9 Ways to Strengthen Children’s Immune Systems

The immune system is not one single entity - it's a complex interconnected system that evolves as we age. Apart from fighting viruses, bacteria, fungi and parasites, the immune system also plays an important role in tissue repair - wound healing, elimination of dead cells, and formation of gut microbiota.

In babies, the immune system is fragile and still developing for the first 3 months of life. Fortunately, nature designed us so that antibodies flood a baby’s system straight after birth to provide protection from infection. These antibodies, when coupled with breast milk, provide immunity for newborns. When reaching senescence, the human immune system once again resembles that of the newborn, with compromised antimicrobial activity, reduced antigen presentation and decreased lymphocyte responses.

The innate and adaptive immune systems mature from infancy to adulthood. Over the past century, developed countries have seen infant mortality rate decline significantly, from 140 per 1000 to 7 per 1000. The main reason for this is good nutrition, hygiene and better protection from infections. The immunological T-cell memory develops over time resulting in young adults suffering fewer infections. Infancy and childhood is the most sensitive period for the immune system.

Here are 9 scientifically-proven ways to support a child’s immune system:

1. Boost Phytonutrient Intake
Serve five servings of fresh fruit and vegetables every day - one serving equals a cup for older kids and two tablespoons for toddlers. Eating a diet rich in vitamin C can help boost the immune system by enhancing lymphocyte activity. Foods that contain the highest amount of vitamin C include: Yellow Bell Peppers, Acerola Cherries Rose Hips, Guava, Kiwi, Oranges and Blackcurrants.

2. Healthy Sleep Hygiene
Establish a healthy bedtime routine to help children sleep easily, for example having a bath and reading a book. Going to bed at the same time every night is important, even on the weekends. A newborn baby should sleep up to 18 hours of the day, toddlers need 12-13 hours, children aged 7-12 should sleep 10 hours and teenagers 8-9 hours.

During sleep, cytokines are released by the immune system and antibodies are boosted. Both sleep and the circadian system help regulate the immunological processes. Studies have shown that sleep enhances adaptive immune response to invading antigens.

3. Washing Hands Often
Hygiene is extremely important when we are looking to strengthen a child’s immune system. Making sure that they wash their hands before eating and after going to the bathroom will help remove pathogenic germs and bacteria. Washing hands helps to prevent the spread of infection. Did you know that one single gram of human feces can contain up to one trillion germs? The simple act of washing hands with soap and water reduces the number of kids who get sick from diarrhea by up to 40% and reduces absenteeism in children by up to 57%.

4. Toothbrushing Routine
Make sure that your child has their own toothbrush and it isn't shared with siblings. If a child does get sick, then throw out their toothbrush straight away and replace it with a new one. Store children’s toothbrushes away from the toilet so that bacteria don’t spread in the air, to the toothbrush. A toothbrush holder inside a cabinet is an ideal place to store a child’s toothbrush.

5. Avoid Smoke Inhalation
Living in a home where people smoke increases a child’s chances of catching infections. According to the Centers for Disease Control (CDC), second-hand smoke makes a child more susceptible to ear infections, asthma, respiratory infections and symptoms as well as increasing their risk for sudden infant death syndrome (SIDS).

6. Reduce Processed Foods
Highly processed foods, like chips, candy and soda compromise the immune system. Processed foods are filled with additives, chemicals and cause havoc on a child’s delicate body. By avoiding these kinds of foods you make way for healthier foods. Additionally mounting scientific evidence shows that processed foods reprogram the immune system.

7. Avoid Antibiotics If Possible
Antibiotics deplete the diversity of microbes in our microbiome - reducing the immune system's ability to fight infection. Most childhood illnesses are not bacterial, they are viral, so an antibiotic will do more harm than good. Antibiotic resistant bacteria are a byproduct of overuse of antibiotics.

Antibiotics kill of beneficial bacteria in the gut and the risk of developing inflammatory bowel disease increases by 300% - in children who are given more than 7 doses of antibiotics. Antibiotic free populations, like those found in Amazon villagers have more diversity in their microbiome, showing that modern lifestyles, like the use of antibiotics kills off beneficial gut bacteria.

8. Daily Exercise
Exercise increases the amount of natural killer cells (NKC) in both children and adults. Children are becoming increasingly sedentary, which is detrimental to their immune system. Why not try some family sports like skiing, hiking, cycling or tennis? A lack of exercise in children can result in health problems and obesity. Studies have shown that moderate intensity exercise has a beneficial effect on a child’s immune system.

9. Prebiotics and Probiotics
A child's gut is home to an enormous population of bacteria. Homeostasis in this vast terrain is critical for the uptake of essential nutrients. Prebiotics are non-digestible nutrients that promote the growth of beneficial gut microbes. Probiotics are bacteria or yeast that improve gut health. Probiotics is the name given to the live microorganisms in vitro.

Both probiotics and prebiotics are essential for healthy bacteria in the gut to flourish. In babies and children, studies have shown that consuming adequate amounts of prebiotics and probiotics enhances neurodevelopment and impacts healthy brain function on into adulthood.

Probiotic-rich foods include: Pickles, kombucha, tempeh, sauerkraut and yogurt.

Prebiotic-rich foods include: Almonds, chicory, chickpeas, garlic, leeks, onions, cabbage, lentils, kidney beans, soybeans, bananas, watermelon, grapefruit, flaxseeds and pistachio nuts.

In Conclusion:
During the first year, breastfeeding provides some immune protection for babies. After this period, the infant becomes more susceptible to infection, especially during fall and winter. Ensuring that a child develops healthy lifestyle habits will boost their immune system.

For Further Reading:
• Harvard Medical School has published an article on this subject, "Boosting your child’s immune system", found at: https://www.health.harvard.edu/blog/boosting-your-childs-immune-system-202110122614
• "8 Ways to Help Your Child's Immune System Stay Healthy" is the subject of an article by Parents.com: https://www.parents.com/health/cold-flu/cold/boost-childs-immunity/
• BBC GoodFood's contribution to this discussion is found at: https://www.bbcgoodfood.com/howto/guide/how-boost-your-childs-immune-system