Are Potatoes More Dangerous for Diabetes?

The problem with white potatoes started in 2006,, when Harvard Nurses’ Health Study (which had been following the lives of many thousands of women over 20 years) found that a higher potato intake is associated with type 2 diabetes. But wait! Most of the 100-plus pounds of potatoes Americans consume each year are deep-fried potato chips and French fries. They looked at baked or mashed potatoes. What did they find? The same connection was found with diabetes. But what would potato-eaters eat more? Let me give you an idea. I will rephrase that to say: What might meat-and potatoes people consume more? People who ate more potatoes were more likely to eat more meat. We also know that increased risk of developing diabetes is linked with animal protein. Researchers tried statistical adjustments to adjust for this, but still discovered an increased risk of potatoes.

What do you put on baked or mashed potatoes? You can also add butter and sour-cream. Researchers tried again to adjust for other factors such as diet and dietary habits. They also looked at plant-to-animal fat ratios and whether potatoes-eaters consumed more soda or ate fewer vegetables. There was still a potato/diabetes connection.

Okay. But that’s just one study. The 2015, Harvard researchers also examined other cohorts to supplement the studies on all-female nurses. They found a slight increase in diabetes risk with potatoes, whether mashed, baked or boiled. However, French fries are nearly five times more dangerous than the potato-based ones. According to the authors, potatoes were considered a healthy vegetable according to dietary guidelines. However, new findings raise serious questions about that conclusion. Walt Willett was the Harvard nutrition chair at that time. He suggested potatoes be kept separate from candy.

A meta-analysis on potato consumption and type 2 diabetes risk published in 2018 gathered all the available prospective studies and found a 20 percent rise in diabetes risk for each potato consumed per day. This suggests that long-term potato high-calorie consumption may strongly be associated with an increased chance of developing diabetes. However, this majority of potato consumption was deep-fried. We know that there are many nasty side effects of deep-fried food, such as advanced glycation products. Researchers were unable to compare French fries with non-fried potatoes. A mere three-week consumption of French fries is linked to a nearly 20% higher risk of developing type 2 diabetes. However, there were only small associated risks with potatoes, which included fries with added ingredients.

This conclusion was disputed by The world’s biggest manufacturer of frozen French fries. They claim that one third of all fries consumed on Earth is frozen french fries. This company has billions in funding and can fund scientific reviews such as this to discredit the science. They do however have a point. Although observational studies cannot prove cause and effect, it is possible that potato intake, or even baking potatoes, could be indicative of a poor diet. Researchers may try to account for other factors but, as the American Journal of Potato Research ) reminds us, there is no way to separate the effect of French fries and potatoes from that of the poor Standard American Diet.

If only there were a country that allowed potato consumption to be associated with a healthy lifestyle. It would be alarming if potato consumption were still linked with diabetes. Here’s a seventh study. This time it was from Iran. People who eat potato primarily rely on boiled potatoes. However, they also eat the best diets and consume the highest amount of whole foods, including fruits, vegetables and beans. The researchers attempted to find out other factors in diet, but those who ate the highest amount of boiled potatoes were half more likely to develop diabetes. It is possible to separate potatoes from the other foods, but this supports the idea that it might be difficult. This systematic review found that although there isn’t any convincing evidence that potatoes are linked with type 2 diabetes, we can still recommend that you eat the fries.