Sperm carries memories of dad's eating habits

At some point in our lifetimes, we have all inherited family heirlooms passed on from generation to generation.

Our bequests could range from say a grandfather's clock or dad's watch to that of our dads teaching us how to ride a bike or even how to handle money.

But besides these obvious material additions and habits, what if our fathers also bequeathed, our own feeding behavior?!

This is precisely the focus of a new study by a team of Scandinavian researchers, led by Dr. Romain Barres, an associate professor at the University of Copenhagen, Denmark.

As his primary motivation behind this study, Dr. Barres says, "Children from obese fathers are more prone to develop obesity later in life, independently of the weight of the mother."

What and how does the father pass on this information to his children?

To conduct their study, Dr. Barres and his team collected sperm samples from two groups of people in their reproductive age- 13 lean and 10 massively obese men. Obesity was characterized by a median Body Mass Index (BMI) value greater than almost 30.

In addition, the researchers also collected sperm cells from six obese men who underwent weight loss surgery called gastric bypass (that limits food intake) at three time intervals- one week before and after surgery, and one year after surgery.

The scientists then studied the epigenetic (on top of the genetic material) content of these sperm cells.

Epigenetics is the study of how environmental factors cause the genes to switch on or off in a heritable manner and as a result, affect how cells read them.

The results revealed, that when compared with lean men, the epigenetic imprint in the sperm cells of obese men was different.

The researchers also found that the genetic imprint of the obese men underwent many changes one week after surgery and more importantly, these changes increased by 65% one year after surgery when the subjects had lost about 30 kilograms on average.

According to Dr. Barres, "The lifestyle of the father before his children are conceived can affect their health."

Now what does this suggest about the offspring of these obese men?

"If this information is transmitted to the next generation, the children of these men could have an altered eating behavior. Our results could explain, at least in part, why children of obese men are predisposed to become obese themselves," remarks Dr. Barres.

Although the main question then is, where could these changes occur in the children to affect their eating behavior? In the brain of course!

"But most strikingly, we found this difference was carried at proximity of genes important for the development of the brain and the regulation of appetite," asserts Dr. Barres.

OK, so does this mean that the sperm carries the information to wire the neurons differently between brains of lean and obese offspring, thereby affecting their eating habits?

The scientists are not sure at this stage but believe that most likely the feeding behavior, in particular, will affect their children.

As a next step, Dr. Barres would like to determine whether the specific marks in the sperm from obese men would affect their children and how they would do so.

"I'd like to determine the lifestyle factors that can positively or negatively influence what we transmit to our children, for instance, exercise- What type, how long before conception etc.," remarks Barres.

So what is the take home message from these results?

As we have all seen in matters related to conception, typically the main focus has been on the woman's lifestyle, weight, eating habits etc. amongst others.

But this insightful study actually highlights a pivotal role that men play in the preconception stage, by imprinting their eating behavior on the genetic materials.

That is indeed quite powerful!

Therefore, Dads beware- as the saying goes, you are what you eat. Not only that, but it seems that your kids are what you eat as well!


Image credit: http://www.h3daily.com/healthy-lifestyle/healthy-gifts-for-dad/