Nutrition: Women have been warned that disordered eating, particularly low-fat diets, can have a serious effect on their fertility levels.
Women put themselves at risk of infertility from being underweight or overweight or if there has been a pattern of disordered eating, according to dietician Susie Langley who works at the Toronto Infertility Clinic in Toronto, Canada.
"Women's fertility is at risk also if they avoid or eliminate major food groups, if they skip meals and snacks regularly or if they smoke, take excess caffeine, alcohol or recreational drugs," warned Ms Langley, who was addressing a conference on nutrition in Dublin last week.
Ms Langley, a Canadian nutrition consultant, said that up to 30 per cent of impaired fertility was related to simple weight loss or weight-related amenorrhea - the absence of periods.
Discussing the links between low-fat diets and infertility, Ms Langley explained how cholesterol was essential for the synthesis of the female hormone, oestrogen, and the male hormone, testosterone - adequate levels of which are needed for conception to occur.
"Women who regularly eat high-fibre, low-fat, plant-based diets and no red meat have lower circulating oestrogen levels and are more likely to have irregular menstrual cycles than omnivores," she said.
From a group of 300 female infertile patients attending her clinic, Ms Langley found that 41 per cent were on a low-fat/low- cholesterol diet and 26 per cent were vegetarian. Eighty-one per cent took dietary supplements, the inappropriate use of which Ms Langley cautioned against.
Studies have shown that losing 10-15 per cent of usual body weight can decrease oestrogen and testosterone levels while losing 25 per cent of usual body weight decreases sperm production. Gaining weight to within 95 per cent of usual body weight can return hormone levels to normal.
Ms Langley recommended that dieticians assist doctors in screening for nutrition and other lifestyle factors such as highly stressful jobs that may affect fertility status. She said that for some women who were overweight or underweight, nutritional therapy could be a very cost-effective way of returning their bodies to normal levels of fertility. She also noted that hormone therapy for infertility often did not work when patients were obese.
"Weight loss should be considered as a first option for women who are infertile and overweight," she said.
Ms Langley was addressing the American Overseas Dietetics Association (AODA) conference on Prevention, Wellness and Nutrition Intervention Across the Lifespan in Dublin last Thursday and Friday. The value of nutritional screening of older people in residential care setting and the rise of type 2 diabetes in children and teenagers around the world were other topics discussed. The conference was attended by dieticians from more than 28 countries.
See www.eatrightoverseas.org
