UNSW experts have questioned new research that found potatoes increase your risk of high blood pressure, saying it is important to look at the whole diet and not just individual foods.
The study, published in the British Medical Journal, is the first to identify potatoes as a key source of hypertension.
The US-based researchers, at Brigham and Women’s Hospital and Harvard Medical School, gathered results from three observational studies which followed 187,453 men and women for more than 25 years.
After considering other risk factors for hypertension, the researchers found that four or more servings a week of baked, boiled, or mashed potatoes was associated with an increased risk of hypertension for women. Men who ate potatoes in the same form didn't. Eating a lot of fried potatoes increased the risk of high blood pressure in both men and women.
The study authors said no firm conclusions can be drawn about cause and effect. However the high glycaemic index of potatoes, which can trigger a sharp rise in blood sugar levels, could be one explanation for the findings.
In a linked editorial to the study, UNSW Professor Mark Harris, Director of the Primary Health Care and Equity (CPHCE), said that studying overall dietary patterns and risk of disease is more useful than focusing on individual foods.
“We seem to be constantly assailed by media reports of studies, and sometimes conflicting recommendations about the risk posed by specific dietary foods,” Professor Harris said.
“This is a major challenge for clinicians, not only in responding to patients’ questions but also in giving advice about what diet to follow to lower the risk of disease.
“The best strategy for reducing your risk of diseases, such as diabetes, heart disease and high blood pressure is to consume a diet rich in fruit, vegetables, whole grains and low fat dairy foods, and limiting sugar, sweetened foods and drinks, red meat and added fats.”
Dr Rebecca Reynolds, a lecturer in nutrition at UNSW, said boiled or mashed potatoes should be part of a healthy, balanced diet with potato chips only an occasional food.
“Potato chips are often deep fried in unhealthier oils, have more added salt and are more energy dense, which are factors more likely associated with hypertension,” Dr Reynolds said.