WEST LAFAYETTE, Ind. — Potatoes tend to be a dieting no-no for people laying off of starchy foods and carbohydrates. In that same light, French fries often fall into the “junk food” category as eaters cover them in ketchup and salt. Now, a new study finds this popular vegetable may be getting a bum rap. Researchers from Purdue University say eating more potatoes can actually help keep blood pressure under control better than taking certain supplements.
The key to the potato’s nutritional goodness comes from potassium. Study authors explain that increasing dietary potassium from foods like baked and boiled potatoes helps to reduce sodium retention in eaters consuming a typical American diet. Eating more potatoes also results in a greater drop in systolic blood pressure than taking potassium supplements, according to the study. The research, conducted by scientists at Purdue University, was funded by the Alliance for Potato Research and Education..
In an experiment involving 30 pre-hypertensive to hypertensive men and women, researchers also discovered that French fries aren’t necessarily bad for the heart. In fact, their study shows having a 330-calorie serving of baked French fries along with a normal diet had no effect on the participants’ blood pressure.
“While significant emphasis is often placed on reducing dietary sodium intakes to better control for blood pressure and cardiovascular disease risk, that’s only half of the story,” explains primary investigator Connie Weaver, PhD, in a media release. “Potassium plays just as an important role, and perhaps the ratio of potassium to sodium is most important in the context of the entire food matrix, as the potato meal resulted in a greater reduction of sodium retention than the potassium supplement alone.”
Potatoes are already a major part of the American diet
Study authors note that there has been little research into potassium’s impact on blood pressure. Their report is one of the first to look at adding dietary potassium as a means of preventing hypertension.
“It’s important to establish clinical trials that follow observational research to establish a causal link between diet and health,” Weaver says. “For example, in this clinical study baked French fries had a null effect on blood pressure, which counters observational findings, at least in the short term, and helps to prioritize the importance of focusing on a total diet approach for maintaining health versus one that overemphasizes avoidance of any single food or food group.”
Potatoes make up about 20 percent of America’s vegetable intake, delivering other key nutrients such as fiber. Researchers say eating just one medium-sized potato provides about 10 percent of a person’s daily potassium needs. Despite the amount of potatoes the typical American already eats, study authors note they generally aren’t eating enough to reach recommended potassium goals. Overall, potatoes and French fries account for seven percent and three percent of the average American’s potassium intake, respectively.
“Considering Americans fall significantly short in meeting daily potassium intakes, these findings show the importance of promoting, not restricting, whole food good-to-excellent sources of potassium in Americans’ diets, like potatoes,” Weaver adds.
No need to hold the French fries if they’re baked
In this study, researchers split the 30 volunteers into four potassium intervention groups for 16 days. One group ate a control diet including 2,300 mg of potassium each day. This diet reflects the typical American diet, which scientists consider low in potassium intake.
The other diets included the same diet but added either 1,000 mg of potassium from baked, boiled, or pan-heated potatoes, 1,000 mg of potassium from baked French fries, or a 1,000-mg potassium-gluconate supplement.
Those results revealed the beneficial impact of eating potatoes on systolic blood pressure, the top or first number which shows how much pressure your blood is exerting against your artery walls when the heart beats.
“All clinical studies are faced with limitations; however, despite those found in this study, the rigor of the study design is strong and unlike any other studies that have investigated the effect of a whole food – and potassium – on high blood pressure,” Weaver concludes. “Through our carefully controlled balance study, we could determine the mechanism by which potatoes reduced blood pressure. Overall, we concluded that boiled or baked potatoes can help reduce systolic blood pressure – and baked French fries have no adverse effects on blood pressure and can be included as part of an overall healthy diet.”
The findings appear in the journal Nutrients.