You’ve probably seen quite a few stories in the media in recent years about the health benefits of a group a foods that some people have labeled as “superfoods.” But just what makes a food “super,” and which foods really deserve this label? And how do the positive attributes of these “superfoods” help contribute to good health and longer life?

In fact, while many researchers recognize the benefits of many of the so-called superfoods, the term has no specific medical, scientific, or legal definition. In general, however, superfoods tend to be low in calories while being high in many essential vitamins and nutrients. Many are excellent sources of antioxidants, which are believed to contribute to the prevention of chronic illnesses including cancer and heart disease. Other superfoods have anti-inflammatory properties, which can be helpful in preventing conditions such as cancer, arthritis, and atherosclerosis (hardening of the arteries).

Superfoods have been credited with helping to prevent three of the most debilitating diseases affecting the U.S. population – cancer, heart disease, and diabetes. Lets look at each of these diseases and see how superfoods work to prevent them, as well as which foods are considered the most “super” in terms of their beneficial effects.

Cancer

Claims for the cancer-fighting properties of superfoods center around two key compounds – antioxidants and phytochemicals. Antioxidants have been credited with inhibiting the production of free radicals, highly reactive chemical agents that can cause damage to cells that may result in cancer. Common antioxidants found in many superfoods include beta-carotene, vitamin C, and lycopene. Phytochemicals are naturally-occurring compounds found in plants. According to researcher Jed Fahey of Johns Hopkins University School of Medicine, studies have shown that phytochemicals have the potential to protect cells from damage and mutation that lead to cancer. There are literally hundreds of phytochemicals found in a wide variety of plant foods.

Superfoods identified as particularly powerful cancer prevention agents include broccoli, spinach, berries, tomatoes, and carrots. A review of nutrition studies conducted by the World Cancer Research Fund and the American Institute for Cancer Research found that broccoli and all kinds of berries can protect against cancer of the mouth, esophagus, and stomach. A study by the National Institutes of Health showed that spinach also acts a preventive agent against those cancers. Lycopene, a substance found in abundance in tomatoes, has been show in laboratory tests to inhibit the growth of cancer cells in breast and lung tissue.

Heart Disease

The antioxidant properties of superfoods are also considered to help reduce the risk of heart disease, and some of the foods on the list of cancer-preventing agents are also among those thought to be best at preventing heart disease. For example, the antioxidant anthocyanin that is found in blueberries, is thought to reduce the accumulation of LDL cholesterol (or “bad” cholesterol) that can clog arteries and contribute to heart attacks and stroke. Spinach is another cancer-fighting superfood that does double-duty against heart disease.  In addition to antioxidants, spinach contains omega-3 fatty acids that prevent blood platelets from clumping together to form clots or buildup on the walls of arteries. It also contains folate that helps reduce the level homocysteine, an amino acid linked to the development of cardiovascular disease. Two other superfoods high in omega-3 fatty acids are salmon and soy protein, both of which are high on the American Heart Association’s list of heart-healthy foods.

Diabetes

The American Diabetes Association has compiled a list of superfoods that help prevent this debilitating disease. One thing all of them have in common is a low glycemic index, or GI, which measures the rise of blood sugar (glucose) after consuming a particular food. Foods with a low GI help maintain healthier levels of glucose, which can help in preventing Type 2 diabetes.

Some old friends among the superfoods that help prevent cancer and heart disease are also on the ADA’s list of diabetes fighters. These include spinach, tomatoes, berries and salmon. Whole grains, which are loaded with nutrients including folate and omega-3 fatty acids, are also recommended by the ADA. Other superfoods highly recommended by the ADA include nuts, sweet potatoes, and citrus fruit such as oranges, lemons, and grapefruit.

References

American Diabetes Association: http://www.diabetes.org/food-and-fitness/food/what-can-i-eat/diabetes-superfoods.html

Maeda N, Matsuraba K, Yoshida H, Mizushina Y. Anti-cancer effect of spinach glycoglycerolipids as angiogenesis inhibitors based on the selective inhibition of DNA polymerase activity. Mini Rev Med Chem. 2011 Jan;11(1):32-8.

World Cancer Research Fund / American Institute for Cancer Research (2007) Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. Project Report. The American Institute for Cancer Research, Washington, DC.