Just an old adage or are there actual health benefits? As it turns out, an apple - or Apple - holds great promises.

In 2015 in the inaugural April Fools’ Day issue JAMA Internal Medicine published a report entitled “Association Between Apple Consumption and Physician Visits: Appealing the Conventional Wisdom That an Apple a Day Keeps the Doctor Away” (JAMA Intern Med. 2015;175(5):777-783.doi:10.1001/jamainternmed.2014.5466). It is nonetheless a rigorous study based on actual nutrition data collected from nearly 8,400 people. Disappointingly, the study concludes, “Evidence does not support that an apple a day keeps the doctor away; however, the small fraction of US adults who eat an apple a day do appear to use fewer prescription medications.”

The fruity sort of apples may have failed this critical scientific test, but what about Apple Inc.?

The Apple Heart Study (AHS) was presented in a Late-Breaking Clinical Trials during the American College of Cardiology (ACC) 2019 Scientific Session in New Orleans.

In this observational study, adults armed with an Apple Watch and an iPhone model 5s or later were invited to download the AHS app and wear the iconic smartwatch as a heart-rhythm monitor. More than 400,000 did. If the watch sensed possible atrial fibrillation (AF), the participant was asked to wear an electrocardiography (ECG) patch for up to a week to confirm any arrhythmia. The trial aim was to see how effective and reliable the AHS app is at detecting atrial fibrillation.

The study sought to shed some light on the question of whether the increasingly available and popular wearable digital devices can be used as reliable screening tools - or whether they are simply not accurate enough and their use results in unnecessary concern on the part of patients with ensuing wasted medical appointments and diagnostic testing.

The technology might prove especially useful for people with asymptomatic AF who could not otherwise be offered anticoagulation, potentially preventing a catastrophic stroke.

Overall, only 0.5% of participants received irregular pulse notifications, an important finding given concerns about potential over-notification. The notifications were impressively accurate; 84% of the time, participants who received irregular pulse notifications were found to be in atrial fibrillation at the time of the notification. 57% of those who received irregular pulse notifications sought medical attention.

“The results of the Apple Heart Study highlight the potential role that innovative digital technology can play in creating more predictive and preventive health care,” said Lloyd Minor, MD, dean of the Stanford School of Medicine. “Atrial fibrillation is just the beginning, as this study opens the door to further research into wearable technologies and how they might be used to prevent disease before it strikes - a key goal of precision health.”