Soda consumption remains high in the United States, and hip fractures in the elderly can impact quality of life in a major way, therefore, prevention is important. Professor Teresa Fung recently published one of the first studies on soda consumption and the increased risk of hip fractures in postmenopausal women.
What were the key findings?
Data from following a large group of postmenopausal women found that higher consumption of soda was associated with higher risk of hip fractures. Each serving increase in soda consumption was associated with 14% risk. This association didn't seem to be driven by a particular type of soda and we couldn't figure out what exactly is the mechanism. The analysis was well controlled for risk factors for osteoporosis such as body weight, physical activity, smoking and calcium intake.
Was there anything about the research that surprised or stood out to you?
The risk for hip fractures wasn't driven by a particular type of soda. We investigated, regular vs. diet, caffeinated vs. not, cola vs. non-cola, but there wasn't a particular type.
What is the mechanism by which soda might affect bone health? The fact that it's all kinds of sodas, does that undermine the mechanism argument?
Theories abound on how soda would be bad for bones. But our study was unable to narrow down to a particular mechanism because not one particular type of soda stood out as having the strongest risk. We have tried to get an idea of the mechanism by looking at diet versus non diet soda, cola versus non cola, caffeinated vs not, but nothing stood out.
Is it reasonable for the consumer to conclude that because soda is a low nutrient beverage, it is preventing women from getting the nutrients they need (in a beverage) and increase their risk of hip fractures?
In my study, we controlled for calcium intake as well as intake of other nutrients, but we still see a direct association between consumption and hip fractures. So we don't think it is because of displacement of important nutrients.
What might you recommend based on this study? Reduce your consumption of soda and drink more milk/calcium supplement at all ages?
Definitely reduce consumption of soda. Not consuming any is the best because there is no nutritive value and there are plenty of more nutritious and tasty beverages out there. Regarding calcium and vitamin D, I am not picky about what sources people get them from, be it food, beverage, fortified food/beverage, or supplements. Vitamin D is only abundant in a small number of foods (e.g. salmon, mackerel), therefore, probably more convenient to get it from fortified foods or supplement.
And then, more generally, what does this study add to what we already know about a possible connection between fracture and sodas?
There isn't a lot of studies on actual fractures as studies so far concentrated on changes in bone mineral density or biological markers of bone breakdown. However, what is most important is fracture risk. So while we can't say definitively that soda is a risk factor for hip fractures in postmenopausal women, this is a piece of data that tips the scale in that direction.