Higher consumption of potatoes (whether fried, boiled, baked, or mashed) is associated with an increased risk of high blood pressure, according to a study published in the British Medical Journal.
The research suggests that replacing one daily serving of potatoes with other, non-starchy vegetables could reduce the risk of developing hypertension.
The researchers, from Harvard Medical School in the US, followed over 187,000 men and women from three large US studies for more than 20 years. They measured dietary intake, including frequency of potato consumption, with a questionnaire. Blood pressure was measured by a health professional.
After taking into account other risk factors for hypertension, the researchers found that four or more servings a week of potatoes was associated with an increased risk, compared with less than one serving a month. However, consumption of crisps was not found to increase risk.
The researchers wrote: ‘These findings have potentially important public health ramifications, as they do not support a potential benefit from the inclusion of potatoes as vegetables in government food programs but instead support a harmful effect that is consistent with adverse effects of high carbohydrate intakes seen in controlled feeding studies.’
The authors point out that, as potatoes have a high glycaemic index, they can trigger a sharp rise in blood sugar levels, which could partly explain their findings.
This research is fairly robust, but it is always extremely difficult to allow for confounding factors where lifestyle and diet are involved, particularly when subjective data (in this case a questionnaire) is being compared. As for the bigger picture, focusing on individual foods is less useful than examining overall diet and lifestyle. Certainly the celebration or vilification of specific foods seems to be a hallmark of media health stories — something that we need to move away from.
Research score: 3/5