Eating purple potato may lower blood pressure for the overweight

The humble potato, much maligned lately, might have shot at redemption. A study finds that purple spuds might help obese and overweight people lower their blood pressure.

The small crossover study, presented recently at the national meeting and exposition of the American Chemical Society in Denver, focused on 18 overweight or obese people who had high blood pressure.  They ate six to eight small microwaved purple potatoes with skins (or biscuits containing an corresponding amount of potato starch) twice a day for four weeks, then ate no potatoes for four weeks.

Purple potatoes were chosen for their phytochemical content -- phytochemicals are plant compounds such as beta carotene and folic acid that are thought to be beneficial to health.

After eating the potatoes, participants’ average drop in diastolic blood pressure was 4.3%, and the average decrease in systolic blood pressure was 3.5%. This occurred despite the fact that most of the study participants were already taking blood pressure medication. None gained weight.


The study was funded by U.S. Department of Agriculture’s Agricultural Research Service State Cooperative Potato Research Program.

“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 in a news release. Vinson, who headed the study, added: “Mention ‘potato’ and people think ‘fattening, high-carbs, 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.”

The potato came under fire in June 2011 when a study in the New England Journal of Medicine blamed the starchy vegetable for making people pack on the pounds. Researchers found eating an extra serving of potatoes a day caused more weight gain than consuming an additional helping of red or processed meats, or gulping an extra 12-ounce can of a sugar-sweetened drink. That was true for any type of potato, be it fried or baked.

Although purple potatoes are becoming easier to find in grocery stores and farmers markets, they’re still rare in some areas. Researchers said red-skinned or even white potatoes may produce similar effects.