The same uric acid that can crystallise to cause gout may protect against Alzheimer's disease, medical researchers say.

People who suffer from gout can take comfort in one thing: they may be less likely to develop Alzheimer's disease, researchers say.

The same uric acid that can crystallise to cause gout, a form of arthritis, may protect against Alzheimer's, they wrote in the online journal Annals of the Rheumatic Diseases.

Testing a theory that antioxidant properties in uric acid may protect the brain, experts from the US and Canada looked at the records of 3.7 million people over the age of 40 in a British database of medical charts.

Researchers compared data on people with gout, and those without, who developed Alzheimer's disease in a follow-up period of about five years.

The researchers identified 309 new cases of Alzheimer's among 59,224 gout sufferers with an average age of 65, and 1942 cases among 238,805 non-sufferers.

This amounted to a 24 per cent lower risk of Alzheimer's disease for people with a history of gout, after factoring in differences in age, gender, body weight, lifestyle and health.

"Our findings provide the first population-based evidence for the potential protective effect of gout on the risk of AD (Alzheimer's disease) and support the purported neuroprotective role of uric acid," the authors said in a statement.

Gout happens when excess uric acid builds up in the blood, causing crystals to form around the joints, inflicting extreme pain and swelling.


Copyright AAP 2015