The humble potato is often considered to be an unhealthy food choice – for instance, potatoes don’t count towards your “five a day” of fruit and vegetables.

But now new research has found that a couple of servings a day of potatoes reduces high blood pressure without causing weight gain.

There is a catch though – the potatoes were cooked in a microwave oven without using fat or oil, and were served without any accompaniments such as ketchup, butter or mayonnaise.

In the new study, 18 obese patients with high blood pressure ate around 6 to 8 potatoes a day. The potatoes were of the purple-skinned variety and were eaten whole.

Purple potatoes were chosen because the pigment is rich in beneficial phytochemicals. The researchers then monitored the blood pressure.

Potatoes

The systolic blood pressure was found to drop by an average of 3.5 per cent and the dystolic by 4.3 per cent. Importantly, none of the participants in the study gained any weight after eating the potatoes.

Commenting on these results, study leader Joe Vinson said: “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.”

“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” he added.

He noted that other studies had identified the potato as a possible source of substances similar to ACE-inhibitor medications which are used to treat high blood pressure.

But the high temperatures associated with frying and baking potatoes may destroy most of these beneficial chemicals, hence the use of microwaves to cook them in this study.

The results of the study are published at the National Meeting & Exposition of the American Chemical Society.