April 19, 2007 - While all fruits and vegetables contain good-for-you nutrients, blueberries may pack the biggest health punch. They are tops in free-radical-busting antioxidant activity when compared to 40 other fruits and vegetables, according to the USDA Human Nutrition Research Center on Aging in Boston. "These little fruits are superheroes," says Jennifer Meengs of the Laboratory for the Study of Human Ingestive Behavior at Penn State. "They're packed with chemicals that can help fight disease."
Though many of the studies are in very early stages, blueberries may help ward off heart disease, cancer and age-related memory changes, among other ailments. For example, research presented at the American Chemical Society this past March, showed that a key antioxidant found in blueberries, pterostilbene, can help mop up free radicals triggering colon-cancer growth. Blueberries may also help with heart health, protecting the body against LDL- cholesterol, the so-called "bad" cholesterol that contributes to cardiovascular disease and stroke. Rutgers University researchers found that epicatechin, another antioxidant found in blueberries, helps prevent urinary-tract infections by preventing bacteria from adhering to cells lining the urinary tract. Several studies show that blueberries may help improve eyesight. And the little berries may even help with age-related motor changes and improve memory.
While all species of blueberries are stuffed with antioxidants, the wild ones contain more of the free-radical-fighting chemicals than the more familiar cultivated blueberry. Wild blueberries are smaller, darker and have a more intense taste than their cultivated cousins. Both types are available at grocery stores, but wild blueberries are often more expensive. To get the most health benefits from either the wild or cultivated versions, opt for fresh or frozen berries instead of highly processed or baked forms, which, researchers at the University of Arkansas have found to have somewhat lower levels of antioxidants.
The benefits of blueberries don't stop with health-boosting antioxidants. They are also a great diet food—low in calories (one cup is a measly 81 calories) and full of fiber and vitamins A and C. "There isn't a downside," says nutritionist Keith Ayoob of the Albert Einstein College of Medicine. "Their nutritional profile is incredible. What's not to like?"
Forget soy’s reputation as a tasteless meat substitute for health nuts. Consumption of the high-protein legume has been rising ever since the Food and Drug Administration officially recognized it as a heart-healthy alternative in 1999. From 2001 to 2004, American food manufacturers introduced over 1,600 new foods with soy as an ingredient. In many supermarkets across the country, you can find soy drinks, various kinds of tofu, cultured soy, non-meat alternatives, frozen dairy-free soy treats, soy nuts, soy nut butter, and cereals and bars with soy. As a result, 30 percent of Americans now consume soy products at least once a month.
The FDA boosted soy’s reputation after reviewing 50 studies; it then approved health claims that consuming 25 grams of soy per day will reduce the risk of coronary heart disease. Because soy protein can be added to such a wide variety of foods and beverages, the FDA suggests aiming for four servings a day. Soy foods also contain isoflavones, which may offer additional health benefits including lowered risks of certain cancers and cardiovascular disease. Soy may also help reduce the risk of osteoporosis, although more research is needed to confirm this.
One caveat for women who've been diagnosed with breast cancer: animal and lab studies of breast-cancer cells have indicated that soy may promote the growth of breast-cancer cells in some cases and inhibit it in others. Breast-cancer survivors don't have to avoid soy, but they should eat it in moderation until more is known about how it might affect them.
Besides isoflavones, soy has a high content of polyunsaturated fats, fiber, vitamins, minerals and a low content of saturated fat—which makes it an ideal substitute for less healthy foods. But like anything you eat, deep-frying soy foods like tofu (a favorite vegetarian dish) will increase saturated fats and cholesterol and largely negate the health benefits, so prepare your soy.
When you talk about
good fats, you can't get much better than the
fats found in olive oil.
In the 1960s, it was found that folks in Crete
lived long lives because they had much lower
rates of stroke, heart disease and certain
cancers. Researchers noted that heart-disease
risk was much lower for people throughout the
Mediterranean region, despite the high intake of
monounsaturated fats found in olive oil. And so
began the research into the "Mediterranean
diet."
