According to the IFIC, most Americans believe that they have at least moderate control over their health and that nutrition plays a role even more significant than exercise and family-health history. "Foods for treatment and prevention of disease is an exploding area," says Andrew Weil, M.D. "Any medical journal shows how groups of foods or food components affect health."
If you've heard anything about food's magical powers, it was likely linked to antioxidants. They neutralize cell-damaging agents and possibly reduce your risk of disease. Antioxidants occur naturally in foods of various types such as fruits, vegetables, nuts, fish oil, tea, and numerous others.
Walter Willett, of Harvard School of Public Health, notes that, "We are learning that foods have many more important functions than we had recognized earlier. For example, polyunsaturated fats do much more than lower blood cholesterol levels. They can help prevent blood clots and lower the odds of developing fatal heart rhythms."
The role of essential fatty acids is another huge area of research. Says Weil, "They improve mental function and protect against heart disease and inflammation. The average American diet is seriously deficient in omega-3 fatty acids, and that has health consequences." Good sources for omega-3s include fish, certain seeds, and walnuts.
Plant-based foods such as vegetables, fruits, soy, and whole grains are also recommended as part of an optimal diet. These contain phytochemicals, natural agents which help strengthen the immune system and protect against disease.
Phytochemicals are found in foods such as garlic, legumes, and nuts, among many others. "Fruits and vegetables don't contain disease-promoting substances; they contain thousands of protective ones," says author Dean Ornish, M.D. "It's not just what you exclude from your diet, it's what you include that's important."
Learning about foods is only part of the goal. To live a healthier life, you may need to change your ways. Shopping for, preparing, and eating foods differently may be in order. Making the switch from chips to veggies isn't easy, so how do we find the motivation?
For one thing, using the fear of death to motivate people doesn't work, says Ornish. However, "when you begin making changes in your diet and lifestyle, you start to feel better. You have more energy, you think more clearly, your brain and heart get more blood, you don't need as much sleep and you have more stamina."
New information surfaces continually, so it can get confusing. To decide what makes sense for you, read, consult your doctor or nutritionist and explore new foods. "Try making changes even if it's just for a week. You'll learn from experience how much better you feel. It's a much more organic way of changing," says Ornish. And, as Willett notes, "Decisions about eating shouldn't be made on the basis of a single study; confirmation from various reputable sources is important." That's why PT has put together some of the most interesting findings from 2005. From ginko to omega-3s, here are some studies that show the benefits.
Guard Your Heart
To protect your heart, you already know that you need to exercise and eat a diet low in saturated fats. But studies show benefits in foods you may not have considered. Soy, for one, is believed to reduce the risk of heart disease by lowering cholesterol. Many experts recommend 25 grams of soy protein a day. A study in Diabetes Care shows that soy may help reduce the risk of heart attacks and strokes in postmenopausal women because it contains the antioxidant isoflavones. You can get soy in many forms: edamame (steamed soybeans), tofu and soynuts, for example.
Nuts also have heart-healthy effects, although they were once feared because of their high-fat content. But the Harvard Nurses' Health Study found that women who ate an ounce of nuts at least five times a week for 14 years lowered their risk of heart disease by about 30 percent.
Nuts have monounsaturated and polyunsaturated fats, and according to the IFIC, individuals with diets high in these fats enjoy lower levels of bad cholesterol. Saturated fats, on the contrary, increase "bad," low-density lipoprotein (LDL) cholesterol. Other foods high in healthy fats include avocados, soybean oil, and olive oil.
Omega-3 fatty acids are an equally important fat component that is found in abundance in oily fish such as salmon and mackerel, and to a lesser extent in other forms of seafood. These fatty acids help maintain and repair brain cells, which are made of fat. They also reduce the risk of chronic diseases such as coronary heart disease, stroke and cancer. A study published in the American Journal of Clinical Nutrition found that sudden cardiac deaths occur less frequently in those who eat ocean fish.
Of course, when listing heart-healthy ingredients, don't forget wine and beer. We all know that moderate alcohol consumption can help prevent heart disease, but research indicates that how often you drink may be more important than how much or what you drink. A study from Beth Israel Deaconess Medical Center in Boston reported that people who drink alcohol at least three times a week are less likely to develop heart disease than are nondrinkers and less-frequent drinkers—regardless of what is preferred: beer, wine, or spirits.
In another report, published in the European Journal of Clinical Nutrition, Dutch researchers studied beer-drinking with dinner. In the study of middle-age adults, levels of C-reactive protein, a compound associated with inflammation and blood clots, declined.
Indeed, wine, soy, nuts, and fish are well-known for their heart-healthy benefits. But here are some surprising additions: Honey and chocolate, and the darker the better. Apparently, honey has the same heart-healthy, plaque-fighting antioxidants found in foods such as spinach and apples. At the University of Illinois at Urbana-Champaign, a five-week study of men between ages 18 and 68 found that antioxidant levels in their blood increased after drinking water with honey.
