Potatoes reduce the risk of heart disease and premature death

A recent study published in The Journal of Nutrition found that potato consumption modestly reduced the risk of all-cause mortality and cardiovascular disease in adults.

Potatoes are a staple in many traditional diets and, as a result, one of the most commonly consumed vegetables in the world. Potatoes are rich in potassium, vitamin C, dietary fiber and many bioactive compounds, all of which are important nutrients that benefit cardiovascular health.

Despite containing these beneficial substances, potatoes are generally not considered a recommended vegetable due to their high starch content. In fact, potato consumption is associated with a risk of cardiometabolic diseases due to its high glycemic index.

The latest dietary guidelines in the Nordic countries include potatoes in the normal diet; however, specific quantitative recommendations are not provided due to insufficient evidence. Moreover, previous studies examining the associations between potato consumption and the risk of cardiovascular disease mortality have yielded mixed results.

The current prospective cohort study was conducted in three Norwegian counties: Northern, Southwestern and Central Norway.

The study included 77,297 adults aged 18 to 64 years. Study participants were invited to participate in three cardiovascular examinations conducted between 1974 and 1988.

At each survey, dietary information was collected using semi-quantitative food frequency questionnaires and used to calculate weekly potato intake and average daily intake. Participants also collected data on their civil status, health status and lifestyle, such as smoking habits and physical activity.

Information on mortality from all causes and specifically from cardiovascular disease was obtained from the Norwegian Cause of Death Register using a unique personal identification number assigned to all residents. Appropriate statistical analyzes were performed to determine the association between potato consumption and the risk of all-cause and cardiovascular disease mortality.

Baseline characteristics of participants showed that men were more likely to consume more potatoes than women. Study participants with high potato consumption were more likely to have only compulsory education, be current smokers, report more physical activity, and were less likely to be obese or overweight compared to those with lower potato consumption.

The highest prevalence of diabetes was observed among participants with low potato consumption.

In the first and third surveys, about 68% and 62% of participants respectively consumed six to seven potato meals each week. The average number of potatoes consumed per week at baseline was 13, with about 90% of participants consuming at least two potatoes per meal.

The relationship between potato consumption and mortality

During a mean follow-up of 33.5 years, there were 27,848 deaths among 77,297 participants. Of these deaths, 9,072 were caused by cardiovascular disease, including 4,620 deaths from coronary heart disease and 3,207 deaths from acute myocardial infarction.

Participants who consumed 14 or more potatoes per week had a lower risk of all-cause mortality compared to those who consumed six potatoes or fewer per week. There was a weak inverse association between potato consumption and a lower risk of death from cardiovascular disease, coronary heart disease and acute myocardial infarction.

Based on average daily consumption, each 100 gram per day increase in potato consumption was associated with a 4% reduction in the risk of all-cause mortality and cardiovascular disease. This association remained stable for the risk of all-cause mortality after adjusting for sex, body mass index (BMI), smoking status, and physical activity level.

There was a modest inverse association between long-term habitual potato consumption and the risk of all-cause mortality and cardiovascular disease among Norwegian adults. However, the current study includes a Norwegian population and a dietary sample set in the 1970s and 1980s, which may limit the generalizability of the results to populations with other dietary habits and cultural factors.

Although the food frequency questionnaires used in the current study did not ask about consumption of processed potato products other than potato chips, and did not include potato consumption as part of meals, food consumption surveys in Norway from the 1970s and 1980 's show that 80% of all lunches were served with boiled potatoes. Boiled potatoes are considered a quality source of carbohydrates with a lower glycemic index.

Previous studies reporting a negative or neutral effect of potato consumption on the risk of all-cause mortality often grouped processed potato products with whole potatoes. It is important to note that specific cooking methods affect the nutritional profile of potatoes.