Since some comments are trying to explain away the findings, here is a quote from the article about what variables were controlled for and the results:
> After controlling for family medical history, age, education, diabetes, smoking and many other variables, the researchers found that compared with eating hot food, mainly chili peppers, less than once a week, having it once or twice a week resulted in a 10 percent reduced overall risk for death. Consuming spicy food six to seven times a week reduced the risk by 14 percent.
On the other hand, keep in mind it's an observational study, not an experiment. As such, it's highly succeptible so various biases, including P-hacking (choosing a hypothesis based on data). Most importantly, keep in mind the astonishing number of false & dubious nutritional recommendations made in the past (salt is bad, salt is ok, fat is bad, fat is good, sugar is good, sugar is bad, cholesterol is bad, cholesterol is fine, ...).
I wonder if it has anything to do with the fact that you eat less food when it's particularly spicy? Fasting/caloric intake reduction and better health/longer life have been correlated for a while.
No, people that routinely eat extremely spicy food eat as much of it as anything else. It might put off the occasional eater of spicy food, but regular consumption depletes the neurotransmitters that generate the effect. It is an acquired immunity that can quickly escalate the level of spiciness required to perceive it. (You lose that immunity relatively quickly though.) Being able to eat almost arbitrarily spicy food is a trivially acquired ability.
Source: I eat quite a lot of habaneros and thai chilis, mostly because those are the peppers that taste strongly "spicy" to me on a day to day basis. If I eat too much on an ongoing basis, even the habaneros start to lose their spiciness. Most people have a "spiciness" threshold so low that the pepper is barely detectable to me. I was not born this way, peppers have been a regular part of my diet because I like the flavor and that confers a natural immunity to the effects.
That's unlikely. People will adjust the spiciness before adjusting their usual portions. Don't forget that habitual users will develop tolerance to capsaicin by reducing the number of receptors, so what may seem as a high level to someone may be perceived as normal by someone else.
I just want to point out how terrible the wording is on that paragraph. While I understand what the author means, that is different from what they wrote. I wouldn't bring it up if it was something casual, but come on... this is on *.nytimes.com.
It's impossible to "reduce overall risk for death" - we're all going to die. One may, however, reduce overall risk for death within a given timeframe.
edit: now that I read it again, that first sentence is a total train-wreck.
> After controlling for family medical history, age, education, diabetes, smoking and many other variables, the researchers found that compared with eating hot food, mainly chili peppers, less than once a week, having it once or twice a week resulted in a 10 percent reduced overall risk for death. Consuming spicy food six to seven times a week reduced the risk by 14 percent.