Today, we know that olive oil offers protection against heart disease by controlling LDL ("bad") cholesterol levels while raising HDL (the "good" cholesterol) levels. In fact, some research shows that the risk of a fatal heart attack is cut in half after two to four years of being on the Mediterranean diet, which also includes loads of fruits and vegetables and other good-for-you foods like grains. If you're worried about stomach fat, which has been linked to an increased risk of heart disease, grab some olive oil. Some studies show that olive oil may actually help redistribute body fat, helping to rid us of our jelly bellies. The science is so overwhelming that the FDA allows olive oil manufacturers to place a health claim on bottles linking olive oil to reduced risk of coronary heart disease.
But research, published in the journal Nature, shows olive oil is more than just heart healthy. Scientists from the Monell Chemical Research Center in Philadelphia discovered that olive oil contains a compound that has the same molecular action as ibuprofen, the widely used painkiller. And that means that olive oil may offer the same anti-inflammatory properties as ibuprofen, as well as some of its other benefits, including a reduced risk of heart attack, stroke, certain cancers and Alzheimer's disease. Researchers at Northwestern University's Feinberg Medical School showed in a series of laboratory experiments on breast-cancer cells that the monounsaturated fat called oleic acid, found in olive oil, dramatically cuts the levels of a cancer-promoting gene called Her-2/neu while boosting the effectiveness of treatment. High levels of the gene occur in more than a fifth of breast-cancer patients and are linked with highly aggressive tumors.
About 90 percent of the world's olive oil comes from the Andalusia region of southern Spain. Choosing the best one depends on your taste buds. Depending on the processing involved, olive oil is usually categorized as: extra virgin (considered top-shelf since it is from the first pressing of olives); virgin (the second pressing); pure (minimally processed), and extra light (heavily processed).
Thinking it was good for our hearts, some of us have been adding buckets of garlic to our chicken wings, pasta and anything else we can think of. But researchers now say that these little cloves of pungency aren't as powerful a cardiac protector as once thought.
For years, garlic, a kissing cousin to the onion, was thought to be great at lowering cholesterol levels. But a series of studies over the last several years has discounted that notion. Now a pivotal National Institutes of Health-sponsored study out of Stanford University puts the final kibosh on garlic's once highly touted cholesterol-lowering benefits. And it doesn't even seem to matter whether the garlic is raw, aged, an extract or even a supplement, according to the research published in the Archives of Internal Medicine in February.
"I was ready to buy Dr. Garlic license plates," says Christopher Gardner, a Stanford professor of medicine who led the study. "I was somewhat surprised that even the raw garlic didn't have any effect. But the evidence is very clear. Garlic just doesn't work in lowering cholesterol levels."
There is some good news for garlic lovers. This research doesn't rule out garlic's potential benefits in reducing levels of cardiovascular disease by lowering blood pressure (so far, the evidence is mixed) or atherosclerosis (preliminary evidence suggests garlic may actually slow hardening of the arteries). According to the NIH, some studies suggest consuming garlic as a regular part of the diet may lower the risk of certain cancers. However, there haven't been any clinical trials.
Remember that garlic can thin the blood, just like aspirin. If you're a garlic junkie, talk to your doctor if you are planning to have surgery or even dental work, especially if you have a bleeding disorder. Garlic has been shown to interfere with the effectiveness of saquinavir, a drug used to treat HIV infection. Garlic’s interaction with other drugs hasn't been well studied.
Gardner is planning another trial to measure garlic's effects on C-reactive protein, one marker that is linked to heart disease. "We don't know all the answers," he says, "and garlic may still play some role in heart disease. But it's clear that it has no role as a cholesterol reducer."
By no means stop eating garlic, especially if you like it. And who doesn't? One proven way to lower cholesterol is to eat a plant-based diet, spiced with garlic goodness. "I love the stuff," says Gardner, "but it's not like you can eat garlic cheese fries and think that you are doing something good for your cholesterol."
Licorice is a stickier subject than you might imagine. Strawberry and Cherry Twizzlers, for example, the oh-so-popular movie candies that everybody thinks of as licorice, don't contain licorice of any kind. And real licorice, which is derived from the root of a shrubby plant called Glycyrrhiza glabra, has been linked to an array of health problems.
