Often called a “miracle food” and a “nutritional powerhouse,” an apple a day really may keep the doctor away as they’re one of the healthiest foods a person can eat. These round and juicy fruits are high in fiber and vitamin C, and they are also low in calories, have only a trace of sodium, and no fat or cholesterol.
“Apples are high in polyphenols, which function as antioxidants,” said Laura Flores, a nutritionist based in San Diego. “These polyphenols are found in both the skin of the apples as well as in the meat, so to get the greatest amount of benefits, eat the skin of the apple.”
All of these benefits mean that apples may mitigate the effects of asthma and Alzheimer’s disease, while assisting with weight management, bone health, pulmonary function and gastrointestinal protection.
Apples are loaded with vitamin C, especially in the skins, which are also full of fiber, Flores said. Apples contain insoluble fiber, which is the type of fiber that doesn’t absorb water. It provides bulk in the intestinal tract and helps food move quickly through the digestive system, according to Medline Plus.
In addition to digestion-aiding insoluble fiber, apples have soluble fiber, such as pectin. This nutrient helps prevent cholesterol from building up in the lining of blood vessels, which, in turn, helps prevent atherosclerosis and heart disease. In a 2011 study, women who ate about 75 grams (2.6 ounces, or about one-third of a cup) of dried apples every day for six months had a 23 percent decrease in bad LDL cholesterol, said study researcher Bahram H. Arjmandi, a professor and chair of the department of nutrition at Florida State University. Additionally, the women’s levels of good HDL cholesterol increased by about 4 percent, according to the study.
When it comes to polyphenols and antioxidants, Flores explained that they “work in the cell lining to decrease oxidation resulting in lowering risk of cardiovascular disease.” A 2017 article published in Trends in Food Science & Technology adds that blood pressure may also be reduced in those with or at risk of hypertension, which also lowers the risk of cardiovascular disease. A decreased risk of Type 2 diabetes, which can also lead to cardiovascular disease, was found in a study of more than 38,000 women and was also attributed to certain polyphenols and the high-fiber content of apples.
There may be respiratory benefits to eating apples, as well. “Apples’ antioxidant benefits can help lower the risk of asthma,” Flores told Live Science. A 2017 study published in the journal Nutrients indicates that the antioxidants in a variety of fruits and vegetables, including apples, potentially decrease the risk of asthma by helping control the release of free radicals from inflamed cells in the airways and in the oxygen-rich blood coming from the heart.
“Eating apples in excess will not cause many side effects,” Flores said. “But as with anything eaten in excess, apples may contribute to weight gain.”
Furthermore, apples are acidic, and the juice may damage tooth enamel. A study published in 2011 in the Journal of Dentistry found that eating apples could be up to four times more damaging to teeth than carbonated drinks.
However, according to the lead researcher, David Bartlett, head of prosthodontics at the Dental Institute at King’s College in London, “It is not only about what we eat, but how we eat it.” Many people eat apples slowly, which increases the likelihood that acids will damage tooth enamel.
“Snacking on acidic foods throughout the day is the most damaging, while eating them at meal times is much safer,” Bartlett said in a statementfrom King’s College. “An apple a day is good, but taking all day to eat the apple can damage teeth.”
Dentists recommend cutting up apples and chewing them with the back teeth. They also recommend rinsing the mouth with water to help wash away the acid and sugars.