Eating to Boost Immunity
Adequate nutrition is important for your body to be fully functioning and to have the energy to carry out daily activities. This also includes your cellular activity. In terms of your immune cells, nutrition needs to support their functions, assist in quick and effective pathogen response and help prevent any chronic inflammation. (1) A diet high in fat and calories (overnutrition), or a diet way too low in calories (undernutrition) can induce chronic inflammation that does the opposite of all of this and slows down your immune system leading to disease. (1) The Western diet can be of concern for immune function as it is categorized by a diet of processed foods high in sugar, calories, trans and saturated fats, and low in complex carbohydrates, fiber and micronutrients. (2) A lifelong diet like this leads to a chronic inflammatory state within your body, slowing down your immune systems response time during an illness and recovery time post illness. The other side of the spectrum is undereating. Research has found that those severely undernourished also experience this inflammatory state. The two extremes of these states are obesity and chronic eating disorders. These two populations are at a higher risk if they were to become sick because their immune cells would have to fight through the pre-existing chronic inflammation in the process of killing the disease-causing pathogens. One diet that has been found to reduce chronic inflammation and increase the functioning of the immune system is the Mediterranean diet. This diet is filled with vegetables, fruits, nuts, legumes, fish and ‘healthy’ dietary fats like avocados. (1) The foods in these diets are rich in polyphenols, a group of molecules that help to regulate inflammation in the body. (1) An early 2000’s study of 3000 Grecian men and women assessed the effects that adherence to the Mediterranean diet had on inflammatory markers. (3) They found that those who more strictly followed the traditional Mediterranean diet had lower inflammatory markers in their blood. While this study didn’t look specifically at immune cells, a lowered inflammatory state is helpful for the functioning of immune cells versus a pre-existing inflammatory state.
When pre-existing inflammation in the body is low it sets up the immune cells in a better position to fight pathogens that may cause an illness. When these cells kill the pathogens it naturally creates inflammation, which we experience as a fever. If there is no pre-existing inflammation when this occurs then the immune cells can reduce the inflammation quicker, leading to us being sick for less time and making a fuller recovery. There is some conflicting research on this though. A 2007 study looking at quality of diet and immune function found that there was limited evidence to suggest that healthy eating patterns play a role in enhanced immunity and reduced inflammation. (4) The participants of this study overall had similar inflammatory markers regardless of diet. However, they did show a large association between a healthier diet quality and more active T cells. T cells are responsible for the memory of our immune cells when it comes to fighting pathogens. They remember pathogens they have previously killed so the next time they come across them they can induce an immune response quicker. So, while the participants inflammation state didn’t change depending on their diet, their immune cells were more active. This study how ever was only looking at overweight and obese postmenopausal women so it’s hard to generalize it to other populations. More research needs to be done on this topic among larger population groups in order to make definitive conclusions. Overall though adding in more fruits and vegetables, eating less processed foods and switching out fatty beef for fish a couple times a week is a good start to changing chronic inflammation. These changes alongside a low-risk lifestyle of no smoking, regular exercise, and moderate alcohol intake can play a role in the health of your body’s immune function.
1. Childs CE, Calder PC, Miles EA. Diet and Immune Function. Nutrients. 2019;11(8). doi:10.3390/nu11081933
2. Christ A, Lauterbach M, Latz E. Western Diet and the Immune System: An Inflammatory Connection. Immunity. 2019;51(5):794-811. doi:10.1016/j.immuni.2019.09.020
3. Chrysohoou C, Panagiotakos D, Pitsavos C, et al. Adherence to the Mediterranean diet attenuates inflammation and coagulation process in healthy adults. J Am Coll Cardiol. 2004;44(1):152-158. doi:10.1016/j.jacc.2004.03.039
4. Boyton A, Neuhouser M, Wener M, et al. Associations between health eating patterns and immune function or inflammation in overweight or obese postmenopausal women. Am J Clin Nutr. 2007;86(5):1445-1455. https://doi-org.proxy.lib.fsu.edu/10.1093/ajcn/86.5.1445