Craig Let food be your medicine, Hippocrates said, and for centuries doctors have stressed the importance of a good diet.
As early as grade school, you probably learned that you should get five servings a day of fruits and vegetables, eat more fiber, and avoid fats and empty calories. Based on research over the past several decades, nutritional advice is becoming ever more specific, shifting away from the focus on vitamin deficiencies and RDAs and isolating specific foods and components of food that have been shown to play a role in enhancing health and preventing disease.
Several books now on the shelves detail the findings of scientific studies focusing on antioxidants, essential fatty acids, plant stanols and sterols, flavonoids and phytochemicals. Whatever your specific health or genetic risk may be, these books tell you foods you should seek out, those you should eat less of and others you should avoid.
As opposed to the one-size fits all food pyramid approach, many nutritionists today are advocating a diet more tailored to the nutritional needs of the individual.
A DASH to lower your BP
Eating five servings a day of fruit and vegetables is good advice, but if you've got high blood pressure, you may need even more. The Dietary Approaches to Stop Hypertension diet recommends five servings of fruits plus five servings of vegetables per day.
For people who have hypertension because of salt sensitivity, eating more potassium may even be more important than cutting back on sodium. Many fruits - most notably bananas, oranges and apricots - are high in potassium as well as antioxidants which offer protection against heart disease and cancer.
An apple a day does keep the doctor away; studies have shown that apples can lower cholesterol and triglycerides. They are also a good source of catechins, which are believed to be effective in preventing cancer.
Blueberries, cherries, red grapes, cranberries and strawberries are rich in powerful antioxidant substances. In the 1950s, Ludwig W. Blau, Ph.D., reported in a Texas medical journal that adding six cherries a day to his diet gave him relief from gout so severe that it had him confined to a wheelchair.
Black cherry juice, according to recent reports, has a similar effect on gout. Tart cherries also contain significant amounts of melatonin, a hormone involved in normalizing sleep cycles.
There are many other reasons to eat a variety of fruits and vegetables. In a University of Michigan study, subjects eating greater quantities of ghutathione had lower blood pressure and cholesterol and greater success in weight control. Glutathione is found in abundance in winter squash, avocados, grapefruit, oranges, tomatoes and potatoes.
Kale and other green leafy vegetables are high in antioxidants such as lutein, which, among other benefits, protect against cataracts and age-related macular degeneration.
The beta-carotene in one carrot reduced the risk of stroke by 68 percent, according to one study. A precursor of vitamin A, beta-carotene is found in pumpkin, squash and sweet potatoes as well as carrots. Scientists have also identified more than 500 carotenoids, close relatives of beta-carotene that are believed to bestow numerous health benefits.
One benefit of fruits and vegetables is that they are high in fiber, which aids in weight control, keeps the bowels regular and lowers cholesterol.
Soluble fiber - found in oatmeal, barley, flax seeds, beans and the pulp of apples - is particularly effective in reducing cholesterol. It's believed that this type of fiber dissolves in the intestinal tract, forming a sticky gel that prevents fat and harmful cholesterol from being absorbed. Soluble fiber may also help regulate blood sugar and reduce the risk of diabetes.
Insoluble fiber, which comes from wheat and other whole grains, apple peel, celery, broccoli, greens, carrots, green beans and squash, speeds the passage of food through the intestines, improving weight control and reducing the risk of bowel disorders.
Cereals and breads are basic to a health diet, but it's important to seek out whole grain versions. In a recent study at Tufts, subjects who ate whole grains and cereals had one-third less expansion of their waist measurements over a three-year period compared to those eating white bread and refined grains.
Fat that's good for you
The American Heart Association recommends that Americans make fish a regular part of their diet - primarily because of the omega-3 fatty acids in fatty fish such as salmon, trout, halibut and tuna.
In addition to improving cholesterol and triglyceride levels, omega-3 fatty acids have an anti-inflammatory effect and protect against the irregular heart rhythms that often trigger a heart attack.
Perhaps even more important is the role of omega-3s on the brain. The Rotterdam Study and the Bordeaux Study indicated that a high intake of fish protected against the development of Alzheimer's and other dementias. Another study found a lower rate of depression in countries with a high annual consumption of fish.
Several recent studies have shown promising results using omega-3 fatty acids in the form of fish oil capsules as part of the treatment for psychiatric disorders such as schizophrenia, bipolar disorder and major depression.
Even foods once considered forbidden treats such as nuts, chocolate, honey and tea have recently been found to offer health benefits. Almonds are rich in magnesium, a nutrient crucial to a healthy cardiovascular system; walnuts are a good source of omega-3 fatty acids; and peanuts have high levels of arginine, which aids in the body's production of nitric oxide. In addition to keeping blood vessels healthy, nitric oxide is part of normal erectile function.
Honey, particularly dark honey, is high in antioxidants and beneficial minerals; so are black and green teas. Cocoa and dark chocolate contain antioxidant flavonoids, but also liberal quantities of butter and sugar so it's important to limit yourself to an ounce a day.
Read the labels on the shelves of a health food store, and you'll think you're in a farmer's market. But, there's not much pleasure in getting your nutrition from a brown bottle, and maybe some risk.
When you get your medicine from the brightly colored, intensely flavored foods on your plate, your only risk is eating too much.