NEW YORK, Jan 21 (Reuters Health) -- An analysis of over 50 years of data
suggests that the incidence of anorexia nervosa continues to rise among young
females.
Researchers at the Mayo Clinic looked at rates of the disease among
residents of Rochester, Minnesota, between 1935 and 1989. They found that while
the rate has stabilized among females in general, it has risen steadily among
females aged 15 to 24 years since the 1930s.
"This is the age group most vulnerable to social and psychological
pressures," explain lead investigator Dr. Alexander Lucas of the Mayo Clinic in
Rochester, Minnesota, and colleagues. "Most authorities agree that the cultural
ethos to be thin has contributed strongly to this trend." The condition remains
relatively rare in men.
The study findings were published in a recent issue of the International
Journal of Eating Disorders.
People with anorexia nervosa develop a distorted body image and starve
themselves to dangerously thin weights. In extreme cases, the disease can cause
serious metabolic and endocrine changes, as well as death.
The researchers reviewed 2,806 medical records of people who were
diagnosed with anorexia nervosa as well as bulimia, eating disorder, and
amenorrhea (cessation of menstruation often due to loss of body fat). These
diagnoses can also signal anorexia.
Data showed that for all females, the rate of anorexia nervosa declined
between 1985-1989 from rates observed between 1980-1984. The authors attribute
this decline to "short-term variation rather than a reversal of the upward trend
since 1950."
Among males and females, incidence rates were highest between the ages of
15 and 19 years. A rise was also noted among 10- to 14-year-old females for each
decade since the 1950s.
However, "in the most vulnerable group, 15- to 24-year-old females, a
continual rise in incidence was observed throughout the 55 years of the study,"
Lucas and colleagues note.
The investigators found a rapid rise in rates of anorexia nervosa between
1970 and 1984 which has not been sustained, possibly due to an increase of
bulimia nervosa.
Bulimia nervosa is characterized by bingeing on extremely large quantities
of food and then purging the food by vomiting or with laxatives.
