1. Kick the Habit
Although we all know that smoking isn't good for you, there's yet another reason to avoid or kick the habit: decreased fertility. Both women's and men's reproductive systems appear to be affected by cigarette smoke--whether inhaled directly or as secondhand smoke. Many harmful substances found in cigarette smoke including nicotine, carbon monoxide and carcinogenic and mutagenic compounds. Panayiotis Zavos, PhD, University of Kentucky, says: "The argument against smoking holds true for anyone wishing to conceive, but it is particularly imperative for individuals (male or female) having difficulty in conceiving." (1)

In England, researchers report that smoking diminishes fertilization in women by two-thirds. A study by the University of Bristol and St. George's Hospital Medical School revealed that cotinine, the main by-product of nicotine, is a long-lasting substance that concentrates in the follicular fluid of the ovaries (2) and affects conception.

Women who smoke harmed their ovaries, according to a University of Iowa study. Cigarette smoke decreased the number of eggs a woman produces each month. This may be partially due to the higher levels of male hormones such as androgen and testosterone found in smoking women. Smoking also tends to decrease estrogen, the hormone responsible for producing fertile mucus and making the cervix more receptive to sperm (3).

Smoking also interferes with reproduction because of its effect on nutrients. For example, vitamin C levels decrease 20 to 40 percent in men who smoke one pack of cigarettes per day. When vitamin C drops, a man's sperm are not only more sluggish, but they tend to clump together. Less vitamin C also results in more abnormally formed sperm and fewer sperm overall.

A Galveston, Texas research team decided to test the effect of vitamin C supplementation on male smokers. On average, the subjects' semen contained 43 percent less ascorbic acid (vitamin C) than what is generally found in healthy young adults. However, when two of the test groups received either 200 mg or 1000 mg tablets of vitamin C each day, these levels improved within the first week. The supplemented men showed weekly recovery in sperm health. Most impressive, however, was the substantial sperm health improvement the 1,000 mg group exhibited over the men taking only 200 mg of vitamin C. Overall, the men taking more vitamin C experienced an average improvement of 40 percent in six different sperm qualities. Those taking 200 mg improved by 15 percent. There was no change in the placebo group (4).

Nicotine and its by-products can hurt reproductive tissues. If the vitamin C depleted due to smoking isn't replaced, this nutrient can't do its job and repair the damage. Of course, men should quit smoking rather than try to compensate for the harm smoking does to their reproductive systems.

2. Dump your Diet
Debates rage on about the safety and effectiveness of weight loss diets. When considering the pros and cons of dieting, you need to include fertility.

Recent evidence indicates it's not only fat, but where fat's distributed on the body that influences fertility. A Dutch research group studied 500 women who came to their clinic for artificial insemination. They discovered women whose hips were larger than their waist were more likely to get pregnant than women whose waists were wider. This abnormal fat distribution is associated with a masculizing effect on the body and may be responsible for decreased fertility. The researchers point out, however, that a woman of normal weight is more fertile than one who is either too fat or too thin (5).