Eating more potatoes may lower your risk of heart disease and early death, study finds

A recent study published in The Journal of Nutrition finds that potato consumption moderately reduces the risk of all-cause mortality and cardiovascular disease-specific mortality in adults.

Study: Potato consumption and all-cause and cardiovascular disease mortality – a long-term follow-up of a Norwegian cohort. Image Credit: Pixel-Shot / Shutterstock.com

Are potatoes healthy?

Potatoes are a staple food in many traditional diets and, as a result, are one of the most commonly consumed vegetables globally. Potatoes are a rich source of potassium, vitamin C, dietary fibers, and many bioactive compounds, all of which are vital nutrients with cardiovascular health benefits.

Despite containing essential nutrients, potatoes are generally not considered a recommended vegetable due to their high starch content. In fact, potato intake has been linked to cardiometabolic disease risk due to their high glycemic index.

The most recent Nordic Nutrition Recommendations have mentioned including potatoes in regular diets; however, no quantitative guideline has been provided due to the lack of evidence. Moreover, previous studies investigating associations between potato intake and risk of cardiovascular disease-specific mortality have produced mixed results.

About the study

The current population-based prospective cohort study was conducted in three Norwegian counties: Northern, South-Western, and Central Norway.

A total of 77,297 adult individuals between 18 and 64 years of age were enrolled in the study. Study participants were invited to participate in three cardiovascular health screenings conducted between 1974 and 1988.

At each screening, semi-quantitative food frequency questionnaires were used to collect dietary information, which was used to calculate weekly potato intake and daily cumulative mean intake. Data on civil status, health status, and lifestyle factors, such as smoking habits and physical activity, were also obtained from the participants.

Information on all-cause and cardiovascular disease-specific mortality was obtained from the Norwegian Cause of Death Registry using the unique personal identification number assigned to all residents. Appropriate statistical analyses were conducted to determine the association between potato intake and risk of all-cause and cardiovascular mortality.

Study findings

The baseline characterization of participants revealed that males were more likely to have higher potato intake than females. Study participants with high potato intake were more likely to have only compulsory education, be current smokers, report greater physical activity, and be less likely to be obese or overweight as compared to those with the lowest potato intake.

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

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

Association between potato intake and mortality

A total of 27,848 deaths were reported among 77,297 enrolled participants during the mean follow-up period of 33.5 years. Among these deaths, 9,072 were due to cardiovascular disease, including 4,620 deaths from ischemic heart disease and 3,207 deaths from acute myocardial infarction.

Participants who consumed 14 or more potatoes each week had a lower risk of all-cause mortality than those who consumed six potatoes or less each week. A marginally inverse association was observed between potato intake and a lower risk of death due to cardiovascular disease, ischemic heart disease, and acute myocardial infarction.

Considering daily cumulative mean intake, a 4% reduced risk of all-cause mortality and cardiovascular disease-specific mortality was observed with each 100 grams per day increment in potato intake. This association remained stable for all-cause mortality risk after adjusting for sex, body mass index (BMI), smoking status, and physical activity level.

A significant association with potato intake was observed only in men regarding cardiovascular disease-specific mortality risk.

Conclusions

A modest inverse association was observed between long-term habitual intake of potatoes and risk of all-cause and cardiovascular disease-specific risks among Norwegian adults. Nevertheless, the current study includes a Norwegian population and diet pattern followed during the 1970s-80s, which might limit the generalizability of the findings to populations with other dietary habits and cultural factors.

Although the food frequency questionnaires used in the current study do not include questions on processed potato product consumption, except potato chips/crisps, and nor do they capture intake of potatoes as an ingredient, consumption surveys in Norway from the 1970s and 1980s indicate that 80% of all dinners were served with boiled potatoes. Boiled potatoes are considered a high-quality carbohydrate source with a lower glycemic index.

Previous studies reporting either an adverse or no impact of potato intake on all-cause mortality risk have often grouped processed potato products with whole potatoes. Importantly, specific methods of preparation are known to influence the nutritional profile of potatoes.