Scientists have compared fat samples from humans and other primates and found that changes in DNA packaging affected the way the human body processes fat.
Our bodies need fat to store energy and protect vital organs, this is clear. Fat also helps the body absorb some nutrients and produce important hormones. Dietary fats include saturated fats, trans fats, monounsaturated fats, and polyunsaturated fats, all of which have different properties.
In general, we should all try to avoid or consume saturated fat in moderation, as it increases levels of low-density lipoprotein (LDL) cholesterol, or “bad cholesterol.” Monounsaturated and polyunsaturated fats, however, can lower LDL cholesterol levels.
Triglycerides are the most common type of fat in the body. They store excess energy from the food we eat. During digestion, our bodies break them down and transfer them to cells through the bloodstream. Our bodies use some of this fat for energy and store the rest within cells.
Fat metabolism is key to human survival , and any imbalance in the process can lead to obesity, diabetes, and cardiovascular disease.
How humans became the ‘fat’ primate
Modern eating habits and lack of exercise have contributed to the obesity “epidemic,” but new research highlights the role evolution played in the increasing formation of human body fat.
Scientists found that changes in the way DNA is packaged within fat cells reduce the human body’s ability to convert “bad” fat into “good” fat.
“We are the fat primates,” says study co-author Devi Swain-Lenz, a postdoctoral associate in biology at Duke University in Durham, North Carolina, in the journal Genome Biology and Evolution that publishes the study.
The researchers, led by Swain-Lenz and biologist Greg Wray, compared fat samples from humans, chimpanzees and other primates using a technique called ATAC-seq, a method that analyzes how DNA from fat cells is packaged in the bodies of different species.
We have a lot of fat
The findings revealed that humans have between 14% and 31% body fat, while other primates have less than 9%. Additionally, DNA regions in humans are more condensed, limiting accessibility to genes involved in fat metabolism.
The experts also found that around 780 regions of DNA were more accessible in chimpanzees and macaques compared to humans. This means that the human body has a reduced ability to transform bad fat into good fat.
Not all fat is the same
Swain-Lenz explains that most fats are made up of “calorie-storing white fats.” This is the type of fat that accumulates in our abdomen and around the waist. Other fat cells, called beige fat (brown in white) and brown, help burn calories.
The results of this new study revealed thatOne of the reasons humans carry more fat is because the DNA regions that should help convert white fat to brown fat are compressed and do not allow this transformation to occur.
“It is possible to activate the limited brown fat in the body by doing things like exposing people to cold temperatures, but we have to work to achieve that,” adds Swain-Lenz.
The authors believe that early humans may have needed to accumulate fat not only to protect and give consistency to vital organs, but alsoto nurture their growing brains. In fact, the human brain tripled in size during evolution, and it now uses more energy than any other organ.
Scientists have been working to understand whether to promote the body’s ability to convert white fat into brown fat.could reduce obesity,but more research is needed.
“Maybe we could discover a group of genes that we need to turn on or off, butwe are still a long way from that“, concludes Swain-Lenz
Referencia: Comparative analyses of chromatin landscape in white adipose tissue suggest humans may have less beigeing potential than other primates Devjanee Swain-Lenz Alejandro Berrio Alexias Safi Gregory E Crawford Gregory A Wray Genome Biology and Evolution, evz134, DOI: https://doi.org/10.1093/gbe/evz134
