The type of dietary fats consumed by middle-aged men, especially polyunsaturated fats and linoleic acids, may be more important than total fat intake in reducing the risk of cardiovascular deaths, according to a study in the January 24 issue of Archives of Internal Medicine.
According to background information in the article, substitution of dietary polyunsaturated fat has been recommended for several decades in the primary prevention of cardiovascular disease (CVD), but few studies have provided scientific support for the advice. Some metabolic studies show that polyunsaturated fats lower serum low-density lipoprotein cholesterol (LDL-C) concentration [the so-called ‘bad cholesterol’], while saturated fat increases LDL-C. Linoleic acid is a liquid polyunsaturated fatty acid abundant in plant fat and oils (e.g., flaxseed, linseed oil).
David E. Laaksonen, M.D., Ph.D., from University of Kuopio, Finland, and colleagues, assessed the dietary linoleic and total polyunsaturated fatty acid (PUFA) intake with cardiovascular and overall rates of death in 1,551 middle-aged men living in eastern Finland. The assessments were made through food records and blood tests for glucose and serum cholesterol levels.
“During the 15-year follow-up, 78 men died of CVD and 225 of any cause,” the researchers report. “Middle-aged men with proportions of serum linoleic acid, n-6 (omega-6) fatty acids, and especially PUFA in the upper third were up to three times less likely to die of CVD than men with proportions in the lower third. Dietary intake of linoleic acid and total PUFA as assessed with a 4-day food record was also inversely associated with CVD, but total fat intake was not.”
In conclusion the authors write: “Dietary fat quality thus seems more important than fat quantity in the reduction of CVD mortality in middle-aged men. 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.”