Allergies_Woman Sneezing

9 Ways to Strengthen Your Immune System

Katherine Lik,ND

Squash and apples are coming in to season, kids are going back to school, and oranges and browns are showing up in department store windows. Soon the weather will chill and cold and flu season will be upon us! This is the perfect time to plan ahead to prevent one of these nasty bugs from wreaking havoc with your health. The best way to do this is to support your immune system so it can detect and destroy bacteria and viruses before they cause infection. 

1. Sleep

Sleep is always number one on my list for immune support. This is when we heal. If you are not getting enough sleep it not only takes away from your time to scavenge infection-causing microbes and to heal from any damage they have done, but it also further taxes your body. Sleep is free, requires no pill swallowing, and is very enjoyable. Take advantage of this powerful immune aid. Shoot for 7-9 hours per night for maximum immune support.

2. Wash your hands frequently

This tip is simple but true. Microbes are everywhere. We touch them on door knobs, elevator buttons, while shaking hands. Once harmful microbes are on our hands they can be easily rubbed into our eyes, nose, and mouth. Make sure to wash your hands frequently throughout the day: when you get home, before eating, obviously after using the bathroom, and possibly more frequently if everyone around you is starting
 to cough or sneeze.

3. Protein

Protein and the amino acids that they are made of are vital for many biological processes including immune function. Protein is necessary to make immune cells and antibodies, and to absorb nutrients such as Vitamin A. Studies have shown that even a 25% reduction in protein intake significantly reduces immune function. I usually encourage patients to have five small protein meals a day. Protein is in all animal-derived foods (meat, fish, and eggs). Plant foods like beans, nuts, seeds, rice, quinoa, corn are good vegetarian sources for protein.
While I encourage patients to eat more plant foods, plant proteins do not have as wide a range of amino acids as animal proteins. To resolve this, mix two types of plant proteins with each meal, the classic combination to make a complete vegetarian protein is rice and beans.

4. Vitamin A

Vitamin A is important for immune function on several levels. It supports the production of B and T immune cells and is also important in the production of cytokines, molecules that help our immune cells communicate. Additionally, Vitamin A helps to maintain mucosal surfaces in our respiratory tract, digestive tract, and skin to keep microbes out of our bodies. Make sure you eat plenty of foods containing vitamin A, and its precursor beta-carotene.
The fruits richest in Vitamin A and beta-carotene are cantaloupes, grapefruit, guava, mango, papaya, passion fruit, tomato, and watermelon. Good vegetable sources are leafy greens and orange colored foods like bok choy, broccoli, Brussels sprouts, kale, leeks, spinach, rapini, squash, carrots, and sweet potatoes. Nuts, especially chestnuts, pecans, and pistachios, are also great sources. As vitamin A is a fat soluble vitamin, it is a good idea to consume these foods with a fat, such as olive oil.
Caution should be taken with Vitamin A supplementation as it is possible to take in too much Vitamin A. Speak to your health care professional regarding proper doses with supplementation.

5. Vitamin C (Ascorbic Acid)

Studies have shown that Vitamin C can reduce the length of time and severity of symptoms in a viral upper respiratory tract infection. Vitamin C helps T cells, neutrophils and macrophage immune cells work better. Foods rich in Vitamin C are peppers, guava, thyme, oregano, leafy greens, cruciferous vegetables (broccoli, cauliflower, kale, mustard greens, Brussels sprouts, watercress), papaya, citrus fruits, and strawberries.
Vitamin C is safe to take in supplemental form even in large quantities, although if your stool becomes loose, cut back on dose or switch to a buffered form which is less likely to cause loose stool or diarrhea. 

6. Zinc

Zinc is also a great immune booster. It increases the production of T immune cells, and is necessary for the absorption and proper use of Vitamin A. Too much zinc however can actually reduce immune function by inhibiting macrophage and neutrophil cells. Supplementation with zinc is appropriate if you are coming down with a cold or if everyone around you is sick. For general maintenance of immune function, focus on food.
Zinc-rich foods are oysters, liver, lamb, venison, scallops, shiitake and crimini mushrooms, leafy greens, squash, asparagus, maple syrup, shrimp, green peas, yogurt, oats, pumpkin seeds, sesame seeds, turkey, miso, and spelt. Speak to your health care provider regarding proper supplementation doses.

7. Garlic

Garlic is a great antimicrobial, meaning it can kill bacteria, viruses, and fungi. It is also delicious. Garlic is most potent when consumed raw. However, due to its distinctive odor, this is not always socially possible! Instead, try to cook with it as much as possible. For those who don’t like the flavor or with the onset of cold or flu symptoms, supplementation would be a great alternative. 

8. Astragalus

Astragalus, haung qi in Chinese, is a root used for thousands of years in Chinese medicine as an immune stimulant. Modern studies on this herb support its use as an immune stimulant showing that supplementation increases interferon, antibody production, and the T cells, B cells, and natural killer immune cells. Astragalus is found in tea form and in supplemental form. Check with your health care professional to determine what dose is best for you. 

9. Medicinal mushrooms

The cell walls of mushrooms contain polysaccharides (complex sugars) called beta-glucans which look like bacterial cell walls to our immune system. Beta-glucans cause an up-regulation of many immune cells including T cells, B cells, cytokines, natural killer cells, macrophages, and neutrophils. This causes your body to locate and destroy bacteria, virus, and even cancer cells more quickly. Mushrooms also contain several sugars necessary for your immune system to make antibodies. Mushrooms, especially shiitake and crimini, are also a great source of zinc.
Reishi, cordyceps, blazei, maitake, lion's mane, chaga, shiitake and turkey tail are the best studied mushrooms for immune support but likely all mushrooms will benefit immune function. Mushrooms are most beneficial when cooked especially because many raw mushrooms can be toxic to the liver. Mushrooms supplementation is also an option for those who do not like the flavor. 
"Dr. Raby is extremely intelligent and experienced in integrative medicine. She is an exceptional, highly respected physician with access to critical resources."

- Raby Institute patient