People who are severely socially isolated have a higher risk of dying from coronary heart disease compared to those with moderate or high levels of social connection; however, there is no meaningful...

We analyzed the available evidence and found that severe social isolation is linked to a higher risk of dying from coronary heart disease. The evidence we’ve reviewed includes 58 studies or assertions that support this connection, with none that contradict it [1]. People who experience severe social isolation — meaning very little contact with family, friends, or community — appear to face a greater chance of death from heart-related causes compared to those who have at least moderate levels of social connection. This doesn’t mean that more social contact always leads to better outcomes. The evidence suggests there’s no meaningful difference in risk between people with moderate and those with high levels of social connection. In other words, simply having some connection seems to be enough to lower risk compared to being severely isolated. We don’t know exactly why this link exists. It could be related to stress, lifestyle habits, or how the body responds to loneliness over time, but the evidence we’ve reviewed doesn’t clarify the mechanism. We also can’t say whether improving social ties would reduce the risk — only that the pattern of higher death rates is consistently seen in those with little to no social connection. What we’ve found so far points to social isolation as a factor worth paying attention to, especially for people with existing heart health concerns. If someone is spending long periods without meaningful contact with others, it may be helpful to consider ways to build even small, regular connections — not because it’s guaranteed to change outcomes, but because the pattern we’ve seen suggests it could matter.