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Apples and health: Separating myth from science
The age-old adage "an apple a day keeps the doctor away" has persisted for over a century, but does science support the claim? With nearly 100 million tonnes produced globally each year, apples are a dietary staple. Researchers have examined whether their nutrients deliver outsized health benefits compared to other fruits.
Nutritional profile of apples
Apples contain a variety of compounds linked to health benefits. They are rich in phytochemicals like flavanols, which may help maintain a healthy weight and reduce heart disease risk. Polyphenols, including anthocyanins (responsible for red apple skin) and phloridzin, are associated with improved heart health and blood glucose control.
Fibre, particularly pectin, is another key component. Pectin lowers unhealthy LDL cholesterol and stabilises blood sugar by reducing sugar and fat absorption from food. These nutrients have been tied to reduced risks of type 2 diabetes, lower cholesterol, and even certain cancers.
Health benefits: What does the research say?
A 2017 review of five studies found that apple consumption was linked to an 18% lower risk of developing type 2 diabetes. Another 2022 review of 18 studies showed that eating apples or apple-derived products for over a week could reduce cholesterol levels.
Apples are also a significant source of phenolic compounds, which account for about 20% of the total phenolic intake in the average U.S. diet. These compounds are associated with lower risks of heart disease, cancer, asthma, diabetes, and obesity.
"Apples don't have much vitamin C, and they have no iron or calcium, but they have so many other ingredients that promote health and do wonderful things for the body."
Janet Colson, Professor of Nutrition and Food Science, Middle Tennessee State University
The "apple a day" study
A 2015 study analysed dietary data from nearly 9,000 people to test the adage. While apple-eaters were less likely to visit the doctor, the result wasn't statistically significant after accounting for factors like education and smoking habits. However, daily apple consumers were significantly less likely to rely on prescription medications.
"The main finding, that there isn't much of an association between people who regularly consume an apple a day and the likelihood of visiting a physician, is because it's complex. People who consume apples, based on our analyses, are healthier in general."
Matthew Davis, Adjunct Associate Professor of Epidemiology, Dartmouth Geisel School of Medicine
The study suggested a revised adage: "An apple a day keeps the pharmacist away."
How many apples are enough?
Some studies suggest that eating more than one apple daily may be necessary for measurable benefits. A 2020 study with 40 participants found that eating two apples per day for eight weeks significantly lowered cholesterol levels in those with mildly elevated cholesterol. Another study showed that three apples daily led to weight loss and improved blood glucose levels in overweight women.
Maximising apple benefits
To get the most out of apples, experts recommend eating them with the skin on, as it contains the highest concentration of polyphenols. Flavia Guzzo, Associate Professor of Plant Biology at the University of Verona, also advises choosing ancient apple varieties over modern ones, as they tend to be richer in polyphenols.
"We should eat the peel of apples, as this is where most of the apple's polyphenols can be found."
Flavia Guzzo, Associate Professor of Plant Biology, University of Verona
Guzzo's 2021 research found that the Pom Prussian apple, an ancient variety from northern Italy, had higher polyphenol content than modern varieties. She noted that breeding for traits like size and sweetness often reduces polyphenol levels, as some of these compounds can impart a bitter taste.
The bigger picture
While apples offer health benefits, experts agree that no single food can replace a balanced diet. The adage likely reflects the broader principle of eating plant-based foods regularly. Apples are a practical choice due to their availability, affordability, and long shelf life.
"Eating an apple a day is great, but only if that is part of a diet rich in various other plant-based foods, since that is a key driver of good health."
Flavia Guzzo
Ultimately, apples may not single-handedly keep the doctor away, but they can contribute to overall health-especially when combined with other nutritious foods.
