Nutrient Density and Phytochemical-rich foods
By Joel Fuhrman, M.D.
The key to excellent health and longevity is to eat predominantly those foods that have a high proportion of micronutrients compared to macronutrients. Macronutrients are fat, carbohydrate and protein; the nutrients that contain calories, thereby supplying us with energy. Micronutrients are those nutrients that don’t contain calories, but have other essential roles. Micronutrients are vitamins, minerals and phytochemicals. There are thousands of them. The wave of new research on more than 8,000 recently identified phytochemical nutrients in natural (unprocessed) plant foods has generated excitement in the scientific community unparalleled since the first vitamin was discovered in the early 1900’s. These compounds work synergistically to detoxify cancer-causing compounds, deactivate free radicals and enable DNA repair mechanisms. These phytochemicals play a major role in human immune system defenses. The outcome is even more spectacular when they are missing – a nation of diseased children and adults. From arthritis to depression, the lack of these phytonutrients found in fresh fruit, vegetable, beans and raw nuts have an inevitable consequence – chronic diseases like diabetes, heart disease, and cancer. Though many accept that disease is the result of genetics or luck, the reality is that for the vast majority, nutrition, exercise and environment overwhelm genetics.
This basic principle of nutritional science can be represented in my Health Equation:
Health = Nutrients / Calories (H = N / C)
This is a concept I call the nutrient density of your diet. This means your future health can be predicted by the micronutrient per calorie density of your diet. A food is good or not-so-good based on how much fiber, photochemicals, antioxidants, minerals, vitamins and other unnamed (or yet to be discovered) nutrients it contains in proportion to its calories. Based on this N/C criterion, you can grade food quality, construct menus, and make food choices to support excellent health.
The diet during childhood has a significant impact on health not only during childhood, but also for the future. During childhood, when cells are rapidly dividing, the body is most vulnerable to damage from toxic substances in unhealthy foods and in the environment. For this reason, childhood diets are a major contributor to adult cancers(1). Similarly, the beginnings of heart disease – fatty streaks in the arteries – also begin during childhood. Therefore, eating a health-promoting diet starting during childhood(2) is far more protective than beginning to eat these foods in adulthood.
From the high occurrence of ear infections in our children, to acne, autoimmune illnesses, allergies, digestive complaints and headaches in early adult life, we visit physicians and receive toxic medication which further impedes our delicate but protective immune defenses, placing ourselves more readily vulnerable to future illness. Another option exists. That option is superior nutrition to prevent disease. Micronutrients – vitamins, minerals, and phytochemicals – fuel various clever host defense mechanisms, such as phagocytosis (surrounding and eating viruses) and antibody production. Deficiencies in virtually any known vitamin and mineral can compromise these host defense functions. Multiple micronutrients including lutein, lycopene, folic acid, bioflavoinoids, riboflavin, zinc, selenium, and many others have immunomodulating functions – they influence the susceptibility of a host to infectious diseases and the course and outcome of such diseases. These micronutrients also possess antioxidant functions that up-regulate immune function of the host. Viruses are able to assume a more virulent form and new more severe infections are more likely to emerge when nutritional deficiencies are present in the host. The most effective artillery we have to protect ourselves against the potential damaging effects of infectious diseases is nutritional excellence.
The major groups of health-promoting foods are green vegetables, onions, mushrooms, beans, seeds, and berries. These are the foods that have the most documented power to protect, heal, and prolong human lifespan.
Many green vegetables (such as bok choy, broccoli, collards, arugula, kale, cabbage, and watercress) belong to the cruciferous family, vegetables that contain potent anti-cancer compounds(3). Green leaves are perhaps the most powerful longevity-inducing foods of all.
All vegetables contain protective micronutrients and phytochemicals, but cruciferous vegetables have a unique chemical composition – they contain sulfur-containing compounds which are responsible for their pungent or bitter flavors. When cell walls are broken by blending or chopping, a chemical reaction occurs that converts these sulfur-containing compounds to isothiocyanates (ITCs) – compounds with proven anti-cancer activities.
Different ITCs can work in different locations in the cell and on different molecules – they can have combined additive effects, working synergistically to remove carcinogens and kill cancer cells. Some ITCs have anti-inflammatory, antioxidant, or even immunologic effects.
Cruciferous vegetables are twice as powerful as other plant foods. In population studies, a 20% increase in plant food intake generally corresponds to a 20% decrease in cancer rates(4), but a 20% increase in cruciferous vegetable intake corresponds to a 40% decrease in cancer rates. Twenty-eight servings of vegetables per week decreased prostate cancer risk by 33%, but just 3 servings of cruciferous vegetables per week decreased prostate cancer risk by 41%(5). One or more servings of cabbage per week reduced risk of pancreatic cancer risk by 38%(6).
