Many women who complete treatment for breast cancer notice that their thinking is not as sharp as it used to be. People often call this “chemo brain” or “brain fog”. AÂ new study from UCLA suggests a supplement called oxaloacetate may help.
Doctors estimate that 15% to 25% of breast cancer survivors live with lasting thinking problems. These can go on long after treatment ends and can make daily life more difficult.
The name “chemo brain” is a little misleading. Researchers now believe chemotherapy is only one possible cause. The cancer itself, hormone-blocking drugs, inflammation and hormonal changes may all play a part. Because the causes are so mixed, few proven treatments exist. “Cancer-related cognitive impairment can persist long after treatment ends,” said Dr Patricia Ganz, the study’s lead author and a professor at UCLA. She added that we have only a few effective options.
Oxaloacetate is a substance your body already makes. It helps cells produce energy, and it helps manage glutamate, a chemical messenger brain cells use to communicate. Scientists think inflammation from cancer and its treatment can disrupt both. That could lead to foggy thinking and mental tiredness. So the team wanted to see whether a supplement could help restore balance.
How the Study Worked
The trial included 18 women with early-stage breast cancer. All were one to five years past diagnosis, and all reported significant trouble with thinking. Their average age was about 50. Most had received chemotherapy, and nearly 90% were taking hormone-blocking therapy during the study.
Each woman took 500 milligrams of oxaloacetate twice a day for eight weeks. Researchers used questionnaires and standard thinking tests to assess attention, memory, processing speed and executive function. That last term covers skills like planning, focusing and managing tasks. They also tracked fatigue, sleep, mood and overall health, and they watched for side effects.
What They Found
Sixteen women finished all eight weeks, and every one of them reported real improvement in thinking symptoms, including memory and concentration. On the study’s main scale for self-rated thinking problems, the average score rose from 29.1 to 55.5. That moved the group from an impaired range into a normal one. Gains showed up by week four and usually grew by week eight.
The women also reported less fatigue, including less mental fatigue, and better physical function. Thinking tests showed gains in processing speed and executive function, though the researchers say these results are early.
The supplement was generally well tolerated. The most common complaints were stomach-related, such as indigestion, bloating, constipation, diarrhoea and nausea. Two women stopped taking it because of these problems. No serious side effects were reported.
What It Means
It is easy to get excited about these numbers, but the study has clear limits. It was very small, and no one took a placebo, or dummy pill, for comparison. So we cannot be sure the supplement caused the improvements. Some women may have felt better because they expected to, or simply because time passed. The researchers say this openly.
A larger trial with a placebo group is expected to open in late 2026. Studies in mice are also underway to learn how the supplement works in the body. “These early findings give us a strong reason to continue studying oxaloacetate,” Dr Ganz said. The work was funded in part by the Breast Cancer Research Foundation and the National Cancer Institute.
For now, the study is a hopeful early result, not a final answer. If you are a survivor with ongoing brain fog, speak with your doctor before trying any supplement. Even natural products can interact with other medicines, including cancer therapies.
