Plant fat intake confers modest protection against overall, CVD mortality

Consuming high amounts of plant fat, especially those from grains and vegetable oils, appears to be associated with a small reduction in the risk of both overall and cardiovascular disease (CVD) mortality, according to a large prospective cohort study.

The study included 407,531 men and women (mean age 61.2 years, 56.9 percent male) who participated in the National Institutes of Health–AARP Diet and Health Study. A validated food frequency questionnaire was used to collect information about specific food sources of dietary fats, among others. Specific causes of death were determined via follow-up linkage with the Social Security Administration Death Master File.

A total of 185,111 deaths, including 58,526 from CVD, were documented over 8,107,711 person-years of follow-up.

Multivariable-adjusted Cox proportional hazards regression showed that the highest vs lowest quintile of intake of plant fat was associated with a 9-percent reduction in the risk of overall mortality (hazard ratio [HR], 0.91; 24-year adjusted absolute risk difference [ARD], –1.10 percent; p<0.001 for trend) and 14-percent reduction in the risk of CVD mortality (HR, 0.86; adjusted ARD, −0.73 percent; p<0.001 for trend).

Lower overall and CVD mortality was consistently observed for the highest vs lowest intake quintile of fat from grains (HRs, 0.92 and 0.86; adjusted ARDs, −0.98 percent and −0.71 percent; p<0.001 for trend) and vegetable oils (HRs, 0.88 and 0.85; adjusted ARDs, −1.40 percent and −0.71 percent; p<0.001 for trend).

Conversely, the highest vs lowest intake quintile of total animal fat correlated with an increase of 16 percent in the risk of overall mortality (HR, 1.16; adjusted ARD, 0.78 percent; p<0.001 for trend) and of 14 percent in the risk of CVD mortality (HR, 1.14; adjusted ARD, 0.32 percent; p<0.001 for trend). This held true for dairy fat (HRs, 1.09 and 1.07; adjusted ARDs, 0.86 percent and 0.24 percent; p<0.001 for trend) and egg fat (HRs, 1.13 and 1.16; adjusted ARDs, 1.40 percent and 0.82 percent; p<0.001 for trend).

Substituting 5 percent of energy from animal fat with a similar amount of plant fat, primarily from grains or vegetable oils, was associated with a 4-percent to 24-percent decrease in overall mortality and a 5-percent to 30-percent reduction in CVD mortality.