The classic white potato sure won’t win any beauty contests. But depending on how it’s dressed up, these little spuds can be a good source of vitamins and minerals. Unfortunately, these starches can also cause blood sugar to soar, perhaps even more than eating pure sugar.
You Say Po-tay-toe, I Say Po-tah-toe — The Need-to-Know
Potatoes may be a cheap way to feed a large family, but their high glycemic load (or how they affect blood sugar) sends them into the nutritional danger zone Role of glycemic index and glycemic load in the healthy state, in prediabetes, and in diabetes. RIccardi,G., Rivellese, A.A., Giacco, R. Department of Clinical and Experimental Medicine, Federico II University, Naples, Italy. American Journal of Clinical Nutrition. 2008 Jan;87(1):269S-274S. . High-glycemic foods cause sugar to rush into the bloodstream, causing a spike in blood sugar Glycemic index and glycemic load: measurement issues and their effect on diet-disease relationships. Venn, B.J., Green, TJ. Department of Human Nutrition, University of Otago, Dunedin, New Zealand. European Journal of Clinical Nutrition. 2007 Dec;61 Suppl 1:S122-31. The role of glycemic index concept in carbohydrate metabolism. Ciok, J., Dolna, A. Pracownia, Prewencji Pierwotnej Chorób Uwarunkowanych Zanieczyszczeniami Zywności i Wadliwym Zywieniem Zakład Bezpieczeństwa Zywności i Zywienia, Instytut Zywności i Zywienia w Warszawie. Przeglad Lekarski. 2006;63(5):287-91. . The pancreas then releases extra insulin to keep the sugar situation under control Sirt1 regulates insulin secretion by repressing UCP2 in pancreatic beta cells. Bordone, L., Motta M.C., Picard, F., et al. Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. PLoS Biology. 2006 Feb;4(2):e31. Epub 2005 Dec 27. . With nowhere to put the extra glucose, the excess insulin signals cells to store it as fat.
Carbohydrates are great at giving the body energy, but when foods with a high glycemic load are eaten in excess, not only does the pancreas get a little tired of sending out all that extra insulin, but the cells don’t respond like they used to. This cycle can gradually cause insulin resistance, leading to serious health conditions like type II diabetes, coronary disease, obesity, and even certain types of cancer International table of glycemic index and glycemic load values: 2002. Foster-Powell, K., Holt, S.H., Brand-Miller, J.C. Human Nutrition Unit, School of Molecular and Microbial Biosciences, University of Sydney, NSW, Australia. American Journal of Clinical Nutrition. 2002 Jul;76(1):5-56. .
But some potato fans argue the spudly nutrients are well worth the spike in blood sugar White potatoes, including french fries, contribute shortfall nutrients to children's and adolescents' diets. Freedman, MR., Keast, DR. Department of Nutrition, Food Science & Packaging, San Jose State University, San Jose, CA USA. Nutrition Research. 2011 Apr;31(4):270-7. Epub 2011 Apr 13. . Potatoes are relatively low in calories and sodium, yet are also a good source of potassium (which can help muscles function and regulate blood pressure). They also pack iron and copper (key for nerve function and metabolism). And let’s not forget the skin, which is rich in vitamin C, essential for the growth and repair of body tissue.
Dress the Potato for Success — Your Action Plan
Potatoes become even more menacing when they are prepared in unhealthy ways, like French fried, baked and loaded, or mashed and gravy-ed. Not only will a loaded baked potato or an order of fries wreak havoc on blood glucose, but each can have more than 500 calories per serving. And with the many varieties of potatoes, glycemic load varies, too Glycaemic index values for commercially available potatoes in Great Britain. Henry, C.J, Lightowler, HJ., Strik, CM., Nutrition and Food Science Group, School of Biological and Molecular Sciences, Oxford Brookes University, Gipsy Lane Campus, Headington, Oxford, UK. British Journal of Nutrition. 2005 Dec;94(6):917-21. .
The saving grace for the potato may lie in the cooking methods, some of which might reduce the glycemic load Glycemic index of potatoes commonly consumed in North America. Fernandes, G., Velang,i A., Wolever, T.M. University of Toronto, Ontario Canada. Journal of the American Dietetic Association. 2005 Apr;105(4):557-62. . Boiling is one of the healthiest methods, and the benefits increase if they are left to cool or reheated later on Glycemic index of potatoes commonly consumed in North America. Fernandes, G., Velang,i A., Wolever, T.M. University of Toronto, Ontario Canada. Journal of the American Dietetic Association. 2005 Apr;105(4):557-62. . So if the potato is going to remain part of the family, it may be time to boil the little spuds and eat them as leftovers loaded with something like reduced-fat sour cream, low fat cheese, or salsa— and skip the fries and gravy entirely.
Now while other varieties— like sweet potatoes, for example— may look similar, the nutrition profiles can be vastly different between types, so before writing off all tubers, remember that not all are created equal.