by Alison Bowler

Created on: June 10, 2009   Last Updated: April 27, 2010

Smoking tobacco was at one time the sophisticated and correct thing to do. Matinee idols were all seen smoking and advertising cigarettes. We have now been made aware of the damage to our health that both smoking and passive smoking can cause. The toxic chemicals found in tobacco smoke are known to cause pulmonary diseases such as lung cancer.

Knowing that tobacco smoke can affect cell growth and cause cancer, scientists have been looking at the chemicals in tobacco to see if they can also affect the reproductive organs. This article reviews the results from three studies on the effects of smoking on semen quality.

The ideal scientific way to test for sperm damage by smoking would be to carry out a fertility test on non-smokers then encourage them to smoke so any changes in the quantity or quality of the sperms may be assessed. This type of test, however, would be against all medical ethics. Instead, comparative surveys are used. In these, matched groups of smokers and non-smokers are tested for factors that can affect male fertility. The groups are matched for age, occupation and other environmental factors that can affect sperm quality.

One of the tests commonly used in assessing male fertility is the sperm count. Parameters measured in a sperm count are volume, liquefaction, concentration of sperm per milliliter, motility of the sperm, the percentage of abnormal spermatozoa and the total number of sperm. Other studies include the measurement of male hormone levels and specialist assays designed to test the ability of sperm to penetrate and fertilize the ova.

In one such study (1), semen and blood samples were collected from 2562 men along with a filled health questionnaire. Complete data was available from 2542 men. Statistical analysis of the sperm count results showed a decrease in semen volume as well as total sperm count and sperm motility in men who smoked tobacco. Heavy smokers, within the study group, showed a 19 % decrease in sperm concentration when compared to their non-smoking counterparts. Hormone assays measuring testosterone, LH and the free testosterone/LH ratio all showed an adverse response in the smoking group.

While the numbers of sperm may be lower, another study (2) has shown that the sperm present within a semen sample from a smoker can still penetrate and, therefore, fertilize an ovum. This study did not find any difference in sperm motility between smokers and non-smokers although it confirmed that smokers have a lower sperm count.

• 1
• 2
• Next Page >>