Zinc is a micronutrient that is essential for human health.
It is found in high abundance in the human body and is necessary for the function of over 300 enzymes. Foods that are high in zinc are red meat, poultry, dairy products, beans, nuts and seeds, shellfish like crab and lobster, whole grains and fortified cereals. The current recommended dietary allowance (RDA) for zinc in adults is 11 mg for men and 8 mg for women.
Several Key Functions of Zinc are:
- Immune function
- DNA replication
- Making proteins
- Cell death
- Antioxidant activity
***Even a moderate deficiency in zinc can cause decreased immune function putting someone at risk for delayed wound healing and prevent the body from fighting off bacterial and viral infections.
Research has identified that zinc deficiency can cause intestinal hyperpermeability (weakened junctures between intestinal cells which allow bacteria to easily pass into the bloodstream) ultimately leading to increased diarrhea.
Several studies have observed lower zinc levels in people with diarrhea predominant IBS.
The GI tract is the site for zinc absorption and excretion. Gut dysbiosis (imbalance of gut microbes) and diarrhea may be linked to decreased zinc absorption leading to a possible deficiency. Another possible reason for zinc deficiency could be due to food avoidance; many people tend to avoid dairy and certain meats as they may cause IBS symptoms (these foods are also rich in zinc). If you are avoiding these foods you might consider getting your zinc levels checked via lab work.
Testing for zinc levels can be done to identify for zinc deficiency but not all tests are sensitive and as mentioned above, even a slight drop in serum zinc levels may reflect symptoms of a zinc deficiency.
Additional research is needed to identify specific pathophysiology in regards to zinc and its role in IBS but current research suggests that zinc supplementation may be beneficial as well as consuming foods that are higher in zinc as tolerated (varies from person to person based on food sensitivities).
As always, discuss with a registered dietitian before starting supplements. Your zinc level can be checked and ways to incorporate more zinc-rich foods can be discussed. It should be noted that taking excessive zinc supplements can lead to difficulty with copper and iron absorption and it can also cause symptoms like nausea and vomiting.
Low FODMAP foods higher in zinc:
- Canned lentils and chickpeas
- Whole grains (brown rice, quinoa, teff, millet, oats, buckwheat)
- Firm tofu
- Nuts and seeds
Chasapis, C.T., Ntoupa, PS.A., Spiliopoulou, C.A. et al. Recent aspects of the effects of zinc on human health. Arch Toxicol 94, 1443–1460 (2020). https://doi.org/10.1007/s00204-020-02702-9
Hujoel IA. Nutritional status in irritable bowel syndrome: A North American population‐based study. JGH Open. 2020;4(4):656-662. doi:10.1002/jgh3.12311
Rezazadegan M, Soheilipour M, Tarrahi MJ, Amani R. Correlation between zinc nutritional status with serum zonulin and gastrointestinal symptoms in diarrhea-predominant irritable bowel syndrome: A case–control study. Digestive Diseases and Sciences. 2022. doi:10.1007/s10620-021-07368-6