Somewhere along the line our idea of beauty was transformed from the shapely, buxom Hollywood actress Marilyn Monroe to the androgynous British supermodel Twiggy. Monroe, the woman idolized as a sex symbol, wore a size twelve dress. By today's standards, that would be considered chunky or even “fat.” Although Twiggy turned sixty-two in 2011, her super skinny look, which was popularized in the mid to late 1960s, continues to be idealized. Today's ultrathin models depict the “ideal beauty” in our advertisements and create a skewed definition of what is considered “normal.” Practically every woman thinks she needs to lose weight. Weight loss products and programs abound.
We come in all different colors, shapes, and sizes, and few fit these idealized pictures. Our young women are barraged with media messages that may be harmful to their body images. Preteen and underweight models portray this unrealistic image of “physical perfection.” Teenagers and young adults are especially vulnerable to feeling dissatisfied with their own bodies.
Victoria Beckham, who rose to fame in the late 1990s with the all-girl pop group the Spice Girls, was dubbed Posh Spice. She revealed in her autobiography Learning to Fly that magazine and newspaper articles labeling her “Podgy Spice” or “Fat Spice” led to her eating disorder. She wrote that those articles affected her perception of herself. She would think, “Yes, you're disgusting. Society says you've got to be thin.” Doctors and other concerned groups are calling for a stop to the promotion of unhealthy, ultrathin bodies that make eating disorders appear glamorous.
Other well-known women have let the public know about their struggles with eating disorders. The late Diana, Princess of Wales, revealed that she suffered from bulimia. Outwardly, she looked gorgeous and composed, but inside she was at war with herself. Princess Diana's decision to publicize her harrowing battle with an eating disorder resulted in a more than doubling of the number of sufferers coming forward for treatment. Doctors dubbed it the “Diana Effect.”
Pressures out of the limelight are just as great. Today, more kids are overweight than ever before. First Lady Michelle Obama chose the fight against childhood obesity as her mission. We have to be smart about how we approach the subject of weight with kids. Too many have the tendency to go to extremes, and others lose weight even if they do not need to. Advice on dieting should balance warnings about overeating with discussion of the dangers of extreme dieting.
Eating disorders cause problems with bone health that may not be reversible. A woman who was a patient advocate for osteoporosis vividly brought the long-term consequences to my attention. In front of a congressional committee, I heard this woman in her early forties give emotional testimony about the pain and suffering from four spine fractures. She had a visible hump in her upper back and looked older than her years.
She wove her story around her fractures. First one, then a second, and a third fracture drastically altered her life. She had the “million dollar” work-up to look for uncommon problems or obscure diseases. Finding none, her physicians were dumbfounded. Finally, one day she came “clean.” She confessed to her doctors that she had had anorexia since her early teens, and it had lasted over a decade. She was testifying that day and revealing her medical story in hopes of helping others avoid the pain and misery that she was experiencing.
WHO IS AT RISK?
Teenage years are the most common time for eating disorders to start. Approximately one in every two hundred adolescent girls develops anorexia nervosa. An estimated 1 to 4 percent of college-aged women have the disorder. Even larger numbers of adolescents have disordered eating without meeting the full criteria for anorexia nervosa. Teens who are underweight may escape detection because the focus of healthcare is on overweight and obese kids. Although we think of this illness as predominantly affecting girls and young women, 5 to 10 percent of all cases occur in males.
ANOREXIA IS DOUBLE TROUBLE FOR THE BONES: NUTRITION AND HORMONES
More than 90 percent of adolescents and young women with anorexia have low bone mass. Bone density may be lower not because they are actually losing bone but rather because they are missing the accrual of bone that occurs rapidly during the adolescent growth period. In as little as six months, permanent effects on bone density can develop.
Chronic caloric restrictions may occur either from failure to take in calories or from purging. Sometimes it is a combination of both. Even too much exercise may contribute. The end result is low body weight. The loss of body fat takes away the necessary building blocks for sex hormones, and menstrual periods stop (amenorrhea). Anorexics have even lower bone mass than young women with amenorrhea who are of normal weight. Poor nutrition coupled with lack of sex hormones means double trouble for bone.
Approximately 90 to 95 percent of the skeleton's foundation, called peak bone mass, is built by age eighteen. Approximately 40 to 60 percent of this peak bone mass is acquired during the adolescent years. By missing the important building blocks during this time, it is unlikely peak bone mass will be achievable. Bone mass may not be recovered at a later time even after weight is regained. An unexpectedly high rate of persistent low bone mass is reported following recovery from anorexia. Age of onset and duration of illness are the best predictors of decreased bone density.
