Macronutrient intake and mortality risk Original paper

In this meta-analysis of observational studies, a higher intake of fat or plant protein was associated with lower all-cause mortality risk.

The association between dietary macronutrient intake and the mortality risk for cardiovascular disease, stroke, cancer, and all causes.

The risk of having a cardiovascular disease event or stroke was also studied.

A total of 5,107,821 men and women (ages 19–99).

A meta-analysis of 124 cohort studies was performed. The studies were conducted in North America (58 studies), Europe (33 studies), Asia (29 studies), Australia (2 studies), South America (1 study), and multiple locations (1 study). The follow-up duration ranged from 2.2 to 30 years.

The participants reported their dietary intake using Food Frequency Questionnaires, 24-hour recalls, or food records. All of the studies adjusted for at least four of the following confounding factors: energy (calorie) intake, age, sex, socioeconomic status, health conditions, or lifestyle factors (e.g., smoking and physical activity). In all of the analyses, the highest intake of each macronutrient was compared with the lowest intake of that macronutrient.

There was no association between total protein intake and all-cause mortality, cardiovascular disease mortality, or cancer mortality. However, a higher plant-protein intake was associated with a lower risk for both all-cause mortality (−8%, based on 10 studies) and cardiovascular disease mortality (−15%, based on 13 studies). Higher total protein intake was associated with a lower risk for cardiovascular disease (−10%, based on 15 studies) and stroke (−16%, based on 5 studies), and plant and animal protein intakes were associated with a 15% and 23% lower risk of cardiovascular disease, respectively (based on 5 studies each).

Higher fat intake was associated with an 8% lower all-cause mortality risk (based on 16 studies). Higher saturated fat intake was associated with a 10% higher risk for cancer mortality (based on 11 studies).

Additionally, higher intakes of monounsaturated fat and polyunsaturated fat, respectively, were associated with a lower risk of the following:

• 8% and 9% for all-cause mortality (based on 18–20 studies)
• 11% and 8% for cardiovascular disease mortality (based on 22–23 studies)
• 5% and 6% for cancer mortality (based on 11 studies each)

Higher carbohydrate intake was associated with a 7% higher risk of cardiovascular disease (based on 20 studies).

A limitation of this meta-analysis is that it didn’t provide percentages or grams per day for the highest and lowest intakes of each macronutrient, making it difficult to provide recommendations based on the findings.