What to Eat for a Strong Immune System
When it comes to immunity, you are what you eat! Diet plays a key role in the functioning and strength of the immune system.
Unfortunately, many foods harm our immunity rather than enhance it. The underlying culprit? Inflammation. Studies have shown that dietary inflammation could be a main cause of many illnesses and poor immune health.
Switching to an anti-inflammatory diet is a simple way to fight back and regain a powerful immune system.
Immune Health and Inflammation
Research consistently shows that inflammation has a major impact on health. From increasing build up in our arteries to aggravating pain conditions to playing a role in severe chronic diseases, unmanaged inflammation is a troublesome health concern for most of us.
While it gets a bad rap, inflammation is actually a necessary healing process. It is the inflammatory response that helps tissues to heal after an injury or fight pathogens during illness. When inflammation becomes chronic or misplaced, however, the immune system suffers.
Our diet is a common source of unnecessary inflammation that can be managed easily with better choices and habits.
The Science Behind the Anti-Inflammatory Diet
Many diet plans promise health benefits, but the anti-inflammatory diet’s power to boost the immune system is backed by science.
The Fight Against Free-Radicals
The anti-inflammatory diet consists mainly of fresh fruits and vegetables, healthy fats, and vibrant herbs and spices with one important similarity: antioxidants. Antioxidants are famous for their ability to reduce the oxidative damage done by free radicals. Since oxidation can destroy immune cells and slow the body’s immune response, antioxidants are a powerful dietary ally for immunity.
Activate and Support Natural Killer (NK) Cells
NK cells are part of the body’s innate immunity and are crucial for immunological memory, adaptive immunity, and cancer prevention. Inflammation, however, can suppress natural killer cells. Studies show that probiotics and certain antioxidants (like resveratrol which is found in grapes, blueberries, and cranberries) can have a strong effect in reversing the negative effects of inflammation on the body’s natural killer cells. In these studies, resveratrol consumption was linked to a decrease in inflammation and an increase in virus and malignant cell destruction by NK cells.
Regulation of Immunoglobulins
Immunoglobulins are produced and regulated by the immune system in response to a pathogen. Studies show that antioxidants present in the anti-inflammatory diet (like vitamin E and beta-carotene) increase the presence of these disease-fighting immunoglobulins and support the protective immune response.
Reduce General Inflammatory Damage
Of course, the anti-inflammatory diet also improves immune function by reducing harmful inflammation. Along with antioxidants, omega-3 fatty acids found in the anti-inflammatory diet work to reduce specific inflammation-causing proteins (called C-reactive proteins). Another specific inflammatory protein, IL-17A, has been shown to suppress and slow the maturation of natural killer cells to negatively impact the body’s innate immunity. The anti-inflammatory diet fights against these inflammatory proteins and protect immune cells.
What to Eat on an Anti-Inflammatory Diet
Switching to an anti-inflammatory diet takes some practice if you are used to eating the typical Standard American Diet. But, as with any diet plan, there are a few general tips that can help make the transition simple.
Fruits and Vegetables
Focus the bulk of your diet on a rainbow of produce: fresh, colorful fruits and vegetables. Plants are often rich sources of potent antioxidants, vitamins, and nutrients that feed your immunity.
Choose: grapes, blueberries, blackberries, strawberries, cranberries, cherries, kale, spinach, broccoli.
Avoid: Processed vegetables like French fries, chips.
Nuts and Seeds
Nuts and seeds make an excellent anti-inflammatory snack as they are high in antioxidants and healthy fats that boost both the immune and nervous systems.
Choose: walnuts, almonds, pistachios, pumpkin seeds, chia seeds, flax seeds.
Avoid: Heavily salted, sugared, or flavored peanuts or other nuts.
Fat is necessary for many body processes, and crucial for keeping inflammation at bay. The type of fat matters immensely. Where the omega-6 fatty acids that make up fats like butter cause inflammation, omega-3 fatty acids found in healthy fats reduce inflammation.
Choose: olive oil, flaxseed oil, avocado oil, walnut oil.
Avoid: butter, margarine, lard, vegetable oils.
Oily Fish, Lean Protein
Changing your protein source can make a big difference in inflammation. Red meat and pork are more inflammatory than lean poultry or vegetable protein sources (like soy or beans). With fish, however, opt for oily fish as they are rich in anti-inflammatory omega-3 fatty acidsviii.
Choose: tuna, salmon, herring, mackerel, chicken, beans, lentils.
Avoid: excess red meat, pork.
