For many people undergoing chemotherapy or radiation, one of the most difficult side effects is oral mucositis—painful sores and inflammation in the mouth that can make eating, drinking, and even talking a struggle. A new analysis of 16 studies, involving over a thousand patients, looked at whether zinc supplements could help prevent this problem. The findings are promising and show that timing matters a lot. Zinc was found to delay the start of these mouth sores. It also reduced the overall risk of getting them at both 2 weeks and 7-9 weeks into treatment. For severe sores, zinc showed a strong protective effect at 2 weeks and again at 5-6 weeks. The analysis suggests a two-part strategy: using topical zinc early on to help control symptoms, and then switching to an oral dose of at least 150 mg per day in the middle and later stages of treatment to powerfully prevent severe sores. Zinc also helped reduce pain scores at 3 and 6 weeks and eased dry mouth symptoms at 6 weeks. The researchers concluded that zinc is safe and effective, with benefits that change over the course of treatment, offering a way to potentially shield patients from some of the most debilitating mouth-related side effects.
Can a simple mineral help cancer patients avoid painful mouth sores from treatment? New analysis says yes, with timing being key.
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What this means for you:
Zinc supplements can help prevent painful mouth sores from cancer treatment, but their effectiveness depends heavily on when and how you take them. What this means for you:
Zinc supplements can help prevent painful mouth sores from cancer treatment, but their effectiveness depends heavily on when and how you take them. View Original Abstract ↓
OBJECTIVE: To evaluate the effect of zinc supplements in preventing chemotherapy and radiotherapy-related oral mucositis (OM) in cancer patients.
METHODS: We retrieved randomized controlled trials (RCTs) on the prevention of OM after chemotherapy and radiotherapy using zinc supplements. These studies were sourced from nine databases, including PubMed, Embase, Cochrane, Web of Science, Scopus, and SinoMed, covering the period from their inception to October 2025. Two researchers independently screened studies and extracted data. The Cochrane risk of bias tool was used to assess the quality of the included studies, and Stata 16.0 software was used for analysis.
RESULTS: A total of 16 randomized controlled trials (RCTs) comprising 17 comparison groups and involving approximately 1076 patients were included. Zinc supplementation significantly delayed the onset of OM (MD = 1.37, 95% CI: 0.78 to 1.95, P < 0.001). Regarding the overall incidence of OM, zinc significantly reduced the risk at both 2 weeks (RR = 0.69) and 7-9 weeks (RR = 0.33) of treatment. For severe OM (grade ≥ 3), zinc exhibited a significant protective effect at both 2 weeks and 5-6 weeks of treatment (RR = 0.26 for both time points). Subgroup analyses revealed key dose duration, and administration route effects: (1) In the early phase of treatment (2 weeks), topical zinc demonstrated a beneficial trend in reducing both the incidence and severity of OM; (2) in the mid-to-late phase (5-6 weeks), oral administration of moderate to high doses (≥ 150 mg/day) was markedly effective in preventing severe OM (RR = 0.07, 95% CI: 0.02 to 0.36), showing superior efficacy compared to topical application; (3) zinc supplementation significantly alleviated pain scores at 3 and 6 weeks of treatment (MD = -1.82 and -2.02, respectively), as well as xerostomia symptoms at 6 weeks (MD = -0.60, 95% CI: -0.81 to -0.40, P < 0.001).
CONCLUSION: Zinc supplementation is safe and effective, demonstrating a significant time-dependent, bimodal therapeutic effect: it reduces the incidence of OM during the second and the seventh to ninth weeks and significantly decreases the occurrence of severe OM in the second and fifth to sixth weeks. Additionally, zinc supplementation offers certain benefits in alleviating oral pain and xerostomia. A phased intervention strategy is recommended: in the early stage, combine zinc with topical agents to control symptoms, and in the mid-to-late stages, administer oral medium-to-high doses (≥ 150 mg/day) to prevent severe OM, particularly in patients with head and neck tumors.