Does drinking a lot of coffee increase the risk of bone fractures?
For most people, coffee does not appear to be a proven cause of bone fractures, but for women who drink a lot of coffee some caution is reasonable; in that case, make sure to get enough calcium and vitamin D in your diet.
A large meta-analysis of more than 500,000 participants found that the risk of hip fracture in coffee drinkers was barely different from that in people who drink little coffee. Bone density also did not differ in any measurable way. Two separate studies that used genetic variants to investigate causality -- a method that is less susceptible to confounding factors such as lifestyle -- reached the same conclusion: drinking coffee probably has no causal effect on bone density or fracture risk, in either men or women.
There is one caveat for women. One large umbrella review, a summary of multiple meta-analyses, found an association in women between high coffee consumption and an increased fracture risk. In men, that association was absent. This is a statistical association, not a proven cause-and-effect relationship. Moreover, other large analyses contradict this association in women, so the picture on this point is divided.
At the molecular level there are indications that caffeine can promote bone breakdown by influencing calcium metabolism. But in studies in humans, this mechanism does not translate in a consistent way into measurable bone loss or more fractures. Laboratory findings and what actually happens in people therefore diverge here.
Excessive coffee consumption is mentioned in several review articles as something to be mindful of when preventing osteoporosis, alongside proven risk factors such as smoking, vitamin D deficiency, and low calcium intake. Smoking was, in the genetic research, causally linked to a higher fracture risk; for coffee that was not found. No specific threshold is known above which coffee definitively becomes harmful to your bones.
Evidence based on one umbrella review (PMID 29167102), one meta-analysis of 20 studies with >500,000 participants (PMID 37374383), two Mendelian randomisation studies (PMID 31482193 and 40692555), and three narrative/mechanistic reviews (PMID 34981132, 34002830, 23871889). The causality question is most robustly answered by the genetic studies.
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.
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.
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.
How much impact does smoking have on your bone density?
Smoking substantially increases the risk of bone loss and hip fractures; quitting helps, but it takes at least ten years before your fracture risk decreases noticeably.
Do carbonated drinks damage your bones?
Regularly drinking large amounts of sugary carbonated drinks is associated with lower bone density, especially in women and during puberty. Moderate consumption appears less harmful, but it is preferable to replace soft drinks with beverages that support bone development.