Healthy Whole Grains
Where processed, refined grains like white flour or white rice can cause inflammation, whole grains work to fight inflammation. Whole grains are also rich in fiber, a necessary nutrient for healthy digestion.
Choose: whole wheat, quinoa, oatmeal, millet, faro, brown rice.
Avoid: Products made with refined white flour, white rice.
Probiotics are a key source of nutrition for one of our biggest sources of immune power: our gut microbiome. The bacteria in our gut need probiotics to maintain a healthy balance and support the immune system’s natural killer cells.
Choose: miso, kombucha, kefir, kimchi.
Avoid: yogurts with sugar added.
Salt can increase the inflammatory response and pose health problems for those with cardiovascular conditions. Instead, replace salt with flavorful herbs and spices. You’ll also benefit from the spices’ antioxidant properties.
Choose: ginger, turmeric, parsley, oregano, rosemary, garlic.
Avoid: excess salt, butter.
Skip Processed Foods
Processed packaged foods, fast food, and sodas are inflammatory by nature. Many of these products include chemicals, colorings, artificial flavors, and other ingredients that irritate the digestive lining and lead to increased inflammation.
Manage Alcohol and Smoking
Excess alcohol consumption and smoking increase inflammation. You can enjoy a moderate amount of alcohol on the anti-inflammatory diet but stick to one drink or less per day.
The Anti-Inflammatory Lifestyle
To make the most of your new anti-inflammatory diet, consider ways you can improve your entire lifestyle to fully support your immune system. An anti-inflammatory lifestyle focuses on reducing unnecessary inflammatory habits like smoking, excess drinking, and stress. Exercising regularly, prioritizing a healthy sleep routine, and reducing stress can reduce the harmful effects of inflammation and help you embrace a whole-body approach to immunity.
- Ricordi C, Garcia-Contreras M, Farnetti S. “Diet and Inflammation: Possible Effects on Immunity, Chronic Diseases, and Life Span.” J Am Coll Nutr. 2015;34 Suppl 1:10‐13.
- Pahwa R, Goyal A, Bansal P, et al. “Chronic Inflammation.” StatPearls Publishing; 2020 Jan.
- Pinti, Marcello et al. “Aging of the immune system: Focus on inflammation and vaccination.” European journal of immunology vol. 46,10 (2016): 2286-2301.
- Phaniendra, Alugoju et al. “Free radicals: properties, sources, targets, and their implication in various diseases.” Indian journal of clinical biochemistry : IJCB vol. 30,1 (2015): 11-26.
- Hughes DA. “Effects of dietary antioxidants on the immune function of middle-aged adults.” Proc Nutr Soc. 1999;58(1):79‐84.
- Leischner, Christian et al. “Nutritional immunology: function of natural killer cells and their modulation by resveratrol for cancer prevention and treatment.” Nutrition journal vol. 15,1 47. 4 May. 2016.
- Brambilla, Daria et al. “The role of antioxidant supplement in immune system, neoplastic, and neurodegenerative disorders: a point of view for an assessment of the risk/benefit profile.” Nutrition journal vol. 7 29. 30 Sep. 2008.
- Sproston, Nicola R, and Jason J Ashworth. “Role of C-Reactive Protein at Sites of Inflammation and Infection.” Frontiers in immunology vol. 9 754. 13 Apr. 2018
- Xuefu Wang et.al. “IL-17 constrains natural killer cell activity by restraining IL-15–driven cell maturation via SOCS3.” Proceedings of the National Academy of Sciences Aug 2019, 116 (35) 17409-17418.
- Bendich A. “Physiological role of antioxidants in the immune system.” J Dairy Sci. 1993;76(9):2789‐2794.
- Monica H. Carlsen et.al. Nuts and Seeds in Health and Disease Prevention. 2011, Pages 55-64
- Gutiérrez, Saray et al. “Effects of Omega-3 Fatty Acids on Immune Cells.” International journal of molecular sciences vol. 20,20 5028. 11 Oct. 2019.
- Harvard Health Publishing. “Foods that fight inflammation.” https://www.health.harvard.edu/staying-healthy/foods-that-fight-inflammation
- Kiecolt-Glaser, Janice K. “Stress, food, and inflammation: psychoneuroimmunology and nutrition at the cutting edge.” Psychosomatic medicine vol. 72,4 (2010): 365-9.
- Oliveira A, Rodríguez-Artalejo F, Lopes C. “Alcohol intake and systemic markers of inflammation--shape of the association according to sex and body mass index.” Alcohol Alcohol. 2010;45(2):119‐125.