How a Plant-Based Diet is Better for the Immune System

The function of the immune system is very complicated and its role in disease prevention is broadly recognized by medical experts. The immune system functions to protect the body against infectious pathogens (i.e. bacteria, viruses, fungi, parasites, etc.) but also functions on a daily basis to prevent cardiovascular disease, neurodegenerative conditions, auto-immune diseases, and cancer, largely in terms of how it modulates inflammation in the body. In essence, our immune system is constantly at work to keep us healthy. In the last 10-20 years, medical research has clearly established the importance of inflammation in our body and its link to many chronic diseases related to aging, poor diet, and a sedentary lifestyle. The good news is we can use this knowledge to harness the immune system’s incredible power for long-term health and wellness. 

There are four foundational factors for healthy living: good sleep, limited stress/substance use, regular exercise, and a balanced diet. These factors work best in synergy when each is receiving adequate attention as part of a healthy lifestyle. Sleep may be the most important factor for a healthy immune system, but lots of sleep can be quickly negated by a sedentary lifestyle and poor diet. Furthermore, an active person with a great diet could suffer from multiple health issues if they have extreme levels of stress in their life. As the old adage goes, balance is key. 

In this blog post, I will focus on three key ways in which a plant-based diet can support optimal immune system function. The best plant-based diets incorporate high levels of the following elements: antioxidants, Vitamin C, and anti-inflammatory foods.   

1) Antioxidants: these are compounds that help fight “oxidative damage” of our cells which leads to many different chronic diseases of aging. Vitamin C, Vitamin E, Carotenoids (beta-carotene and lycopene), and Polyphenols are four well-recognized antioxidants. Plant sources that are high in Vitamin E: almonds, sunflower seeds, avocados, broccoli, spinach, and swiss chard. Plant sources that are high in Carotenoids: kale, apricots, carrots, tomatoes, and bell peppers. Finally, plant sources that are high in Polyphenols: apples, onions, berries, tea, and cocoa. 

2) Vitamin C has long been touted as an immune booster for a variety of reasons as it supports many cellular functions of the immune system. The evidence for daily supplementation with Vitamin C is not that clear but incorporating natural sources of Vitamin C is critical for maintaining robust immune system function. Plant-based foods that are high in Vitamin C: kiwis, bell peppers, strawberries, oranges, papaya, broccoli, and tomatoes.  

3) Anti-inflammatory foods: these are foods that help reduce levels of inflammation in our body through a variety of mechanisms including antioxidant pathways and reduction of inflammatory compounds that the immune system uses to signal infection or disease. Foods rich in omega-3 compounds will be important in this process. Oily fish are generally the best sources of omega-3 compounds but excellent plant-based sources are walnuts, almonds, chia seeds, flaxseed, avocado, and edamame. Other plant-based anti-inflammatory foods: pomegranates, berries, cherries, oranges, green tea, turmeric, and ginger. 

There are plenty of plant-based foods that have a significant impact on immune function and can help maintain good overall health and wellness. Incorporating the foods listed above especially those listed in multiple categories (i.e. broccoli, spinach, blueberries, cherries, avocados) will bring the greatest benefit for overall immune system function. Mom has been right all along...eat your broccoli!

Words by Dr. Paul Gross, PlantX Medical Advisor.