The Effect of Potassium and Calcium Enriched Diets on Blood Pressure: A Class Project for Advanced Statistics for Clinical Practice

Allen, Angela, Terry Aims, Clarisse Carter, Michele Collins, Lori Glenn, Belinda Ice, Lori Glenn, Christine Worgess, Jake Frimenko, and Carla Groh

Background: Hypertension is a major public health issue in the United States. Many people with hypertension prefer not to take prescribed medications and are trying alternative strategies for lowering their blood pressures. A myriad of strategies are being used (e.g. yoga, meditation, visualization and foods high in nutrients) that are purported to reduce blood pressure; however, there is a paucity of evidence to support the effectiveness of these strategies.

Aims: The purpose of this research was to determine if a relationship exists between potassium and calcium enriched diets and blood pressure.

Methods: This was a repeated measures design. Recruitment consisted of students from the Advanced Statistics for Clinical Practice (NUR7450) and one additional woman of the student’s choice who met the inclusion criteria (e.g. women between 18 and 60 years of age; not currently taking calcium or potassium supplements or antihypertensive medication; free of hypertension, renal failure, diabetes and heart disease; able to read and write English, and consent to participate). The student and recruited woman were considered a ‘pair”. Each pair was randomly assigned to either the potassium or calcium enriched diet. A manual blood pressure was obtained at baseline, 7-days and 14-days. The participants were asked to consume at least three foods enriched with potassium or calcium and to record their daily intake for a 2 week period.

Findings: A total of 16 women participated in the study (potassium group = 9; calcium group = 7).Repeated measures were calculated for the three data collectionpoints. No significant differences were detected on blood pressure readings between baseline, 7-days or 14-days.

Implications for Nursing Practice: The findings of this study were non-significant e.g. neither a potassium or calcium enriched diet impacted blood pressure readings over a 2-week period. There were several study limitations that might explain these negative findings. First, the sample was small (n=17). A larger sample may have detected differences. Second, the subjects recorded the number of high, moderate and low enriched foods they ate but portion size was not recorded so it is hard to determine the amount of potassium and calcium actually ingested. Third, the 2-week time frame for the study was insufficient to detect changes in blood pressure readings, if changes were to occur as a result of a diet enhanced with potassium and calcium. Despite these limitations, the findings do offer suggestions for future research studies.