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Ultimate Nutrition Column
Power Foods
Susan M. Kleiner, PhD, RD, FACN, CNS, FISSN The idea that certain foods may help you be healthier and live longer is not a recent phenomenon. Garlic is of such antiquity as a cultivated plant that it's difficult to trace the country of its origin with any certainty. In The Odyssey, Homer tells us that it was to the virtues of the "yellow garlic" that Ulysses owed his escape from being changed by Circe into a pig, like each of his companions. The ancient Mayans prized a daily beverage made of cacao powder, vanilla bean and dried chili pepper (capsicum) as the beverage of life and health. Today we can use science to help us determine which foods may possess the greatly sought after elixir of health.Power Food Factors Fibers There are many "food factors" that have been identified as health promoting properties in foods. One of the first was fiber, found only in plant foods and identified as an important component to a healthy diet in the 1950's. There are several different types of fibers and each one offers a slightly different function and health benefit. For instance, the water-soluble fibers in beans, oatmeal and the skins of some fruits slow down the processing of food through your digestive tract. This leads to a lowering of cholesterol levels and better management of blood glucose levels. The water-insoluble fibers found in whole grains and the skins of some fruits speed up digestion, enhancing gut motility and reducing the risk of many diseases of the intestinal tract, including diverticulosis and cancer. Phytoestrogens Some chemicals in foods are close enough in structure to chemicals and hormones produced in our bodies that they can mimic their functions in some way. Phytoestrogens, plant chemicals that mimic the hormone estrogen in humans, although weaker in their effects, have been associated with several health benefits. There are two different groups of phytoestrogens, classified by their chemical structures: isoflavones such as soy, and lignins that occur in flaxseed, grains and vegetables. There is much interest on the effects of these compounds on menopausal symptoms, heart disease, bone and cancer. Healthy Fats The benefits of "healthy fats" are much in the news these days. Monounsaturated fats found in nuts, seeds, olives, olive oil and canola oil are getting rave reviews in the heart-health and fat-loss departments. Marine oils, known as omega-3 fats, are high on the health and longevity register. Found only in foods from the ocean, particularly fish and shellfish, omega-3 fats are renowned for protecting against heart disease, blood clots and stroke. At the same time omega-3 fats boost your brainpower, enhance your mood, and reduce arthritic pain. An added benefit of eating fish is that it helps with weight management. Probiotics Commonly found on a list of longevity foods is yogurt and other cultured dairy products. Along with containing a complete set of all the nutrients required for bone-building, yogurt is created by a culture of live bacteria called probiotics. Unlike the bad bugs found in food that make you sick, these bugs are normal inhabitants of a healthy human digestive tract. Their job is to help with digestion and create an environment that disocourages the growth of bad bugs. Probiotics confer a remarkable arry o f benefits on the human body. They
Additionally, the whey protein from dairy foods is high in the amino acid trytophan, a precursor to serotonin. Studies show that whey protein decreases stress and anxiety in stress-prone subjects, and enhanced mood. Serotonin also promotes restful sleep. Antioxidants The process of oxidation in the body causes tissue and cellular damage, and is involved in the promotion of most chronic degenerative diseases and aging. What's more, further oxidation occurs as a consequence of disease processes, such as inflammation, and from tobacco smoke, environmental pollutants, food constituents, drugs, alcohol and radiation. The dietary intake of antioxidants, food factors that enhance the naturally occurring oxidation-fighting machinery of the body, has been suggested to reduce the oxidative damage that leads to aging and disease. Many observational and experimental scientific studies support the hypothesis that diets high in the antioxidants vitamin E, vitamin C, and ß-carotene were associated with reduced oxidative-stress relative to disease. Despite these studies, when each individual nutrient is studied as a single supplement to a diet to reduce disease, the results are not always supportive of the theory. There are several thousand antioxidants in foods consumed in the diet, many of them not even yet identified by researchers. Rather than working alone as single "bullets", it is likely that the multitude of antioxidants in foods work in concert with each other to promote health and prevent disease, more like a specialized fighting unit. To promote the categorization of foods relative to their antioxidant potential, researchers participating in an international multi-center study measured the antioxidant capacity of 1113 foods consumed in the United States and ranked them according to their antioxidant compound content. The food categories containing the highest antioxidant contents, in order, were spices and herbs, nuts and seeds, chocolate and sweets, vegetables and vegetable products, ready-to-eat cereals, desserts and cakes, and berries and berry products. Overwhelmingly, foods from the plant kingdom, such as fruits and vegetables, were highest in antioxidants compared to foods from the animal kingdom. (1) The researchers then compared the foods relative to their typical serving sizes and came up with a list of the top 50. Even though spices and herbs were at the top of the list of food categories highest in antioxidants, because a typical serving size of a spice is minute compared to fruits or vegetables, only cloves are on this list. Of the top 50 products based on serving size, 15 were fruits or fruit juices, 10 were vegetables, 6 were berry products, 4 were chocolate based, 2 were breakfast cereals (fortified by manufacturer) and 2 were nuts. Red wine and coffee were also among the top 50 items. Table 1. Top Twenty foods with the highest antioxidant contents per serving size.
Lecithin Eggs have fallen into an unjust disfavor. Their protein is of the highest quality. It receives a perfect score for bioavailability, meaning your body gets to use prett much all of it. Most proteins can't make that boast. The egg yolk has been particularly scorned, but that is a particularly important source of nutrients. It contains protein and iron, but the secret treasure inside the yoke is lecithin. Lecithin is made up of two phospholipids: phosphatidylcholine and phosphatidylserine, which are crucial for nerve transmission in the brain. That conductivity has a big impact on how your memory machinery is working. Egg yolks and soy foods that are not fat-free are the best sources of lecithin in our diets. An egg yolk every day is a perfectly healthy diet strategy for anyone in good heart health. You can also alternate egg with soy every other day. Protein Protein is crucial for muscle growth and repair, for enzyme and hormone production, immune function, for keeping your mood high and your appetite in check. The dark meat of turkey and other poultry give you not only very lean, high-quality protein but also critical nutrients such as iron, zinc, vitamin B6 and B12, and thiamin. Many other foods are bereft of those. Turkey is also high in tryptophan, making it a mood lifter during the day and helping you relax after dinner. The Fluid Factor No article about health and longevity-promoting foods would be complete without mentioning water. The health benefits of water are legion. You likely already know that water is required for every biochemical reaction that occurs in your body from energy production to joint lubrication to reproduction. What may be news to you is that many observational studies now report that people who drink 5-6 cups of water every day have a significantly decreased risk of developing urinary tract stones, many cancers, coronary heart disease and mitral valve prolapse (a type of heart murmur) (2). Design a fluid plan with the same rigor as you apply to eating. To cover your minimum intake, drink 2 cups of fluid upon waking in the morning, followed by 2 more each at midmorning, lunch, midafternoon, and dinner. Make at least 5 of them water. Then add what you need to stay well hydrated before, during and after exercise. Keep in mind that a number of factors could bump up your minimum fluid requirements. These include high temperatures, low humidity, high altitude, exercise, pregnancy, nursing, dieting, illness, and travel. References Halvorsen BE, Carlen MH, Phillips KM, Bohn SK, Holte K, Jacobs DR, Blomhoff R. Content of redox-active compounds (ie, antioxidants) in foods consumed in the United States. Am J Clin Nutr 2006;84:95-135. Kleiner SM. Water: An essential but overlooked nutrient. J Am Dietet Assoc 1999;99 (2):200-206. Kleiner SM, O'Connell J. The POWERFOOD Nutrition Plan. Rodale, Inc. 2006
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