Children whose parents consume a high-fat diet are more likely to develop obesity and diabetes, according to new research. While parents normally transmit genetic information to their children through DNA, scientists now believe that changes in a chromosome without alterations in the DNA sequence, also known as epigenetic inheritance, may also be passed on the offspring's genetic material.
In recent decades, the world has seen a rise in diabetes so rapid that it seems unlikely that DNA mutations are to blame. Epigenetic inheritance, on the other hand, could offer some explanation as to the sudden expansion of the condition. The new finding on transmission of obesity to offspring further strengthens the view that epigenetic factors are directly transmitted through sperm and eggs.
According to the authors of the current study, parents could pass on to their children traits that they acquire as a result of exposure to environmental influences. However, the extent to which such environmental conditions impact future outcomes remains unclear.
Researchers in Germany fed mice that were genetically identical a high-fat, low-fat or normal diet over a period of six weeks. Mice that consumed a high-fat diet developed obesity and glucose intolerance.
The team then created a new generation by implanting embryos using sperm and eggs from the mice that had eaten different diets into healthy surrogate mothers. The use of surrogates enabled them to separate environmental factors from the epigenetic factors that were present only in the sperm or eggs.
The new generation of mice was then found to consume a high-fat diet. Offspring of two obese parents gained significantly more weight on a high-fat diet than those with only one obese parent. Offspring of two lean parents gained the least weight on a high-fat diet. Similar patterns emerged for glucose intolerance. Moreover, female offspring were more prone to severe obesity, while males were more affected by blood glucose levels than females.
The researchers concluded that epigenetic factors in sperm and egg play an important role in passing on the risk of obesity and diabetes from parents to offspring. The researchers believe this is the first study to demonstrate that offspring can inherit an acquired metabolic disorder epigenetically, through eggs and sperm.