White potatoes aren’t going away any time soon. In 2012, the world produced 365 million metric tons of potatoes, making them the fourth most common staple food on earth (behind corn, rice and wheat). Despite the abundance and affordability of white potatoes, not everyone is a fan. Some people believe white potatoes are a major contributor to America’s biggest health issue—obesity. But is this based on fact? Are white potatoes actually healthy, or are they just another risky food we should avoid? STACK investigates.
The humble potato has been an important food in the history of human civilization. First domesticated in the Andes mountains, potatoes sustained the great Incan empire. When Spanish explorers landed in South America, they were enamored with the novel crop. By the late 1500s, potatoes were being exported by the Spanish back to France and the Netherlands. They spread around Europe, and by the end of the 18th century, potatoes had become a staple thanks to their convenience, affordability and resilience.
The potato is still going strong today, serving as a staple in many cultures. One reason potatoes have become so popular? They’re nutrient-dense, meaning they serve up a lot of the stuff humans need to live in a small package.
A large number of varieties fall under the category of “white potatoes,” but we will look specifically at “Grown in Idaho” Russet potatoes, since they are one of the most well-known varieties in America.
According to the Idaho Potato Commission’s website, one such potato contains 110 calories, 0 grams of fat, 0 grams of sodium, 620 mg of potassium, 26 grams of carbohydrate, 2 grams of fiber, 1 gram of sugar and 3 grams of protein. They also contain at least 5 percent of the RDV for the following vitamins and minerals:
- Vitamin C (45%)
- Vitamin B-6 (10%)
- Magnesium (6%)
- Phosphorus (6%)
- Iron (6%)
- Thiamin (8%)
- Niacin (8%)
- Folate (6%)
That’s a lot of nutrition in a very small package. At 110 calories, a potato also has about as many calories as a medium-sized banana. Zero grams of fat make it a lean choice, and 0 grams of sodium is welcome during a time where the average American is eating way too much of it. The 620 mg of potassium (18 percent of the recommended daily value) is impressive; a potato actually has 220 mg more potassium per serving than a medium banana. Potassium is crucial for heart health, normal digestion and optimal muscular function.
The two grams of dietary fiber are also welcome, since fiber is perhaps the single most important nutrient for corralling hunger. In addition to controlling blood sugar, fiber slows down digestion, which helps you feel fuller for longer after you eat.
Like most fruits and vegetables, potatoes are largely composed of water. Foods high in water take up more room in your stomach, enhancing fullness. In fact, a 1995 study published in the European Journal of Clinical Nutrition found that boiled white potatoes had the highest satiety index of 38 tested foods. The fact that potatoes fill you up so efficiently cannot be overlooked, because it can help you avoid mindless snacking.
The potatoe’s protein content (3 grams) is another plus. The human body needs protein to adequately rebuild and repair muscle and get stronger over time. The body can also use protein as a source of energy. Just 1 gram of sugar per serving is awesome, considering that the average American consumes 88 grams (equivalent to 22 teaspoons) per day. Potatoes can be a way to help break our nation’s addiction to sugar-filled foods.
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The abundance of vitamins and minerals is also advantageous. Vitamin C is needed for the growth and repair of all bodily tissues. Vitamin B-6 helps the body produce antibodies and maintain normal nerve function. Magnesium activates enzymes and helps regulate important nutrient levels inside the body. Phosphorus helps build strong bones and teeth and produce the genetic building blocks known as DNA and RNA. Iron is a key component of hemoglobin and is critical for transporting oxygen-rich blood around the body. Thiamin, niacin and folate help the body turn carbohydrates into energy.
With all this good stuff packed into a single potato, why would anyone want to avoid them? The answer has to do with the glycemic index.
The Problem with Potatoes
The glycemic index (GI) is a a measurement of how quickly a carbohydrate food affects blood sugar levels compared to pure table sugar. High GI foods cause quick spikes in blood sugar, thanks to their quickly digesting carbohydrates. It’s believed that high GI foods can lead to blood sugar and insulin management issues. White potatoes rank quite high on the GI. A boiled white potato, for example, ranks 82 on the GI—in the same neighborhood as pretzels, cheese pizza and Gatorade.
Insulin is a hormone that’s key to metabolism and energy. When we eat carbohydrates, our digestive tract breaks them down into glucose. When glucose enters the bloodstream, the body releases insulin to help turn it into energy. Insulin unlocks cells throughout the body so they can absorb the glucose and use it for energy. High GI foods cause more insulin to be released than low GI foods. Over time, this can cause serious issues. Persistent high levels of insulin inside the body predispose weight gain and a condition known as “insulin resistance.” Insulin resistance occurs when cells do not respond properly to insulin and thus don’t easily absorb the glucose from the bloodstream. Over time, insulin resistance can lead to Type 2 diabetes and prediabetes.
Since potatoes rank high on the GI, it’s believed that they can cause blood sugar and insulin management issues, in turn leading to obesity and obesity-related problems. This is really the one big criticism of white potatoes, but it’s enough to turn off legions of people.
Why White Potatoes Are Still Healthy
However, a food’s GI impact is based on eating it in total isolation.
A food’s GI can be significantly altered by what you eat with it. Combining fat (olive oil, avocado), acid (salsa, citrus), protein (meat, legumes), fiber (legumes, leafy greens) and/or low GI foods (most fruits, non-starchy veggies, lentils) can greatly reduce the GI load of a potato. Fiber, particularly soluble fiber, is excellent at slowing down the body’s absorption of sugars. “Fiber slows down digestion, resulting in the sugar being absorbed more slowly,” says Brian St. Pierre, sports dietitian and nutrition coach at Precision Nutrition. This delayed digestion gives the liver more time to metabolize the sugar, which keeps blood sugar relatively stable.
The carbs in potatoes also offer some benefits. Much potato carb content can be attributed to resistant starch, which isn’t digested. Instead, it is fermented in the gut to produce short-chain fatty acids, which aid in nutrient absorption, reduce inflammation, fuel healthy gut bacteria and keep you full longer.
These are just some of the reasons why five out of five nutritional experts recently told TIME that people should eat potatoes. If you’re already overweight or obese, eating a white potato by itself on a regular basis might not be the best idea. But if you’re eating it as part of a meal with other, lower GI foods, much of the negatives can be mitigated. If you’re a healthy, active person who isn’t struggling with your weight, the GI impact of potatoes should be even less of a concern. In fact, a 2014 study found that potato intake “did not cause weight gain” in a free-living population of men and women over a 12-week period.
Remember, this article is solely about white potatoes in their whole form. You can bake them, microwave them, boil them, etc., but turning them into potato chips or French fries drastically alters their nutrition—and not for the better. Potatoes themselves are healthy, but many potato-derived products are not. So stick to whole spuds if you’re going to be eating potatoes, and don’t drown them in butter, bacon and sour cream.
Another tip? Always eat the skin. The skin packs more nutrients—iron, calcium, potassium, magnesium, vitamin B6 and vitamin C—ounce-for-ounce than the rest of the potato. If you ditch the skin, you’ll instantly lose the majority of the potato’s iron content and roughly half of its fiber.