05.15.2016
Study: Aged Cheese Lowers Blood Pressure
Small randomized trial suggests effect of Grana Padano on par with antihypertensives

by Crystal Phend
Senior Associate Editor, MedPage Today

NEW YORK — A few tablespoons of Grana Padano cheese every day had the blood pressure-lowering impact typical of antihypertensive medications in a small blinded, randomized trial.

A daily 30-g dose of the Italian hard cheese, which is similar to Parmesan, lowered office blood pressure by a mean 6/5 mm Hg more than did a placebo of shredded bread scented to mimic the cheese and with the same fat, calcium, and sodium profile (from 139/88 mm Hg at baseline to 130/81 versus 136/86 mm Hg, P<0.05).

The effect on automated office blood pressure readings was a similar 6/4 mm Hg greater with the cheese (P<0.05), Giuseppe Crippa, MD, of Guglielmo da Saliceto Hospital and Catholic University in Piacenza, Italy, and colleagues reported here at the American Society of Hypertension meeting.

Body mass index, total and HDL cholesterol, triglycerides, and serum sodium and potassium were unaffected.

The trial included 30 patients with mild-to-moderate essential hypertension (mean age 54, 13 women), who were on stable pharmacologic and other treatment regimens for the prior 3 months at least.

Participants were randomized in a double-blind, crossover design to 30-g Grana Padano cheese or placebo for 2 months, with individualized dietary counseling for both groups to keep other dietary habits unchanged for the duration of the study.

The amount of sodium in that serving size of cheese — 128 to 189 mg — is on par with a similarly sized 1-oz serving of potato chips, Crippa noted.

Fermentation of cow’s milk-proteins by cheese-making bacteria produces bioactive oligopeptides that have been shown to have ACE inhibition activity in vitro.

The mechanism isn’t far-fetched, as ACE inhibition stemmed from research on snake venom and its vasoactive properties, commented Joseph L. Izzo MD, of New York’s University at Buffalo. “It isn’t so unlikely that you’d find other biological processes that might be ACE inhibitory.”

However, more work is needed both to replicate the findings in a larger cohort and to confirm what mechanism really is at play, he cautioned in an interview with MedPage Today. “No claims should be made.”

Also, generalizability to other cheeses isn’t clear, Crippa suggested. Whereas Grana Padano is aged 9 to 12 months, fresher cheeses might not have had the time to develop these compounds and longer aging as typical for Parmesan cheese could break them down, he speculated.

Isolating the peptides of interest into pill form, instead of cheese, showed only a small, albeit, significant impact on office systolic blood pressure in clinical trials, Crippa noted, likening the situation to the cardiovascular benefit of red wine versus its resveratrol compound when isolated.

The study also collected 24-hour ambulatory blood pressure, but those results were not presented.