I was taught a rather simplistic view of nutrition in medical school. Nutritional supplementation was viewed with disdain and diets were defined primarily by which foods patients were to avoid. Someone with high blood pressure, for example, was to eliminate table salt, which is high in sodium. An individual with a family history of heart disease was to limit egg consumption, since eggs are high in cholesterol. A person who was overweight was to cut calories by eating less. Little or no attention was paid to the benefits provided by specific foods or food groups.

This is still the norm in our society. Ask someone to define the term “diet” and he or she is likely to respond with answers such as “Low-carb”, “Low-calorie”, or “Cutting back”. Rarely do we think of what we might add to or include in our daily diet to improve our health and enhance our chances of avoiding premature death or disability.

A great deal has been learned about the health benefits of specific foods in recent years. Understanding what each has to offer can add excitement to meal planning in the present and years of productive life in the future. I suggest the following foods be considered candidates for the Super Food Hall of Fame.

Topping the list is what has been referred to as the “incredible, edible” egg. I give it this spot not only for what it offers, but because it has been so unjustifiably maligned over the past thirty-five years. Old school nutritionists still hold to the belief that a healthy diet can include no more than two eggs per week from any source.

The humble egg is one of the most complete food sources available. When I consider that the yolk (ironically, the part most vilified by dietitians) provides all of the building blocks required to produce a living, breathing, walking chick I am awestruck. It is almost unbelievable that all of the needed chemical energy, all of the necessary proteins, vitamins, and minerals for the development of the chick’s bones, internal organs, muscles, and feathers are contained within a single egg yolk.

An egg contains all nine essential amino acids, the protein building blocks that we cannot manufacture and must obtain from external sources. One measure of dietary protein is called its biological value, which refers to how efficiently it can be used to grow and repair muscle, skin, and other body tissues. Biological value also takes into account the importance of the protein in the manufacturing of vital compounds including antibodies, hormones, and enzymes. Egg protein ranks first in biological value, surpassing that of milk, fish, meat, and legumes. As such, nutritional scientists use egg protein as the standard by which all others are measured.

Eggs provide a broad range of vitamins and minerals, but several important egg nutrients are often overlooked. Two of these are the carotinoids, lutein and zeaxanthin, that have been shown to prevent macular degeneration, the most common cause of blindness in people over the age of fifty. Because these nutrients are fat soluble, the fats naturally accompanying them in eggs make them more highly absorbable than those in vegetable sources such as carrots and spinach. Two-thirds of the fats found in eggs are polyunsaturated and monounsaturated, which are often deficient in American diets.

“But what about cholesterol?” you may be asking. “Aren’t egg yolks high in cholesterol?” Yes, egg yolks contain cholesterol, but cholesterol obtained from foods has almost no effect upon blood cholesterol levels. Blood cholesterol levels are determined primarily by the amount of cholesterol manufactured by the liver, not absorbed from the digestive tract. It is dietary fat, rather than dietary cholesterol that influences the amount of cholesterol that is manufactured and released into the bloodstream.

Because the fat contained in eggs is predominantly unsaturated, evidence is now suggesting that including eggs in one’s diet may actually result in improved LDL/HDL cholesterol ratios. (The ratio of LDL to HDL cholesterol is the most significant factor in determining whether or not an individual is at increased risk for atherosclerosis on the basis of cholesterol.)

Another nutrient found in egg yolk may be even more significant in preventing atherosclerosis. Egg yolk is the richest dietary source of a chemical called lecithin. Lecithin is a rich source of choline, which is needed for the production of acetylcholine. Acetylcholine is a chemical that transmits messages between nerve cells. Acetylcholine is critical to learning and memory.

Choline is also needed for the manufacture of phosphatidyl choline, a component of cell membranes. Phosphatidyl choline and similar phospholipids have been shown to prevent gallstones by keeping cholesterol in solution rather than allowing it to assume a solid consistency. Liquid cholesterol is never a problem. Only when it solidifies as gallstones or as arterial plaque does it present a challenge. Maintaining cholesterol in solution is one of the primary benefits of including sources of lecithin in the diet. When an adequate amount of lecithin is consumed, the melting point of cholesterol is lowered from 180 degrees, nearly double body temperature, to 60 degrees, well below normal body temperature. I have personally seen individuals dissolve gallstones and avoid surgery by supplementing lecithin daily.

