Researchers at UCLA Health Jonsson Comprehensive Cancer Center found early evidence that a supplement containing oxaloacetate may help relieve cognitive problems and fatigue in breast cancer survivors.
Oxaloacetate is a naturally occurring molecule already present in the human body that plays a role in cellular energy production. In a phase II clinical trial with 18 women diagnosed with early-stage breast cancer one to five years prior, participants took 500 milligrams of oxaloacetate twice daily for eight weeks.
The results, published in JCO Oncology Advances, showed improvements across multiple measures. Before treatment, participants had an average cognitive impairment score of 29.1. After eight weeks, that score rose to 55.5, placing them in the normal range. Standardized cognitive tests showed improvements in processing speed and executive function. Participants also reported less fatigue and improved physical function.
Of the 18 women enrolled, 16 completed the full eight weeks. Every participant who finished reported significant improvement in cognitive symptoms. Signs of improvement appeared after four weeks and generally became more pronounced over time.
"Cancer-related cognitive impairment can persist long after treatment ends and can have a significant impact on a person's daily life, yet we still have very few effective treatments for it," said Dr. Patricia Ganz, the study's first author and a distinguished professor of medicine at UCLA's David Geffen School of Medicine and UCLA Fielding School of Public Health.
Most study participants had undergone chemotherapy, and nearly 90 percent were still receiving endocrine therapy during the trial. Oxaloacetate was generally well tolerated, though the most frequent side effects involved the digestive system, including indigestion, bloating, constipation, diarrhea, and nausea. Two women stopped taking the supplement because of gastrointestinal symptoms. No serious adverse events occurred.
The researchers emphasized that the results remain preliminary because the trial was small and lacked a placebo control group. Without a comparison group, it is unclear whether oxaloacetate itself caused the improvements. UCLA researchers are preparing a larger randomized, placebo-controlled phase II trial expected to begin enrolling participants in late 2026. The team is also conducting preclinical research in mice to understand how oxaloacetate affects the body and brain.