The key to supporting a child’s immune system is diet. Introduce these top 20 immune boosting foods early so that they acquire a taste for good things.
Choose fresh, whole foods over supplements. Each food might fulfill a specific need, such as being prebiotic or vitamin C-rich. It will have many other nutritional benefits.
Please read my article What Is Creche Syndrome? And 8 Ways To Survive It. It has other tips for increasing your preschooler’s immunity.
The top 20 immune boosting foods and why they work
Look for the top 20 immune boosting foods highlighted in green.
Looking after your GUT microbiome
The GUT is often the first line of defense against infections.
“The bacteria that live naturally in your child’s intestines need looking after. They help the immune system to stay healthy and act as competition for infection-causing bacteria.”
Prebiotic foods
Feed the microbiome. The microbiome feeds on and breaks down complex carbohydrates and fiber to form valuable nutrients. These vitamins, free fatty acids, and other metabolites keep your intestine wall, immune system, and body healthy.
1. Apples
We all know the saying, “An apple a day keeps the doctor away.” It is true.
Apples contain pectin, a prebiotic that promotes the growth of gut bacteria, including lactobacilli. It also helps strengthen the cells that line the intestine. 1
2. Bananas
Avoid overripe bananas too often as they have a high GI and may cause sugar spikes. To boost immunity, eat them just as they ripen; they still contain insoluble prebiotic fiber. They are an excellent source of potassium.
3. Oats
4. Wheat bran
Start at six months old by introducing oats and wheat bran cereals for breakfast. Feed the microbiome and boost the immune system. Add cinnamon, banana, apples, berries, or nut butter to make these grains more interesting.
Wheat bran is excellent for preventing constipation in babies and preschoolers. 2
Oats and wheat bran add lifelong value by lowering cholesterol and stabilizing sugar.
5. Flax seeds
They don’t have much flavor, so they are easy to add to a kid’s diet.
Edwena Kennedy, a pediatric dietician, recommends the following serving sizes for ground flaxseeds (up to twice a day):
- 1 tbsp serving (5g) for babies ages 6-12 months
- 2 tbsp serving (10g) for children ages 1-3 years
- 3 tbsp serving (15g) for kids 4+ years.
She suggests measuring the milled seeds into a shaker. Make a game of it; let your toddler shake them onto their food at mealtimes. Read more in her blog on seeds.
6. Onions
An easily available and cheap source of the prebiotic inulin. Use this GUT microbe booster to flavor foods from 6 months old. Add cooked onions to vegetable puree, minced meat, mashed potato, omelet, or soup. 18,19
7. Barley
Rich in prebiotic and insoluble fiber. It is a diet must-have from childhood; introduce it from 6 months old instead of rice. As with oats and wheat bran, it regulates sugar and fat levels.
Probiotic support daily
8. Yogurt
Add low-fat, live-culture, probiotic-rich yogurt to your kiddie’s daily diet.
It supports gut health and, thus, immune function. 17
Avoid sweetened products if possible. Most 6-month-olds will eat plain yogurt.
Sweeten if necessary with mashed fruit, or add nut butter. Only consider introducing honey after your baby’s first birthday. Preferably avoid all honey and free-sugar until after two years old.
Daily probiotic supplements are a contentious issue because of conflicting data about immune support. In my pediatric experience, they were life-changing for some children and made no difference to others. Give them a six-month trial to see if doctor visits diminish. You have nothing to lose.
9. Nutritional yeast
Research has shown that Saccharomyces cerevisiae (baker’s, brewer’s, or nutritional yeast) increases mucosal immunity. This means that saliva antibodies increase. This helps prevent and reduce the severity of common viral infections. 4,5 It is due to the β-Glucan in the cell wall of the yeast stimulating the immune system.
A study done in China showed that children got far fewer infections if they took an eighth of a teaspoon of nutritional yeast (35g) a day. “A dusting of Baker’s yeast,” to quote Dr Greger, daily, might help you through the creche years. 3
Watch the full video to learn how it stimulates the immune system.
Vitamin D
Vitamin D deficiency is associated with increased infection risk. 6 Sunshine remains the best source.
Recommended daily allowance of vitamin D 7
| AGE | RDA |
|---|---|
| 1 year old | 400 IU/day |
| > 1 year old | 600 IU/day |
The best way for kids to get oral vitamin D is via a healthy diet and not supplements.
Food sources will not cause toxic levels of vitamin D; supplements might. Consider having your child’s vitamin D blood levels checked before supplementing.
10. Fish
Fish is the best dietary source of vitamin D: salmon, sardines, herring, and mackerel.
Try to stick to these above as they have low levels of mercury.
You can introduce well-cooked fish from 6 months old. One to two servings a week; a serving is 1 ounce or 30 grams.
