(Yes, the title is inflammatory on purpose.  Deal with it.)

The Beeb published an article today about soy foods being responsible for decreased sperm counts:

A regular diet of even modest amounts of food containing soy may halve sperm concentrations, suggest scientists.

The study, published in the journal Human Reproduction, found 41 million fewer sperm per millilitre of semen after just one portion every two days.

The authors said plant oestrogens in foods such as tofu, soy mince or milk may interfere with hormonal signals.

Now, this is a perfect counterargument for two popular vegetarian arguments:  (a) the human body was never designed to process animal proteins, or (b) a soy diet contains everything you’d otherwise get from meats.

Effectively halving your sperm count is not a good long-term survival strategy.