Jeremy Corbyn is “going through the process” of eating more vegan food, he has said – he just has to bring himself to give up the brie, verboten under vegan rules, along with eggs, milk and everything animals produce. Later, as if fearful of a backlash, his spokesperson issued a statement denying he was vegan. But the Labour leader was right to be proud of his efforts. Vegans are often unreasonably mocked as do-gooders and sniped at for making dinner parties awkward for those who don’t like lentils quite so much. This is unfair: the diet does do the world good and if vegans provoke their friends into going vegan too, so much the better.

There is now a great deal of convincing data that breeding animals for food dirties the air and chews up the earth. One recent peer-reviewed study from the London School of Hygiene and Tropical Medicine calculates that should the world go vegan, annual greenhouse gas emissions would halve and the new land used every year for each person would near-halve. The diet is also healthier: some meat products have been linked to cancer and saturated fat from meat and dairy products can cause heart disease. A study published in Proceedings of the National Academy of Sciences of the USA predicts that global veganism would lead to 8.1 million fewer deaths per year.

Vegans should be encouraged: their choice is high in moral as well as digestive fibre. Their detractors should stop crying over spelt milk.

• This article was amended on 7 September 2017 to correct the name of the publication referred to regarding predicted reduced annual mortality figures arising from global veganism