FEATURE — The immune system is our body’s defense network. It protects us from germs and other harmful substances that could make us sick. Without our immune system, we’d have no way of fighting off illness.

Its main functions are to prevent or limit infection by detecting and removing pathogens (such as bacteria, viruses and parasites), recognizing and neutralizing harmful environmental toxins and fighting changes caused by other noninfectious agents in the body, like cancer cells.

Immune cells are numerous and reside in specific organs and tissues throughout the body – such as skin and bone marrow – or circulate through the bloodstream and lymphatic system. The immune system itself is made up of two subsystems: the innate immune system and the adaptive immune system.

The innate, or natural, system is the one we were born with. It is our rapid response system and provides a general or nonspecific protection. It mostly comprises killer cells and phagocytes (eating cells) that react immediately upon recognizing a foreign substance by surrounding and engulfing it.

The adaptive, or acquired, system works with the innate system to produce antibodies that protect our bodies from specific invaders. After developing over a period of days, antibodies can then recognize and more easily fight these specific pathogens if we are exposed to them again. Vaccinations work in this way by training our immune system to produce the antibodies that protect against specific diseases.

Our immune system does such a great job of protecting us against disease that we almost don’t notice it’s there – until it fails us. When our immune system is weak or cannot respond as needed then problems can arise, like an infection. The more underlying health issues we have, the harder it is for our bodies to fight illness. As we age, our immune response declines as the number and quality of immune cells decreases.

While we don’t have absolute control over the genetics and environment that affect our health, there are lifestyle factors that can strengthen or weaken your immune system.

Nutrition

Consuming the right nutrients in the right amount is required for the health and function of all cells. Each stage of the immune response depends on the presence of critical micronutrients such as vitamin C, vitamin D, selenium, iron, zinc and protein. Diets that consist primarily of processed foods lack these necessary nutrients and can negatively affect a healthy immune system.

The USDA’s MyPlate guidelines provide a simple, effective way to eat a balanced diet and prevent nutrient deficiencies. See page 10 of the fall 2020 issue of HEALTH for more information on the importance of nutrition and immunity.

Exercise

Regular exercise improves cardiovascular health, lowers blood pressure, helps control body weight and protects against many diseases. It promotes circulation, which allows immune cells to work more efficiently, and may have an anti-inflammatory effect. It is also known to reduce stress and anxiety. The general recommendation is about 30 minutes a day for five days a week, which can easily be done with regular brisk walks.

Sleep

Adequate sleep is imperative for a properly functioning immune system. Without sufficient sleep, the body produces fewer cytokines – a type of protein that targets infection and inflammation. It is also during deep sleep that the body works to repair muscles, organs and other cells.

For most adults, seven to eight hours of sleep per night is optimal. Research shows that people who don’t get enough sleep (less than six hours) are more likely to get sick after being exposed to a virus and take longer to recover from illness. Long-term sleep deprivation can also increase the risk of obesity, diabetes and cardiovascular disease.

Stress

Chronic stress can cause systemic inflammation and increase the risk of chronic diseases like atherosclerosis, the buildup of plaque in artery walls that can restrict blood flow. Chronic stress has also been shown to activate latent viruses, such as the one that causes shingles.

While it’s impossible to totally eliminate stress, it can be minimized by giving yourself adequate nutrition, exercise and sleep, along with spending time in nature, nurturing relationships with friends and family and self-care. You can even seek counseling when needed. A professional therapist can help identify sources of stress and recommend coping strategies.

Smoking

Smokers are generally less healthy than nonsmokers, suffering more health problems and requiring more doctor visits and hospitalizations. Smoking can lower the level of protective antioxidants in the blood. If you don’t smoke, don’t start. If you are a smoker, talk with your doctor about options for quitting. You can also call 1-800-QUIT-NOW or visit Way to Quit for free resources.

Alcohol

Since the body can’t store alcohol, metabolizing it becomes a priority, which interrupts other normal processes. Excess alcohol not only weakens the immune system but can also cause liver disease, cardiomyopathy (a weak heart), pancreatitis (inflammation of the pancreas) and increase the risk of some cancers. According to the Mayo Clinic, no amount of alcohol is risk-free.

There’s no magic shield to protect us from every harmful thing that comes our way, but optimizing these factors in your favor, practicing good personal hygiene and keeping up to date on vaccines can help keep your body primed to fight infection and disease.

Written by SHANA CHAVEZ, Southwest Utah Public Health Department Clinical Assistant.

This article was originally published in the Fall 2020 issue of HEALTH Magazine.

Copyright © Southwest Utah Public Health Foundation, all rights reserved.