Obese Male Mice Father Offspring With High Levels Of Body Fat; How Do Genes Cause Behavioral Changes?
A study shows that the likelihood of offspring becoming obese increases if they are fathered by an obesity-plagued parent. An offspring's high levels of body fat show paternal obesity as a strong indicator of offspring obesity, leading researchers to look at the responsibility of parental behavior as opposed to simply genetics. Researchers have been looking more closely at epigenetics instead of DNA mutations. Epigenetics are the way genes are expressed, which is impacted by environmental and lifestyle factors as opposed to what's "hard-wired into the genes."
"We've identified a number of traits that may affect metabolism and behavior of offspring dependent on the pre-conception diet of the father," said the study's lead author, Felicia Nowak, an associate professor of biomedical sciences at Ohio University.
Previous research has primarily focused on female mice parents and their diet as an impact on offspring. The effect of a parent's diet and weight on children has shown conclusively the direct correlation. If a parent has a poor diet and weight issues such as high body fat, diabetes type 2, or obesity, his or her offspring is likely to face the same dangerously unhealthy future.
Nowak and her team decided to study the issues in mice to learn more about the biological activity that causes the relationship between parent and offspring health. The team studied the impact of mice on a high-fat diet for a little over a year.
Researchers fed male mice a high-fat diet for 13 weeks before they mated with females who were fed a low-fat diet. For a control group, the researchers used a comparison basis — mated male and female mice who were both fed on a standard low-fat diet. Both groups were observed after a day, six weeks, six months, and 12 months in order to watch progressive behavior and development changes within the mice.
The male mice, who were fathered by diet-induced obesity dads, had high body weight at six weeks of age, compared to the control mice who were fed and fathered by mice of a low-fat diet. The trend continued as expected; the high-fat diet male mice were also obese at the six- and 12-month mark. The male offspring with obese fathers also had different patterns of body fat, which is a key marker that indicates propensity for disease.
More than one-third of U.S. adults (35.7 percent) are obese and share the ominous marker of obesity-related conditions such as heart disease, stroke, type 2 diabetes, and certain types of cancer.
Most obese adults were once children with poor eating habits, unhealthy parents, and a majority of them remain under the poverty line — but is it a genetic disposition, or learned behvaior? According to the Centers for Disease and Prevention (CDC), approximately 17 percent (12.5 million) children and adolescents between the ages two and 19 are obese.
With the evidence of paternal relationship to obesity in offspring, it is important to look at how this can affect the human relationship. American society, specifically, has become characterized for abundance, overconsumption, and instant gratification, which can make it difficult for children to thrive with healthy lives for themselves and their families. The promotions of unhealthy food and physical inactivity only strengthen the relationship of poor habits from parent to offspring.
Although the mice were comparably fatter than the offspring with low-fat diet fathers, the offspring of obese paternal mice showed more physical activity. At six weeks, the male offspring voluntarily ran more, even when compared to their female siblings. They continued to demonstrate the same behaviors at the six- and 12-month mark.
Nowak's team is currently studying and hypothesizing the possible causes for this behavior, which might eventually offset the male offspring's high body fat and eventually reduce the risk of metabolic diseases such as diabetes and heart disease.
"Early detection and prediction of risk for obesity, diabetes, and related diseases will enable individuals and health care workers to delay or prevent the related disabilities and increase life expectancy," Nowak said.
Given these findings, the next phase of research will look to identify the genes responsible for physiological and behavioral changes based on relationships between parent and offspring.