It all started with a strong statement in the LA Times:

If early humans had been vegans we might all still be living in caves.

It says nothing and everything at the same time … Not eating meat would have stopped our “evolution” from early humans? Not eating meat would make us dumber? Or does it have something else to do? It does.

The original article on PLoS ONE is in fact a study about the impact of carnivory on human development and evolution. And the method used is a model of weaning in Mammals (thus no intelligence test per se). Psouni and her colleagues showed that:

• Brain mass is a better fundamental predictor of time to weaning than is female body mass (figure 2);
• Limb biomechanics is a predictor of time to weaning (figure 3);
• Dietary profile is a predictor of time to weaning (figure 4) and that
• Time to weaning in humans is quantitatively predictable from a carnivorous diet (figure 5).

So eating meat made human women wean more rapidly than if we stayed vegetarian. Their model suggests that “the contribution of carnivory was to shorten the duration of lactation and suckling despite the overall prolongation of development associated with increased adult brain mass”. Nothing about intelligence thus.

However this paper came to my knowledge after OAD published a (quite long) infographics about the dangers of red meat (not meat in general). On the presentation-side, I’m not sure such long vertical banner is powerful enough: after some time you are tired to scroll down. On the content-side, it’s a well-known fact that red meat comes with a lot of healthy risks. On top of that, the infographics focuses a lot on the USA, one of the countries where the consumption of red meat is high. This reminded me a TV programme from Jamie Oliver where he showed how meat is processed in the USA …

It’s “good” to be reminded of all this only once you’ve come back from there …

Key messages? Always read the original paper (even diagonally it’s better than general press) and know what you eat!

Edited on May 12, 2013 to remove the link to the original infographics (as it was not present anymore).