Following a Mediterranean diet for 3-months reduces home measured systolic blood pressure (SBP) in older Australians; results from the Mediterranean diet for cognition and cardiovascular health in the elderly (MedLey) trial

Abstract

<jats:p>The Mediterranean diet (MedDiet), reported to have cardiovascular health benefits, consists of a variety of foods including fruit and vegetables, wholegrain cereals, legumes, nuts, red wine, olive oil, fish, poultry and red meat delivering valuable nutrients like fibre, vitamins, minerals, omega‐3 fatty acids and polyphenols. We sought to evaluate the health benefits of a Mediterranean diet in comparison with habitual diet on blood pressure (BP) in older Australians (mean age 71±5yrs) in the MedLey trial. Participants (were randomly allocated either a MedDiet (n=80) or continue their habitual diet (HabDiet) (n=72) for 6 months. Volunteers received some study foods and followed a prescribed MedDiet plan as advised by the study dietitian. All volunteers attended the clinic on a fortnightly basis to have their weight measured, discuss the intervention and receive study foods. Blood pressure was measured at home, three times daily (morning, afternoon, evening), taking 3 measures per reading for 6 days providing 54 blood pressure readings of which the average BP was obtained. Data was analysed using random effects model that included fixed effects for Diet, Visit, Diet x Visit interaction (STATA). Differences between diets were then assessed using the overall Diet x Visit interaction term and the marginally adjusted mean values. 137 volunteers completed the trial (MedDiet n=74, HabDiet n=63). Compliance to the MedDiet was maintained (92%) throughout the intervention according to 3‐day weighed food records collected at each time‐point. Mean SBP at baseline, 3 and 6 months, respectively, were: 124.9±1.4mmHg, 119.3±1.4mmHg and 118.9±1.6mmHg for MedDiet; and 127.8±1.5mmHg, 123.9±1.5mmHg and 122.1±1.7mmHg for Hab Diet. The MedDiet group had a significantly greater reduction in SBP than the HabDiet group at 3 months (P=0.031 for interaction) which was also significantly reduced for the afternoon measure of systolic BP alone (P=0.024 for interaction). Although both groups had clinically relevant decreases in SBP, following the MedDiet resulted in a greater reduction in SBP than for the habitual group. This dietary pattern could be utilised in Australia as part of a diet and lifestyle intervention for the control of elevated BP.</jats:p><jats:p><jats:bold>Support or Funding Information</jats:bold></jats:p><jats:p>This project was supported by a grant from the National Health Medical Research Council of Australia.</jats:p>