What is the therapeutic dose of L-glutamine (L-glutamine) for colon cancer patients?

From the Guidelines

There is no established therapeutic dose of L-glutamine specifically for treating colon cancer patients, and its use should be approached with caution due to the potential for promoting tumor growth. L-glutamine is not currently approved or recommended as a standard treatment for colon cancer. While glutamine is an amino acid that serves as a fuel source for rapidly dividing cells, including cancer cells, the research on its use in colon cancer treatment remains inconclusive and controversial, as noted in the ESPEN guidelines on nutrition in cancer patients 1. Some studies suggest that glutamine supplementation might actually feed tumor growth, while others indicate it may help reduce chemotherapy side effects like mucositis or intestinal toxicity 1.

Key Considerations

• The safety and efficacy of L-glutamine specifically in colon cancer patients requires further research before definitive dosing recommendations can be made.
• For patients experiencing treatment-related gastrointestinal side effects, oncologists sometimes recommend doses ranging from 5-30 grams daily, but this is for symptom management rather than as a cancer treatment.
• The ESPEN practical guideline on clinical nutrition in cancer highlights the heterogeneity of data on glutamine's effects and the lack of information on its impact on tumor response, leading to no recommendation on its therapeutic use 1.
• A systematic review analyzing 15 prospective and retrospective trials in cancer patients undergoing chemo-, radio or radio-chemotherapy found positive effects of oral glutamine on mucositis in 11 of these 15 trials, but among the six prospective and placebo-controlled trials, only two trials reported a benefit of glutamine while in four trials no effect was observed 1.

Recommendations for Clinical Practice

• If colon cancer patients are considering L-glutamine supplementation, they should first consult with their oncologist before taking any dose, as it could potentially interfere with cancer treatments.
• Given the lack of clear evidence supporting the use of L-glutamine in colon cancer treatment, its use should be individualized and closely monitored by healthcare professionals.
• The focus should remain on established treatments for colon cancer, with L-glutamine considered only for managing specific side effects under the guidance of an oncologist, as suggested by the ESPEN guidelines on parenteral nutrition: non-surgical oncology 1.

From the Research

L-Glutamine Therapeutic Dose for Colon Cancer

• The therapeutic dose of L-glutamine for colon cancer patients is not explicitly stated in the provided studies, but the studies suggest that L-glutamine supplementation can be beneficial in reducing chemotherapy-induced side effects and improving quality of life 2, 3, 4, 5.
• A study published in 2020 suggests that a high protein diet with 10 grams/day of L-glutamine supplementation can reduce symptoms and improve quality of life in cancer patients 3.
• Another study published in 1999 found that parenteral glutamine supplementation reduced chemotherapy-induced mucositis and ulcerations in patients with metastatic colorectal cancer 5.
• However, a study published in 1994 found that glutamine supplementation can stimulate proliferation and inhibit differentiation in human colon cancer cell lines, which may be deleterious in patients with cancer 6.
• The optimal dose and duration of L-glutamine supplementation for colon cancer patients require further research and should be determined by a healthcare professional 2, 4.

Key Findings

• L-glutamine supplementation can reduce chemotherapy-induced mucositis, diarrhea, and other side effects in colon cancer patients 2, 3, 4, 5.
• L-glutamine supplementation can improve nitrogen balance, immune system, and wound healing after surgery in colon cancer patients 2.
• The role of L-glutamine supplementation in reducing radiation-induced side effects is not well established 2.
• Further studies are needed to determine the optimal dose and duration of L-glutamine supplementation for colon cancer patients 2, 4.