Causal relationship between diet and knee osteoarthritis: A Mendelian randomization analysis

Area of Science:

• Nutritional Epidemiology
• Genetic Epidemiology
• Osteoarthritis Research

Background:

• Knee osteoarthritis (KOA) is a widespread disabling condition with limited understanding of dietary causal factors.
• Investigating the relationship between diet and KOA is crucial for public health.
• Mendelian randomization (MR) offers a robust method to explore causal dietary links to KOA.

Purpose of the Study:

• To determine the causal effect of various dietary intakes on the risk of developing knee osteoarthritis.
• To utilize genetic variants as instrumental variables for dietary factors in a Mendelian randomization analysis.
• To identify specific dietary components that may influence KOA etiology.

Main Methods:

• Employed summary-level data from genome-wide association studies (GWAS) for dietary intake and KOA.
• Selected genetic variants for 18 distinct dietary factors as instrumental variables.
• Conducted univariate and multivariate Mendelian randomization analyses, including sensitivity analyses to ensure validity.

Main Results:

• Higher coffee consumption was linked to increased KOA risk.
• Increased intake of dried fruits, grains, cheese, and oily fish showed an association with reduced KOA risk.
• Coffee and oily fish impacts on KOA may be mediated by obesity, BMI, diabetes, hypertension, and prolonged standing.

Conclusions:

• This study provides novel causal evidence linking dietary intake to knee osteoarthritis risk.
• Recommendations include increasing intake of dried fruits, grains, cheese, and oily fish, while decreasing coffee consumption for potential KOA prevention.
• Further investigation is required to confirm these findings and understand the underlying mechanisms.