Can jet lag trigger mental illness? It sounds absurd, but in fact it's just one of the many strange medical theories that could actually be true. Here, Roger Dobson looks at other extraordinary claims and the evidence behind them... DOGS GIVE WOMEN BREAST CANCER Could it really be true that keeping a dog increases the risk of the disease? Both dogs and humans carry the same virus that can induce cancer Analysis of breast cancer cases by researchers at the University of Munich showed that patients with this type of cancer were significantly more likely to have kept a dog...