Here are some ideas to get your kids eating and loving fish from BBC Good Food:
11. Egg yolk
High in vitamin D, eggs also contain some fat to aid its absorption. They are also a fantastic source of iron, essential amino acids, and vitamin B12.
Edwena Kennedy recommends introducing eggs at six months old because they are very nutritious. Early exposure also reduces the chance of developing egg allergy. For babies under one-year-old, cook them through. Prevent picky eating by serving them in various ways.
For ideas on how to serve them to your baby and toddler, listen to Edwena’s podcast on everything about eggs.
12. Button mushrooms
Mushrooms boost antibodies in saliva. Your immune system’s first line of defense. 9 You can introduce them from 6 months of age with other solids.
Button mushrooms also provide vitamin D 8, B vitamins, zinc, and potassium. Increase the vitamin D in mushrooms by slicing them and putting them in the sun for 30 minutes.
They are an unusual preschooler food; you will need to get creative.
Here are some recipes your kids might enjoy.
Vitamin C
Vitamin C supports the immune system in various ways. 10
- It keeps GUT and skin barrier (epithelial) cells strong.
- It is essential to enhance the white cells’ (the soldiers of the immune system) bacterial and viral fighting ability.
Prevent infection by doubling your child’s RDA of Vitamin C. 11
To help fight infection, you can even go higher as it is not a toxic vitamin. However, there are limits; refer to the table below. 11
Vitamin C daily recommendations:
| AGE | RDA | TOLERABLE UPPER INTAKE LEVELS |
|---|---|---|
| 1 to 3 years | 15 mg | 400 mg |
| 4 to 8 years | 25 mg | 650 mg |
13. Oranges
The poster child for vitamin C.
¾ of a cup of juice (93mg) contains more Vit C than a medium orange (70mg). 11
Juice is easy to incorporate into the diet, but whole fruit has the benefit of fiber.
14. Strawberries
Fresh sliced strawberries are a good source of vitamin C, and children love them. (49g per ½ cup) 11
15. Red and green sweet peppers
Red sweet peppers have more vitamin C than oranges, believe it or not. (95mg per ½ cup) 11
Finely chopped, they are delicious in minced meat, omelets, mashed potato, or barley. For older kids, cut fresh crunchy strips to dip into hummus or yogurt.
16. Broccoli
Cooked broccoli (½ a cup, 51mg) is higher in vitamin C than raw (½ cup, 39mg). 11
There is nothing more yummy than broccoli topped with white sauce and cheese.
Vitamin E
Everyone forgets about poor vitamin E. It is one of the most important vitamins for immune function. Found in high levels in immune cells. It also modulates allergy reactions and prevents and improves asthma. 12
Deficiency is rare, but topping up your blood levels decreases infections.
17. Almonds
Almonds are rich in vitamin E. You can introduce them in a nut-butter form from 6 months old. Only give whole nuts from 5 years of age due to the risk of choking.
18. Garlic
Garlic directly stimulates immune cells and decreases inflammation. 13 It is a rich source of prebiotic inulin and grows your microbiome immunity. 18,19
You do not need to give your toddler a clove of garlic to chew. Add it as flavoring to meals. It is also an important ingredient of the food listed next.
19. Hummus (Chickpeas)
Chickpeas are a nutritional powerhouse. They are a prebiotic fiber, full of antioxidants, fatty acids, amino acids, vitamins, calcium, magnesium, and potassium. 14,15
Make homemade hummus. Store-bought usually contains a lot of salt, not good for kids.
Try this delicious recipe for baby-friendly hummus.
Dip carrot or sweet pepper sticks into hummus as a snack. Smear it onto a sandwich instead of butter.
20. Spinach
Spinach contains some vitamin D and lots of vitamin A. Both are essential for immune cell function. 16 It is also a prebiotic fiber.
It is delicious lightly steamed with fresh lime juice, but for fussy eaters, find recipes that sneak in spinach via this link.
Avoid fortified sweet cereals
But don’t they contain all the necessary nutrients to boost immune systems?
That is irrelevant. Sugar is one of the most inflammatory substances and might even decrease immunity. 20
Breakfast is a tricky meal. You’re rushing to get kids up and ready for school. You need to get to work. It is tempting to stick a bowl of well-marketed sweet cereal in front of them.
Sugar should not be introduced in any form other than whole foods before the age of two. It should be limited thereafter. Dr Greger proves the point.
References
- Larsen, N., Bussolo de Souza, C., Krych, L., Barbosa Cahú, T., Wiese, M., Kot, W., Hansen, K. M., Blennow, A., Venema, K., & Jespersen, L. (2019). Potential of Pectins to Beneficially Modulate the Gut Microbiota Depends on Their Structural Properties. Frontiers in microbiology, 10, 223. https://doi.org/10.3389/fmicb.2019.00223
- Becker, M., & Rosskamp, R. (1987). Therapie der Obstipation mit Weizenkleie im Säuglings- und Kleinkindesalter [Therapy of constipation with wheat bran in infancy and early childhood]. Monatsschrift Kinderheilkunde : Organ der Deutschen Gesellschaft fur Kinderheilkunde, 135(8), 522–524.
