1. Eat green vegetables

Green, leafy vegetables are rich in vitamins that help you maintain a balanced diet — and support a healthy immune system. According to a study of mice, eating cruciferous vegetables sends a chemical signal to the body that boosts specific cell-surface proteins necessary for efficient immune-system function. In this study, healthy mice deprived of green vegetables lost 70 to 80 percent of cell-surface proteins.

2. Get Vitamin D

Reports indicate that many Americans fall short of their daily vitamin D requirements. Deficiencies in vitamin D may lead to symptoms such as poor bone growth, cardiovascular problems, and a weak immune system.

Results from a 2012 study in the journal Pediatrics suggest that all children should be checked for adequate vitamin D levels. This is especially important for those with dark skin, since they don’t get vitamin D as easily from exposure to sunlight.

Foods that are good sources of vitamin D include egg yolks, mushrooms, salmon, canned tuna, and beef liver. You can also buy vitamin D supplements at your local grocery store or pharmacy. Choose supplements that contain D3 (cholecalciferol), since it’s better at raising your blood levels of vitamin D.

3. Keep moving

Staying active by following a regular exercise routine — such as walking three times a week — does more than keep you fit and trim. According to a study published in the journal Neurologic Clinicians, regular exercise also:

• keeps inflammation and chronic disease at bay
• reduces stress and the release of stress-related hormones
• accelerates the circulation of disease-fighting white blood cells (WBCs), which helps the body fight the common cold

4. Get enough sleep

Getting adequate sleep is extremely important if you’ve been exposed to a virus, according to a study published in the Archives of Internal Medicine. Healthy adult participants who slept a minimum of eight hours each night over a two-week period showed a greater resistance to the virus. Those who slept seven hours or less each night were about three percent more likely to develop the virus after exposure.

One reason may be that the body releases cytokines during extended periods of sleep. Cytokines are a type of protein. They help the body fight infection by regulating the immune system.

5. Skip the alcohol

New research shows that drinking alcohol can damage the body’s dendritic cells, a vital component of the immune system. An increase in alcohol consumption over time can increase a person’s exposure to bacterial and viral infections.

A studyTrusted Source in the journal Clinical and Vaccine Immunology compared the dendritic cells and immune system responses in alcohol-fed mice to mice that hadn’t been supplied alcohol. Alcohol suppressed the immunity in mice to varying degrees. Doctors say the study helps explain why vaccines are less effective for people with alcohol addiction.

6. Calm down

For years, doctors suspected there was a connection between chronic mental stress and physical illness. Finding an effective way to regulate personal stress may go a long way toward better overall health, according to a 2012 study published by the National Academy of Sciences. Try practicing yoga or meditation to relieve stress.

Cortisol helps the body fight inflammation and disease. The constant release of the hormone in people who are chronically stressed lessens its overall effectiveness. This can result in increased inflammation and disease, as well as a less effective immune system.

7. Drink green tea

For centuries, green tea has been associated with good health. Green tea’s health benefits may be due to its high level of antioxidants, called flavonoids.

According to a study published in the Journal of the American College of Nutrition, several fresh-brewed cups a day can lead to potential health benefits. These include lower blood pressure and reduced risk of cardiovascular disease.

8. Add color to meals

Do you have trouble remembering to eat your fruits and vegetables at every meal? Cooking with all colors of the rainbow will help you get a wide range of vitamins such as vitamin C.

Shop for vitamin C.

While there’s no evidence that vitamin C can reduce the severity or length of illness, a 2006 study from the European Journal of Clinical Nutritionshows that it may help the immune system ward off colds and flus, especially in those who are stressed.

9. Be social

Doctors have long seen a connection between chronic disease and loneliness, especially in people recovering from heart surgery. Some health authorities even consider social isolation a risk factor for chronic diseases.

Research published by the American Psychological Association suggests that social isolation may increase stress, which slows the body’s immune response and ability to heal quickly. In the study, male rats were slightly more susceptible to damage from social isolation than females.

10. Get a flu vaccine

The Centers for Disease Control and PreventionTrusted Source recommends that all people over six months of age get a yearly flu vaccine. However, exceptions should be made for certain people, including those who have severe allergic reactions to chicken eggs. A severe allergy leads to symptoms such as hives or anaphylaxis.

People who have had severe reactions to influenza vaccinations in the pastshould also avoid yearly vaccines. In rare instances, the vaccine may lead to the development of Guillain-Barré syndromeTrusted Source.

11. Practice good hygiene

Limiting your exposure to illness by avoiding germs is key to remaining healthy. Here are some other ways to practice good hygiene:

• Shower daily.
• Wash your hands before eating or preparing food.
• Wash your hands before inserting contact lenses or performing any other activity that brings you in contact with the eyes or mouth.
• Wash your hands for 20 seconds and scrub under your fingernails.
• Cover your mouth and nose with a tissue when coughing or sneezing.
• Carry an alcohol-based hand cleaner for on-the-go use. Disinfect shared surfaces, such as keyboards, telephones, doorknobs, and remote controls.

12. Keep it personal

Flu viruses can generally survive on surfaces for 24 hours, according to the National Health Service. That leaves plenty of time for germs to spread among family members. Just one sick child can pass an illness to an entire family in the right setting.

To avoid sharing germs, keep personal items separate. Personal items include:

• toothbrushes
• towels
• utensils
• drinking glasses

Wash contaminated items — especially toys that are shared — in hot, soapy water. When in doubt, opt for disposable drinking cups, utensils, and towels.

Takeaway

Staying healthy is more than just practicing a few good techniques when you don’t feel well. It involves regular exercise, healthy foods, and staying hydrated throughout the day.

Your body works hard to keep you moving and active, so make sure to give it the food it needs to remain in tip-top shape.