Scientists in the U.S. have produced a chemical that can perform a dramatic reversal of the aging process. In mice.

According to the new research, published in the journal Cell on Thursday, scientists used a naturally-occurring chemical to revitalize muscle in old mice, and found that the rodents' tissues showed characteristics that were comparable to those found in much younger animals.

“The aging process we discovered is like a married couple -- when they are young, they communicate well, but over time, living in close quarters for many years, communication breaks down,” David Sinclair, a professor of genetics at Harvard Medical School and the study’s senior author, said in a statement. “And just like with a couple, restoring communication solved the problem.”

According to the researchers, a series of molecular events enable communication inside cells, and as the communication breaks down, aging accelerates. The research focused on NAD, a chemical which declines in cells with age. Without sufficient NAD, cells lose their ability to generate energy, and signs of aging and disease become apparent. The scientists said that this is a newly discovered mechanism of aging, which they managed to reverse.

During the experiment, the scientists boosted NAD levels in mice by giving them a naturally-produced compound that cells transform into NAD. According to the researchers, one week of medication in two-year-old mice meant their muscle tissues would resemble that of six-month-old mice in terms of muscle wastage, inflammation and insulin resistance. In case of humans, the transformation would be like a 60-year-old person transforming into a 20-year-old.

However, the transformation did not improve muscle strength but the scientists predict that muscle strength also could return with a longer treatment regimen.

“It’s certainly significant to find that a molecule that switches on in many cancers also switches on during aging,” Ana Gomes of the department of genetics at Harvard Medical School said. “We're starting to see now that the physiology of cancer is in certain ways similar to the physiology of aging. Perhaps this can explain why the greatest risk of cancer is age.”

Asked if it is a permanent cure for aging, the scientists said that this could never be the solution for aging, which is connected to many other aspects such as damage to DNA that cannot be reversed.

“This is an intriguing and exciting finding that some aspects of the aging process are reversible,” Tim Spector of Kings College London told BBC News. “It is however a long and tough way to go from these nice mouse experiments to showing real anti-aging effects in humans without side effects.”