Dr. Jorge E. Chavarro, MD, and his colleagues examined the correlation between carbohydrate intake and semen quality using data from 189 male test subjects, between the ages of 18 and 22 years. The researchers concluded that higher carbohydrate intake lowered sperm concemtration and motility in the test subjects.
Another study at the Harvard School of Public Health was spearheaded by Dr. Myriam Afeiche, PhD. She also assembled a pool of 189 men and concluded that the consumption of full-fat dairy could impair sperm quality in men. Higher full-fat dairy intake was associated with decreased sperm concentration and lower motility.