Short-Term RCT Of Increased Dietary Potassium From Potato Or Potassium Gluconate: Effect On Blood Pressure, Microcirculation, And Potassium And Sodium Retention In Pre-Hypertensive-to-Hypertensive Adults
|Values||BP at end of diet: Systolic: Diet with baked+boiled potato: 126.2 ± 0.93 mmHg; Control diet: 129.3 ± 0.90 mmHg; BP change during diet; Systolic; Diet with baked+boiled potatoes: −6.0 ± 1.1; Control diet: −2.6 ± 0.9.|
|Trial Design||Randomized trial|
|Trial Length||2-4 Weeks|
|Number of Subjects||30|
|Body Types||Obese, Overweight|
This randomized controlled crossover trial was conducted using 30 people (mean age of 48, mean BMI of 31.4) with prehypertension or hypertension. Participants were assigned in random order to 4 dietary conditions lasting 17 days, with each diet period separated by a 4-day washout period. The 4 dietary conditions were (1) a control diet (with 2,300 mg of potassium per day), (2) a diet supplemented with baked and boiled potatoes (with 3,300 mg of potassium per day), (3) a diet supplemented with French fries (with 3,300 mg of potassium per day), and (4) a diet supplemented with potassium gluconate (with 3,300 mg of potassium per day). All diets were designed to be nutritionally similar aside from potassium content.Funding issues for this study:
The primary outcome was end of treatment blood pressure differences between diets (taken on days 15, 16, and 17) adjusted for baseline blood pressure. A secondary outcome was change in blood pressure during the entire diet, with changes compared between groups.
For the primary outcome, end of treatment blood pressure (both systolic and diastolic) did not differ between groups, although systolic blood pressure was lower in the baked+boiled potatoes diet compared with the control diet (126.2 mmHg versus 129.3 mmHg) and this difference was near statistically significant (p=0.06). For blood pressure change throughout the trial, systolic blood pressure decreased in the baked+boiled potatoes group compared with the control diet (—2.6 mmHg) with no other differences between groups.
Sodium retention was lower during the baked+boiled potato diet compared with the control diet, due in part to higher urinary excretion of sodium (2,791 mg per day versus 2,183 mg per day).
The trial was funded by the Alliance for Potato Research and Education, a non-profit affiliated with the potato industry (e.g., farmers and food manufacturers).