With the popularity of low-carb dieting, potatoes got relegated to the same status as weight-loss no-nos such as white bread and pastry. “They are high in carbohydrates and low in protein, which means that they won’t keep you full for as long as, say, a slice of lean meat – but they are full of goodness. And remember that starchy carbs are the body’s preferred source of energy,” says registered nutritionist Dr Carina Norris.

“You just have to prepare them in healthy ways – boiling or baking, rather than roasting or frying.” And now research indicates that, for overweight people with hypertension, they can even reduce blood pressure levels without piling on pounds.

Researchers from the University of Scranton, Pennsylvania, US, looked at the effects of eating two small servings of purple potatoes (Purple Majesty) every day. They chose this variety because it contains high levels of antioxidants. With 18 study participants, who were overweight with high blood pressure, the researchers had each of them to eat either six to eight microwaved potatoes every day or none at all.

Purple potato

After four weeks, each participant swapped to the other diet so the researchers could ascertain the effects of eating potatoes on all 18 individuals. They found that diastolic blood pressure dropped by 4.3% and systolic pressure decreased by 3.5%. While this may not sound like a huge amount, it is, say the researchers, enough to potentially reduce the risk of heart disease.

Potatoes are a surprising source of vitamins and minerals too. “We eat a lot of potatoes and this needn’t be a bad thing – if they’re prepared without fat – because they are a useful source of vitamin C, making them handy in winter when you want to give your immune system a boost,” says Norris. “They’re also good sources of potassium, which is good for blood pressure, among other things.”

Look out for Purple Majesty in supermarkets or grow your own from seed.