Potatoes Glycemic Index and Healthy Diet Tips

High on the Glycemic Index, Keep Potato Portions Small

pink potatoes
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Potatoes are a humble tuber, often subjected to many forms of ridicule. Think of spud guns and a popular child's toy shaped like a potato. But they are also a staple of many diets and are cultivated worldwide. Potatoes have been boiled, mashed, fried, roasted, baked, curried, scalloped, shredded, stuffed, and made into casseroles. While there are some health benefits from potatoes, most varieties are loaded with carbohydrates, and rate fairly high on the glycemic index (GI). A couple of varieties Nicola and Rosamunda are actually good for you.

French Fries – Friend or Foe?

Potatoes are rated fairly high on the glycemic index, which means that after you eat them, the carbohydrates cause a spike in your blood sugar levels. You may feel full and satisfied when demolishing a baked spud. But hunger will return in a couple of hours when the carb buzz plummets after you digest all of that. This may explain why we sometimes eat potato chips and French fries in great quantities, only to want more. When we do that, however, and our blood sugar levels are peaking, we are sailing along on glucose, and in response, our bodies secrete insulin and insulin-like growth factor (IGF). These two substances promote cell growth and inflammation. And when you have too much of them, they can pave the way for the development of cancer.

Health Benefits of Potatoes

Potatoes provide you with starchy carbohydrates. A small percentage of that starch is classed as resistant starch (a type of dietary fiber), which gives you some health benefits when it reaches your large intestine. Potato fiber will protect you against colon cancer, and help you tolerate glucose and insulin, and may lower your cholesterol. Potatoes have vitamins and minerals that are good for you — vitamins C and B6, potassium, iron, and thiamin, to name a few. Phenolic acids are present in fresh or boiled potato peels, while both peel and flesh contain beneficial flavonoids and carotenoids.

Healthiest Ways to Cook and Eat Potatoes

Half of the healthiest part of the potato is the peel. This is good news for those of us that are tired of trying to peel spuds. Leave that brown jacket on the potato, and don't apologize for the dark flecks in the resulting dish. Potato peels contain high concentrations of beneficial phenolic acids. Microwaving or boiling an unpeeled potato preserves more of its health benefits than oven baking, which breaks down its vitamins and minerals. Cold potato salad made with vinaigrette dressing, stored overnight in the fridge, is by far the healthiest way to eat potatoes. A long chilling will increase the potatoes' resistant starch content by more than a third. The acid in the vinaigrette, whether you make it with citrus juice or vinegar, slows your digestion, allowing your stomach to more completely process the vegetables. This combination of cooled starch and acidic dressing results in a lower glycemic spike, which is healthier for your body.

Meet Nicola and Rosamunda Potatoes

If you want to eat potatoes and avoid high blood sugar, look for Nicola and Rosamunda. Nicola (Solanum tuberosum L. cv. Nicola) is hard to find. But it is an oval, smooth-skinned potato with a pale to yellow skin and yellow to deep yellow flesh, that seems to have originated in Germany. Nicola has a glycemic index rating of 58, making it healthy to eat (in modest portions). Rosamunda (Solanum tuberosum L. cv. Rosamunda) is an oval, smooth-skinned potato with a red skin and cream to light yellow flesh that was bred in Sweden. Nicola and Rosamunda were cooked and tested in a Finnish food study and were found to have the highest levels of phenolic acids, in comparison to all of the 40 types of potatoes in the study. Phenols are aromatic compounds that have powerful antiseptic and antibacterial properties, which may discourage the growth of cancer.

Seeing the Potato in a New Light

From its high-altitude beginning in the Peruvian Andes, to its present life as an international culinary favorite, the potato is here to stay. Modern potatoes have been genetically modified to cook up into stronger, crispier French Fries. They have been grown to take on new colors (blue, purple), and have loaned their extracts to appetite-suppressant nutraceuticals. But they should be consumed in moderation, and with the peel included, because their carbohydrates can cause a spike your blood sugar levels. Cancer thrives on sugar. So if you eat potatoes, take small portions, and choose Nicola and Rosamunda whenever you can find them.

Glycemic Index of Common Potato Foods

Potato Foods Glycemic Index Rating
Baked Russett Burbank Potato (without fat) 111
Instant Mashed Potatoes (Idaho) 97
Baked (Jacket) Potato 85
Mashed Potato 70
New Potatoes 62
Canned Potatoes, Heated in Microwave Oven 61
Nicola potatoes 58
Potato Chips (Crisps), Salted 57
Boiled potatoes (Canadian) 56
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Article Sources
  • Phenolic Acids in Potatoes, Vegetables, and Some of Their Products Pirjo Mattila, Jarkko Hellstrom. Journal of Food Composition and Analysis, Volume 20, Issues 3-4, May 2007, Pages 152-160.
  • University of Sydney, Australia, Glycemic Index Database. Database Pages Created by Associate Professor Gareth Denyer and Scott Dickinson using data collected by Professor Jennie Brand-Miller & SUGIRS. Last Modified: December 13, 2005.