Mediterranean-Style Diet Improves Systolic Blood Pressure and Arterial Stiffness in Older Adults

Abstract

We aimed to determine the effect of a Mediterranean-style diet, tailored to meet dietary recommendations for older adults, on blood pressure and arterial stiffness. In 12 months, randomized controlled trial (NU-AGE [New Dietary Strategies Addressing the Specific Needs of Elderly Population for Healthy Aging in Europe]), blood pressure was measured in 1294 healthy participants, aged 65 to 79 years, recruited from 5 European centers, and arterial stiffness in a subset of 225 participants. The intervention group received individually tailored standardized dietary advice and commercially available foods to increase adherence to a Mediterranean diet. The control group continued on their habitual diet and was provided with current national dietary guidance. In the 1142 participants who completed the trial (88.2%), after 1 year the intervention resulted in a significant reduction in systolic blood pressure (-5.5 mm Hg; 95% CI, -10.7 to -0.4; P=0.03), which was evident in males (-9.2 mm Hg, P=0.02) but not females (-3.1 mm Hg, P=0.37). The -1.7 mm Hg (95% CI, -4.3 to 0.9) decrease in diastolic pressure after intervention did not reach statistical significance. In a subset (n=225), augmentation index, a measure of arterial stiffness, was improved following intervention (-12.4; 95% CI, -24.4 to -0.5; P=0.04) with no change in pulse wave velocity. The intervention also resulted in an increase in 24-hour urinary potassium (8.8 mmol/L; 95% CI, 0.7-16.9; P=0.03) and in male participants (52%) a reduction in pulse pressure (-6.1 mm Hg; 95% CI, -12.0 to -0.2; P=0.04) and 24-hour urinary sodium (-27.1 mmol/L; 95% CI, -53.3 to -1.0; P=0.04). In conclusion, a Mediterranean-style diet is effective in improving cardiovascular health with clinically relevant reductions in blood pressure and arterial stiffness. Clinical Trial Registration- URL: http://www.clinicialtrials.gov . Unique identifier: NCT01754012.

Keywords: aging; blood pressure; potassium; pulse wave velocity; sodium.

Figure 1.

Flowchart of participants in the NU-AGE trial (New Dietary Strategies Addressing the Specific Needs of Elderly Population for Healthy Aging in Europe).

Figure 2.

Percentage change in key dietary components of the Mediterranean-style diet after 1 y of follow-up in the intervention and control diet groups. Bars represent means adjusted for study center, age, sex, and body mass index (BMI). * indicates a significant difference between intervention and control groups (P<0.05, ANCOVA).

Figure 3.

Mean difference in systolic blood pressure after 1 y of follow-up in the intervention and control diet groups stratified by baseline antihypertensive use. Bars represent mean (95% CI) adjusted for baseline measure, age, sex, baseline body mass index (BMI), baseline smoking status, self-reported diabetes mellitus, and level of dietary compliance in participants using antihypertensive medications (A) and participants not using antihypertensive medications (B). P value for difference between intervention and control groups (ANCOVA).

Figure 4.

Mean difference in arterial stiffness after 1 y of follow-up in the intervention and control diet groups in the UK study center. Bars represent mean (95% CI) adjusted for baseline measure, age, sex, baseline antihypertensive use, baseline body mass index (BMI), baseline smoking status, self-reported diabetes mellitus, and level of dietary compliance for pulse wave velocity (A) and Augmentation Index (B). P value for difference between intervention and control groups (ANCOVA).