The geneticist Professor Steve Jones began his recent talk held as part of the University of East Anglia’s Autumn Literary Festival 2019 by describing himself as “a serial plagiarist”.

He said this because the title of his latest book, Here Comes the Sun, is, of course, taken from a song by The Beatles.

While the name of Jones’s book may not be new, he showed during his presentation that much of the content is, however, highly original – and surprising.

A key focus is the reality that many of us do not get enough sun. While exposure to the sun can cause significant harm, notably because of skin cancer, in Britain this effect seems to be outweighed by the downsides of too little sun. Sunlight is, said Jones, “very, very good for you in many unexpected ways”.

He showed a map of Britain indicating that life expectancy tends to be higher further south and east in the United Kingdom – mirroring the pattern of increasing sunlight duration. Some parts of the country get three times as much sun as others.

Of course, as Jones acknowledged, socioeconomic factors are also at play, but life expectancy’s relationship to sunlight duration is nevertheless striking.

“There’s quite an uncanny parallel between the two,” said Jones, before going on to note that multiple sclerosis, cancer, heart disease, rickets, birth defects, depression, suicide and infectious diseases are all more common in Scotland than in England, which receives significantly more sun.

A key effect of sunshine is, of course, the way that it causes the body to produce Vitamin D which is important for the heart, liver and kidneys, as well as mental health.

Vitamin D actually a hormone rather than a vitamin, Jones said, adding that this “extremely potent chemical” acts as a chemical messenger throughout the body and switches on a variety of genes.

Sunshine has, said Jones, driven much of human evolution. When our ancestors moved from the trees to the ground, their immediate environment became much hotter, so standing upright helped to reduce the amount of skin surface exposed to the sun. This, in turn, made early hominids more effective hunters. Also, people evolved dark skin.

“If you shave a chimpanzee, it’s got light skin,” said Jones.

Humans then made the “big mistake” of moving out of Africa to other, colder parts of the world – and suffered from Vitamin D deficiency as a result.
“North of Birmingham, you cannot make enough Vitamin D from sunshine,” said Jones, which is a sobering comment considering that Norwich is, just, north of Birmingham.

In Scotland in Spring, two-thirds of people are “dangerously low” in Vitamin D, despite the fact that the Scots are the “palest people in the world”, with the highest incidence of red hair and pale skin.

A worrying development is that people spend less time outside than they used to, with British children, for example, outside for an hour a day less than they were a decade ago.

“We’ve become indoor creatures. This is, needless to say, having an unfortunate effect,” said Jones.

Vitamin D deficiency is becoming more common and, as a result, so is the bone disease rickets, a condition that once afflicted one-third of children in London before largely being eliminated.

While noting that in Scotland nursing women and children are given Vitamin D supplements, Jones said that “the problem of Vitamin D deficiency is not going to be solved by the health service”.

“It’s going to be solved by human behaviour. I hope that people’s behaviour will change. There’s not much sign that’s happening yet, but I think that it will begin to happen,” he said.

– The remaining events in the UEA Autumn Literary Festival 2019 are David Owen (October 30), Mary Beard (November 6), Elizabeth Strout (November 13) and Christopher Bigsby with Louis de Bernieres (November 20). Further details are available at https://www.uea.ac.uk/litfest/programme