Low American life expectancy seems to result from other factors (obesity, high homicide rates, etc).
This is contrary to what I recall reading previously, so I looked up some sources. One study says: “When people come to the United States, they are positively selected, so people coming here are usually younger and healthier,” Baluran said. “What researchers found is that the longer people [immigrants] stay in the U.S., their health begins to deteriorate; by the time [they] reach the second and third generation, the health advantage that immigrants have almost disappeared.”
https://asamnews.com/2021/12/23/immigrants-asians-live-healt...
For example, the data distortion caused by having younger asians in the United states is an example of Simpson's paradox. These can be eliminated using survival analysis
My aim isn't to cherry pick but simply to describe the distribution of outcomes we currently observe.
Otherwise wevcan cherry pick pairs of data points to match up with whatever belief one likes to hold.
https://en.wikipedia.org/wiki/Survival_analysis
Even survival analysis is far from perfect because its correlational, not causal. There are other techniques such as front door criteria etc. to figure these out.