Where does obesity come from?
Once seen as the result of a lack of willpower and self-control, the biological nature of obesity has proven to be much more complex and related to some specific stages of development. All the details of the study from Baylor College of Medicine in Houston
Obesity has more to do with the brain than ever thought. This is stated in the journal Science Advances by research that used epigenetics to demonstrate that obesity is linked to nutrition during some stages of development.
THE CAUSES OF OBESITY
An improper diet,lack of exercise and lack of 'good' sleep are among the best known causes of obesity, a disease responsible for premature and preventable deaths.
Now, however, research from Baylor College of Medicine in Houston (Texas) has shown in mice that environmental and nutritional changes during pregnancy and early development can cause epigenetic changes in the area of the brain linked to food intake, activity and metabolism.
The work also highlights some links between the human and mouse genomes, suggesting that similar epigenetic changes can also occur during human fetal development.
THE GENETIC FACTOR
As the study points out, it is widely recognized that body weight is also influenced by genetics. The US Centers for Disease Control and Prevention (CDC) say over 50 different genes have been associated with obesity. Genes, in fact, determine the signals that are transmitted by hormones to the brain, where they direct the body to eat or move.
OBESITY AS A NEURAL DEVELOPMENT DISEASE
However, as Dr. Robert A. Waterland, a professor at Baylor College of Medicine, told Medical News Today : 'Genetic variations certainly contribute to individual body weight differences, but early environmental influences on the development of weight regulation mechanisms may , in general, have a greater role in determining the individual propensity to obesity ”.
In this regard, the study states that "obesity is mainly a neurodevelopmental disease strongly influenced by nutrition during some critical ontogenetic phases".
THE EPIGENETIC APPROACH
To prove this thesis, the researchers used epigenetics, which is the branch of genetics that studies the functioning of genes, allowing scientists to observe how behavior and the environment can alter it.
Epigenetic changes don't change the DNA sequence, but the way the body reads it.
I STUDY
The study therefore focused on epigenetic development at the arcuate nucleus level of the hypothalamus, a region that regulates food intake, physical activity and metabolism.
The researchers observed that the arcuate nucleus undergoes extensive epigenetic 'maturation' during postnatal life, a period also sensitive to the regulation of body weight.
To figure this out, mice between the ages of 2 and 4 months were monitored during pregnancy and their pups were studied during postnatal development.
THE RESULTS
The researchers noted that the postnatal period in mice is critical for epigenetic changes related to obesity and energy balance regulation, suggesting that obesity could be a "consequence of unregulated epigenetic maturation".
Furthermore, a strong correlation was also observed between regions of the human genome linked to body mass index (BMI) and areas of epigenetic changes in mice, suggesting that obesity may be determined in part by epigenetic development in the arcuate nucleus. .
FROM MOUSE TO MAN
“[…] An obvious next step is to determine when this BMI-associated epigenetic maturation occurs in humans. Because many neurodevelopmental processes occur earlier in humans than in mice, this hypothalamic epigenetic maturation is likely to occur during late fetal development in humans, ”Waterland said.
Additionally, Medical News Today reports, the effect of nutrition during early development in human studies has shown that food shortages during the first trimester of pregnancy lead to higher obesity rates, while during the last trimester and early months. of life are related to lower levels.
THE DATA ON OBESITY
Obesity, writes Health Newspaper , has grown rapidly in recent decades and affects more than two billion people worldwide.
And just today Istat data photograph the situation in Italy. Estimates indicate a worsening of the situation in 2020 and confirm a trend already underway before the advent of the pandemic.
In our country, says the institute, among children from 3 to 5 years old, one in three is affected by overweight or obesity (33.2% in 2020, +1.6 percentage points compared to 2018) and in the age group which also includes adolescents (3-17 years), the share is 26.3% (29.2% among males, 33% in the South).
This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/sanita/da-dove-deriva-lobesita/ on Mon, 17 Oct 2022 06:15:54 +0000.