Cruciferous vegetables are not only the most powerful anti-cancer foods; they are also the most nutrient dense of all the vegetables.
Beans and other legumes, like peas and lentils, are among the world’s most perfect foods. They stabilize blood sugar, making them a great food for preventing diabetes(7).
Beans are rich in fiber, which a nutrient essential to human health. Beans provide both insoluble and water-soluble fibers. Soluble fiber has complex physiological effects in the digestive tract that help to lower cholesterol, and regular bean consumption is associated with decreased cancer risk(8). Soybeans get the most attention for preventing reproductive cancers, but all beans have beneficial anti-cancer effects.
The Allium family of vegetables, which includes onions, garlic, leeks, and scallions, are known to have beneficial effects on the cardiovascular and immune systems, as well as anti-diabetic and anti-cancer effects.
Epidemiological studies have found that increased consumption of Allium vegetables is associated with lower risk of gastric and prostate cancers. These vegetables contain chemoprotective organosulfur compounds that are released when the vegetables are chopped, crushed, or chewed. These compounds prevent the development of cancers by detoxifying carcinogens, halting cancer cell growth, and preventing tumors from obtaining a blood supply(9).
In addition to the organosulfur compounds, onions also contain high concentrations of flavonoids. Flavonoids are a class of antioxidant molecules which help to protect us against oxidative damage, a byproduct of oxygen-utilizing metabolism thought to be involved in the progression of many chronic diseases, including cancers(10).
Mushrooms are another food category with documented anti-cancer, anti-inflammatory, and immune-supporting properties. Mushrooms contain polysaccharides that are thought to inhibit tumor growth and viral infection by stimulating various cells of the immune system(11). In humans, consuming mushrooms regularly has been shown to decrease risk of breast cancer by over 60%(12). There is a large variety of mushrooms that can make interesting additions to the diet – cremini, shiitake, porcini, maitake.
Nuts and seeds contain a spectrum of micronutrients including LDL-lowering phytosterols, circulation-promoting arginine, minerals – potassium, calcium, magnesium, selenium, and antioxidants including flavanoids, resveratrol, tocopherols (vitamin E), and carotenoids.
Countless studies have demonstrated the cardiovascular benefits of nuts(13). Seeds share these benefits, also containing healthy fats and minerals, but have even a richer micronutrient profile, abundant in trace minerals, and each kind of seed is nutritionally unique. Flaxseeds are an extremely rich source of omega-3 fats. Sunflower seeds are especially protein- and mineral-rich. Pumpkin seeds are rich in iron, calcium, and phytochemicals, and omega-3 fats. Sesame seeds have the greatest amount of calcium of any food in the world, and provide multiple vitamin E fractions.
Research on the anti-cancer effects of nuts and seeds are preliminary, but a few studies have shown decreased risk of certain cancers in women. A number of components of nuts and seeds, including vitamin E, selenium, magnesium, and other phytochemicals may potentially have anti-cancer effects(14).
Fresh fruits are natural, nutrient-rich, health-promoting foods, and berries in particular are true super foods. Adding more fresh fruit to the diet can decrease the risk of diabetes(14). How much fruit your children eat is also a strong determinant of their future health – a sixty-year study of about 5,000 participants found that those who were in the highest quartile of fruit consumption during childhood were found to have 38% lower incidence of all types of cancer as adults(15). Researchers have discovered substances in fruits – especially berries – that have unique effects on preventing aging and deterioration of the brain(16). Blueberries, strawberries, blackberries, and raspberries are rich in a variety of antioxidant molecules – flavonoids, proanthocyanidins, ellagitannins, gallotannins, phenolic acids, stilbenoids, lignans, and triterpenoids – that can either prevent or repair cellular oxidative damage, thereby reducing the oxidative stress and inflammation central that are central to chronic disease(17).
To truly consume a healthy diet, the vast majority of the diet must be composed of health-promoting foods, and disease-promoting foods must be avoided. Ninety percent of the daily diet should be made up of nutrient rich plant foods, whose calories are accompanied by health-promoting phytochemicals: green and other non-starchy vegetables; fresh fruits; beans and legumes; raw nuts, seeds, and avocados; starchy vegetables; and whole grains. By keeping low nutrient foods like animal products, sweets, and processed foods to a minimum and striving to eat at least 90% of calories from unrefined plant foods, you construct a health-promoting, disease-preventing diet and flood your body with protective substances. Children eating in this style will be afforded maximum protection against not only ear infections, asthma, and allergies, but also against heart disease and cancer in adulthood.
Dr. Fuhrman is a family physician, nutritional researcher and best-selling author. Visit him at DrFuhrman.com. Recipes from Dr. Fuhrman’s book, Eat For Health and from DrFuhrman.com member center.
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