Exploring causal links between multifaceted dietary exposures and stroke subtypes: Results from a two-sample...

Area of Science:

• Nutritional Epidemiology
• Genetic Epidemiology
• Cardiovascular Disease Research

Background:

• Observational studies suggest links between diet and stroke, but causal relationships are unclear.
• Mendelian randomization (MR) offers a method to infer causality using genetic variants.
• Stroke remains a leading cause of disability and mortality worldwide.

Purpose of the Study:

• To investigate the potential causal associations between various dietary intakes and the risk of stroke using a two-sample Mendelian randomization approach.
• To differentiate between observational associations and potential causal effects of diet on stroke incidence.

Main Methods:

• Utilized a two-sample Mendelian randomization (MR) design.
• Extracted genetic instrumental variables from large-scale genome-wide association studies (GWAS) databases (IEU OpenGWAS, GWAS Catalog).
• Employed the inverse variance weighted (IVW) method for primary analysis and conducted sensitivity analyses to assess result robustness.

Main Results:

• Dried fruit intake showed a causal association with reduced overall stroke risk and specific subtypes like ischemic, small-vessel ischemic, and lacunar stroke.
• Oily fish intake was associated with a reduced risk of stroke.
• Non-oily fish intake reduced lacunar stroke risk, and pork intake reduced intracerebral hemorrhage risk.
• No significant causal links were found for processed meat, salad/raw vegetables, fresh fruits, beef, cooked vegetables, poultry, lamb/mutton, or coffee.

Conclusions:

• Provides genetic evidence supporting causal roles for dried fruit, oily fish, non-oily fish, and pork in modifying stroke risk.
• These findings have potential implications for public health dietary guidelines and stroke prevention strategies.
• Highlights the utility of MR in establishing diet-stroke causality beyond observational data.