Simple Ways to Activate Your Immune System

When it comes to boosting your immune system, pumping up your intake of fruits and vegetables is an important — and relatively easy — step. Likely, vitamin C or ascorbic acid immediately comes to mind, and there’s a good reason for that. A recent study shows ascorbic acid in the vitamin enhances natural killer cells or NK cells in people who recently underwent chemotherapy. These lymphocytes induce apoptosis, the death of cancer cells.

But citrus fruits and supplements aren't the only nutrient options for keeping your immune system at an optimal level. Also on this lengthy list: the allicin in garlic appears to help white blood cells battle viruses, and probiotics can reduce bad gut bacteria that can cause illness and may lessen the severity of respiratory infections.

Fats have long received negative press, but in recent years, more and more people are embracing the benefits of the healthy types. While it's still not ideal to consume excess fried and processed foods, the fats found in olive oil, fatty fish like salmon, and other natural options — specifically omega-3 fatty acids — can give your immune system an added kick. One of the ways these previously maligned nutrients give back is by decreasing inflammation. Though it's a natural reaction to invading pathogens, inflammation can suppress immunity, leaving you more prone to catching the latest bug. Be sure to balance fat intake with other healthful foods, though, as too much fat overall has been linked to lowered immunity.

While many assume goal-focused exercise is all about weight loss, research shows fitness practices can boost the immune system in at least four ways. Exercise speeds up the response time of antibodies, enabling them to detect illnesses faster and maybe even prevent them. It also slows the release of stress, which can lead to illness, and doctors believe that the body's thermogenic response to exercise wards off infection. Finally, research shows that while moderate exercise improves immunity, it can also rid the body of respiratory infections.

Getting up and intentionally exercising once a day for an hour is great, but if you spend the rest of your day sitting down, those benefits decrease. Being sedentary for hours, whether it's during the long commute or at a desk, can impact how well the immune system works, leaving you more prone to inflammation. Increasing physical activity during the day improves circulation and enhances immune function throughout the day. Simple activities such as standing during phone calls and taking a walk and lunch can make a difference.

Some people think of sleep as a luxury they have to do without, in order to get everything finished, but getting adequate sleep allows the immune system to perform properly, and this can give you more energy. During sleep, the body releases proteins called cytokines. These anti-inflammatory chemicals become more abundant when there’s an infection. Getting enough slow-wave sleep regularly allows your body’s natural immune response to evolve and build-up its long-term immunological memory.

Over 75 percent of people report feeling stress that negatively affects their physical health. When the body is under that kind of strain, corticosteroids flood the system and lower lymphocyte levels. When stress is chronic, it affects all aspects of life, including sleep and diet. Managing stress through mindful meditation and practices like yoga protects the immune system by stemming the levels of cortisol and reducing the risk of inflammation that can feed gastrointestinal and autoimmune diseases.

Excessive alcohol consumption reduces the body’s ability to fight off infections and may make people more susceptible to pneumonia and other respiratory problems. This does not mean that all amounts of alcohol immediately suppresses immunity. Research shows that moderate consumption of phenol-rich wine or beer, a maximum of 12 grams for women and 24 grams for men, can be beneficial to immune system function by triggering humoral immune responses.

People get dogs for a variety of reasons, but usually not for their positive effect on the immune system. In a study of 55 college students, subject saliva samples after petting a dog had higher levels of IgA than those who only pet a stuffed animal. Another study suggests that petting a dog with which you share a companion bond results in the same level of relaxation as quiet reading.

Smoking exposes the body to more than 7,000 chemicals that can lead to numerous health problems, including cancer. The practice reduces respiratory function in general, and increases lung infection risk in particular, leaving people more vulnerable to pneumonia and the flu. Smoking also leeches the body of protective vitamins, such as vitamin C, and minerals, which can lead to more prolonged illnesses.

Strong social connections with friends, family, community, and work are simple pleasures that increase longevity and improve all-around health. Apart from decreasing stress levels, healthful interactions reduce inflammatory markers, which mitigate the risk of cardiometabolic issues. On the flip side, chronic exposure to poor relationships leads to negative habits that undermine physiological and mental health.