Like pears, apples are a member of the Rosaceae family. Apples are a very good source of quercetin, fisetin, phloretin, and ursolic acid, as well as some anthocyanins (red peeled varieties only), all of which have chemopreventive properties. Apples are a also good source of dietary fiber, including pectin. The peel has the most micronutrients, however, nonorganic apple peels are likely to be contaminated with pesticides. Red, red-streaked or rosy apples have more antioxidant and antiproliferative phytochemicals than green or yellow apples.
Breast cancer-related effects of eating apples
Several studies have reported that the consumption of apples is associated with reduced risk of breast cancer, including when the results were adjusted for factors such as age, education, body mass index (BMI), and physical activity. One 2016 study reported that adolescents with high apple intake had reduced risk of breast cancer in adulthood.
Apples have been shown to shrink the size of mammary tumors in rats and to induce apoptosis (programmed cell death) in both hormone receptor positive (ER+/PR+) and triple negative (ER-/PR-/HER2-) breast cancer cells. Apple peel contains chemicals that appear to be important for this effect.
One study reported that an apple peel diet significantly inhibited the growth of mammary tumors in a mouse model of breast cancer. The same study reported that a triterpenoid found in apple peel induced apoptosis (programmed cell death) in triple negative breast cancer cells.
The apple flavonoid phloretin has been shown to reduce the growth and migration of triple negative breast cancer cells. Phloretin has also been shown to increase the anti-cancer effects of the chemotherapy drugs Taxol (paclitaxel) and cisplatin.
It is worthwhile to buy organic apples
Organic U.S. apples are the best choice. Conventionally grown apples typically are produced using relatively high levels of pesticides. Such apples are normally washed after picking, which removes some of the pesticide residue, but also strips off some of the natural apple wax (the waxy cuticle, which contains ursolic acid and other compounds) that is part of the peel. Food grade wax is then applied to the apples, which can seal in some of the remaining pesticide residue. Non-organic apples must be washed very thoroughly to remove pesticide residue as much as possible.
Most apple juice is not desirable
Apple juice is not particularly beneficial compared to raw apples, however cloudy apple juice has more antioxidants than clear apple juice. Apple juice processing and filtering removes some of the nutrients and fiber found in apple pulp.
There have also been reports of meaningful levels of arsenic in apple juice produced from apples grown in countries that use certian pesticides no longer approved for use in the U.S. According to the FDA, even U.S. organic apples can come from trees grown in soil that may contain arsenic. This is because arsenic-based pesticides were commonly used in the U.S. until 1970, leaving traces that persist in some soils. However, the situation in other countries can be far worse. Unfortunately, it can be difficult to determine where the apple juice concentrate used to make juice is sourced. Asia and South America are major suppliers of apple juice concentrate used in the U.S.
Below are links to recent studies concerning this food. For a more complete list of studies, please click on apples.