A natural compound found in green tea forms a powerful brain cleaner when combined with a common vitamin, researchers have found, potentially putting the brakes on the buildup of waste associated with diseases such as Alzheimer's.
What makes the discovery particularly exciting is that these substances can be attained through a healthy diet and are widely available as dietary supplements that have been cleared as safe by regulators.
The findings are the result of a study by researchers at the University of California Irvine (UC Irvine) on the antioxidant epigallocatechin gallate and nicotinamide, a type of vitamin B3 that's made naturally in the body from niacin-rich foods such as cereals, fish, nuts, legumes, and eggs.
Related: Drinking More Green Tea Each Day Cuts Risk of Dementia Brain Lesions
"By supplementing the brain's energy systems with compounds that are already available as dietary supplements, we may have a new path toward treating age-related cognitive decline and Alzheimer's disease," says biomedical engineer Gregory Brewer.
In tests on lab-cultured mouse neurons, epigallocatechin gallate and nicotinamide were shown to boost the energy molecule guanosine triphosphate (GTP), found in brain cells. GTP provides essential energy for cleaning up dead cells, with a lack of the compound previously being linked to the development of Alzheimer's in aging brains.
GTP-boosted neurons were shown to help the brain clear out damaging clumps of amyloid beta proteins, which have long been linked with the progression of Alzheimer's. The compounds also reversed damage associated with age in brain cells.
While GTP has previously been linked with neurodegeneration, the study reveals how levels can drop over time, especially when Alzheimer's is involved. The researchers speculate that the combination of epigallocatechin gallate and nicotinamide may return GTP to levels found in younger cells.
"This study highlights GTP as a previously underappreciated energy source driving vital brain functions," says Brewer.
Earlier this year, a separate study linked green tea with fewer white matter lesions in the brain, and in turn a lower dementia risk, though the research didn't prove direct cause and effect. Nicotinamide has also been implicated in protecting neurons from the effects of stroke and neurodegeneration.
Thanks to this research, we know that GTP might be part of the reason why – and that epigallocatechin gallate and nicotinamide could make a critical difference together. It's going to take some time to turn this into a treatment, and it's important to note that this has only been tested in mouse cells in vitro, but the results are encouraging.
"As people age, their brains show a decline in neuronal energy levels, which limits the ability to remove unwanted proteins and damaged components," says Brewer.
"We found that restoring energy levels helps neurons regain this critical cleanup function."
The research has been published in GeroScience.