Consider Eating Some of These Everyday: Three Important Food/Nutrients to Support Your Immune System

Omega-3 fatty acids, pre- and probiotics and cruciferous green vegetables.

The human immune system is our protector. Its job is to defend the body against diseases and other invaders and foreign bodies.

Immunology is a branch of biomedical science that specializes in all aspects of the immune system. The immune system works by first identifying alien bacteria, viruses, fungi and parasites lurking in the body, and then sends in its troops — white blood cells — to destroy the invaders and the tissues they infect.

A healthy immune system is vital to warding off colds, flu and other ailments. More and more research is being done on how the combination of lifestyle, environment and a nutrient-dense diet are the three-legged chair important for supporting the immune system to ward off foreign invaders that want to make us sick, tired, depressed and chronically ill.

For example, research consistently shows that sleep deprivation depresses the immune system's disease-fighting abilities. Immunologically this happens when the proliferation of cells called T-helper cells are diminished. Even a single night of poor sleep can impair the immune system by reducing the number of natural killer T-cells.

How does the food you eat contribute to a healthy immune system?

Your body absorbs nutrients that help and support the strengthening of tissues and systems in your gut, and the ability of your cells to communicate properly between your gut, lymph and brain. When we don’t choose foods with the nutrients to support these processes, our GI tract and gut microbiota become damaged or rife with pathogens which make us experience negative symptoms ranging from fatigue and brain fog to chronic illness and even cancer.

Nutritional Immunology investigates the role of dietary factors and their interactions with other things like environmental factors of the immune and inflammatory responses. Many studies have been done that point to the ability of nutrients in food to support the immune system and help build powerful defenses to help your body ward off illnesses, disease and modulate symptoms that might otherwise of have been exacerbated.

Our gut microbiota play a significant role in our metabolic processes. They help with things like the regulation of cholesterol absorption, blood pressure, and glucose metabolism. They are involved in a of host immune modulation activities, so the link between the food you eat, gut microbiota, the immune (and endocrine system) and the brain is so important to your health and wellbeing.

Beneficial intestinal bacteria have numerous and important functions like producing various nutrients to support metabolic processes in the body that are important for health like preventing infections by intestinal pathogens and helping to manage a balanced immunological response.

Adding probiotics and prebiotics to your diet create a favorable environment for the intestinal microbiota. The two however, play different roles in gut and nutritional health.

Prebiotics nurture specific changes in the composition and/or activity of the gastrointestinal microbiota favoring the probiotic beneficial bacteria. They come from carbs (mostly fiber) that humans can't digest. The beneficial bacteria in your gut feed on the prebiotic fiber.

Probiotics are the live bacteria found in certain foods or supplements. They can provide numerous health benefits and may be consumed in the form of raw vegetables and fruit, fermented foods like sauerkraut, kimchi and pickles, or dairy products like yogurt (and even non-dairy fermented products like coconut yogurt). Probiotic microorganisms such as Lactobacillus plantarum, Lactobacillus reuteri, and Bifidobacterium adolescentis are natural producers of B group vitamins (B1, B2, B3, B6, B8, B9, B12). These microorganisms increase the efficiency of the immune system, enhance the absorption of vitamins and mineral compounds and stimulate the generation of beneficial organic and amino acids.

The role of cytokines

Cytokines are proteins that act to transmit information among the cells involved in immunological responses. They bind specifically to receptors on the surface of target (antigen) cells. They can often be considered the “hormones” of the immune system. Cytokines have important roles. Their job is to promote, sustain, and terminate the immunological response appropriate toward a pathogen or antigen. Studies have shown that nutrients in the food you eat can affect cell signaling and internal responsiveness to cytokines.

Healthy fats.

One important nutrient from food to be sure you consume each day is dietary omega-3 PUFAs (polyunsaturated fatty acids) which can be beneficial in reducing an inflammatory response by a cytokine called Interferon gamma. Its role is to help with receptor signaling and expression. How do eating healthy fats actually work to improve an immune response? One example points to how PUFAs can effect inflammatory cytokines. In a study conducted in patients with Type II diabetes looked at how a diet high in omega-3 PUFA’s could improve insulin resistance by reducing the destruction of mitochondrial membrane from Interferon gamma. The action of the PUFA’s on this cytokine can lead to increased energy responsiveness and an improved outlook for the incidence of T2 diabetes.

Another important food that helps strengthen the body to initiate immune responses is vegetable-derived phytonutrients from greens and vegetables, especially cruciferous ones. It turns out that cruciferous vegetables (broccoli, cauliflower, cabbage, kale, bok choy, arugula, brussel sprouts, collards, watercress and radishes) are the source of a chemical signal that is important to a fully functioning immune system. They are a rich source of carotenoids (beta-carotene, lutein, zeaxanthin), vitamins C, dietary fiber and a major source of bioactive compounds which have been shown to have anticarcinogenic properties (good for fighting cancer). At the molecular level, these beneficial phytonutrients support us by ensuring that our intestinal protective cells called epithelial lymphocytes (IELs) are function properly. These IEL cells make up the intestinal epithelial barrier which play an essential role in maintaining our body’s homeostasis. It is composed of epithelial cells organized as a barrier with tight junctions to block invaders, and a mucus layer. This barrier regulates absorption of nutrients from the food we eat, and prevent these pathogenic bacteria invaders.

When we consume foods without the proper nutrients to support this important epithelial layer, the tight junctions break down and damaging bugs and fluids enter into our gut and digestive system that cause intestinal permeability, which can lead to pathogenesis, illness, malaise and even disease. This is also known as “leaky gut.”

Those of just a few of the beneficial nutrients that support the processes that keep our immune systems strong. I’ve outlined a few of the benefits from consuming these foods here that can help support our GI process, but there is so much more that these foods do in our bodies to protect the healthy process in our gut and brain.

Increasing consumption of these foods each day, or even at each meal, will help to create healthy gut flora and support a strong immune system.

References:

1. Li P, Zhao Y, Wu X, et al. Interferon gamma (IFN-γ) disrupts energy expenditure and metabolic homeostasis by suppressing SIRT1 transcription. Nucleic Acids Res. 2012;40(4):1609-1620. doi:10.1093/nar/gkr984

2. Feng C, Keisler DH, Fritsche KL. Dietary omega-3 polyunsaturated fatty acids reduce IFN-gamma receptor expression in mice. J Interferon Cytokine Res. 1999;19(1):41-48. doi:10.1089/107999099314405

3. Irons R, Fritsche KL. Omega-3 polyunsaturated fatty acids impair in vivo interferon- gamma responsiveness via diminished receptor signaling. J Infect Dis. 2005;191(3):481-486. doi:10.1086/427264

4. Upadrasta A, Madempudi RS. Probiotics and blood pressure: current insights. Integr Blood Press Control. 2016;9:33-42. doi:10.2147/IBPC.S73246

5. Eating green veggies improves immune defenses. ScienceDaily. https://www.sciencedaily.com/releases/2011/10/111013121509.htm. Accessed August 29, 2019.