Oats are another super food. Just as an egg yolk is sufficient to provide all of the elements required to turn a single cell into a completely developed chick, oats contain enough nutrients to maintain the strength and vitality of a horse. Oats have been a major horse food since the days of the Roman Empire. Greeks and Romans considered oats a diseased version of wheat, fit only for horses. They scoffed at Germanic tribes as “oat-eating barbarians”. The disdain for oats as a food for people continued for some time. Samuel Johnson’s dictionary is said to have stated that while oats are eaten by people in Scotland they are only fit for horses in England. This prompted one Scotsman to respond, “That’s why England has such good horses, and Scotland has such fine men!”

It is estimated that even today less than 5 % of commercially grown oats find their way into the human food supply, most as breakfast cereal. This is largely related to the efforts of several individuals who began milling oatmeal in the late nineteenth century and who consolidated in 1888 to form the American Cereal Company. American Cereal changed its name to Quaker Oats in 1901.

While not as complete as egg protein, oats have the best amino acid balance of all cereal grains. Oats also contain more soluble fiber than other grains. They are particularly rich in a substance called hemicellulose, which enables bacteria within the digestive tract to produce fatty acids that nourish intestinal cells. Hemicellulose also mixes with water to form a gel that passes slowly through the body. This improves the sensation of satiety, or stomach fullness. As it passes through the digestive tract it slows the absorption of sugar, limiting swings in blood sugar. This is particularly beneficial to diabetics and those prone to episodes of hypoglycemia. Hemicellulose also inhibits the reabsorption of bile into the system, which helps to lower blood cholesterol.

Several studies have shown a significant reduction in the risk of developing heart disease and other cardiovascular diseases among individuals who consume oats on a regular basis. Most researchers credit this reduction in cardiovascular disease to the ability of hemicellulose to lower blood cholesterol levels. It is quite likely, however, that a different mechanism is responsible for this benefit.

Oats contain unique antioxidant compounds called avenanthramides, which are very effective in protecting LDL cholesterol from free radical damage. It is damaged LDL, referred to as oxidized LDL, that is associated with plaque formation and atherosclerosis. Oat avenanthramides have also been shown to suppress the attachment of white blood cells to arterial walls. It is this attachment that is the first stage of plaque development. Avenanthramides also exhibit anti-inflammatory effects and enhance the effectiveness of vitamin C and vitamin E in the body.

In addition, oats are a rich source of beta-glucan, a substance that stimulates macrophages, the white blood cells that seek out and destroy viruses and other invaders. As a result, people who include oats in their diets are more resistant to colds and other infections.

Spinach is a food that is usually promoted as a super food for the wrong reason, but has other attributes that make it a legitimate dietary superstar. Spinach, of course, is the vegetable that gives Popeye his incredible strength. This image is based upon the supposed high iron content of the leafy green. Spinach, unfortunately, does not contain the high concentration of iron most assume it to have.

Spinach’s reputation as a rich source of iron came about because of an error in punctuation. In 1870 Dr. E von Wolf published his findings on the nutritive value of foods. A misplaced decimal point gave spinach an iron value ten times higher than its actual amount. The error was not discovered until 1937 when German scientists reinvestigated the plant and discovered the error. Their findings were not publicized until 1981. By then the “spinach is high in iron” myth was firmly entrenched.

Spinach is high in lutein, however. This substance, also found in egg yolk, is highly effective in preventing macular degeneration. People who include five servings of leafy green vegetables such as spinach each week have been shown to reduce their risk of developing macular degeneration by 43 percent.

Fresh spinach is rich in other nutrients such as folic acid and carotenoids. Vitamin nutrients are lost quickly after harvesting, however, and few remain if the leaves have not been eaten within several days. These nutrients are spared if the leaves are fresh frozen or cooked and canned within two or three days of being picked.

Tomato is another food that is being recognized for its health benefits. Unlike most plants, which have been eaten for millennia, tomatoes were first grown for food in the sixteenth century. Even then, they were slow to catch on. Tomatoes were not cultivated in North America until the eighteenth century, and then only as an ornamental plant. The fruit was considered highly poisonous due to the odor given off by the leaves of the plant. The adverse effects of eating a tomato were said to be turning one’s blood to acid, frothing at the mouth, appendicitis, stomach cancer, and brain fever.

Thomas Jefferson was one of the earliest Americans reported to include tomatoes in his diet. He began growing them in his garden in 1809 and his daughter and granddaughters developed numerous recipes that called for tomatoes.

It is only recently that tomatoes have emerged as a health food. Several studies in 1998 and 1999 reported that men who regularly included tomato products in their diet had a lower risk of developing prostate cancer. This was confirmed by a 2002 study that reviewed the dietary habits of over 47,000 men. Researchers reported that eating tomato paste or tomato sauce twice a week lowered prostate cancer incidence by 20 percent.

