by Dr. Charlotte Nussbaum 

All kids are exposed to a ton of viruses from each other, especially when they first start day care or school. We may wonder why some kids are able to get through colds without severe symptoms while some go on to develop more serious or prolonged illnesses. There are ways we   can we help our kids’ immune systems to do their job well. 

Here are some of the simplest, most effective ways of strengthening their immunity. 

GUT HEALTH 

Eighty percent of our immune cells are in our gut. This means that our immune health is very dependent on our gut health and the health of our microbiome (the bacteria living in our gut and regulating our immune function as well as many other bodily functions). Important components of keeping our gut healthy are supporting the gut lining and maintaining a healthy balance of bacteria in the gut microbiome. 

Include the following in a child’s diet to optimize their gut health: 

Bone broth is an incredibly healing food for our gut. So many traditionally healing foods were relied on for generations because they actually work, and chicken soup is one of them.   

Prebiotics are food substances that are not digested by us, but they nourish and promote growth of beneficial bacteria in our gut microbiome. Some Prebiotic sources include raw honey, blueberries, blackberries, garlic, onion, beets, nectarines, white peaches, grapefruit, dried dates, cashews and breast milk. 

Probiotics are live microorganisms such as bacteria and fungi. They help to maintain a healthy gut microbiome and help repair gut lining. They are also antibacterial and antifungal, which is one reason why some infections are treated with probiotics. Probiotic foods such as sauerkraut, beet kvass, raw milk kefir and yogurt provide the richest sources of probiotics with much greater diversity of bacteria within them than in probiotic supplements. However, probiotic supplements can be helpful as an alternative if necessary.  

NUTRIENTS 

Proper nutrition is so essential in optimizing our children’s immunity. While there are many important nutrients, the following are especially critical for immune health: 

Zinc is an essential trace element for immune cells to function properly, including activation of T cells. It also has anti-inflammatory and has antioxidant properties. Rich sources of zinc include oysters and beef such as chuck roast or beef brisket and ground beef (though not as much as in the previous cuts mentioned). We can get zinc from plant-based foods such as pumpkin seeds, sunflower seeds, cashews, pecans and lentils.   

Vitamin C is an essential micronutrient for immune function and a powerful antioxidant. It affects almost every part of our immune system, especially the function of our neutrophils, which are immune cells that kill bacteria and other microbes. People often think of citrus, which is a great source of vitamin C, but there are plenty of other rich sources. One of the best sources of vitamin C is actually red bell peppers; others include strawberries, kiwis, papaya, guava, leafy greens and sauerkraut (live, fermented sauerkraut).   

Vitamins A and D work together in many functions in our bodies, but especially in immune health. They directly support function of our immune cells and also support immunity by promoting a healthy gut microbiome and preventing leaky gut. Because most of us do not effectively convert beta carotene to active vitamin A, plant-based sources of beta carotene (a vitamin A precursor) are unlikely to maintain adequate levels of active vitamin A. Best food sources of preformed vitamin A (retinol) are liver and egg yolks. Other sources include butter and shellfish. 

As for vitamin D, the best way to maintain healthy levels is sunlight exposure. Our bodies make vitamin D when our skin is exposed to ultraviolet light from the sun. Allowing our children to play outside in all weather (dressed appropriately, of course) helps maintain their vitamin D levels. However, they do need to have skin exposed (for at least 15 to 30 minutes for paler kids and longer for kids with darker skin) to really increase their vitamin D. In our New Jersey climate, that is not always possible in the winter. 

During months where our children don’t get a lot of sun, dietary sources will be especially important. These include salmon (ideally wild caught), trout, mackerel, oysters, beef liver, fish eggs (like salmon roe) and egg yolks (from pasture-raised chickens because all that sunshine gives them much higher levels of vitamin D). 

The only plant-based source is mushrooms, but mushrooms alone will not contain enough vitamin D to achieve optimal vitamin D levels in your child. Again, high-quality cod liver oil is a safe supplement for both vitamins A and D.  

ANTIMICROBIALS 

In addition to consuming foods that benefit our gut and our immune cells, there are foods and bee products with direct antimicrobial effects that have the ability to kill bacteria, viruses and other pathogens. Here are some of the ones that have been studied and are commonly found: 

Garlic has many compounds that enhance our immune system by stimulating specific immune cells and modulating antibody (immunoglobuilin) production.  

Ginger, which has been used for centuries in food preparation to ward off food borne disease, has been found to have direct antimicrobial properties. It has mainly been studied in its antimicrobial effects on specific bacteria and retains its antimicrobial properties once cooked or boiled (for example, in ginger tea).   

Raw honey has strong antimicrobial properties (in addition to including both prebiotics and probiotics). One of many components that create honey’s antimicrobial power is natural production of hydrogen peroxide within honey.   

SUPPLEMENTAL HERBS/PLANTS 

There are several immune-boosting herbs and plants, but two that are easily found and well-studied include echinacea and elderberry: 

Echinacea is native to North America and has been used by Native Americans for many centuries to treat infections. Several studies have found that echinacea modulates our immune system in various ways including T cell production, phagocytosis (engulfment of pathogens by immune cells), activation of many immune cells (natural killer cells, macrophages and polymorphonuclear leukocytes) and antibody binding.   

Elderberry has been used to treat infections in folk medicine for centuries. It contains vitamin C and has been found to modulate our immune system and to have antiviral activity against influenza.  

LIFESTYLE FACTORS 

Although people tend to focus only on food and supplements when it comes to natural ways of boosting immunity, there are some key lifestyle factors that we can also modify to really get our immune system working at its best. 

Sleep is essential for us to overcome infections, which is why when our children get sick, one of the first things we may notice is that they seem more tired than usual and need to sleep more.  That’s one of their body’s most important ways of ensuring that their immune system is working at its best. 

Stress management is a critical part of maintaining our immune health. Many of us have noticed that we tend to get more infections during periods of stress. Chronic stress (stress lasting more than a few hours) can really compromise the immune system. Some effective ways of reducing stress in kids include: 

• Spending time in nature: free unstructured play, creating art, reading books, doing yoga
• Exercise is an immune-boosting lifestyle component that is sometimes forgotten in discussions on immunity. Just like with other aspects of our overall health, it is important to stay active to maintain our immune function.   
• Spending time outdoors has many health benefits that we all know about, and it is also known to improve our immune function.   

Combining this knowledge with the importance of activity, we can see how outdoor activities are particularly helpful for keeping our children’s immune system healthy. 

Charlotte Nussbaum, M.D., MPH, based in Medford, is triple board-certified, including board certifications in pediatrics and internal medicine, and trained in functional medicine. For more information or to make an appointment, call 609-969-4844 or visit MedfordFunctionalMedicine.com.