Substituting Polyunsaturated for Saturated Fat Can Reduce Cardiovascular and Ove

Substituting Polyunsaturated for Saturated Fat Can Reduce Cardiovascular and Overall Mortality
Dietary fat quality seems more important than fat quantity in the reduction of cardiovascular mortality. Substituting polyunsaturated fatty acid (PUFA) for saturated fat in the diet reduces cardiovascular and overall mortality, according to the results of a population-based study.

“Substitution of dietary polyunsaturated for saturated fat has long been recommended for the primary prevention of cardiovascular disease (CVD), but only a few prospective cohort studies have provided support for this advice,” write David E. Laaksonen, MD, PhD, MPH, from the University of Kuopio in Finland, and colleagues. “In contrast, evidence for reduction of total fat intake without modification of fat quality in the prevention of CVD is weak.”

Using a four-day food record and measurements of serum fatty acid composition, investigators in the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study determined the association of dietary linoleic and total PUFA intake with cardiovascular and overall mortality in a population-based cohort of 1,551 middle-aged men.

During 15 years of follow-up, 225 men died of any cause, and 78 died of CVD. Total fat intake was not associated with CVD or overall mortality.

After adjustment for age, men with an energy-adjusted dietary intake of linoleic acid or PUFA in the upper third were less likely to die of CVD than men with intake in the lower third (relative risk [RR] for linoleic acid, 0.39; 95% confidence interval [CI], 0.21 – 0.71; RR for PUFA, 0.38; 95% CI, 0.20 – 0.70). CVD-related deaths were also lower for men in the upper vs lower third of serum esterified linoleic acid intake (RR, 0.42; 95% CI, 0.21 – 0.80) and PUFA intake (RR, 0.25; 95% CI, 0.12 – 0.50). Multivariate adjustment weakened all these associations to some extent. Serum and to a lesser degree dietary linoleic acid and PUFA also were related inversely to all-cause mortality.

“Dietary polyunsaturated and more specifically linoleic fatty acid intake may have a substantial cardioprotective benefit that is also reflected in overall mortality,” the authors write. “Dietary fat quality seems more important than fat quantity in the reduction of cardiovascular mortality in men.”

Study limitations include limited generalizability to high PUFA and low saturated fat diets or to other ethnic groups.
“Carrying out recommendations to replace saturated fat with polyunsaturated fat in the primary prevention of cardiovascular disease may substantially decrease CVD and to a lesser degree overall mortality,” the authors conclude.
Arch Intern Med. 2005;165:193-199