Summary: | Background: Polyphenols may lower the risk of cardiovascular disease (CVD) and other chronic diseases due to
their antioxidant and anti-inflammatory properties, as well as their beneficial effects on blood pressure, lipids and
insulin resistance. However, no previous epidemiological studies have evaluated the relationship between the intake
of total polyphenols intake and polyphenol subclasses with overall mortality. Our aim was to evaluate whether
polyphenol intake is associated with all-cause mortality in subjects at high cardiovascular risk.
Methods: We used data from the PREDIMED study, a 7,447-participant, parallel-group, randomized, multicenter,
controlled five-year feeding trial aimed at assessing the effects of the Mediterranean Diet in primary prevention of
cardiovascular disease. Polyphenol intake was calculated by matching food consumption data from repeated food
frequency questionnaires (FFQ) with the Phenol-Explorer database on the polyphenol content of each reported
food. Hazard ratios (HR) and 95% confidence intervals (CI) between polyphenol intake and mortality were estimated
using time-dependent Cox proportional hazard models.
Results: Over an average of 4.8 years of follow-up, we observed 327 deaths. After multivariate adjustment, we
found a 37% relative reduction in all-cause mortality comparing the highest versus the lowest quintiles of total
polyphenol intake (hazard ratio (HR) = 0.63; 95% CI 0.41 to 0.97; P for trend = 0.12). Among the polyphenol subclasses,
stilbenes and lignans were significantly associated with reduced all-cause mortality (HR =0.48; 95% CI 0.25 to 0.91; P for
trend = 0.04 and HR = 0.60; 95% CI 0.37 to 0.97; P for trend = 0.03, respectively), with no significant associations apparent
in the rest (flavonoids or phenolic acids).
Conclusions: Among high-risk subjects, those who reported a high polyphenol intake, especially of stilbenes and
lignans, showed a reduced risk of overall mortality compared to those with lower intakes. These results may be useful
to determine optimal polyphenol intake or specific food sources of polyphenols that may reduce the risk of all-cause
mortality.
Clinical trial registration: ISRCTN35739639.
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