Yes, it's not a myth, "An apple a day keeps the doctor away."
A nationally recognized nutritionist and researcher "Margaret A. Sitton professor, maintains that apples are a "miracle fruit," with lots of fiber. Studies have shown that pectin and polyphenols in apples improve lipid metabolism and lower the production of pro-inflammatory molecules. According to Bahram H. Arjmandi, Ph.D., a registered dietician and chair of the Department of Nutrition, Food and Exercise Sciences of Florida State University reported there is truth. Arjmandi's surprising results that women who ate apples for six months experienced a 23 percent decrease in bad cholesterol LDL. "An apple a day" showed lower levels of C-reactive protein (helps with inflammation in the body). Add an apple to your diet daily - it's not only delicious, it's full of nutrition.
Source: Federation of American Societies for Experimental Biology