A new study at Sydney's Victor Chang Cardiac Research Institute showed that traits can be changed through "epigenetic" changes, which could have implications for a number of trends and changes in our population, such as the obesity epidemic.

Epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. It considers how genes are switched on or off, usually through an environmental stimulus, such as a change in diet.

However, unlike the genetic changes, epigenetic changes do not involve permanent mutations in the genetic code.
In their study, the researchers fed a group of mice a diet rich in supplements such as folate, zinc and vitamin B12, which help to suppress obesity in mice by turning a particular gene off.

The researchers found that when the diet was continued in the lean mice over five generations, the epigenetic effects were inherited which resulted in the increase in the proportion of lean and healthy specimens in each subsequent generation, without any change to the genetic code of the mice.

However, when the researchers later fed the mice with an unsupplemented diet, the proportion of lean mice started to fall within three generations.

Their findings showed that diet-induced epigenetic changes were reversible, unlike genetic changes, which cannot be undone, the researchers said.

Dr. Cath Suter, head of the Epigenetics Laboratory at the Victor Chang Institute, who led the study said that this "reversibility could be very advantageous if a change in environment was only temporary, say, a change in climate. Populations could adapt quickly but retain the ability to revert back if necessary."

Co-author Dr. Jennifer Cropley added that while genetic changes can take thousands of years to spread in a population, epigenetic changes may occur much more rapidly.

Other studies have proposed the use of epigenetics in the treatment of aging, inherited diseases and cancer.
Scientists are focusing on the field of epigenetics in its study of cancer which is not due just to the DNA, but passed along from parents with all its various mutations and recombinations.

According to researchers, epigenetics can be used for early detection of cancer because the DNA changes in methylation, a signal of the beginning of cancer or other disease.

Epigenetics can also play a role in cancer prevention because studies show how things like diet or environment affect the epigenome. This means that a person can deliberately prevent cancer by altering the epigenome.

The application of epigenetics may also be used to combat disorders caused by aging, providing the opportunity to turn on genes shut down by the aging process.

Epigenetics is also at the heart of the hope for stem cell therapy, researchers said.