Why do people who eat lots of apples live longer?
Women who eat an apple a day don’t just keep the doctor away — they’re 35 percent less likely to die young, according to a study conducted by researchers from the University of Western Australia.
The scientists believe that similar benefits would be seen from other fruits and vegetables. However, they examined apples because people eat them in high enough quantities to make them an important dietary source of the plant compounds known a flavonoids.
“Apples are amongst the top contributors to total flavonoid intake,” researcher Jonathan Hodgson said.
“We have previously shown that flavonoid intake from apple skin improved artery relaxation. We have now shown that higher apple intake was associated with lower risk of all-cause mortality and cancer mortality in older women.”
Flavonoids and fiber
Researchers followed 1,456 women between the ages of 70 and 85 for 15 years, and used information from food frequency questionnaires to look for differences in mortality rates. They found that women who ate just 100 grams of apple a day, the equivalent of a small fruit, lived dramatically longer.
Hodgson said the health benefits likely come from the high fiber and flavonoid content of apple skin in particular.
Flavonoids are a class of plant chemical with powerful antioxidant effects. Like other antioxidants, they deactivate the “free radical” molecules that cause oxidative damage to cells in the body. Oxidative damage is believed to be a major contributor to chronic diseases including inflammatory diseases, heart disease, cancer and cognitive decline.
Flavonoids have also been shown to help reduce the amount of sugar that is absorbed from the diet, perhaps lowering the risk of diabetes and obesity. Apples are high in one particular flavonoid, quercetin, that has been linked to lower blood pressure, lower heart disease risk and even protection from the effects of certain heavy metals.
The high fiber content of apples has also been linked to lower levels of blood pressure and cholesterol, and to a lower cancer risk. And apples are high in micronutrients including vitamin C, magnesium and potassium.
Eat brightly colored fruits and vegetables
Another likely explanation for the connection between high apple consumption and longer life is a simple one: People who eat lots of apples probably eat lots of other fruits and vegetables as well. And they’re probably more likely to make other healthy choices, such as getting enough exercise and not smoking.
Hodgson admits that apples are a stand-in, in the study, for any fruit.
Current research supports this idea. For example, a recent study by researchers from Harvard University and the University of East Anglia found that people who ate diets high in flavonoids — that is, in fruits and vegetables — were more likely to lose weight and less likely to gain it. Whereas the average woman gained 2 lb 3 oz over the course of four years, and the average man gained 4 lb 6 oz, the average person who ate the flavonoid-containing equivalent of 2.8 oz of blueberries every day instead lost 2 lb 10 oz.
“Just a single portion of some of these fruits per day would have an important impact on health at a population level,” researcher Aedin Cassidy said.
Indeed, all kinds of nutritious food can provide life-saving health benefits. Dark red, blue and purple fruits in particular — which are high in chemicals known as anthocyanins — have been linked to improved cardiovascular health and lowered rates of disease. And a 2011 study in the Archives of Internal Medicine found that people with the highest blood levels of alpha-carotene — indicating high consumption of bright orange, yellow and green vegetables — were significantly less likely to die early, particularly from heart disease or cancer.