COLLEGE STATION — When it comes to disarming disease causing agents in the body, potatoes pack a punch more powerful than many other vegetables.
New research has found that while vegetables such as bell pepper, onions and carrots remain valuable dietary sources of disease-preventing antioxidants, potatoes rank near the top of that category.
“We were surprised to find that potatoes are second only to broccoli in terms of antioxidant activity,” said Dr. Creighton Miller, Texas Agricultural Experiment Station potato breeder. He said people should not only put potatoes on every plate, but should eat them skins and all.
Discovery of the potato’s high antioxidant activity is reported in the current issue of the Journal of Food Science.
Miller, Experiment Station food scientist Dr. Luke Howard, and graduate student Mohamed Al-Saikhan were screening potatoes, looking especially at the pigments in yellow flesh varieties, when the high antioxidant activity was observed. That led them to compare the potato to several well-known antioxidant-high vegetables.
“This is important because there are so many oxidative activities in the body that contribute to cancer and heart disease,” Howard said.
The oxidative activity — from naturally occurring metabolic process in the body and from exposure to pollution and smoking tobacco — produces ‘free radicals’ which destroy DNA in the body, thus opening the door for the development of diseases, Howard explained. Antioxidants slam cell doors shut in the face of the harmful free radicals.
“This research shows that in addition to eating lots of broccoli, we should include potatoes in the diet as well,” Miller noted.
Lab results indicated that on a scale of 100, broccoli had an antioxidant value of almost 96, potatoes had about 69, carrots had 32, onions had 25 and bell peppers had 15. The greatest concentration of antioxidants in the potato was in the skin, Howard noted.
Preliminary studies by Miller and Howard point to patatin, the major water-soluble protein in potatoes, as being the possible source of the antioxidant activity.
“This shows another health attribute for potatoes,” Miller said. “People tend to think of potatoes only as high in starch and carbohydrates.”
Indeed, many people don’t realize that one potato also contains half of the daily recommended amount of vitamin C and 750 milligrams of potassium, an element linked to the possible prevention of such ailments as stroke, he said. Potatoes also are high in dietary fiber and iron.
Yet even though the excellent nutritional value of potatoes may not be common knowledge, the fleshy tuber already is the fourth most important food crop in the world, only slightly behind rice, wheat and corn. Potatoes are a much-loved food in the United States where annual per capita consumption is 125 pounds.
That, plus its $2.5 billion value each year for U.S. potato farmers, underscores the importance of the antioxidant research finding.
The researchers plan to examine the effect of cooking on antioxidants as well as the influence of the environment on potato plants in the field, the variability of antioxidants among potato varieties, and genetic markers in potato varieties with the highest antioxidant activity. Miller said finding answers to these questions will help breeders develop an even more nutritious and health-promoting potato.