When the saying "An apple a day keeps the doctor away" was coined, there probably wasn’t much research to back it up — but people knew it intuitively. In recent years, though, more and more scientific studies have shown why the adage is actually quite accurate. New research shows that a compound in apples, ursolic acid, can prevent the muscle atrophy that comes from many illnesses and the wasting that accompanies aging.
Mice eating a regular diet of lab chow were given ursolic acid supplements. Their muscle mass actually increased compared to control mice who did not receive the supplements.
It is known that certain genetic changes underlie muscle wasting, so the researchers behind the current study reasoned that targeting compounds that have the opposite effect on genes would be an effective method. They analyzed dozens of compounds, and finally arrived at ursolic acid, found in apple skins, as a potential protector against the genetic changes underlying muscle atrophy.
They gave the compound to mice who were deprived of food for a 24-hour period (fasting is known to tip off muscle atrophy). The University of Iowa team found that atrophy was significantly lessened in mice who were given ursolic acid, compared to controls. In another part of the experiment, mice eating a regular diet of lab chow were given ursolic acid supplements. Their muscle mass actually increased compared to control mice who did not receive the supplements.
The findings are important since muscle atrophy is a significant problem in a vast range of diseases and it can cause considerable distress for patients who experience it. Even worse is that there’s no cure for it, according to the researchers. While it’s still unknown whether the findings will apply to humans – and what dose of ursolic acid would be required – the findings are still encouraging, as they suggest a promising avenue for future research.
Whether adding an apple or two to your diet will prevent muscle atrophy is unclear, but given the number of health benefits that apples have been shown to provide, it’s probably not a bad idea anyway. Author Christopher Adams puts it plainly: "We know if you eat a balanced diet like mom told us to eat you get this material. People who eat junk food don't get this."
The research was published in the June 8, 2011 issue of Cell Metabolism.