Though it seems benign, licorice is a "good news and bad news kind of herb," says registered dietitian Roberta Anding of Texas Children's Hospital. For centuries, licorice has been used to treat a multitude of ailments, including stomach ulcers, bronchitis, sore throat and viral infections. A review of several clinical trials found that glycyrrhizic acid, a molecule found in licorice root, might actually reduce complications from hepatitis C in some patients. But the "trials were poorly designed," says Anding, and there isn't enough evidence to actually say that licorice can help with any medical problems.
But it might cause a few. According to the National Institutes of Health, licorice has been linked to salt and water retention and low potassium levels. It can also cause an increase in levels of cortisol, a hormone linked to high blood pressure. Some research suggests it may even cause preterm labor. To top it off, licorice may not be good for the libido. Hormonal imbalances have been reported with the use of licorice, such as abnormally low testosterone levels in men.
Most licorice candies (especially those in the U.S.) are flavored with anise oil (a spice with a licorice taste) or made with a licorice root extract called DGL (deglycyrrhizinated licorice root) that does not contain glycyrrhizic acid. DGL is not associated with many of the adverse effects of licorice. But if you satisfy your sweet tooth on occasion with some real-deal licorice candy available at import stores or online, don't panic. Levels of licorice root in a serving-size portion of candy are not as high as those found in herbal supplements. But don't binge on it, either. Limit yourself to a few pieces. And avoid it if you have high blood pressure or heart disease.
If you plan on buying a licorice root supplement at your local health food store, be smart and talk to your doctor. Once you get an OK, follow dosing guidelines, which may differ depending on the product you purchase. High doses of licorice root (50 grams or more per day) and taking it longer than two to six weeks, may cause high blood pressure, among other problems. "Licorice is an herb that should be taken very seriously," says Christine Gerbstadt, M.D., R.D., spokesperson for the American Dietetic Association. "Just because something is natural doesn't mean it's safe."
When it comes to Twizzlers, it's actually sugar that you need to think about. Only the black (licorice) version contains licorice extract, minus the acid. One serving of the licorice or strawberry flavor—four pieces—contains 20-21 grams of sugar. That's about five teaspoons of sugar per serving. Although you won't have any of the bad biological effects from licorice root, "you're going to have one heck of a sugar buzz if you eat the whole bag at the movies like most of us do," says Gerbstadt.
The avocado's rep is that of a somewhat decadent vegetable, but it's actually a vitamin-packed fruit. This delight is rich in 25 essential nutrients including fiber, potassium, vitamin E, B-vitamins and folic acid. And while the 30 grams of fat packed into each avocado scares some dieters away, research has shown that not only is the fat 'good' monounsaturated fat, but adding avocados (in moderation) to a well-rounded diet can lower your levels of LDL cholesterol and triglycerides, both of which are related to heart disease.
As aficionados will tell you, avocados are almost as diverse and subtle as wine. Their name comes from the Spanish word aguacate, and they originated in south-central Mexico, between 5,000 and 7,000 B.C., but the first domesticated avocado seeds were found in Peru dating back to 750 B.C. Today California is the leading American avocado producer, growing 90 percent of the domestic supply. There are eight varieties of varying consistency, size and flavor grown in the United States. The Hass, for instance, which is the leading type of California avocado, has a light green skin that turns purplish-black when it ripens and the meat is pale green with a creamy texture. The Zutano, on the other hand, is a larger variety and it has a shiny, thin, yellow-green skin that stays bright when ripened and the meat is pale green with a light flavor.
How much is too much avocado for waistline watchers? The recommended serving size is two tablespoons, or one-sixth of a medium-sized avocado, which provides 5 grams of fat and 55 calories, a much better choice on a sandwich than butter or mayonnaise, which each pack 22 grams of fat and 200 calories in a two tablespoon serving.
Green tea is one of the most popular beverages to hit the U.S. market in the last decade. Unlike black tea or oolong, green tea is made from unfermented tea leaves. Because it is does not go through a fermentation process, research suggests that it contains the highest concentration of polyphenols, antioxidants that rid of the body of free radicals. Some preliminary research shows that green tea's polyphenols, particularly ECGC, stop the free-radical damage that may lead to cancer and heart disease.
