Wednesday November 26 2014
All women's breasts are uneven to a certain degree
"How your breast size affects your mental health: Having uneven or bigger boobs lowers self-esteem and causes eating disorders, study finds," reports the Mail Online.
But the second part of the headline, which mentions eating disorders, is both misleading and inaccurate.
The study in question, which took place in the US, looked at young females (aged 12 to 21) who had asymmetrical or abnormally large breasts (macromastia) and were attending breast clinics, comparing them with controls attending other hospital clinics.
Researchers found females in the former group tended to have lower reported self-esteem, but there was no evidence they developed eating disorders because of their breasts.
There were also no differences between their responses to questionnaires about general, physical and mental health after body mass index (BMI) was taken into account. Females with macromastia reported significantly worse physical problems and symptoms of pain, such as neck pain.
If very large breasts are causing you trouble, you may be eligible for breast reduction on the NHS. You will probably have to pay for breast reduction surgery if it is being performed for cosmetic reasons. The current cost of private surgery is around £5,000.
If you, or someone you know, are concerned about asymmetrical breasts, it's worth remembering many girls' breasts will take on a more symmetrical appearance once puberty has passed.
Where did the story come from?
The study was carried out by researchers from Boston Children's Hospital and Harvard Medical School.
It was funded by the Plastic Surgery Foundation and the authors report no conflicting financial interests.
The study was published in the peer-reviewed medical journal Plastic and Reconstructive Surgery.
The Mail Online's headline is misleading for a number of reasons:
- A case-control study can never prove cause and effect.
- After BMI was taken into account, there was no significant association between asymmetrical breasts or macromastia and disordered attitudes to eating.
- None of the participants were diagnosed with an eating disorder – they just filled out a questionnaire about their eating attitudes.
What kind of research was this?
This was a case-control study that aimed to compare the psychological, emotional and physical impact of having asymmetrical breasts or macromastia compared with having breasts within the average range.
This type of study is appropriate to look for associations, but it cannot account for all possible factors influencing the results (confounders).
The research was described as a prospective cohort study, but this involves following participants up over a period of time and monitoring changes. This study was conducted over a period of five years, but information for each participant was only collected at one time point.
What did the research involve?
Adolescents and young women aged 12 to 21 with either asymmetrical breasts or macromastia and controls were recruited to the study at Boston Children's Hospital from 2008 to 2013.
The groups were compared in terms of self-esteem, quality of life, any disordered eating, and age-adjusted BMI.
Females with asymmetrical breasts were eligible if there was at least one cup size in difference, and 59 adolescents agreed to participate. Cup size difference was measured using a standard bra that fitted the larger breast, using sizing pads on the other side until the breasts looked symmetrical.
160 females with macromastia enrolled in the study. Macromastia was defined according to Schnur criteria as overgrowth in both breasts "requiring a minimum resected amount of tissue based on the patient's body surface area". Macromastia can cause problems such as backache and neck pain.
The controls were 142 females who attended the same hospital, but did not have breast problems, an eating disorder, severe mental illness, or chronic medical or surgical problems.
They were enrolled at clinics within the Department of Plastic and Oral Surgery and the Division of Adolescent/Young Adult Medicine.
All participants completed three questionnaires:
- the 36-Item Short-Form Health Survey, which measures health-related quality of life in several domains, each rated from 0 (low) to 100 (high)
- the Rosenberg Self-Esteem Scale, ranging from 10 (poor) to 40 (good)
- the Eating Attitudes Test, with scores of 20 or more indicating disordered eating (though not necessarily an eating disorder such as anorexia nervosa or bulimia)
The control group also completed a short survey to identify if they had any concerns about their breasts their doctor was not aware of, including:
- satisfaction with their breasts
- if they were contemplating breast surgery to increase, decrease or make both breasts the same size (though none differed by a cup size)
What were the basic results?
Significantly more females with asymmetrical breasts or macromastia were overweight or obese (66.1%) compared with controls (40.1%).
After adjusting the results to take BMI into account, females with asymmetrical breasts scored significantly lower on one domain of the Short-Form 36 questionnaire: role limitations caused by emotional problems.
There were no significant differences for the rest of the domains:
- general health
- social functioning
- physical function
- physical role
- body pain
- mental health
After adjustment for BMI, females with asymmetrical breasts had lower self-esteem on the Rosenberg Self-Esteem Scale compared with controls.
Females with macromastia scored significantly lower on the following domains of the Short Form-36 than those with asymmetrical breasts after their higher average age was taken into account:
- social functioning
- physical function
- physical role
- body pain
There were no significant differences between females with macromastia or asymmetry for general health, emotional role, self-esteem or disordered eating attitudes.
A quarter of controls (32) were "so dissatisfied with the appearance or size of their breasts" that they would consider surgical intervention.
How did the researchers interpret the results?
The researchers concluded that, "Breast asymmetry may negatively impact the psychological quality of life of adolescents similar to macromastia [large breasts]."
They go on to say that, "Breast asymmetry is not just a cosmetic issue. Providers should be aware of the psychological impairments associated with asymmetry and provide proper support."
This study found young females with macromastia report lower quality of life and physical health, as well as more pain and poorer mental health than females with asymmetrical breasts or those with average breasts.
However, in this study, females with asymmetrical breasts of more than a cup size difference did report lower self-esteem.
Contrary to the media reporting, the study did not assess the impact of any treatment or surgical interventions on self-esteem, physical or mental health.
The study also did not find that females developed eating disorders because of their breasts. The researchers found women with asymmetrical breasts scored higher on a questionnaire about disordered attitudes to eating than controls, but this was no longer significant if BMI was taken into account.
In addition, none of the women with asymmetrical breasts or macromastia were reported to have an eating disorder, and the controls were not eligible for the study if they had an eating disorder.
While self-esteem was found to be lower in females with asymmetrical breasts, there were no differences between their responses to questionnaires about general, physical and mental health after BMI was taken into account. Females with macromastia reported significantly worse physical problems, pain and mental health.
A limitation of this study is the composition of the control group. They were matched to the females attending the breast clinic in terms of age, but no other features.
For example, a control group is usually matched in terms of smoking, alcohol consumption and socioeconomic status.
They were also described as "healthy" and did not have breast problems, an eating disorder, severe mental illness, or chronic medical or surgical problems, so it is not clear why they were still attending hospital outpatient clinics.
The reasons for their attendance could have a bearing on their answers to questionnaires on vitality, quality of life, and physical and mental health. In turn, this could be why very few differences were seen on these scales between females with asymmetric breasts and the controls.
If you are concerned about asymmetrical breasts of more than a cup size difference, or have symptoms such as back pain or neck pain caused by very large breasts, you can find more information on the provision of breast reduction services by the NHS.
Surgical intervention is not usually recommended for teenagers, as their breasts are still developing, so any problem with appearance or size may correct itself without the need for surgery.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.