Consuming more plant-based fat reduces the risk for overall, CVD morality

Key takeaways:

• Consuming more plant-based fat may decrease the risk for overall and CVD-related mortality compared with animal fats.
• Fat from grains and vegetable oils may be linked to a decreased risk of overall mortality.

A greater intake of plant fat, particularly fat from grains and vegetable oils, was tied to lower overall and cardiovascular disease mortality, a study in JAMA Internal Medicine showed.

In comparison, a diet with a higher intake of animal-based fat increased the risk for both overall and CVD mortality.

“Dietary fats are critical macronutrients that play important roles in various biological functions including metabolic fuel [and] maintaining cell membrane structure,” Bin Zhao, PhD, from the Second Xiangya Hospital of Central South University in China, and colleagues wrote. “Although earlier cross-national and experimental research suggested beneficial effects of lower total dietary fat intake, recent cohort studies, clinical trials, and meta-analyses have yielded inconsistent results.”

In the prospective cohort study, the researchers assessed links between the risk for several types of mortality and plant and animal fat intake using 1995 to 2019 NIH-AARP Diet and Health Study data on 407,531 people (mean age, 61 years; 56.9% men).

A total of 185,111 deaths that occurred during the follow-up period, including 58,526 CVD deaths.

Overall, a greater intake of plant fat reduced the risk for overall mortality (HR = 0.91) and CVD mortality (HR = 0.86).

The researchers pointed out that plant fat from grains (HR = 0.86) and vegetable oils (HR = 0.85) drove the reduction in CVD mortality.

Additionally, they reported significantly reduced risk for overall mortality among individuals who had a high intake of plant fat from vegetable oils (HR = 0.88) and grains (HR = 0.92)

Meanwhile, greater intake of total animal fats (HR = 1.16), dairy fat (HR = 1.09) or egg fat (HR = 1.13) increased the risk for overall mortality.

An increased risk for CVD mortality was tied to a higher intake of egg fat (HR = 1.16), total animal fats (HR = 1.14) or dairy fat (HR = 1.07).

A higher intake of egg fat was also associated with an increased risk for stroke mortality (HR = 1.22).

Greater intake of fat from red meat was initially tied to increased risks for overall, CVD and heart disease mortality, but these associations were attenuated after the researchers adjusted for red meat consumption.

Zhao and colleagues found that the replacement of 5% energy from animal fat with 5% energy from plant fat — particularly fat from vegetable oils or grains — was associated with a 4% to 24% risk reduction for overall mortality and a 5% to 30% risk reduction for CVD mortality.

They explained that the benefits of vegetable oils “may be partially attributed to a reduction in lipogenesis, an increase in beta-oxidation, a decrease in intestinal cholesterol uptake and enhancement of endothelial function.”

The researchers identified several study limitations. For example, they could not rule out residual confounding. Meanwhile, the food frequency questionnaire used to assess food intake “could be subject to measurement error (eg, underreporting or overreporting of dietary intakes),” they wrote.

Still, the findings “offer detailed insights relevant to dietary guidelines that could be useful for improving human health and related outcomes,” Zhao and colleagues concluded.