A study published in the American Journal of Obstetrics and Gynecology (Vol. 194, e35-e38) found women taking oral contraceptives have lower levels of the antioxidants coenzyme Q10 and vitamin E, and could possibly benefit from supplements.

“If our findings are confirmed by larger studies, women who receive oral contraceptives may be considered for coenzyme Q10 and/or alpha-tocpherol supplementation,” wrote lead author Prabhudas Palan from the Albert Einstein College of Medicine in New York.

Coenzyme Q10 and alpha-tocopherol (a form of vitamin E) are both lipid-soluble antioxidants found in cell membranes. They are capable of reducing the amount of free radicals that can lead to oxidative stress which has been linked to a variety of significant diseases such as   Alzheimer's, cardiovascular disease and cancer.

The researchers recruited 55 pre-menopausal women (average age 33) with regular menstrual cycles. 15 women were taking an oral contraceptive (OC) (norgestimate/ethinylestradiol) while the other 40 were not taking any (OC). Women already taking multivitamins or Co-Q10 supplements were excluded.

Non-fasting blood samples were taken randomly during the menstrual cycle allowing serum levels of a variety of antioxidants to be accurately measured. These showed gamma-tocopherol, alpha- and beta-carotene, and lycopene levels were similar between the groups. However, serum levels of Co-Q10 were 37 per cent lower in the OC group, and alpha-tocopherol levels were 24 per cent lower.

“The results clearly show that the use of OC significantly lowered the serum levels of coenzyme Q10 and alpha-tocopherol, compared with levels in non-OC users,” wrote the researchers, who concluded “The potential value, if any, for coenzyme Q10 and alpha-tocopherol supplementation in OC users and the effect of menstrual cycle phase on oxidative stress deserve further investigation.”