With busy work schedules, families to take care of and a diet of unhealthy foods, your immune system can be compromised, which can lead to illness.

Ideally, it is better to get your nutrients from food rather than a supplement. To keep you healthy this season, E. Catalina Portillo, registered dietician and certified culinarian at Keck Medicine of USC, suggests adding the following nutrients by way of whole foods to your regular diet:

1. Zinc.

Zinc stimulates the immune system by increasing the effectiveness of T-cells. Only 15-25 mg per day is recommended (an excess of zinc can actually decrease functioning of your immune system), so it is better to rely on food sources instead of a supplement. Good sources of zinc are oysters, red meat, poultry, fish, beans, nuts, pumpkin seeds, lentils, quinoa/whole grains, and mushrooms.

2. Vitamin C.

Vitamin C boosts the immune system by supporting antibody production. Specifically, when you have a cold, vitamin C reduces congestion and the constriction of bronchi that leads to asthmatic symptoms. Vitamin C can also help you feel calmer by reducing the release of the stress hormone, cortisol. While excess supplementation does not prevent cold onset, deficiency may increase susceptibility to illness. Research shows adequate intake may help reduce the severity of cold symptoms in some cases; this remains a topic controversy. Foods with ample vitamin C are oranges, Brussels sprouts, green peppers and berries.

3. Vitamin A.

Vitamin A maintains the integrity of mucosa lining of the respiratory and gastrointestinal tract to reduce the incidence of infection. Vitamin A rich foods are sweet potatoes, eggs, carrots, kale, bell peppers, apricots, spinach and other leafy greens.

4. Vitamin B6.

Vitamin B6 enhances the maturation and differentiation of lymphocytes into infection fighting B and T cells. Food sources, such as sunflower seeds, pistachios and meat, are recommended.

5. Vitamin D.

Vitamin D activates and increases antibody response to a range of pathogens. Deficiency can occur during the winter months due to reduced sun exposure, but vitamin D rich foods such as fatty fish, fortified milk, juice, or cereal, as well as liver and egg yolks can compensate for the body’s reduced vitamin D synthesis.

6. Probiotics.

Probiotics increase the “good” bacteria in your digestive system to fight off infection in the GI tract. Choose a yogurt that contains “live and active cultures” to increase the number of infection fighting T-cells in the body.

Stress also takes a toll on the immune system and is a major factor for increased incidence of illness. Luckily, there are foods that reduce the effects of stress:

  • Complex carbohydrates, such as bread, rice and pasta, increase the production of serotonin, which promotes a relaxed state of mind.
  • Omega-3 fatty acids reduce stress hormone fluctuations, mild depression and PMS. Its anti-inflammatory effects also protect against heart disease. Good food sources include fatty fish, nuts and seeds.
  • Magnesium rich foods have been shown to improve sleep quality and relieve mood changes and muscle cramps. Studies show that magnesium reduces depression and irritability by modulating the stress response. Good sources of magnesium are whole grains, leafy greens, nuts and beans.
  • Green tea contains polyphenols that can reduce mental fatigue as well as oxidative stress. Sipping on hot green tea with meals can also aid digestion-an added bonus at holiday meals.
  • Chamomile tea induces a mild sedative effect, which can reduce insomnia and anxiety. Chamomile is also known to promote muscle relaxation.

Make this one of your healthiest seasons by incorporating a variety of the above foods to your everyday diet.

If you are making these changes and are still under the weather, you may need the help of a primary care physician to figure out an action plan to get you back on track.

If you’re in the Southern California area and are in search of a primary care physician, call (800)USC-CARE (800-872-2273) or visit www.keckmedicine.org/request-an-appointment to schedule an appointment.

By Cortney Montgomery