Study Shows You Could Have Been Born To Be Overweight

       Study Shows You Could Have Been Born To Be Overweight - Overeating not only shows up as excess poundage, but also affects our DNA in a way that can be passed on from one generation to the next, according to a worrying new international study.

Published in the London-based scientific journal Nature, the study showed that a high body mass index (BMI), a weight-to-height ratio, led to “epigenetic” changes at nearly 200 positions of genes on human chromosomes.

The study suggests that children do not get obese just because the family over-eats, but are born with the tendency, even if their grandparents are thinner.

These changes – in the form of chemical compounds that attach to the DNA – aren’t to the genes themselves but can affect their activity.

A common epigenetic change involves the attachment of so-called methyl groups – each consisting of one carbon atom and three hydrogen atoms – to a gene, which inactivates it.

While the genes hardly change at all over a person’s lifetime, lifestyle can directly influence the epigenome, the multitude of chemical compounds that can tell the genes what to do.

Up to now there has been little research on how the epigenome is altered by being overweight.

“This issue is particularly relevant because an estimated one-and-a-half-billion people throughout the world are overweight, especially considering that being overweight can have adverse consequences and lead to diabetes and diseases of the cardiovascular and metabolic systems,” said the study’s lead author, Simone Wahl.

The scientists examined blood samples from more than 10,000 men and women in Europe. A large number of them were ethnic Indian Londoners, who according to the authors are at high risk for obesity and metabolic diseases.

In the first step with more than 5,000 samples, the research team found 207 gene loci, or positions, that had been epigenetically altered dependent on the BMI. Further tests confirmed 187 of these. Additional studies indicated that the changes were predominantly a consequence of being overweight – not the cause.

The scientists said there had been significant changes mainly to genes responsible for fat metabolism, and that inflammation-related gene loci had also been affected.

They identified epigenetic markers – chemical compounds attached to DNA that modify its function – that they said could predict the risk of developing type 2 diabetes.

They hope this will lead to new strategies for predicting and possibly preventing type 2 diabetes and other consequences of being overweight.

A number of researchers, including from the German Research Centre for Environmental Health’s Institute of Experimental Genetics, where Wahl works, had earlier shown in experiments with mice that obesity and diabetes caused by improper diet could be passed on epigenetically to the next generation.