Bisphenol A, found in hard plastic containers, may interfere with how we learn and remember, researchers at the University of Guelph have discovered.

Continuous, low doses of Bisphenol A (BPA) affect the communication between neurons in the brain, which help us understand and remember experiences.

"It dramatically impairs the formation of synapses in the regions of the brain important to learning," biomedical science professor Neil MacLusky said. "These findings are worrisome because BPA is one of the most widely-used chemicals in the world."

BPA is used in:

• plastic water bottles
• some baby bottles
• dental prostheses and sealers
• the lining inside of food cans

The chemical can leak from the products and be absorbed through eating or drinking.

The findings will be published in the Proceedings of the National Academy of Sciences. There have been several studies done on the effects of BPA, but this is the first to track ongoing exposure to the chemical.

Researchers exposed African Green monkeys on the Island of St. Kitts to low levels of the chemical for a month. They found that even low doses of BPA slow down the synapses in the brain, a process normally caused by estrogen.

"Estrogen is more than just a female reproductive hormone. It enhances the rate at which some types of synapses are formed and is vital in maintaining normal neuronal structure in regions of the brain that control learning, memory and mood state," MacLusky said. "When we have BPA in our systems, it seriously impairs this process."

Researchers say there is a possibility that BPA might be a factor in brain diseases such as Alzheimer's, depression and schizophrenia.