The impact of dietary fat and fatty acid consumption on human health: A comprehensive review of meta-analyses and the Global Burden of Disease study 2021

Abstract

Background

Understanding the impact of dietary fats on human health and the latest global health burden attributable to unbalanced intake of fatty acids remains a challenge.

Scope and approach

We assessed the existing meta-analyses based on randomised controlled trials or prospective cohort studies, up until May 13, 2024. We extracted data on the prevalence and attributable burden of unbalanced fatty acid intakes from 1990 to 2021 by locations, ages and sexes, according to the Global Burden of Disease 2021.

Key findings and conclusions

This study included 167 systematic reviews and meta-analyses. Moderate-quality evidence revealed beneficial relationships between the intake of omega-6 fatty acids and cardiovascular disease (CVD) mortality (class II), overall cancer mortality (class II), and all-cause mortality (class II). Furthermore, moderate-quality evidence suggested that seafood-derived omega-3 fatty acids were associated with reduced triglyceride levels (class IV), elevated high density lipoprotein cholesterol (class IV), and a decreased risk of coronary heart disease (class III). However, a significant global prevalence of inadequate omega-6 and seafood omega-3 fatty acid intakes still existed, a situation particularly marked in less-developed regions and nations. The regions in Sub-Saharan Africa and Latin America have recently experienced an increase in summary exposure values and attributable burden for diets low in omega-6 and diets low in seafood omega-3 fatty acids. Moreover, CVD mortality attributable to unbalanced fatty acid intakes was higher in the elderly aged 75+. We also observed that the associations between total fat consumption and multiple important health outcomes were not statistically significant, such as type 2 diabetes mellitus, stroke, CVD mortality, and cancer mortality. Therefore, dietary guidelines that currently advise limitations on total fat intake should consider our findings when revising their future recommendations. Furthermore, daily intake of polyunsaturated fatty acids, especially omega-6 and seafood omega-3 fatty acids, should be increased, particularly in some less-developed regions and countries. Future efforts should prioritize interventions targeting individuals aged ≥75 years to optimize fatty acid intake and CVD management, such as enhancing nutritional education and improving the food supply chain.