The headline asserts outright that the taurine content of energy drinks is a causal factor in colorectal cancers.

? The headline says, "Energy drinks linked to rise in colorectal and blood cancer". 'Linked' doesn't mean 'causes', and that's especially true in any science news or any other journalism. 'Jones linked to Chase robbery' doesn't mean they robbed the bank, but that they somehow had a connection to someone.