I read somewhere once that if we removed all disease and consequences of old age from the equation, life expectancy would be about 400 years, but at some point

I read somewhere once that if we removed all disease and consequences of old age from the equation, life expectancy would be about 400 years, but at some point you would die due to some accident, violence, or natural disaster. Wish I could find a source on this, maybe an actuary can chime in. I don't need immortality, but I could do without the long slow failing of my body until it gives out around 80 or so.