Sperm Boosters: Fact or Fiction?
In the last ten years or so in the U.S., we have seen an explosion in the number of over-the-counter dietary supplements for all manner of ailments as well as for the promotion of general health. Some are vitamins with well-known beneficial properties. Some are herbal supplements with a history of traditional Chinese medicine yet with little in the way of Western scientific studies to substantiate their use. Many other supplements contain elements and substances with very little known benefit. Now there are several preparations being marketed to promote fertility. In this article, I chose to review three of the major products being actively marketed for the purposes of improving sperm. The oldest supplement is . ProXeed is a citrus-flavored powder and can be dissolved in juice or other cold beverages. It is recommended by the manufacturer to be taken twice a day. The active ingredients in Proxeed are L-carnitine, L-acetyl carnitine and fructose. The cost is approximately $335.00 per 3-month supply. Fertile One® is a pill that contains L-carnitine, anti-oxidant vitamins (ferulic acid, vitamins C and E, garlic, co-enzyme Q10 and selenium), ginseng root, zinc and B-complex vitamins (B-6, B-12, B-9 and folic acid). Cost is approximately $273.00 per 3-month supply. FertilityBlend® for Men is a supplement containing L-carnitine, ferulic acid, vitamins E, B6, B12, and the elements selenium and zinc. The cost is only about $80.00 per 3-month supply. Several studies have shown that the amino acid L-carnitine may promote sperm development. In a recent clinical trial1, 102 men with low sperm motility were treated with L-carnitine and acetyl L-carnitine. There was a significant correlation between higher levels of carnitine in the seminal (sperm) fluid and better sperm concentration, total sperm count, sperm total motility, rapid forward progression, live sperm count, membrane function, nuclear DNA integrity, capacity for cervical mucus penetration, linearity of spermatic movement, and amplitude of lateral sperm head movement after 3 and 6 months of L-carnitine/acetyl L-carnitine treatment. Another high quality study, a randomized, placebo-controlled trial of L-carnitine and acetyl L-carnitine showed that after 6 months of treatment increases were seen in all sperm parameters and the most significant improvement in sperm motility was present in patients who had lower initial absolute values of motile sperm (<4 million forward or <5 million total motile spermatozoa per ejaculate)2. There are no published randomized controlled trials looking at pregnancy rates on L-carnitine. Several studies on the B Vitamins have been published showing anti-oxidant effects and virtually all find some benefit to the addition of this group to a daily vitamin regimen. Ferulic acid is found in various medicinal herbs, has recently been shown to scavenge oxygen free radicals and increase the intracellular cAMP and cGMP (energy molecules). The only published article on ferulic acid involved adding this substance to previously ejaculated sperm specimens where it was shown to improve sperm motility3. A medline search did not reveal any studies on sperm after ingestion of ferulic acid. It is interesting that Fertile One® contains garlic; at least one study has reported an inhibitory effect on garlic on sperm motility and survival in human and mouse sperm4 and crude extracts of garlic bulbs have been shown to immobilize ram sperm and are being investigated as a potential male contraceptive5. Selenium is a trace mineral that is incorporated into several anti-oxidant proteins. It has been shown to improve human sperm parameters6 and fertility improved slightly when selenium-deficient mice were treated with it 7. What is not clear is whether most men with a normal diet would be selenium-deficient. Folic acid supplementation may also be beneficial, especially for men who smoke Cigarettes8. Treatment of men with folic acid and 5 mg zinc improved sperm counts by 60% and also improved morphology (shape)9. Vitamin E has also been shown to improve sperm parameters and sperm-egg binding10. Co-enzyme Q10 has been shown in one small uncontrolled study to improve sperm motility in males11 but studies of men with a varicocele (dilated scrotal veins) suggest that high levels of seminal fluid Co-enzyme Q10 are found with men with the lowest sperm motility, suggesting that Co-enzyme Q10 would not be beneficial for men with a varicocele12. Considering all these studies, there does seem to be a beneficial role for dietary supplementation for men with low sperm counts and low motility. The supplement marketed as FertilityBlend® for Men has almost all of the most well studied ingredients and is considerably less expensive than the others. Avoidance of garlic extracts and further supplementation with folic acid may also be beneficial. -- Carolyn Givens, MD References: 1. Correlation between seminal carnitine and functional spermatozoal characteristics in men with semen dysfunction of various origins. De Rosa M, Boggia B, Amalfi B, Zarrilli S, Vita A, Colao A, Lombardi G. Drugs R D. 2005;6(1):1-9. 2. A placebo-controlled double-blind randomized trial of the use of combined l-carnitine and l-acetyl-carnitine treatment in men with asthenozoospermia. Lenzi A, Sgro P, Salacone P, Paoli D, Gilio B, Lombardo F, Santulli M, Agarwal A, Gandini L. Fertil Steril. 2004 Jun;81(6):1578-84. 3. Effects of ferulic acid on fertile and asthenozoospermic infertile human sperm motility, viability, lipid peroxidation, and cyclic nucleotides. Zheng RL, Zhang H. Free Radic Biol Med. 1997;22(4):581-6. 4. Spermicidal effect in vitro by the active principle of garlic. Qian YX, Shen PJ, Xu RY, Liu GM, Yang HQ, Lu YS, Sun P, Zhang RW, Qi LM, Lu QH. Contraception. 1986 Sep;34(3):295-302. 5. Sperm immobilization activity of Allium sativum L. and other plant extracts. Chakrabarti K, Pal S, Bhattacharyya AK. Asian J Androl. 2003 Sep;5(3):230. 6. Male fertility is linked to the selenoprotein phospholipid hydroperoxide glutathione peroxidase. Foresta C, Flohe L, Garolla A, Roveri A, Ursini F, Maiorino M. Biol Reprod. 2002 Sep;67(3):967-71. 7. Sperm oxidative stress and the effect of an oral vitamin E and selenium supplement on semen quality in infertile men. Keskes-Ammar L, Feki-Chakroun N, Rebai T, Sahnoun Z, Ghozzi H, Hammami S, Zghal K, Fki H, Damak J, Bahloul A. Arch Androl. 2003 Mar-Apr;49(2):83-94. 8. Low seminal plasma folate concentrations are associated with low sperm density and count in male smokers and nonsmokers. Wallock LM, Tamura T, Mayr CA, Johnston KE, Ames BN, Jacob RA. Fertil Steril. 2001 Feb;75(2):252-9. 9. Effects of folic acid and zinc sulfate on male factor subfertility: a double-blind, randomized, placebo-controlled trial. Wong WY, Merkus HM, Thomas CM, Menkveld R, Zielhuis GA, Steegers-Theunissen RP. Fertil Steril. 2002 Mar;77(3):491-8. 10. A double-blind randomized placebo cross-over controlled trial using the antioxidant vitamin E to treat reactive oxygen species associated male infertility. Kessopoulou E, Powers HJ, Sharma KK, Pearson MJ, Russell JM, Cooke ID, Barratt CL. Fertil Steril. 1995 Oct;64(4):825-31. 11. Coenzyme Q(10) supplementation in infertile men with idiopathic asthenozoospermia: an open, uncontrolled pilot study. Balercia G, Mosca F, Mantero F, Boscaro M, Mancini A, Ricciardo-Lamonica G, Littarru G. Fertil Steril. 2004 Jan;81(1):93-8. 12. Coenzyme Q10: another biochemical alteration linked to infertility in varicocele patients? Mancini A, Milardi D, Conte G, Bianchi A, Balercia G, De Marinis L, Littarru GP. Metabolism. 2003 Apr;52(4):402-