Though that is presumably an indirect factor of the socioeconomic position that intelligence is likely to afford.

On average, though with numerous exceptions, higher IQ -> better employment prospects -> better housing in an environmentally healthier area + access to superior healthcare -> longer life expectancy.

True, higher intelligence may also give one a greater capacity to understand, see the value of, and follow medical advice regarding diet and other lifestyle choices, which would on average (with numerous exceptions again) extend life expectancy.