance.
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"Coffee may therefore, in some people, help thwart type 2 diabetes," says Zied.
A review of 15 studies on coffee and type 2 diabetes published in The Journal of the American Medical Association found that people who regularly drank coffee had lower risk of type 2 diabetes. Most people in the studies drank coffee prepared with the drip method. Decaffeinated coffee was not always identified, but in two of the studies, the decaf drinkers had a lower risk of type 2 diabetes.
Still, researchers are not ready to recommend that everyone drink large doses of coffee, as this habit is associated with less healthy lifestyles. So enjoy your coffee in moderation, and keep in mind that a healthy diet, normal body weight, and regular exercise are your best defense against developing type 2 diabetes.
One real benefit for java lovers: your morning wake-up call can help satisfy your body's daily fluid needs. Studies show that coffee does not dehydrate habitual drinkers, as once believed, and can count toward your daily fluid quota, says Zied.
Another plus is that coffee is naturally calorie-free. But if you load it up with cream, sugar, whipped cream, and/or flavored syrup, the extra fat and calories can undermine any potential benefits.
More Than 5 Foods
Of course, it takes more than five foods to make a healthy diet.
The real key to preventing disease and promoting health is a lifestyle of regular physical activity and healthy eating patterns that include a variety of nutritious foods.
And remember that portion size does matter, even with healthful foods. If you gain weight because you're eating superportions of any foods, you'll negate the health benefits because of the health risks of being overweight.
Published Thursday, March 23, 2006.
SOURCES: Jeffrey Blumberg, PhD, professor, Friedman School of Nutrition Science and Policy, Tufts University. Elisa Zied, MS, RD, CDN, spokeswoman, American Dietetic Association; author, So What Can I Eat?!. Journal of Agricultural and Food Chemistry, June 9, 2004. Diabetes Care, January 2004. Annals of Internal Medicine, May 2, 2005. American Heart Association Dietary Guidelines. van Dam, R.M. The Journal of the American Medical Association, July 6, 2005; vol 294: pp 97-104. Tomas DePaulis, PhD, research scientist, Vanderbilt University's Institute for Coffee Studies; research assistant professor of psychiatry, Vanderbilt University Medical Center, Nashville. Peters, U. (2001) American Journal of Epidemiology, 2001; vol 154: pp 495-503. Huxley, R.R. and Neil, H.A. (2003) The relation between dietary flavonol intake and coronary heart disease mortality: a meta-analysis of prospective cohort studies. American Heart Association: "High Blood Pressure." News release, American Heart Association; American Society of Hypertension Nineteenth Annual Scientific Meeting and Exposition, New York, May 18-22, 2004. Charalambos Vlachopoulos, MD, Athens, Greece. Naomi Fisher, MD, associate professor of medicine, Harvard Medical School, Boston. Taubert, D. The Journal of the American Medical Association, Aug. 27, 2003; vol 290: pp 1029-1030; Grassi, D. American Journal of Clinical Nutrition, March 2005; vol 81: pp 611-614. 64th Annual Scientific Meeting of the American Psychosomatic Society, Denver, March 1-4, 2006. Sarah Conklin, PhD, postdoctoral fellow, cardiovascular behavioral medicine program, department of psychiatry, University of Pittsburgh School of Medicine. WebMD Weight Loss Clinic: "10 Amazing Disease-Fighting Foods."
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