The puzzle of why humans are growing taller and reaching puberty earlier than ever before can be explained by a sensor in the brain, scientists say, BBC reported.

BBC reported that average height in the UK rose by 3.9 inch (10cm) during the 20th Century, and up to 7.8 inch in other countries, as nutritional health improved. But exactly how this happens has never been understood.

Also read: Oil tanker explodes at gas station in Sierra Leone, at least 80 dead

The discovery could lead to drugs to improve muscle mass and treat delayed growth, UK researchers say.

It is also said that scientists have known for a long time that humans with good diets and reliable access to food tend to grow taller, and mature more quickly.

For an instance, in South Korea, adult height has rocketed as the nation transformed from a poor country to a developed society. Yet in parts of South Asia and Africa, people are only slightly taller than 100 years ago.

It’s known that signals from food reach a part of the brain called the hypothalamus, telling it about the body’s nutritional health, and triggering growth.

Also read: A dozen drug gangs fighting for Mexico’s Caribbean, officials say

This new study, published in Nature, and led by researchers from the University of Cambridge alongside teams from Queen Mary University of London, University of Bristol, University of Michigan and Vanderbilt University, has discovered the brain receptor behind that process.

It is called as MC3R and is the crucial link between food and sex development and growth.

“It tells the body we’re great here, we’ve got lots of food, so grow quickly, have puberty soon and make lots of babies,” said Prof Sir Stephen O’Rahilly, study author, from Cambridge.

Also read: Roads, transit, internet: What’s in Joe Biden’s infrastructure bill

When the brain receptor does not work normally in humans, the researchers found people tended to be shorter in height, and started puberty later than other people.

The team searched through the genetic make-up of half a million volunteers signed up to the UK Biobank – a huge database of genetic and health information – to confirm this was true.

BBC quoted the scientists and said that the children found to have gene mutations which disrupt the brain receptor, were all shorter and weighed less than other children, which shows the effect starts early in life.

Also read: Overthinking? Try these methods to relax your brain

The research team found one person who had mutations in both copies of the gene for MC3R, which is extremely rare and damaging. This person was very short, and started puberty after the age of 20.

Drugs for the future

But humans are not alone in this – researchers studied mice to confirm that the same pathway is at work in animals.

Also read: Air pollution linked to heart scarring in adults with kidney disease: Report

The discovery could help children with serious delays in growth and puberty, as well as those who become frail with chronic diseases and need to build up muscle.

“Future research should investigate if drugs that selectively activate the MC3R might help redirect calories into muscle and other lean tissues, with the prospect of improving the physical functionality of such patients,” Prof O’Rahilly said.

Scientists had already identified a brain receptor which controls appetite, called MC4R, and those who lack it are usually obese.