Does cycling really damage men’s sexual organs?

Jessica Brown: New research refutes the theory that pressure from saddles can cause erectile dysfunction, and says cycling could actually improve performance in older men

High-vis, low-conflict: Kampala gets its first Critical Mass cycle ride

Uganda’s first ever Critical Mass is missing the air of protest normally found in Europe or the US. This may be for the best in a country where dissent is often quashed with rubber bullets and tear gas

Raw water: the unsterilised health craze that could give you diarrhoea

Its adherents say it is full of good things that ordinary filtered tap water has lost. Its critics say it might well give you ‘beaver fever’ – among other illnesses

‘I feel less stuffed after dinners – and less guilty’: why I stopped eating meat

My journey towards vegetarianism started 30 years ago for practical reasons, but the more I eschew animal products the better I feel about everything

David Davis’s ignorance: now that’s what I call health and safety madness

Austerity has already driven a coach and horses through environmental standards – and we haven’t even got to the Brexit cliff edge yet, writes the Guardian columnist Polly Toynbee

The Guardian view on the Nobel prize for medicine: about time

Editorial: The discovery of two interacting genes which make a body clock shared by all living things is a triumph that deserves its prize

Vivienne Westwood on her secret to staying young: bathe once a week

Fashion designer, 76, says not washing too much is the secret to seeming young, while her husband, Andreas Kronthaler, says he washes even less often

Experience: a ladybird nearly killed me

My foot looked like a giant’s. I was shocked. I was 31 and very fit. I’d never been ill in my life

‘Brexit virus’: an EU-plot to sabotage the great British breakfast

A strain of hepatitis E carried by some continental pigs has been given a topical nickname. So, do we need to vote leave on bacon?

Air pollution linked to poor sleep, study finds

Exposure to nitrogen dioxide and airborne particles affects sleep efficiency, says medical professor