Causal Effect of Macronutrient and Micronutrient Intake on Stroke: A Two-Sample Mendelian Randomization Study

Area of Science:

• Nutritional Epidemiology
• Genetic Epidemiology
• Cardiovascular Disease Research

Background:

• Investigating nutrient intake's causal link to stroke is crucial for prevention, but observational studies face confounding and reverse causation.
• Mendelian randomization (MR) offers a robust method to assess causal effects of modifiable risk factors like nutrition on disease.

Purpose of the Study:

• To estimate the causal association between intake of various nutrients and the risk of stroke and its subtypes using a two-sample Mendelian randomization approach.
• To identify key nutrients that could be targeted for public health strategies in stroke prevention.

Main Methods:

• A two-sample Mendelian randomization (MR) analysis was conducted.
• Genetic summary statistics for 4 macronutrients and 14 micronutrients were obtained from 15 genome-wide association studies (GWAS).
• Stroke and subtype data were sourced from the MEGASTROKE consortium.

Main Results:

• Genetically predicted higher magnesium levels were significantly associated with reduced risk of cardioembolic stroke (OR: 0.011).
• Vitamin C intake showed a significant association with lower risk of cardioembolic stroke (OR: 0.759).
• Vitamin B9 intake was linked to a reduced risk of small vessel stroke (OR: 0.574).
• Vitamin B6 showed a potential association with increased large-artery stroke risk (OR: 1.546), requiring cautious interpretation.
• Magnesium also showed suggestive evidence for decreasing the risk of any stroke and ischemic stroke.

Conclusions:

• Magnesium, vitamin C, and vitamin B9 demonstrate protective roles in stroke prevention, supporting their consideration in public health initiatives.
• The association between vitamin B6 and large-artery stroke risk warrants further investigation due to limited supporting genetic variants.
• MR analysis provides valuable insights into nutrient-stroke relationships, guiding future research and preventative strategies.