But even though green tea gets a lot of props for its reputation as a healing brew, most of the studies on its effects have been done in the laboratory or in animals. The bulk of human studies have been population-based, those that follow large groups of people over a specified period of time. The results of those studies have been inconsistent. Because of that data, the Food and Drug Administration says there is no scientific evidence that drinking green tea reduces heart disease, and the agency rejected a petition last year that sought to allow the claim on tea labels. The FDA previously said that green tea probably does not reduce the risk of breast, prostate or any other type of cancer. "Green tea has a lot of wonderful active compounds that may play a role in fighting cancer and heart disease and even protecting the lining of the arteries," says Dave Grotto, spokesperson for the American Dietetic Association. "But there needs to be a lot more research."
Despite many claims to the contrary, it probably doesn't help with weight loss, either. Some studies suggest that green tea's polyphenols may boost metabolism and help burn fat. Unfortunately, "there's nothing magic about green tea," says Dr. Frank Greenway, head of the outpatient clinic at the Pennington Biomedical Research Center in Baton Rouge, La., who studies herbal supplements and obesity. "I'll be surprised if it is shown to have any profound effect on weight loss."
Don't throw out your green tea just because the studies have been less than impressive. "Herbs always play catch-up when it comes to research," says Greenway. "Green tea won't hurt you." And maybe it will do some good. Some studies show that some green-tea drinkers may actually get more health benefits than others. Try it freshly brewed, which provides more antioxidants than bottled green-tea drinks.
Mother Nature is trying to tell you something when you crack open a walnut. The little heart-shaped nut offers some powerful cardiovascular benefits. So powerful, walnuts were the first food to receive an FDA-qualified health claim in 2004, allowing companies to say on their packaging that eating 1.5 ounces every day can reduce the risk of heart disease.
he muscle behind walnuts' heart-health profile is omega-3 fatty acids, particularly alpha-linolenic acid (ALA). Aside from raising HDL cholesterol (the so-called good cholesterol), researchers have found that ALA helps keep your blood flowing smoothly through your arteries—even after you eat a lot of saturated fats, which can harden the arteries, potentially contributing to heart attack and stroke. "What we're learning is that specific fats have specific benefits and risks," explains Dr. Michael Roizen, chief of anesthesiology and critical-care medicine at the Cleveland Clinic and author of “You: On A Diet.” "The fat found in walnuts actually decreases inflammation in the arteries and helps keep them flexible."
Walnuts are also rich in antioxidants. These natural compounds, found in plants, help rid the body of unstable molecules called free radicals, which can lead to cancer. Early research is also showing that walnuts may offer some protection against the bone-thinning disease osteoporosis. And they're good for your teeth, too. "Walnuts can lower the acidity made by sweets and fruit juices," says nutritionist Keith Ayoob, associate professor of pediatrics at the Albert Einstein College of Medicine. "If you can't brush, chew a few walnuts at the end of a meal and you'll get some good cavity protection."
Because of their fat, fiber and protein content, walnuts are also one of those nutrient-dense foods that help increase satiety, that feeling of fullness you get after a meal. Roizen recommends eating six walnuts twice a day, 30 minutes before lunch and 30 minutes before dinner. Not only will you feel full, but you'll get the health benefits, too.
For a good nut, walnuts can go bad fairly quickly. Especially if you compare them to dry roasted almonds, which can last three to four years. The folks from Whole Foods recommend storing shelled walnuts in the refrigerator in an airtight container, which will keep them fresh for about six months. Freeze them and they will last for one year. You should store unshelled walnuts in the refrigerator, too. But they will keep for up to six months in any cool, dark place. Storage may be moot. Considering how good they taste and their health benefits, it's unlikely you'll keep a package around longer than a week.
After more than 2,000 years of folklore touting ginger as a treatment for nausea and inflammation, it turns out that the ancients were right. Though the robust taste is not for the timid, ginger successfully quelled nausea and dizziness in several clinical studies and showed an excellent track record in preliminary trials as an anti-inflammatory agent.
