It's also in the context of the comment I replied to, which also contains conclusions based on personal experience. And when speaking about nutrition these days, most known facts are based on flawed studies or anecdotes.
And HN itself is filled with anecdotes. It's actually in this community's culture to talk in anecdotes.
So I don't get your call for refraining.
Also what is mentioned has been observed multiple times in several countries.
"Anecdote is not data waa waa waa" or in your example, " No. They don’t die. Mick Jagger. Keith Richard" it certainly does not condone drug usage, but it certainly shows there are exception to "drugs are bad and you will die early" (especially given the amount consumed)
But please let us know if eggs are good or bad for people this week.
I agree that we should all rely more on actual facts and studies and that we tend to perpetuate myths heard from a friend of a friend, which is just bad, especially for us since we should think like scientists. However it is not our job to do studies on nutrition and the available studies on nutrition are either biased or not conclusive of anything - listening to your gut feeling about what is right is actually the better path to take at this point in time.
Also, I could have added details, such as race (Caucasian), geography (Europe, temperate climate, hills), family history (war veterans, poverty after communism came, rough life), etc... but I usually don't because these are personal details and I like my privacy on the Internet, even though you could probably find plenty about me or my family if you wanted to, but that doesn't mean I have to make that info easy to find.
You also misunderstood me. I actually think that genetics, lifestyle, local culture are all factors that play a role, so I don't disagree with you. I also haven't said that my grandfather's diet would be healthy for everybody, I only said that it was healthy for him personally, so you have to be careful about making generalizations based on limited data and biases.
For the record, I'm not crash hot about this anonymous anecdotal evidence either. I think that eating unhealthily is bad no matter whether you are on a farm or not. But to tell someone to be quiet? That's a losing argument - refute it, don't silence anyone.
But "lived until 99" was not useless until very recently (in history terms)
So, there is something which we do called "observation." This is when we want to know the truth of something, so we set up some sort of meaningful experiment which we can do in the world, and find out. We go out and observe.
The reason that an anecdote is not an observation is because it comes to you first. That is, you already know the result of the anecdote before you select the data; it is something you "remember" when you hear about a new situation. This invokes all kinds of biases about how you remember, because you tend to remember anomalies -- and you tend to misremember their content. In anecdotes there is no "control group" and there isn't even a hope for a control; it's all been selected out anyway.
In this respect a single observation is not anecdotal, because they come from separate places. If a doctor puts a flow-meter in an artery after a bypass surgery to see if there is blood flowing at a normal cardiac rate, that is not an "anecdote", that is an "observation." It is not based on some sort of human reckoning; "I've done many bypass surgeries and I once saw an artery which looked just like that and was not, in fact, obstructed," but rather it's something reliable: at this time, a normal amount of blood was flowing through this artery.
Most health-related studies are not true observational studies. Rather, they rely on self-reported (i.e., anecdotal) "data" from study participants.