Potatoes Reduce Blood Pressure

Many dieters put potatoes on the top of their list of foods to avoid, but the potato’s stereotype as a fattening food is getting a makeover. Scientists report that just a couple servings of spuds a day reduces blood pressure almost as much as oatmeal without causing weight gain.

But don’t order French fries for lunch or reach for the catsup, vinegar or mayonnaise. The research was done with potatoes cooked without oil in a microwave oven. Although researchers used purple potatoes, they believe that red-skin potatoes and white potatoes may have similar effects.

“The potato, more than perhaps any other vegetable, has an undeserved bad reputation that has led many health-conscious people to ban them from their diet,” said Joe Vinson, Ph.D., who headed the research. “Mention ‘potato’ and people think ‘fattening, high-carbs, and 'empty calories’. In reality, when prepared without frying and served without butter, margarine, or sour cream, one potato has only 110 calories and dozens of healthful phytochemicals and vitamins. We hope our research helps to remake the potato’s popular nutritional image," he continued in a press release.

The new research studied 18 patients who were overweight or obese and had high blood pressure. Each patient ate six to eight purple potatoes (each about the size of a golf ball) with skins twice daily for a month. Purple potatoes were used in the study because their pigment (the component that gives fruits and vegetables color) is especially rich in beneficial phytochemicals.

Scientists monitored the patients’ blood pressure, both systolic (the higher number in a blood pressure reading like 120/80) and diastolic. The average diastolic blood pressure dropped by 4.3 percent and the systolic pressure decreased by 3.5 percent, said Vinson, who is with the University of Scranton in Pennsylvania and has done extensive research on healthful components in foods. The majority of subjects took medication for high blood pressure and still had a reduction in blood pressure. None of the study participants gained weight.

Vinson said that other studies have identified substances in potatoes with effects in the body similar to those of the well-known ACE-inhibitor medications, a mainstay for treating high blood pressure. Other phytochemicals in potatoes occur in amounts that rival those found in broccoli, spinach, and Brussels sprouts, and also may be involved, Vinson added.

Unfortunately for fans of French fries and potato chips, high cooking temperatures seem to destroy most of the healthy substances in a potato, leaving mainly starch, fat, and minerals. Potatoes in the study were simply microwaved, which Vinson said seems to be the best way to preserve nutrients.

The purple potatoes used in the study are becoming more widely available in supermarkets and especially in specialty food stores and farmers’ markets. Vinson said that he strongly suspects a future study using white potatoes, now in the planning stages, will produce similar results.