Over the centuries, sages in China, India, Japan and Greece have celebrated the root’s medicinal qualities in treating a host of ailments ranging from migraines to cholera to inflamed livers. Thought to have originated in Southeast Asia, the spice has appeared in the earliest medical books touting its calming effects and aid in troubled circulation. By the Middle Ages, Arab trade had brought the root to England, where it became popular in sauces, gingerbread and as crystallized candy. Even King Henry VIII was reputed to have a fondness for ginger at a time when it was known as a powerful aphrodisiac.
Today, ginger is finding a place in medicine again as researchers explore the qualities that have made this humble root so appealing for so long. Most documented is ginger’s effectiveness in soothing all kinds of nausea from morning sickness during pregnancy to chemotherapy side effects and postoperative dizziness. “It’s a really cool way to suggest a possible treatment for women who are pregnant because it doesn’t have the harmful side effects of nausea medication,” says Christine Gerbstadp, dietician and spokesperson for the American Dietetic Association. Doctors recommend 2 to 4 grams a day for nausea or, for travel sickness, about the same amount 30 minutes before boarding the vessel or vehicle.
Prospects also look good for ginger as an anti-inflammatory agent to treat those who suffer from such illnesses as arthritis. “The evidence is preliminary and promising,” says Tieraona Low Dog, medical doctor and director of education for the program in Integrative Medicine at the University of Arizona. “We have the basic science (for how it works), we have animal studies and we have a few clinical studies. But our challenges are what’s the best dose and what’s the best way to give it to somebody.” Researchers also believe ginger has antioxidant properties, which could help prevent chronic diseases such as cancer, diabetes and heart disease.
There are simple and yummy ways to get your ginger. The spice is a great complement for any stir-fry or salad, and a cup of hot water with ground ginger and honey could easily become a comforting nighttime routine. For those who dislike its strong taste, though, caplets with ginger powder are an alternative.
Ginger is not for everyone. Those on prescription blood thinners should consult their physicians before going on a ginger gorge, as agents in ginger could react poorly with the drugs. Also, since ginger flavor is so potent, use common sense if eating it causes any discomfort. “Like all spices, if you add too much, it upsets your stomach,” says Low Dog. “That’s going to be the trick for future research: how are we going to get ginger into people at that level without upsetting the stomach?”
Even if ginger doesn’t become a medicinal mainstay, its place as a delicious treat is secure. “Those ginger candies?” Low Dog says: “Oh, my God.”
A diet with liberal servings of fish, nuts and seeds rich in nutrients called omega-3 fatty acids can help lower a person’s blood pressure, according to a study.
“A large percentage of people between ages 20 and 60 have a rise in blood pressure, and by middle age many have high blood pressure,” said Dr. Jeremiah Stamler, professor emeritus of preventive medicine at Northwestern University in Chicago, who worked on the study.
“We’re looking at dietary factors that may help prevent that rise, and omega-3 fatty acids are a small, but important piece of the action,” Stamler said.
The study looked at diet and its relation to blood pressure in 4,680 men and women, ages 40 to 59, who lived in Japan, China, Britain and the United States.
They all provided in-depth details about their diets and alcohol consumption, gave urine samples and had their blood pressure measured twice at each of four study visits.
Researchers then adjusted for 17 variables known to influence blood pressure such as age, gender, weight, salt intake and exercise.
The people who ate diets rich in omega-3 fatty acids had slightly lower blood pressure, on average, than people who ate diets with less of the nutrient, the researchers reported in the American Heart Association Journal Circulation.
“With blood pressure, every millimeter counts. The effect of each nutrient is apparently small but independent, so together they can add up to a substantial impact on blood pressure,” said Dr. Hirotsugu Ueshima of Shiga University of Medical Science in Otsu, Japan.
“If you can reduce blood pressure a few millimeters from eating less salt, losing a few pounds, avoiding heavy drinking, eating more vegetables, whole grains and fruits (for their fiber, minerals, vegetable protein and other nutrients) and getting more omega-3 fatty acids, then you’ve made a big difference,” Ueshima said in a statement.