Blood pressure risk from spuds four times a week

A Sri Lankan labourer with sacks of potatoes and onions in Colombo. Photo / AP

A weekly diet which includes at least four servings of the humble potato is linked to an increase in the risk of high blood pressure, say researchers.

They found adults who had a higher intake of boiled, baked or mashed spuds and fries had an increased risk of hypertension.

Replacing one serving a day of boiled, baked, or mashed potatoes with one serving of a non-starchy vegetable is associated with a lower risk of developing hypertension, the US-based researchers said in a study published online in the British Medical Journal.

But a linked editorial, by experts from two Australian universities, said that studying overall dietary patterns and risk of disease is more useful than a focus on individual foods or nutrients.

The researchers, based at Brigham and Women's Hospital and Harvard Medical School, followed more than 187,000 men and women from three large US studies for more than 20 years.

Dietary intake, including frequency of potato consumption, was assessed using a questionnaire, while hypertension was reported by participants based on diagnosis by a health professional.

Compared with consumption of less than one serving a month, participants who consumed at least four servings a week had an increased risk of hypertension of 11 per cent for boiled, baked or mashed potatoes and of 17 per cent for French fries.

But consumption of potato chips was associated with no increased risk.

The authors said potatoes have a high glycaemic index compared with other vegetables, so can trigger a sharp rise in blood sugar levels, and this could be an explanation for the findings.

UNSW nutrition lecturer, Dr Rebecca Reynolds, agreed with the editorial saying people focus too much on population-level studies and foods where certain nutrients and foods are demonised, rather than a whole dietary approach.

"Potatoes when consumed in healthier ways such as cooked in potato salads, baked, boiled, mashed with milk and extra virgin olive oil, going easy on the salt, are a good food to be included as part of a healthy, balanced diet," she said.

- AAP