The study, which examined the height and weight of almost 10,000 people from 14 European countries, suggests a link between the genes that increase a person’s height and those that produce a reduced body weight.
The finding could prove crucial to determining whether genetics play a role in creating national differences in disorders such as dementia, diabetes and heart disease.
It could also help to explain why people from northern European countries – like Sweden, Norway and Finland – have a reputation for being long and lean. That – as well as being taller and slimmer than other Europeans.
The research, led by the University of Queensland (UQ) in collaboration with the University of Melbourne, found the genes that result in greater height correlate strongly with the genes that produce a reduced body mass index (BMI).
“Our findings give a genetic basis to the stereotype of Scandinavians as being tall and lean,” said UQ’s Dr Matthew Robinson.
Quantitative genetics expert Michael Goddard from the University of Melbourne helped develop the methodology used for the study. He said the findings were significant.
“It shows that most genetic variation can explained by variants in the DNA sequence,” said Professor Goddard.
“And this is controversial because the DNA variants that are statistically significant explain only a small part of the genetic variance.”
Fellow UQ researcher Professor Peter Visscher said genetic differences were likely to result from historic natural selection on height and BMI.
“The research suggests that tall nations are genetically more likely to be slim,” Professor Visscher said.
Dr Robinson said that on average, only 24 per cent of the genetic variation in height and eight per cent of the genetic variation in BMI could be explained by regional differences.
“Countries’ populations differ in many ways, from the height of their people to the prevalence of certain diseases,” he said.
The study looked at height and BMI differences in 9,416 people from 14 European countries and used data from genome-wide association studies (GWAS).
Dr Robinson said genetic variation between countries could explain national differences in height, but environmental factors were the main determinant of a population’s BMI.
“This suggests that differences in diet, for example, are more important than genetics in creating differences in BMI among nations.”
Source: The University of Melbourne