Table 1.

Overview of factors affecting development of uterine leiomyomas

Risk factors	Potential risk factors	Preventive factors
Age25 Incidence increases with age and peaks at 50 years of age	Chlamydia infection26 Potential increased risk factor. Further investigation needed	Physical activity27
Early age at menarche28	Diabetes29 Possible inverse association. Further investigation needed	Fruit and vegetable consumption30
Nulliparity31	Pelvic inflammatory disease26 Potential increased risk factor. Further investigation needed	Menopause32
African decent25 Highest incidence among African women. Similar incidence among Hispanic, Asian and Caucasian women	Vitamin D deficiency33 Increased risk proven in animal models	Increased parity34
Increased stress27 35	Use of oral contraceptives36 Studies have demonstrated conflicting data	Smoking37
Hypertension38
Obesity27
Alcohol consumption25
Red meat consumption30
Caffeine consumption30 Increased risk proven in younger women with high caffeine consumption, but not among women of all ages
Thyroid disease39