My mother said it to me everyday before giving me my afternoon snack: “An apple a day keeps the doctor away!” she’d singsong before setting sliced apples in front of me. For those of you with currently contentious relationships with your mother, what I’m about to say could shock you: research shows that your mother really was right. Well, about nutrition mostly.

Apples have been recognized for their health benefits for centuries. In the Middle Ages arose the old English saying “Ate an apfel avore gwain to bed makes the doctor beg his bread.” “Apfel” is the German word for the firm fruit.

So what makes this saying true?

Common Sense

Most of us know that apples are low-calorie, fat-free, cholesterol free, and have heart healthful fiber. Apples also provide the added benefit of cleaning your teeth as you bite and chew them (rather like carrots and other hard vegetables and fruits).

Just make sure you pay attention to the size of your apple if you are counting calories. A super-sized American “Frankenfruit” (genetically altered) apple could have well over 100 calories. An apple with about 80 calories should be the size of a tennis ball.

What Scientists (and your mother) Know

Apples play a role in fighting cancer, coronary heart disease, obesity, and high blood pressure. Never peel an apple, that is where most of the apple’s cancer fighting antioxidants reside; not to mention the heart disease fighter, fiber. Eating an apple before each meal can help to fill you up, allowing you to eat less calories during a meal.

So now you know! It’s ok, you don’t actually have to tell your mother she was right.