Dietary Fat Quality May be More Important Than Fat Quantity in Reducing
Risk of Cardiovascular Deaths in Middle-Aged Men
CHICAGO - 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."
(Arch Intern Med. 2005;165: 193-199.