Can eating disorders such as anorexia cause permanent bone damage?
Anorexia causes permanent bone damage in the majority of cases, particularly when the condition begins during adolescence. Discuss a bone assessment with your doctor if you or someone you know is affected by this.
More than 85% of women with anorexia have a bone density that is more than one standard deviation below the average for their age. Their risk of bone fractures is seven times higher than in people without anorexia. This is not a minor issue: it is one of the most serious physical complications of the condition.
The cause lies in a series of hormonal disruptions. Anorexia leads to the absence of menstruation, low growth factors, and elevated cortisol levels. Cortisol is a stress hormone that breaks down bone. All these factors together systematically hollow out bone structure.
In young people, the damage is especially severe. Bones grow most strongly during adolescence, and anorexia significantly slows that growth. As a result, teenagers with anorexia reach a lower peak bone strength than their peers, and that deficit is difficult to make up later in life.
After recovery, bone density partially improves, but full recovery does not always occur. Weight restoration and the return of menstruation are the best approaches for this. Transdermal oestrogen therapy can normalise bone development in adolescents, but does not fully close the gap. Oestrogen taken via the contraceptive pill is clearly less effective for this purpose. Bone medications such as bisphosphonates can modestly improve bone density in adult women, but are only used in severe cases because they can cause harm to an unborn child.
Even people who do not fall within the classic underweight range but have lost a significant amount of weight are at risk of similar physical complications. Bone damage is therefore not exclusively limited to the most recognisable presentation of anorexia.
All claims are based on multiple published studies (PMID 24882734, 24731664, 24898127, 28298497, 40659363, 40048192, 36508318). The level of evidence for reduced bone density and fracture risk is strong; the treatment options are moderately to limitedly supported.
Are there dietary patterns that have been proven to reduce bone fractures?
Fermented dairy, sufficient vegetables and fruit, and a varied diet with protein and calcium are best supported for bone protection, while soft drinks, alcohol and an overly narrow (vegan) diet without supplementation increase your fracture risk.
Is there a link between sleep deprivation and bone loss?
Sleep deprivation and poor sleep quality are associated with reduced bone formation and, in postmenopausal women, considerably greater bone loss. Getting enough regular sleep is therefore also relevant to your bone health.
Does being overweight affect your bone density?
Being overweight does not straightforwardly increase bone density, and the location and amount of fat strongly determine whether the skeleton benefits or is harmed. If you are considering losing weight, do so gradually and combine it with strength training to limit bone loss.
How do you prevent bone loss when losing weight at an older age?
Strength training while losing weight is the best protection against bone loss, but cannot prevent it entirely. Combine it with adequate protein intake and discuss it with your doctor if you are losing weight quickly or in large amounts.
Does diabetes increase the risk of bone fractures?
Both type 1 and type 2 diabetes clearly and demonstrably increase the risk of bone fractures. If you have diabetes, discuss with your doctor whether your bone health is being properly monitored, as the standard risk score underestimates this risk.
Does too little protein increase your risk of bone fractures as you age?
Yes, too little protein increases your risk of bone fractures in older age. This works through weaker bones as well as through poorer muscle condition. Aim for at least 1.0 to 1.2 grams of protein per kilogram of body weight per day, preferably together with adequate calcium and vitamin D.