Have your parents ever told you that “an apple a day keeps the doctor away”? Well, I hope you followed their advice. Because scientists keep finding new benefits of eating apples and other fruits, including a reduced risk of cancer and an improved memory. But with over half of Canadians eating fewer than five servings of fruits and vegetables per day, it seems like the message may still not be getting through.

Did you know? Based on data from 2010, the average American consumes 9.5 pounds of apples a year.An apple a day may even work as well as cholesterol-lowering drugs when it comes to preventing heart disease. A 2012 study by researchers at Ohio State University shows that polyphenols in apples can lower levels of oxidized LDL cholesterol, the type of cholesterol that can cause inflamed arteries.

More recently, an Oxford University study of British adults over 50 found that eating an apple a day might be a more effective way of preventing death from vascular diseases than taking statins to lower cholesterol. In fact, the study found that prescribing statins would reduce annual vascular deaths by 9,400 and that prescribing an apple a day would reduce them by 8,500.

But you also have to take side effects into account. The researchers estimated that adverse side effects of statins could lead to 1,200 more cases of muscle disease and 12,300 more cases of diabetes. By contrast, “aside from distress caused by a bruised apple and the theoretical risk of identifying half a worm inside, apple-related adverse events are not widely recognised.”*

Did you know? Statins lower cholesterol levels by inhibiting an enzyme called HMG-Coa Reductase, which is involved in cholesterol synthesis in liver cells.So an apple a day can keep the doctor away! At least is can probably prevent vascular deaths about as well as statins and without any negative side-effects.

However, before telling your older friends and family to throw away their heart medication, there are limitations to the study that you need to understand. The researchers did not actually ask a sample of adults over 50 to eat an apple a day, evaluate their health outcomes, and compare them to a sample of people taking statins. Instead, the study used the PRIME comparative risk assessment model, which provides an estimate of how many deaths can be averted or delayed based on changes to diet and lifestyle (in this case, eating an apple a day).

The researchers also assumed 70% compliance, which means they took for granted that only 70% of adults who are told to eat an apple a day will actually do so. (You don’t always follow your doctor’s advice exactly, do you?) So if the real-life compliance rate were lower, the benefits of prescribing apples would probably be less impressive.

Did you know? Low-density lipoprotein (LDL) cholesterol, commonly called “bad” cholesterol, carries cholesterol from your liver to other cells in your body. Over time, it can cause clogged arteries.Furthermore, the study assumed a constant calorie intake, meaning it took for granted that the apple-eaters would cut something else from their diet rather than increasing the total number of calories they consumed. So if the apples-eaters started eating an apple a day on top of what they already ate, it is possible that eating an apple a day might actually have some negative side effects, such as weight gain.

Nevertheless, research strongly suggests that eating apples does have significant health benefits… and that your parents might actually be right! If more people followed their advice on eating fruits and vegetables, there would probably be far fewer deaths from vascular disease, among other causes.

Learn more!

Study: An Apple A Day Lowers Level of Blood Chemical Linked to Hardening of the Arteries (2012)

Ohio State University

Press release on a study suggesting that polyphenols in apples can lower levels of oxidized LDL cholesterol.

A statin a day keeps the doctor away: comparative proverb assessment modelling study (2013)

A. D. M. Briggs, A. Mizdrak, P. Scarborough, BMJ 347(f7267)

Study comparing the effect the rate of vascular death in the UK among adults over 50 prescribed either a statin or an apple a day.

Apple a day vs. statins produces similar outcomes (2013)

CBC News Health

News report on the comparative study published by Briggs, Mizdrak and Scarborough.

Research Shows Benefits Of Apple Juice On Neurotransmitter Affecting Memory (2006)

US Apple Association, Science Daily

Report on research into the positive effects of apple products on brain health.

Fruit and vegetable consumption, 5 times or more per day, by age group and sex (Percentage) (2014)

Statistics Canada

Table showing the percentage of Canadians who consume the recommended number of servings of fruit and vegetables per day.

History behind “An apple a day” (2013)

Margaret Ely, Washington Post

History of the phrase and popular associations of apples with good health.

Getting your cholesterol in check (2014)

Canadian Heart and Stroke Foundation

General introduction to blood cholesterol and its management.

Nutrition Services for Cancer Patients (2014)

Stanford Health Care

General information on the role of nutrition in cancer treatment and prevention.

Michael Ly

I'm currently a 3rd year BSc student at University of Toronto, enrolled in the specialist program in Molecular Genetics. I enjoy reading and learning about diverse fields of science, especially genetics, astronomy & psychology. I also enjoy playing sports, reading fiction novels and hanging out with friends! Science is awesome because it's all around us!

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