153g beef daily lowers systolic blood pressure
The DASH diet (Dietary Approaches to Stop Hypertension) a plant-focused diet, rich in fruits and vegetables, nuts, with low-fat and non-fat dairy, lean meats, fish, and poultry, mostly whole grains, and heart healthy fats, developed to help treat or prevent high blood pressure. However, there have been no studies that have examined the effects pf a DASH-like diet with increased dietary protein from lean beef on blood pressure and vascular health.
Dr. Penny Kris-Etherton, PhD, RD, FAHA, Distinguished Professor of Nutrition, Pennsylvania State University and colleagues examined four diets; DASH-like diets that provided different amounts of protein from lean beef (DASH 28 g beef per day; beef in an optimal lean diet (BOLD) 113 g beef per day; beef in an optimal lean diet plus additional protein (BOLD+) 153 g beef per day) on blood pressure, endothelial function and vascular reactivity versus a healthy American diet (HAD).
The study include 36 participants with normal blood pressure or pre-hypertensive (BP <140/90 mm Hg) men and women, aged 30 to 65 years, with moderately elevated low-density lipoprotein cholesterol (LDL) (110–176 mg dl−1), body mass index (18.5–37 kg m−2) and fasting triglycerides <350 mg dl−1.
Participants were randomly assigned to follow each diet (HAD, DASH, BOLD and BOLD+)at different times throughout the study period. Participants were randomly assigned an order to follow each of the four diet plans for five weeks each, with a break of one week in between each new plan. Blood pressure was taken at the beginning and end of each diet period. On two consecutive days at the beginning of the study (baseline) and at the end of each diet period, participants completed a series of clinical and physical assessments (blood draw, height and weight)
The results showed systolic blood pressure decreased in participants on the BOLD+ diet(111.4±1.9 mm Hg) compared to the HAD diet (115.7±1.9). The DASH and BOLD diets showed no significant effects on the systolic blood pressure.
Augmentation index or AI (a ratio calculated from the blood pressure waveform, it is a measure of wave reflection and arterial stiffness) was significantly reduced in participants on the BOLD diet (−4.1%).
The researchers found no significant effects of the diet son diastolic blood pressure or endothelial function. A moderate protein DASH-like diet including lean beef decreased systolic blood pressure in normotensive individuals. The inclusion of lean beef in a heart healthy diet also reduced peripheral vascular constriction.
"This evidence suggests that it is the total protein intake -- not the type of protein -- that is instrumental in reducing blood pressure, as part of a DASH-like dietary pattern,” according to the researchers.
Dr. Kris-Etherton commented “This research adds to the significant evidence, including work previously done in our lab that supports lean beef's role in a heart-healthy diet.” "This study shows that nutrient-rich lean beef can be included as part of a heart-healthy diet that reduces blood pressure, which can help lower the risk for cardiovascular disease."
The Beef Checkoff Program and the National Institutes of Health-supported Penn State General Clinical Research Center funded this research.
This study is published in the Journal of Human Hypertension.