Heart and head
His team also found a strong link between autoimmune disease and heart and circulatory problems. Overall, people with autoimmune disease were 53 per cent more likely to be admitted to hospital due to cardiovascular disease, and 46 per cent more likely to be admitted for a stroke.
This may explain a large part of the increased dementia risk in people with autoimmune disorders. Vascular dementia is a kind of dementia that involves poor blood flow in the brain. When Goldacre and his team looked specifically at different kinds of dementias, they found that people with autoimmune diseases are 29 per cent more likely to develop vascular dementia, but only 6 per cent more likely to get Alzheimer’s disease.
“It’s striking that increased risk for vascular dementia exceeds that for Alzheimer’s,” says Colm Cunningham at Trinity College Dublin, Ireland. “The impact of autoimmune diseases on cardiovascular disease may be the key common link.”
Nevertheless, the relatively smaller increase in Alzheimer’s risk associated with autoimmune conditions may help researchers understand this disease better. “The results are very compelling and support the notion that neurovascular damage and inflammation are key drivers of risk for Alzheimer’s disease,” says leading Alzheimer’s researcher Rudolph Tanzi, at Massachusetts General Hospital in Charlestown.
For those looking to reduce dementia risk by controlling their inflammation levels, Goldacre says exercise and a healthy diet may help. “These are good for avoiding Alzheimer’s, but for all sorts of other benefits too,” he says.