Nutrients play a crucial role in supporting the immune system. For the immune system to function efficiently, it requires an adequate and appropriate supply of nutrients.
The human immune system is responsible for eliminating pathogens and foreign cells, including cancer cells. Immune responses are regulated by cytokines secreted by immune cells and other body cells. These responses may be either pro-inflammatory or anti-inflammatory, depending on the type of cytokines released.
Inadequate or imbalanced nutrient intake, as well as chronic exposure to toxins, can lead to immune dysfunction—resulting in increased susceptibility to infections, cancer, and allergic diseases.
Macronutrients
- Proteins
Proteins contribute to the production of antibodies and cytokines.- Arginine: An amino acid that supports macrophage activity in eliminating pathogens and parasites. It also possesses anti-inflammatory properties through inhibition of NF-kB. Due to its immune-enhancing effects, arginine also plays a role in cancer prevention.
- Tryptophan: An essential amino acid that must be obtained through diet. It supports cell division and growth. Its metabolites can have both pro-inflammatory and anti-inflammatory effects. Some tryptophan-derived compounds can inhibit cancer growth and metastasis.
- Fats
- Cholesterol: A key component of cell membranes. Diseases such as cancer, infections, and allergies can disrupt cholesterol metabolism, leading to inflammation. When cholesterol regulation is impaired, elevated blood cholesterol levels may contribute to metabolic disorders like atherosclerosis and hyperlipidemia. The immune system then responds via inflammation-mediated cytokine activity.
- Polyunsaturated fatty acids (PUFAs): Divided into omega-3 and omega-6 groups. These fats, along with cholesterol, form part of cell membranes and modulate immune responses. Omega-3s tend to reduce inflammation, whereas omega-6s promote it. A low omega-6 to omega-3 ratio is associated with reduced risk of breast cancer and chronic non-communicable diseases.
Micronutrients
- Vitamins
- Vitamin A: Has both anti-inflammatory and pro-inflammatory effects, particularly in gut inflammation. It has shown anti-cancer effects in pancreatic and metastatic kidney cancers, and is used in treating APL (acute promyelocytic leukemia) via all-trans-retinoic acid.
- Vitamins B1, B2, B3, B12: These B-complex vitamins reduce inflammation and support energy production in cells, including immune cells. Vitamin B3 and B12 may exhibit anti-cancer properties; however, excessive B12 intake has been reported to worsen outcomes in various cancers.
- Vitamin C: An antioxidant that protects cells from inflammation and increases cytotoxic white blood cell counts, enhancing anti-cancer defenses.
- Vitamin D: Possesses anti-inflammatory and anti-cancer properties, and is often used in cancer prevention and supportive treatment.
- Minerals
- Zinc: Exhibits anti-inflammatory effects but may promote inflammation if consumed in excess. It increases CD8+ T cell counts.
- Selenium: Anti-inflammatory and enhances T cell response. It also boosts antibody production following vaccination. Supplementation in cancer patients has been shown to increase IgA, IgG, and neutrophil counts.
Non-Nutrient Compounds
These include phytonutrients, which commonly act as antioxidants, anti-inflammatory agents, immune boosters, and anti-cancer compounds. Examples include:
- Piperine: Derived from black pepper
- Quercetin: Found in white-colored vegetables like onions
- Genistein: Found in soybeans
- EGCG: Found in green tea
- Polysaccharides: Found in mushrooms
- Munteanu C, Schwartz B. The relationship between nutrition and the immune system. Front Nutr. 2022 Dec 8;9:1082500. doi: 10.3389/fnut.2022.1082500. PMID: 36570149; PMCID: PMC9772031.
- Behl T, Kumar K, Brisc C, Rus M, Nistor-Cseppento DC, Bustea C, Aron RAC, Pantis C, Zengin G, Sehgal A, Kaur R, Kumar A, Arora S, Setia D, Chandel D, Bungau S. Exploring the multifocal role of phytochemicals as immunomodulators. Biomed Pharmacother. 2021 Jan;133:110959. doi: 10.1016/j.biopha.2020.110959. Epub 2020 Nov 13. PMID: 33197758.
