People trying to lose weight will be glad to know that there is a tasty, satisfying way to increase their odds of success: Apples. The fruit also may help people avoid some of the metabolic problems associated with being overweight and obese.
Apples are good sources of non-digestible compounds such as fiber and polyphenols, and they are low in carbohydrates. They can improve heart health and protect us from the damage of free radicals.
They also can help protect older people from muscle atrophy.
The balance of bacteria in our colon is determined by the food we eat, and the right balance of bacteria stabilizes metabolic processes that influence inflammation and the feeling of satiety or fullness.
When Washington State University researchers tested several varieties of apples on mice, they found that one spurred the growth of friendly bacteria in the colon that improve metabolic health — the bright green, crisp, tart-tasting Granny Smith.
Enough of the nutrients in Granny Smith apples survived the act of chewing and the effects of stomach acid and digestive enzymes that they arrived in the colon intact. There they were fermented by bacteria and this improved the sustained growth of friendly bacteria.
“The nondigestible compounds in the Granny Smith apples actually changed the proportions of fecal bacteria from obese mice to be similar to that of lean mice,” said Giuliana Noratto, the study’s lead researcher, in a statement.
The finding may help prevent some obesity-related disorders, Naratto says. Obesity causes an imbalance between friendly and unfriendly bacteria in the colon which can lead to low-grade, chronic inflammation. The inflammation contributes to the development of metabolic disorders associated with obesity, such as diabetes.
Though Braeburn, Gala, Fuji, McIntosh, Golden Delicious, and Red Delicious apples are all tasty and nutritious in their own right, none contained as much of the non-digestible compounds and had as much impact on the bacteria in the colon as did the Granny Smith.
“Results from this study will help consumers to discriminate between apple varieties that can aid in the fight against obesity,” stated Noratto.
The study is published in Food Chemistry.