EATING several helpings of potatoes a week increases the risk of high blood pressure, research suggests.
Scientists in America found that four helpings of the starchy food a week raised the likelihood of suffering the condition - also known as hypertension - by as much as 11 per cent.
The study did not ask participants to differentiate between baked, boiled or mashed potatoes.
But the team from Harvard Medical School and Brigham and Women's Hospital did pose questions about how often they ate chips and found there was a 17 per cent greater risk of high blood pressure from four weekly helpings.
The better news for snack lovers was that the research established no association between the condition and eating crisps.
Lead author Dr Lea Borgi said that potatoes had not traditionally been linked with the disease. "There has recently been some suggestion that eating potatoes can be linked to type 2 diabetes, but apart from that, this is a surprise," she said.
"But with fries we have known for some time there are associated health risks."
The study, published in the British Medical Journal, said that replacing one serving a day with non-starchy vegetables led to a 7 per cent drop in the risk of high blood pressure.
The research suggests that it is the high glycaemic index (GI) of the potato that could be to blame.
Foods high in GI release energy more quickly, and therefore raise blood sugar at a fast rate, which can in turn raise blood pressure.
The team said high-GI meals were already associated with the dysfunction of cells in the body, such as oxidative stress and inflammation, as "potentially important mechanisms in the development of hypertension".
The scientists, who studied 187,000 people over 20 years, said their results accounted for factors such as the weight of their participants, which can also influence blood pressure.
However, the authors acknowledged that, as with any observational study, no firm conclusions could be drawn about cause and effect.
The overall analysis of the different cohorts examined in the study showed a roughly equal associated risk between men and women. However, a study earlier this year found women may be at increased risk of diabetes in pregnancy from eating potatoes.
Tom Sanders, Emeritus Professor of Nutrition and Dietetics at King's College London, said: "Potatoes do contain small amounts of alkaloids, but not in sufficient amounts to affect blood pressure. However, potatoes, especially chips, are often consumed with added salt which may be part of the explanation for this association with raised blood pressure."