Latest news with #Cancer Discovery
CBS News
7 days ago
- Health
- CBS News
Sucralose could make cancer treatments less effective, new study says
New research by the University of Pittsburgh and UPMC Hillman Cancer Center suggests that sucralose may be detrimental to those undergoing cancer immunotherapy. Recently published in Cancer Discovery, a peer-reviewed medical journal, the study found that patients with melanoma and non-small cell lung cancer who consumed high levels of sucralose had worse response to immunotherapy and poorer survival than those with diets low in the artificial sweetener. However, supplements that increased levels of the amino acid arginine reduced the harmful effects of sucralose on immunotherapy in mice, a strategy that may soon be explored in clinical trials. "It's easy to say, 'Stop drinking diet soda,' but when patients are being treated for cancer, they are already dealing with enough, so asking them to drastically alter their diet may not be realistic," said lead author Abby Overacre, Ph.D., assistant professor in the Department of Immunology at Pitt and UPMC Hillman. "We need to meet patients where they are. That's why it's so exciting that arginine supplementation could be a simple approach to counteract the negative effects of sucralose on immunotherapy." Senior author Diwakar Davar, M.D., associate professor of medicine at Pitt and a medical oncologist and hematologist at UPMC Hillman, collaborating with Overacre and their team, used mice to show that the negative impacts of sucralose are driven by disruption to gut bacteria. Sucralose altered the composition of the gut microbiome in mice, boosting species that break down arginine. As a result, arginine levels dropped in the blood, tumor fluid, and stool. Immune checkpoint inhibitors like anti-PD1 enhance T cell activity to help them better destroy cancer cells. Arginine plays a critical role in supporting T cell function, particularly in the context of cancer. "When arginine levels were depleted due to sucralose-driven shifts in the microbiome, T cells couldn't function properly," said Overacre. "As a result, immunotherapy wasn't as effective in mice that were fed sucralose." In mouse models of lung and skin cancer, adding sucralose to the diet made anti-PD1 immunotherapy less effective, resulting in bigger tumors and shorter survival. However, when the mice were given arginine—or citrulline, which the body turns into arginine—the treatment started working again. To see if this might apply to people, the researchers studied 132 patients with advanced melanoma or lung cancer who were receiving anti-PD1 immunotherapy, either alone or with chemotherapy. These patients completed detailed diet surveys, including questions about how often they used artificial sweeteners in drinks such as coffee, tea, and diet soda. "We found that sucralose impeded the effectiveness of immunotherapies across a range of cancer types, stages and treatment modalities," said Davar. "These observations raise the possibility of designing prebiotics, such as targeted nutrient supplementation for patients who consume high levels of sucralose." With these new findings, researchers aim to launch a clinical trial to see whether citrulline supplements can influence the gut microbiome and improve the immune system's ability to fight tumors in patients. Researchers are also interested in examining how other sugar substitutes, such as aspartame, saccharin, xylitol and stevia, impact the immune system and response to immunotherapy.
Reuters
01-08-2025
- Health
- Reuters
Health Rounds: Artificial sweetener consumption linked to less effective cancer treatment
Aug 1 (Reuters) - (This is an excerpt of the Health Rounds newsletter, where we present latest medical studies on Tuesdays and Thursdays. To receive the full newsletter in your inbox for free sign up here.) In patients with melanoma or non-small cell lung cancer, consuming high levels of the artificial sweetener sucralose contributes to diminished responses to immunotherapy and poorer survival, researchers reported in Cancer Discovery, opens new tab. When the researchers had 132 patients with advanced melanoma or non-small cell lung cancer answer detailed diet history questionnaires, they found that high consumption of sucralose was linked with lower effectiveness of immunotherapies across a range of cancer types, stages and treatment methods. In experiments with mice, the researchers found that sucralose shifts the composition of microbes in the intestines, increasing bacterial species that degrade arginine, an amino acid that is essential for key immune cells called T cells. 'When arginine levels were depleted due to sucralose-driven shifts in the microbiome, T cells couldn't function properly,' study leader Abby Overacre of the University of Pittsburgh said in a statement. 'As a result, immunotherapy wasn't as effective in mice that were fed sucralose.' Laying the groundwork for a solution to the problem, the same researchers also found in the mice that supplements that boosted levels of arginine mitigated the negative effects of sucralose on immunotherapy, an approach they now hope to test in humans. 'It's easy to say, 'Stop drinking diet soda,' but when patients are being treated for cancer, they are already dealing with enough, so asking them to drastically alter their diet may not be realistic,' Overacre said. 'That's why it's so exciting that arginine supplementation could be a simple approach to counteract the negative effects of sucralose on immunotherapy.' LOW-GRADE IS NOT THE SAME AS LOW-RISK IN PROSTATE CANCER A low-grade prostate tumor is not necessarily low-risk, new research suggests. Biopsy results showing low-grade prostate cancers can sometimes lead to underestimation of disease risk and omission of surgery or radiation in patients who might benefit from such treatments, researchers warned in JAMA Oncology, opens new tab. Among roughly 117,000 men in their study with prostate biopsy results indicating a Grade Group 1, or GG1, tumor – the slowest-growing kind - one in six had intermediate- or high-risk cancer when other factors such as prostate-specific antigen levels in the blood and tumor sizes were also considered, according to the report. Such higher risk cancers are often treated with radiation therapy or removal of the prostate, the researchers noted. 'We don't want to miss aggressive cancers that initially present as Grade Group 1 on biopsy,' study coauthor Dr. Bashir Al Hussein of Weill Cornell Medicine said in a statement. 'Such underestimation of risk could lead to undertreatment and poor outcomes.' Current guidelines that advise regular monitoring – rather than treatment – for men with low-grade prostate tumors were based on studies that examined entire prostate glands after removal from patients. Biopsies test only small areas of the prostate, so they can miss more advanced or aggressive cancer cells, providing an incomplete picture, the researchers said. Some cancer experts have been suggesting recently that GG1 tumors are so slow-growing that they shouldn't even be considered malignant. The new study results could help inform those discussions, the researchers said. 'There is a misunderstanding that low grade and low risk are the same," study coauthor Dr. Jonathan Shoag of Case Western Reserve University said in a statement. "Here, we show clearly that they are not.' (To receive the full newsletter in your inbox for free sign up here)