Lower bone density leads to an increase in fracture risk in later years. Adult women with a history of anorexia lasting an average of six years have an annual fracture rate seven times greater than the fracture rate of healthy women of the same age. During the active phase of anorexia, a higher rate of fracture is also reported. Recent research shows evidence of lower bone strength in young adult women with anorexia. Therefore, less load or force on the bone, such as with a fall, is needed to cause a fracture.
Bone loss in anorexia nervosa is a result of both increased bone breakdown and reduced bone formation. Bone remodeling continues but bone formation associated with growth and bone mass accumulation is reduced. This pattern is in contrast to bone loss in postmenopausal women, which is characterized by increased bone breakdown without interference in bone formation. The amount of bone “loss” in anorexia is more than that observed in early postmenopausal women, who may lose bone rapidly with loss of estrogen.
Researchers at Children's Hospital Boston found marked increases of fat content in the bone marrow of young women with anorexia. Paradoxically, anorectic young women with no body fat have fat in their bone marrow. The bone-forming cells, osteoblasts, are made from the bone marrow's stem cells. However, these same mesenchymal stem cells can also become fat cells. Hormonal changes associated with malnutrition trigger the stem cells to become fat cells instead of osteoblasts. As a result, more fat in the bone marrow means less bone formation.
The rate of bone formation increases with increased nutrition. Therefore, bone formation may be reduced by malnutrition while lower levels of estrogen cause increased breakdown. It is probably not that simple, with a whole host of factors contributing to the bone effects. Other hormonal abnormalities associated with amenorrhea and poor nutrition may affect the bone. Elevated levels of the hormone cortisol and lower production of growth hormone and other related growth factors have also been implicated. In addition, low body weight results in less muscle strain on bone; in the absence of mechanical strain, the activity of bone breakdown cells increases and bone formation decreases.
Treatment: Food First
Psychiatrists usually lead the treatment of patients with anorexia. Multiple approaches are used to control the disorder and restore health. From the bone perspective, bone density improves with weight gain. The challenge is to achieve this goal. Some researchers find that a bone density scan can serve as a strong motivating factor for recovery. Although outwardly the patients may not see a problem, the abnormal bone density is an indisputable measure of the problem.
A common approach to increasing bone density has been the use of birth control pills or estrogen therapy. However, low-dose birth control pills may cause lower bone mass and are not useful in increasing bone density. Estrogen therapy given by pill has not helped, as shown in numerous studies. Estrogen skin patches are being investigated. However, since multiple causes contribute to bone loss, this may not be enough.
Continued poor nutrition may sabotage the effectiveness of estrogen. Estrogen does help decrease bone breakdown. However, without sufficient weight gain, new bone-building cells will not be put in motion. Bone formation is still suppressed. The key to recovering bone density is restoring bone formation. This is done by nutritional support and weight gain.
Since Forteo is the only medicine that increases bone formation, it makes sense that Forteo may be useful for treating these patients. Clinical trials are evaluating the effect of Forteo in this setting. Other researchers are using a hormone that is decreased in anorexia, called IGF-1, which is short for insulin-like growth factor. In small pilot studies, IGF-1 in combination with estrogen showed some benefit. IGF-1 did not show increases when used alone without estrogen.
The bisphosphonates, Fosamax and Actonel, have been shown to improve bone density at the spine and hip in clinical trials. They may be considered for an older woman who is past childbearing.
Of course, adequate vitamin D and calcium are important to bone health in all circumstances. The role of exercise in bone recovery is not clear. Some studies show a benefit from weight-bearing activities. However, if excessive exercise is a factor, then exercise needs to be decreased.
Some of the medicines prescribed by the psychiatrists may also impact the bone. For example, the use of antidepressants, called SSRIs, contributes to bone loss in other patients treated for depression.
The bottom line is that only nutritional recovery works. Even after restoring and maintaining normal weight and regular menstrual periods, the majority of women with a history of anorexia have low bone density. This puts them at higher risk for fractures for the rest of their lives.
Anorexia often begins with normal dieting that gradually escalates to extremes. This pattern must be identified as a problem right away. With earlier intervention, it might be possible to limit bone loss and decrease the high risk of osteoporosis in later life.
BULIMIA
Bulimia nervosa is characterized by binge eating followed by purging behaviors that are used to avoid weight gain. These may take the form of self-induced vomiting, laxative abuse, or the use of diuretics, enemas, calorie restriction, or excessive exercise. As opposed to anorexia nervosa, typical patients diagnosed with bulimia nervosa are often of normal weight. However, some 30 to 40 percent have a past history of anorexia nervosa. This history, rather than the bulimia, puts them at risk for low bone density and fractures. This is a consistent finding in multiple studies that show appropriate bone density for age in normal-weight bulimic patients without a history of anorexia. Normal levels of bone turnover markers also support this finding.
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The Bare Bones
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