Good old apples are a fantastic dietary staple for lots of reasons. Apples lower the risk of diabetes by helping to regulate blood sugar levels. They contain an average of 5 grams of fiber, which can lower cholesterol. And apples also contain a substance called quercetin which is known to lower blood pressure.
They are also a reliable source of vitamin C, potassium, and antioxidants. However, apples do appear on the Dirty Dozen list for pesticide residue, so organic is best if you can afford it.