The credit for this observed decrease in prostate cancer has been given to lycopene, the substance that gives tomatoes their red color. This has resulted in the appearance of lycopene supplements that are promoted as providing protection against prostate cancer. I do not encourage the use of lycopene supplements, however.

While lycopene may ultimately prove to be the factor that accounts for tomatoes’ ability to prevent prostate cancer, there is another candidate. Pectin is a substance that cements together the cells that make up the flesh of the tomato. Pectin is also found in other fruits, particularly citrus fruits and apples. A great deal of research has been done surrounding pectin and cancer, particularly prostate cancer. The emphasis has been on citrus pectin, but there is no reason to believe that citrus pectin is unique in its anti-cancer effects.

The prostate cancer benefits of tomatoes have been associated primarily with processed products such as tomato paste or tomato sauce. Lycopene is absorbed more efficiently from cooked tomatoes, but the heating also stabilizes tomato pectin and preserves its integrity. It may ultimately be demonstrated that the observed benefits accrue not only from lycopene or pectin, but from a combination of the two. For this reason I believe that it is wise to obtain lycopene from processed tomato products rather than from a lycopene capsule.

Sweet potatoes are relegated to the holiday table in most American households, but they are available in supermarkets year-round and deserve to be a stable of the diet because of their many health benefits. The yellow-orange flesh of the sweet potato is one of the richest dietary sources of beta-carotene. It is also high in vitamin C.

Beta-carotene and vitamin C work together to lower the risk of atherosclerosis and cancer by neutralizing damaging free radicals. They also reduce inflammation, improving such conditions as asthma and arthritis. These nutrients may be particularly important for those who smoke or who are exposed to second hand smoke.

Research at Kansas State University has revealed that benzo(a)pyrene, a carcinogen in cigarette smoke, induces vitamin A deficiency. Vitamin A deficiency in turn leads to the development of emphysema. When laboratory animals are exposed to cigarette smoke they develop emphysema at a high rate. Animals fed beta-carotene rich diets, however, are much less likely to develop emphysema when breathing cigarette smoke. Lead investigator, Dr. Richard Baybutt, believes that this may explain why some smokers do not develop emphysema as they age.

The sweet potato’s benefits go far beyond its vitamin content, however. Certain proteins contained within the vegetable are being found to have potent anti-oxidant effects, independent of the effects of vitamin C and beta-carotene. Recent studies have also demonstrated that sweet potatoes help to lower insulin resistance and stabilize blood sugar levels in diabetics. This benefit is felt to be due to the high carotenoid content of the food.

The high fiber content of the tuber is an added bonus. Dietary fiber is known to provide a wide array of health benefits including prevention of constipation, hemorrhoids, diverticulosis, colon cancer and breast cancer. It has also been shown to reduce the risk of heart disease and help lower blood sugar in diabetes.

Given its high anti-oxidant, carotinoid, and fiber content, the sweet potato is one of the most ideal foods for diabetics. In case you are wondering, the yam is one of approximately 400 varieties of sweet potato, and, as such, provides the same benefits.

Although it is generally not considered a food, tea is a substance that can provide significant health benefits when included in the daily diet. Green tea has received the most publicity in this regard, but more recent studies are showing that black tea is just as advantageous.

Green tea has been used medicinally in China for at least 4,000 years. Recent research has shed light on its effectiveness in preventing cancer, improving rheumatoid arthritis, lowering cardiovascular disease risk, decreasing the incidence of infections, and improving immune function.

A 1994 study reported that drinking green tea reduced the incidence of esophageal cancer by sixty percent. This prompted further research directed at identifying the substances responsible. Compounds called catechin polyphenols were discovered. They are powerful anti-oxidants that are capable of inhibiting the growth of cancer cells and even killing cancer cells without harming normal cells. One polyphenol, epigallocatechin gallate (EGCG), has been found to inhibit the formation of abnormal blood clots, which are the leading cause of heart attacks and strokes. EGCG appears to be even more effective that resveratrol, the chemical in grape skins, in preventing heart disease.

Green tea has been shown improve metabolism and improve weight loss in dieters. It contains anti-bacterial properties that can reduce dental plaque buildup and reduce the development of cavities.

Green tea is processed by steaming the leaves, which prevents the breakdown of EGCG. Black tea is processed by fermentation, during which EGCG is converted to other compounds. This was once felt to negate the benefits found in green tea, but more recent studies have demonstrated that compounds contained in black tea, such as theaflavins and thearubigens provide the health benefits previously attributed only to green tea. Because these compounds improve the function of blood vessels the regular consumption of black tea has been shown to reduce the incidence of heart attack by up to fifty percent.