Thermal paper, sometimes used in cash register receipts, may be a source of exposure to the hormone disruptor bisphenol-A (BPA), according to a University of Missouri study in the journal The researchers tested people who handled a thermal receipt after using a hand sanitiser, then ate fries with their hands. It was found that a very large amount of BPA was transferred from the receipt to the hand, resulting in a rapid increase in blood levels of BPA. "The BPA blood levels caused by touching thermal paper are related to many diseases [for example, obesity and diabetes] that are increasing in frequency as the use of BPA is increasing," says study co-author Frederick vom Saal.

Casual skin exposure to sunlight, together with plenty of exercise and a healthy diet, may help prevent the development of obesity in children, say researchers at the Telethon Kids Institute in Perth, Western Australia. In tests on overfed mice, shining UV light slowed weight gain and the mice displayed fewer symptoms linked to diabetes, such as abnormal glucose levels and resistance to insulin. The beneficial effects of UV treatment were linked to a compound called nitric oxide, which is released by the skin after exposure to sunlight. Applying a cream containing nitric oxide to the skin of the overfed mice had the same effect of curbing weight gain, the team found.

Dig out that dictionary: it could be a defence against dementia as you age. Researchers from the University of Santiago de Compostela studied 326 subjects aged over 50, of which about a third had mild cognitive impairment and the rest were healthy. A greater prevalence of mild cognitive impairment was found in participants who achieved a lower score in vocabulary tests. One's vocabulary level is seen as a measure of "cognitive reserve", or the brain's capacity to compensate for the loss of its functions.