A shift from a diet high in animal-based foods, particularly red and processed meats, to one rich in plant-based foods such as nuts, legumes, and whole grains, is associated with a lower risk of all-cause mortality, cardiovascular diseases (CVD), and type 2 diabetes (T2D).

Cardiovascular disease

  • A study analysed the impact of substituting specific animal products with plant-based alternatives. 
  • Replacing 50 grams of processed meat a day with 28-50 grams of nuts resulted in a 27% decrease in the risk of any type of CVD. 
  • Replacement with whole grains lead to a 36% decrease in CVD incidence. 
  • Replacing one egg a day with nuts resulted in a 17% decrease in CVD incidence.

Diabetes

  • In terms of diabetes incidence, replacing butter with olive oil was associated with a slight decline in risk. 
  • Substituting red meat for nuts was associated with an 8% decrease in risk. 
  • The same parameter for replacing processed meat with nuts was 22%, replacing poultry with whole grains was 13%, and replacing eggs with nuts or whole grains was 8% .

The study also found that replacing processed meat with nuts or whole grains was associated with a 21% decrease in all-cause mortality risk.

Replacing eggs with nuts or legumes resulted in a 15% decrease, replacing red meat with nuts or whole grains resulted in a 7% decrease, and replacing butter with olive oil resulted in a 6% decrease.

Associations versus Causation

However, it's important to note that these findings are based on associations and not causation. Causation is usually demonstrated by a clinical trial with a placebo group.

While the studies included in the review were adjusted for major lifestyle confounders such as total energy intake, physical activity, alcohol intake, and smoking, completely eliminating confounding is impossible. 

One alternative explanation for the observed associations is that people on plant-based diets tend to follow healthier lifestyles in general.

Moreover, while plant-based diets are associated with numerous health benefits, they also require careful planning to ensure adequate intake of essential nutrients such as protein, iron, vitamin B12, and Omega 3 fatty acids, which are typically abundant in animal-based foods.

Conclusion

The study suggests that a diet rich in plant-based foods can contribute to improved cardiometabolic health.

However, more research is needed to strengthen the existing evidence and to investigate new associations, especially with a focus on meat and dairy replacement products.

Reference

Image credit and creator

Neuenschwander, M., Stadelmaier, J., Eble, J. et al. (2023). Substitution of animal-based with plant-based foods on cardiometabolic health and all-cause mortality: a systematic review and meta-analysis of prospective studies. BMC Med 21, 404.