As people get older, their blood vessels have a harder time relaxing because they produce less of a helpful chemical called nitric oxide, which makes it tougher for blood to flow freely — this is one reason why older adults are more likely to have heart and blood vessel problems.

As people get older, their bodies make less of a helpful molecule called nitric oxide, which makes it harder for blood vessels to work properly — and this can cause problems in the heart, brain, reproductive organs, and muscles.

As people get older, a key protein called SIRT1 becomes less active, which means it can't help another protein (eNOS) do its job properly—so the body makes less nitric oxide, and blood vessels don't work as well.

When too much nitrate messes up your blood vessels, taking antioxidants like vitamin C or BH4 can fix it—this suggests that harmful molecules called free radicals are what’s really breaking down your blood vessel function.