Eating potatoes or chips increases the risk of high blood pressure, new research suggests.
Four or more servings a week of baked, boiled or mashed potatoes is linked to an 11pc increased risk of high blood pressure, compared with less than one serving a month in women.
Researchers also found that men and women who ate four or more servings a week of fries had a 17pc higher risk of high blood pressure, but eating crisps had no effect, according to the study published in the British Medical Journal (BMJ).
The researchers also noted that replacing one serving a day of potatoes with one of non-starchy vegetables led to a 7pc drop in the risk of high blood pressure.
The team, from the Brigham and Women's Hospital and Harvard Medical School in Boston, Massachusetts, suggested the high glycaemic index (GI) of potatoes could be to blame.
High-GI foods release energy more quickly and therefore raise blood sugar more quickly.
The team said high-GI meals had been associated with dysfunction of cells, oxidative stress and inflammation, "all potentially important mechanisms in the development of hypertension".
The team took account of factors such as the weight of people in the study, but the results still held true.
Overall, they analysed data from more than 187,000 men and women from three large US studies over 20 years.
In January, a separate study found that women who enjoy potatoes may be at increased risk of suffering diabetes in pregnancy.
Those who eat two to four servings of potatoes a week may be around 27pc more likely to suffer diabetes in pregnancy.
Even one serving a week appeared to increase the risk by 20pc compared with women eating less than one serving a week, once body mass index (BMI) was taken into account.
Those eating more than five servings a week had a 50pc increased risk.
When women substituted two servings a week with other vegetables, pulses such as beans, lentils and peas and whole grain foods, they had a 9pc to 12pc lower risk.
"Although a higher consumption of potatoes was associated with high blood pressure, it is still possible that other factors in the diet or lifestyle are also affecting the results," said Victoria Taylor, senior dietitian at the British Heart Foundation.