And chocolate helps your heart as well. Its flavonoids, a family of antioxidants, help the body resist cell damage from free radicals. And, in turn, the sweet may decrease your risk for stroke and heart disease.
Thanks for the Memories
Exercising your brain with crossword puzzles may help keep your thinking cap in order, but studies show that what you eat helps as well. The antioxidants in cranberries, for example, may have anti-aging effects. According to the Human Nutrition Research Center on Aging at Tufts University, cranberries help protect the brain from neurological damage.
Certain foods can also prevent other cognitive-related problems. Linoleic acid is nutritionally essential. It can be found in seed oils such as safflower and sunflower and, according to a Loyola University Medical Center study, may help control hypertension and thus prevent stroke, another leading killer.
Equally important is what you drink. According to a study published in Neurology, people who drink wine moderately have a lower risk of developing dementia, including Alzheimer's disease. Red wine is especially favorable because it is high in flavonoids and resveratrol, which has abundant anti-aging effects.
And antioxidants, of course, are important in maintaining cognitive ability. These disease-fighting agents came into play once again in two studies published in the Journal of the American Medical Association. Researchers found that diets rich in antioxidants—especially vitamin E—may help protect against Alzheimer's.
Don't forget your fruits and vegetables. Cruciferous vegetables such as broccoli and watercress contain phytochemicals called isothiocyanates that help our bodies to break down potential carcinogens. Bok choy, brussels sprouts, cauliflower, kale, mustard greens—there are countless cruciferous vegetables that will give you what you need.
A diet rich in vegetables from the allium food group, such as garlic, shallots, and onions, reduce the risk of prostate cancer, according to a study by the National Cancer Institute. Scallions offer the most protection, but if you prefer garlic, the study suggests that one clove a day will suffice.
Similarly, fruits have these protective powers, as well. Tomatoes, for instance, contain lycopene, which protects cells against carcinogens. Or, if you prefer, a daily serving of berries protects against cancer, as well.
Several studies have found health benefits in berries. Researchers at Ohio State University discovered that berries stop tumors from growing in rats. Black raspberries are considered the most potent because they contain compounds such as anthocyanins—believed to protect against heart disease by lowering LDL cholesterol. Berries are also high in phenols such as ellagic acid, an antioxidant that protects the body's cells.
"People self-regulate their mood continuously with food, usually through sugar and fat," says Robert Thayer, Ph.D.. "It immediately makes them feel better, but unfortunately the effect is short-term."
Thankfully there are healthful foods that can help lift your spirits. Research published in Brain, Behavior, and Immunity reports that there is a link between mood changes and the amino acid tryptophan—found in foods such as turkey, milk, and bananas. Researchers lowered the level of tryptophan in 27 volunteers, and they found that less tryptophan indeed lowered mood.
Additional research shows that chocolate benefits mood. Phytochemicals in chocolate trigger the same reactions as some antidepressants, according to a study in the American Journal of Psychiatry. The study authors found that chocolate releases endorphins, proteins with analgesic properties that occur naturally in the brain. But don't overdo it; just a tiny bit will give you a boost.
Build Your Bones and More
Milk isn't the only thing that prevents bone deterioration. Tea contains fluoride and flavonoids that include estrogen-like plant derivatives—both of which may enhance bone strength. A Taiwanese study published in the Archives of Internal Medicine surveyed 1,037 men and women who were longtime tea drinkers. Increased bone density was found in people who drank an average of two cups a day of black, green, or oolong tea for at least six years.
There are many foods helpful in keeping a strong frame, including collards, broccoli, sesame seeds, sardines and, yes, soy. Postmenopausal women with high concentrations of soy in their diet had stronger bone health according to a study at the University of Illinois at Urbana-Champaign. "Regular inclusion of soy in the diet protects the bones," says Weil. "But it's important for young women to know that you can't reverse osteoporosis by suddenly trying to increase your calcium intake at menopause."
Soy is also important in reducing postmenopausal symptoms. An Australian study of 58 women found a 40 percent decrease in hot flashes among those who consumed 45 grams of soy flour a day over a 12-week period. Not a bad alternative to hormone replacement therapy (HRT), especially in light of HRT's risks—such as coronary heart disease, stroke and blood clots.
Soy, and other vegetables and fruits, contain phytoestrogens—plant compounds that mimic estrogen hormones in animals. "The more women eat a plant-based diet, the more likely they will have less trouble at menopause," Weil says. "That does not mean a vegetarian diet but a diet that emphasizes fruits and vegetables and is low in animal fats."
Mind Over Munchies—Changing Your Ways
You've digested all of this foodwise information—so, now what? Do you start downing bottles of wine, eating tons of chocolate and topping everything with nuts? The challenge ahead is sensibly changing your eating habits and making them stick. Remember that you have high-energy cycles and low-energy cycles throughout the day, says Thayer. Your energy is up in the morning, low in late afternoon, and lowest before bed. "When you are aware that these periods occur, you need to grit your teeth and not give in," he says. He also advises taking a short, brisk daily walk. It will temporarily raise your energy, and with increased energy you can resist food urges.