Scientists are looking at the links between obesity, age, and body chemistry.
Obesity is described as an abnormal or excessive accumulation of fat that is a health problem. This condition has grown to become prevalent throughout the United States. According to statistics collected by the Centers for Disease Control and Prevention (CDC) in 2017-2018, more than 42 percent of adults in the United States and 19 percent of young adults in the United States are obese.
Unfortunately, obesity rates in adults and children continue to rise. From 1975 to 2016, the prevalence of overweight or obesity among children and adolescents aged 5-19 years increased more than fourfold, from 4% to 18%. Obesity is generally thought to be caused by overeating and little movement, but recent studies suggest other factors may be involved.
A research team at Clemson University is making great strides in understanding the link between certain enzymes naturally generated in the body and their role in managing obesity and controlling liver disease.
Three Clemson researchers and colleagues at Emory University School of Medicine analyzed male mice lacking Cyp2b and how the absence of this enzyme affected the mice’s metabolism.
According to William Baldwin, professor and graduate program supervisor in the Department of Biological Sciences in Clemson, the study was motivated in part by a simple observation: male mice without the Cyp2b enzyme gain weight. Cyp2b-null female mice did not show the same effect.
“We noticed that our Cyp2b-null mice were heavier in weight,” said Baldwin, a professor in the Department of Biological Sciences. “They are more likely to be obese – at least, diet-induced obesity – especially in males than wild-type mice, and we’ve been trying to figure out why that is.”
While the observation made to the researchers was straightforward, it turns out that understanding the interactions behind weight gain will be more complex.
“It would be great if there was a nice and simple answer, but maybe there isn’t a nice, simple answer,” Baldwin said.
A variety of roles
Baldwin noted the complexities of the many chemical processes involved in the CYP enzyme, which is part of a superfamily of enzymes that perform a number of functions in humans. According to him, Cyp2b enzymes help in the metabolism of certain toxins and drugs in order to remove them from the body.
But the same CYP enzymes have other functions as well. “They metabolize bile acids. They metabolize steroid hormones. “They metabolize polyunsaturated fats from our diet,” Baldwin said. “This means that all of these things can also interact. If you’re on a high-fat diet, it can impede the metabolism of the drug. Of course…the drugs may inhibit fat metabolism, they may affect steroid metabolism, etc. that. “
The researchers also looked at the relationship between “perturbed lipid profiles” and disease.
The researchers note that susceptibility to disease and general health are greatly influenced by changes in lipids. High-fat diets, such as the Western diet, cause obesity and significantly alter liver lipids, and disturbed lipid profiles are associated with specific liver diseases, such as nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH).
Effect of age and diet
Baldwin previously led research examining the relationship between diet and environmental toxins. The latest study looked at how aging and diet affect these metabolic processes.
What does a bad diet do to us? What does age do to us? That’s kind of the idea here,” Baldwin said of the latest research. “We’re looking at these enzymes. What might happen over time to our profiles in this mouse model compared to a wild-type mouse only. What might happen over time with a high-fat diet, what might happen as we age, and how it differs between a single mouse model without these enzymes, compared to a model with these enzymes. “
Baldwin said simply, “One of the things we’ve seen, not surprisingly, is that getting older is a bad thing. It’s harder for mice to regulate body weight. They gain weight. The weight they have is more white adipose tissue.” [connective tissue mainly comprising fat cells]. …and some of these things were slightly worse in mice lacking Cyp2b enzymes. They were a little heavier. They had a little more fat than their counterparts. Their livers were a little bigger and a little less healthy. So they had a lot of those things that we associate with age.”
The diet also had an effect on the mice’s health.
“Of course, the diet didn’t help either,” Baldwin continued. “It’s the same case: eating a poor diet caused weight gain, and it was a little worse with those [Cyp2b-null] mice, possibly due to poor metabolism. “
He said the exact mechanism by which the Cyp2b enzyme acts is not fully understood.
“You’re removing an enzyme that helps metabolize these, but I don’t think it’s really important that it helps get rid of the fat, but it lets the body know the fat is there. It probably produces signaling molecules that say ‘Hey, we need to figure out what we’re going to do with that fat; We need to distribute this fat. This kind of information. That’s just an educated guess at this time, but I think that’s probably what’s going on.”
Differences in humans
Baldwin said his current research takes a closer look at the mechanisms at hand and how they differ in the human model from mouse studies.
He said the research, which will be part of an as-yet-unpublished research paper, suggests that mouse and human enzymes may not work the same way. The human enzyme appears to make us retain some fat in the liver, and the mouse enzyme appears to drive that into the white adipose tissue. “There are hints here in this paper that this is the case,” Baldwin said.
A National Institutes of Health grant supported the research.
Reference: “Age and diet-related changes in hepatic lipid profiles of phospholipids in male mice: acceleration of lifespan in Cyp2b-Null mice” by Melissa M. S. Baldwin, March 29, 2022 Available here. fat magazine.