The Science Behind an Apple a Day

The Science Behind an Apple a Day

Nancy A. Palermo MD

Everyone knows the saying,” An apple a day keeps the doctor away.”

While this cliché may not be entirely true, there is enough evidence that apples have nutritional value to be considered health-promoting food. Current research into the power of food shows there are real reasons this powerful fruit might just reduce your doctor’s visits.

Apples are nutritional powerhouses.

Providing 4 gm of fiber, Vitamin C, and K, but more importantly, one apple can provide 22% of the phenolic antioxidants. Antioxidants are compounds that help to neutralize free radicals in the body, which can lead to tissue damage. Getting sufficient antioxidants is associated with a reduction in cancer cell proliferation, a reduction in damage to our DNA, a reduction in lipid oxidation, and a reduction in cholesterol, leading to a reduction in cancer and heart disease.

One medium-sized apple contains less than 100 calories and up to 4 gm of fiber.

The fiber provided in an apple has been shown to aid in digestion and bind to fats and sugars in the digestive tract, helping to reduce their absorption. This explains why apple intake has been associated with a reduction in heart disease and diabetes.

Apples contain four significant antioxidants:

• Catechin
• Phlorizin
• Chlorogenic acid
• Quercetin.

Quercetin has received a lot of attention during this pandemic because of its ability to regulate the immune system and specifically in its ability to stabilize the inflammasome in its reaction to the COVID-19 virus. Quercetin also reduces symptoms associated with allergies and asthma. It is felt that this can be done by stabilizing mast cells responsible for releasing histamine in an allergic response. A study in the Journal of Clinical Nutrition looked at over 1600 patients with allergies and asthma in Australia. They found that when individuals consumed at least 2 apples a week, they reduced asthma incidents and overall allergy symptoms. Just think what an apple a day could do for these allergy sufferers.

Apples and pears also contain a substance called pectin.

Pectin is an excellent prebiotic source. Prebiotics are food for your good bacteria. Prebiotics, like pectin, are especially important because they allow your good gut bacteria to make short-chain fatty acids (SCFAs) like butyrate and propionate. Butyrate has been proven to reduce inflammation and to provide energy for gut mucosal cells in the large intestine. Propionate has also been shown to reduce systemic inflammation but has more recently been shown to reduce visceral fat. Did you get that? Yes, this powerful SCFA reduces the fat around your middle and especially around your organs. This is the most dangerous form of fat collection. Pectin is also a natural soluble fiber and can provide a mild laxative effect. Pectin can help to bind fats, sugars and even toxins in the gut help to reduce absorption and to increase removal.

Apples can be kept in the refrigerator for weeks, so it is easy to drop by your local farmers market and pick up a bushel.

Shopping locally is key to avoiding the problems with conventionally grown apples.

The Environmental Working Group ranks apples high on their Dirty Dozen list, so it is very important to buy organic to avoid exposure to heavy pesticides. Wash the fruit well and keep the peels on to benefit from concentrated phytonutrients in the skin. Remember, peeling and juicing apples remove these benefits.  There are many varieties of apples, so it is easy to experiment with the different flavors, from tart (Granny Smith) to sweet and crisp (Gala/Golden Delicious).

While eating an apple a day cannot promise avoidance of the doctor, it can offer a tasteful way to get in vitamins, fiber, and phytonutrients. Fall is the best time to enjoy this fruit, and hopefully, some of our tasty recipes will motivate you to visit the local farmers market and pick up a bushel.