Vegan Versus Ketogenic Diets

Imagine switching up your meals in a big way, ditching meat and dairy for a vegan lifestyle or diving deep into the world of low-carb keto. What happens to your body’s defences, your trusty immune system? A recent study published in Nature Medicine delves into this very question, comparing the impacts of these two popular diets.

Key findings:

• Both vegan and keto diets cause noticeable shifts in the types of immune cells circulating in your blood.
• Keto: Levels of specific cells involved in “adaptive immunity” (remembering past threats) like regulatory T cells and natural killers get a boost.
• Vegan: Cells crucial for “innate immunity” (first-line defence) like activated T helper cells and natural killers see a rise.
• Even the genes within these cells get jiggled around! Keto ramps up genes linked to T-cell activation, while vegan leans towards genes involved in other immune responses.

What does it mean?

This is the first research to show these distinct immune system responses to vegan and keto, potentially influencing our overall health. However, keep in mind:

• The study was small, meaning more research is needed to solidify these findings.
• Long-term effects weren’t explored, so the lasting impact remains unclear.

Nutrition, Immunity and COVID-19

Our immune system protects us from pathogens like viruses, bacteria, cancerous cells, etc. and it can be separated into 2 distinct branches: the innate immune system and the adaptive immune system. Our innate immune system uses cells such as macrophages, neutrophils and mast cells to mount a fast, generic response to pathogens. Inflammation is the hallmark of the innate immune system. On the other hand, the adaptive immune system uses T cells, B cells and natural killer cells to mount a slow, targeted response to pathogens. It’s the adaptive immune system that’s responsible for life-long immunity to certain diseases. In practice, the 2 branches interact to provide a comprehensive immune response.

In a recent article, Butler and Barrientos (2020) summarised the interactions between diet, immunity and COVID-19. They state that the typical western diet (high in saturated fats, refined carbohydrates and sugars, and low in fibre, unsaturated fats and antioxidants) “significantly impairs adaptive immunity while ramping up innate immunity, leading to chronic inflammation and severely impairing host defence against viral pathogens.”

The authors note that “T and B cell counts were also significantly lower in patients with severe COVID-19; thus, there could be a potential interaction between western diet consumption and COVID-19 on adaptive immunity impairment.” They suggest the higher rates of obesity and diabetes among ethnic minority populations may partly account for the health disparities seen in response to COVID-19.

Butler and Barrientos conclude “that individuals refrain from eating foods high in saturated fats and sugar and instead consume high amounts of fibre, whole grains, unsaturated fats, and antioxidants to boost immune function.”