Why do people avoid potatoes? They're packed with potassium and other minerals, fiber, and even have a decent amount of vitamin C. So why the bad rap? It all goes back to the low-carb craze and glycemic index. Glycemic index tells us that some foods make the blood sugar go up more than other foods. These foods are dubbed "high glycemic index foods". When the blood sugar goes up, the hormone insulin kicks in. Insulin escorts the blood sugar into the body's cells and brings blood sugar back down to normal. A spike in the blood sugar could also spike insulin. Too much insulin, the hypothesis goes, can make you fat.

However, there are some problems with this hypothesis. White potatoes may have a high glycemic index - but how often do you eat a plain potato with nothing on it and no other foods along with it? Probably not very often. The other foods that you eat change the blood sugar effects of the potato. Meat, cheese, butter, sour cream, or other vegetables will lower the overall blood sugar effects. The bottom line is this: it does not make nutritional sense to avoid low calorie, nutrient-packed foods based on glycemic index alone. Let's take a look at the benefits you get when you eat potatoes:

  • High Potassium. Diets rich in potassium help lower blood sugar and the risk of stroke. Bananas are not the highest potassium food - potatoes are! A baked potato with the skin has 850 mg of potassium while a banana has 450 mg. We need 3500 mg of potassium a day so eating potatoes makes lots of sense.
  • High Vitamin C: A baked potato with the skin gives you a third of your daily need for vitamin C at 26 mg per serving.
  • High in Fiber: A medium baked potato with the skin has 5 grams of fiber. High fiber diets may lower your risk for heart disease.
  • Good source of Magnesium: This hard-to-get mineral helps lower blood pressure and subsequently, the risk of stroke.
  • Fat Free: Potatoes are fat free leaving room to add some fat and flavor.
  • Inexpensive and easy to cook: Potatoes are really cheap and easy to prepare. The healthiest way to make them is baked. Scrub 'em up and pop them in a hot oven for 45 minutes to an hour or microwave them. Be sure to eat the skin. A fair portion of the nutrients are in the skin.
  • Notice we've focused on baked potatoes with the skin because that's a tasty way to retain all those healthy nutrients. It also keeps fat and calories low with little prep time. It is fine to add some sour cream (which is actually lower in fat and calories than butter), a bit of cheese or butter, or some seasoning salt. Just be careful not to overdo it. You can also sauté up some mushrooms, low-fat smoked sausage, onions, garlic, or other veggies to add a lot of healthy flavor.

    Beth Kitchin MS RD
    Assistant Professor
    UAB Department of Nutrition Sciences