- Meng, F. (2016, June 13). Baker’s Yeast Beta-Glucan Decreases Episodes of Common Childhood Illness in 1 to 4 Year Old Children during Cold Season in China. https://www.longdom.org/open-access/bakers-yeast-betaglucan-decreases-episodes-of-common-childhood-illness-in-1-to-4-year-old-children-during-cold-season-in-china-2155-9600-1000519.pdf
- Vetvicka, V., Richter, J., Svozil, V., Rajnohová Dobiášová, L., & Král, V. (2013). Placebo-driven clinical trials of yeast-derived β-(1-3) glucan in children with chronic respiratory problems. Annals of translational medicine, 1(3), 26. https://doi.org/10.3978/j.issn.2305-5839.2013.07.01
- Moyad M. A. (2008). Brewer’s/baker’s yeast (Saccharomyces cerevisiae) and preventive medicine: Part II. Urologic nursing, 28(1), 73–75.
- Aranow C. (2011). Vitamin D and the immune system. Journal of investigative medicine : the official publication of the American Federation for Clinical Research, 59(6), 881–886. https://doi.org/10.2310/JIM.0b013e31821b8755
- U.S. Department of Health and Human Services. (2023, September 18). Office of dietary supplements – vitamin D. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
- Cardwell, G., Bornman, J. F., James, A. P., & Black, L. J. (2018). A Review of Mushrooms as a Potential Source of Dietary Vitamin D. Nutrients, 10(10), 1498. https://doi.org/10.3390/nu10101498
- Jeong, S. C., Koyyalamudi, S. R., & Pang, G. (2012). Dietary intake of Agaricus bisporus white button mushroom accelerates salivary immunoglobulin A secretion in healthy volunteers. Nutrition (Burbank, Los Angeles County, Calif.), 28(5), 527–531. https://doi.org/10.1016/j.nut.2011.08.005
- Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211. https://doi.org/10.3390/nu9111211
- U.S. Department of Health and Human Services. (2021, March 26). Office of dietary supplements – vitamin C. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/#h3
- Lewis, E. D., Meydani, S. N., & Wu, D. (2019). Regulatory role of vitamin E in the immune system and inflammation. IUBMB life, 71(4), 487–494. https://doi.org/10.1002/iub.1976
- Arreola, R., Quintero-Fabián, S., López-Roa, R. I., Flores-Gutiérrez, E. O., Reyes-Grajeda, J. P., Carrera-Quintanar, L., & Ortuño-Sahagún, D. (2015). Immunomodulation and anti-inflammatory effects of garlic compounds. Journal of immunology research, 2015, 401630. https://doi.org/10.1155/2015/401630
- Jukanti, A. K., Gaur, P. M., Gowda, C. L., & Chibbar, R. N. (2012). Nutritional quality and health benefits of chickpea (Cicer arietinum L.): a review. The British journal of nutrition, 108 Suppl 1, S11–S26. https://doi.org/10.1017/S0007114512000797
- Reister, E. J., Belote, L. N., & Leidy, H. J. (2020). The Benefits of Including Hummus and Hummus Ingredients into the American Diet to Promote Diet Quality and Health: A Comprehensive Review. Nutrients, 12(12), 3678. https://doi.org/10.3390/nu12123678
- U.S. Department of Health and Human Services. (2023b, December 15). Office of dietary supplements – vitamin A and carotenoids. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/
- Hadjimbei, E., Botsaris, G., & Chrysostomou, S. (2022). Beneficial Effects of Yoghurts and Probiotic Fermented Milks and Their Functional Food Potential. Foods (Basel, Switzerland), 11(17), 2691. https://doi.org/10.3390/foods11172691
- Carlson, J. L., Erickson, J. M., Lloyd, B. B., & Slavin, J. L. (2018). Health Effects and Sources of Prebiotic Dietary Fiber. Current developments in nutrition, 2(3), nzy005. https://doi.org/10.1093/cdn/nzy005
- Qin, Y. Q., Wang, L. Y., Yang, X. Y., Xu, Y. J., Fan, G., Fan, Y. G., Ren, J. N., An, Q., & Li, X. (2023). Inulin: properties and health benefits. Food & function, 14(7), 2948–2968. https://doi.org/10.1039/d2fo01096h
- Fang, H., Anhê, F. F., & Schertzer, J. D. (2022). Dietary sugar lowers immunity and microbiota that protect against metabolic disease. Cell metabolism, 34(10), 1422–1424. https://doi.org/10.1016/j.cmet.2022.09.006
