It has been known for years that ursolic acid, a plant substance especially found in apple peels, protects against the diseases of metabolic syndrome, particularly heart disease and breast cancer. A new study has found that these are not just hypothetical benefits. Ursolic acid has measurable effects in amounts that you could come easily across in food. Researchers tested an amount of ursolic acid equivalent to 1 or 2 apples per day and found that this provided a degree of metabolic protection against the effects of a high-fat diet. Apparently this was the result of promoting the growth of muscle cells and fat-burning tissues so that more kinds of fat could be burned for energy the same day they were eaten. This protected against the increased body fat that could otherwise result from a high-fat diet.
Ursolic acid is a waxy substance found most prominently in apple peels, but also in lower concentrations in a wide range of foods, including prunes and peppermint.
A separate study this year found that peaches, nectarines, and plums are also effective against metabolic syndrome. The interesting thing about the stone fruits (called this because of the large pits they contain as seeds) is that they contain four different groups of substances that work separately on four cell types involved in metabolic syndrome. The stone fruits were particularly effective against diabetes and heart attacks.
Both apples and stone fruits appear to work against the weight gain associated with a bad diet. This is consistent with what health experts have been saying in recent years: weight loss strategies may work better if you focus on adding in good food first, and avoiding bad food second.