It’s clear that psychological and social factors can affect heart health. The July issue of the Harvard Heart Letter explains that this is a two-way street: The health of your heart and blood vessels also affects your mind and brain.

Among older people, the most common causes of dementia (damage to the brain that leads to memory loss, confusion, and changes in personality or speech) are blood vessel problems and Alzheimer's disease. Research suggests that cholesterol-clogged arteries, inflammation, and risk factors for heart disease and stroke contribute to both, reports the Harvard Heart Letter.

Restricted blood flow in the brain may contribute to the cascade of events that leads to the tangles and clumps of protein in the brain that characterize Alzheimer’s. Autopsies show that memory loss and changes in thinking skills and personality are more likely to have occurred when tangles and clumps are accompanied by signs of strokes and narrowed, clogged blood vessels feeding the brain. In other words, improving blood flow to the brain and working to prevent strokes may maintain memory well into old age.

The Harvard Heart Letter recommends these strategies:

• Exercise. Walk, cycle, garden, dance — better yet, do them all — to keep both brain and body in shape. Research suggests that the variety of exercise, not just how much or how hard you exercise, may help prevent dementia.
• Keep blood pressure levels low. Untreated high blood pressure speeds aging-related decay in thinking skills and memory.
• Choose dietary fat wisely. Eating a lot of saturated and trans fat may promote dementia, while omega-3 fats (found in cold-water fish and some plants) may protect against the buildup of protein clumps in the brain.