Weak evidence that eating vegetables makes you live longer

Taste and food preferences as predictors of dietary practices in young women (1999, n=157) found that "sensitivity to the bitter taste of PROP was associated with reduced preferences for Brussels sprouts, cabbage, spinach and coffee beverages". But it's behind a paywall, so this is just from the abstract

https://dl.dropboxusercontent.com/u/85192141/1999-drewnowski.pdf

One data point here: I think of myself as a subsupertaster-- most sensitivity to bitterness than most people, less than serious supertasters. I don't like grapefruit or coffee. I can sort of enjoy tea, especially the milder ones, but I don't get around to making it for myself. If I add enough milk and sugar to coffee to make it palatable, a cup gives me an upset stomach. I don't like the taste of alcohol. Does that go with being a supertaster?

On the other hand, I can handle most leafy green vegetables. When I was a kid, I didn't like endive, but I haven't had it for a while.

My tolerance for bitter flavors has increased over the years. I'm 60, and I'm not sure when the shift happened. Probably past age 40. I'm more tolerant of textures (like orange pulp in orange juice, or cooked raisins) that I hated when I was a kid.

I used to hate olives, but now I can handle most olives and rather like the mild ones.

I've also gotten used to peanuts and peanut butter.

Supertaster hell

In Bitter Taste Receptor Polymorphisms and Human Aging (2012, n=941) they tested Calabrians for their bitterness gene variant, and did find that older people were less likely to have the variant for detecting bitterness:

If you make claims like that, how about copying the p value from the article. A p value tell me more than your graph.

Of course, one can come up with other hypotheses, such as that vegetables are bad for some people, and people with genes that make vegetables bad for them have evolved a sensitivity to them to warn them away, and so people who have a gene to warn them away from vegetables don't live as long, and will live even shorter if they eat lots of vegetables.

Neither hypothesis really makes much evolutionary sense, though. If vegetables are good for everyone, and there's a gene that discourages them from eating them, why hasn't this gene been selected out of the gene pool?

"Vegetables" is a very large class of food, most of the are sweetish (because of the starch), not many are bitter. You can eat lots of different vegetables without eating bitter ones.

I doubt the normal diet in Calabria includes a lot of Brussel sprouts or kale...

It might be useful to make a distinction between

• Eating any vegetables at all
• Not eating meat
• Eating only vegetables

and other variants.

So there might be a statistically significant difference in lifespan between Coke drinkers and Pepsi drinkers.

Before reading the post, I thought the title would mean something like ‘the evidence that eating vegetables makes you live longer isn't as strong as you might think’.

Couldn't it be just that the variants of the gene contributes to shorter/longer lifespans regardless of food habits ? Or that the gene is more prevalent in certain ethnic groups who, for other reasons, don't live as long ?

Sure, it is weak evidence, in the sense that the hypothesis "eating more bitter vegetables makes you more healthy, but you don't it as much if you don't like the taste" predicts that correlation, but... it seems a bit far fetched to me to use a proxy like that gene, when we could directly monitor people's eating habits.

Any reason to use such an indirect approach (where the number of possible hypothesis is higher), instead of making direct correlations between eating habits and lifespan ? Is it easier to do, like because people can't lie about their genes but they can about their eating habits ?

I am not so sure about the tobacco case, anymore.

Still think that it's not very healthy, but a minor or bigger revision from the current official medical position wouldn't surprised me at all.