Nancy's Nutrition Corner

"Let food be thy medicine and medicine be thy food," Hippocrates.

Sweet Potatoes

When I think of sweet potatoes I envision the holidays. In my mind's eye I see that glass casserole dish with warm gooey sweet potatoes covered in melted brown sugar and marshmallows. While using the sweet potato as a holiday table specialty is nice, sweet potatoes are actually much more versatile than one might imagine. There are many ways to include them in one's diet—and many reasons one should. Sweet potatoes are ranked highest of all vegetables in nutritional value by the Center for Science in the Public Interest. Ounce for ounce you get a load of nutrients from a sweet potato. This article will focus on just a few that make this tuber an excellent dietary choice for the cold and flu season.

Nutrition and the Immune System:
As we make our food choices we must remember that nutrient intake is an important contributing factor in the immune system's ability to function: lack of nutrients impairs the immune system. Micronutrients that are required for the immune system to function efficiently include vitamin A, folic acid, vitamin B6, vitamin B12, vitamin C, vitamin E, Zinc, Copper, Iron, and Selenium. Turns out sweet potatoes are high in many of these...

Vitamin A:
The intense orange color of the sweet potato is evidence of its high concentration of vitamin A in the form of beta-carotene. In fact, just one has five times the RDA of vitamin A. Besides being recognized as essential for vision, growth and bone development, vitamin A plays a crucial role in immunity. Several aspects of the immune system are influenced by vitamin A such as T-lymphocyte function and antibody response to viral and bacterial infections.

Vitamin C:
Sweet potatoes are considered to be a very good source of vitamin C. Vitamin C plays a complex role in the body. There has been much controversy about its value against the common cold. Some studies have shown little beneficial affect, but most recent reports suggest that vitamin C offers a considerable decrease in the duration and severity of cold symptoms. It has been hypothesized that the antioxidant activity of vitamin C plays a role in this reduction. Vitamin C reacts with oxidized products released from white blood cells as the immune system fights the virus. These reactions squelch the inflammatory effects of the oxidized products and thus reduce the severity of the cold.

Vitamin B6:
Sweet potatoes are a good source of vitamin B6. Studies have demonstrated that low dietary intake of vitamin B6 can result in depressed immune function from a decrease in the quantity of white blood cells and antibodies.

Copper and Iron:
Sweet potatoes are a good source of both copper and iron. Minerals such as these are essential to immunity as they aid in the maturation, function, and activation of defense mechanisms.

Eat Sweet Potatoes! Now that you know the incredible nutritional value of the sweet potato there is just no excuse to reserve them only for the holiday table. Be creative: try adding them to your everyday meals, especially during the cold and flu season!

Nancy Silva, ND is a licensed naturopath with a penchant for good food. Her monthly column discusses the nutritional aspects of some of the foods available through LocalHarvest. You can contact Nancy from her listing on our website.

Back to the November 2008 Newsletter