Epigenetic changes: Obesity is also reflected in the genome
According to a new study, excess pounds are not only deposited on the hips, but also on the DNA. An increased body mass index (BMI) therefore leads to epigenetic changes in almost 200 places in the genome. And that affects genes.
Obesity is not only due to poor nutrition
To put one's own excess weight on "bad genes" is ridiculed by many as an excuse. But even if it is mostly due to the diet and lack of exercise that people are too fat, genes also play an important role. The genes themselves hardly change in the course of a lifetime, but their surroundings do. For example, through certain lifestyle factors. Researchers have now found that obesity can deposit on the genome.
How genes affect weight
It has long been known that the lifestyle of the parents can have an impact on the possible overweight of the offspring. In recent years, scientists around the world have found a lot of new insights into how genes affect weight.
An international team of researchers found a gene responsible for obesity, and Japanese scientists reported late last year that they discovered a gene that burns fat.
Excess pounds are deposited on the DNA
But the other way round, too: obesity can affect the genome. A large international study led by the Helmholtz Zentrum München has now determined that excess pounds can be deposited on the DNA.
The study, which was published in the specialist journal “Nature”, shows that an increased body mass index (BMI) leads to epigenetic changes in almost 200 parts of the genome - with effects on the genes.
Genes hardly change in the course of life
Our genes hardly change in the course of life, but our lifestyle can have a direct influence on their environment. Scientists speak of the epigenome here, i.e. everything that happens on and around the genes, reports the Helmholtz Center in a press release.
So far it has hardly been investigated how the epigenome changes due to being overweight. "The question is quite relevant for an estimated one and a half billion overweight people worldwide," said the first author of the study Dr. Simone Wahl from the Department of Molecular Epidemiology (AME) at the Helmholtz Zentrum München.
"Especially when you know that being overweight can lead to complications such as diabetes, cardiovascular and metabolic diseases."
Relationships between BMI and epigenetic changes
The researchers therefore checked possible connections between the BMI and epigenetic changes. The blood samples of over 10,000 women and men from Europe were examined.
A large proportion of them were residents of London of Indian origin, who, according to the authors, are at high risk for obesity and metabolic diseases.
Changes in genes responsible for fat metabolism
In a first step, the scientists identified 207 gene locations that were epigenetically changed depending on the BMI. 187 of these were confirmed in further tests.
Further examinations and long-term observations also indicated that a large part of the changes were a result of the overweight and not its cause.
"Significant changes occurred primarily in genes that are responsible for fat metabolism and mass transport, but also inflammation genes were affected," explained group leader Harald Grallert from AME.
Predict and prevent secondary diseases of obesity
The team also identified epigenetic markers from the data that could be used to predict the risk of type 2 diabetes.
"Our results provide new insights into which signaling pathways are affected by obesity," explained Christian Gieger, Head of AME. "We hope that this will give rise to new strategies for predicting and at best preventing type 2 diabetes and other consequences of being overweight." (Ad)