Welcome to Straight Talk on Health. I’m your host Dr. Chet Zelasko. Straight Talk on Health is a joint production with WGVU in Grand Rapids MI. I examine the practical application of health information. Nutrition. Exercise. Diet. Supplementation. I look at the science behind them, and let you know whether it’s something to consider or not. You can check out other things that I do on my website Drchet.com and sign up for my free emails.
One of the questions I’ve been asked over the years is this: does drinking soda or other carbonated beverages cause a loss of calcium from bones? The question goes in peaks and valleys. When energy drinks first appeared, that peaked interest but it subsided. Today, there are more types of carbonated drinks from just about any flavor you can think of as well as an increase in alcoholic drinks that are pre-mixed with the alcohol, flavors, and carbonation already present. On top of that, there is the increase in microbreweries that contain every kind of flavor one can imagine. I mean, really, a maple-flavored lager? Let’s take a look at what research there is to dispute or support the concept of carbonated drinks impacting bone health.
The statement “drinking soda leaches calcium from bones” has been examined the most in several types of research. Studies in rodents, children, and adults seem to indicate that animals or humans that drink soda may have lower bone mineral content and more fractures. The problem is that whether it’s animals or humans, drinking soda pop impacts what other liquids are consumed – even in rodents. When given the choice between sugary soda drinks and water, mice and rats choose the sugary soda. The complicating factor is that people who drink more soda have less calcium intake. Is there any research to support that observation?
It turns out that the role soda and carbonation plays in bone health has been studied for over 30 years. Researchers examined high carbonated beverage intake in a group of women and found no differences in serum or urinary markers of calcium metabolism . In a study on adult women, urinary calcium was increased —that means it was lost—after drinking carbonated beverages. But get this, the same happened with milk consumption. However, the calcium immediately lost in urine is compensated for later with a decreased excretion of calcium leading researchers to conclude that there is no effect on long term calcium balance.
What is a concern is the displacement of calcium from milk with carbonated beverages. As far back as 1994, researchers found an increase in teenage girls who consumed carbonated beverages instead of other drinks that contain calcium like milk. They concluded that it was the reduction in calcium intake that was problematic, not the carbonation. In a recent study, researchers discovered that calcium intake was decreased over a 5-year time beginning at the start of high school. During the transition from teenager to young adult, calcium intake declined over 150 mg per day in both boys and girls. The research tends to indicate that it’s not what young adults are eating or drinking that’s the problem. It’s what they’re not. That was before the current trends in the new types of energy and other drinks. Unfortunately, the trend continues based on more recently published studies. Girls and young women are still using carbonated drinks without calcium that may put them at risk for osteoporosis.
Could the risk be greater for older women who may have already experienced bone loss? I couldn’t find research to confirm or dispute it. In a meta-analysis published in 2021, sugar-sweetened drinks of all types were associated with significant bone mineral loss. Carbonated beverages were not found to significantly contribute to bone loss.
In probably the best study on humans to date, researchers from Framingham MA are doing a community-based research project on osteoporosis. Bone mineral density or bone mineral content is a measure of the thickness of a person’s bones. In a study that included over 2500 subjects, consumption of all types of carbonated beverages was not associated with decreases in bone mineral density in either men or women with one exception: cola did show small decreases in bone density. There was no real explanation for the differences between non-cola sodas and cola’s in that study. Other research has identified phosphoric acid and caffeine as potential contributors to bone loss. Phosphoric acid is used to flavor colas. It adds color and has a tart flavor. So if you really want to eliminate one potential source of bone loss, don’t drink colas and stick to other non-cola flavors.
In a recent review paper that examined all manner of factors associated with bone loss, reviewers identified lifestyle choices in childhood and adolescence such as minimal physical activity, excessive caffeine or carbonated beverages intake, malnutrition, cigarette use, or high alcohol consumption and other factors like environmental pollutants as factors that can impact bone health and accelerate the bone loss process.
But the real confounder is exercise. Wolfe’s Law of Bone can be summarized in three words: function determines structure. There has been little quality research on soda, cola drinkers, and exercise on bone mineral content. From research on children and adults, we know that soda drinkers tend to be more sedentary. So the question is would regular physical activity modify what has been observed in the studies on soda drinkers done to date? We don’t know because not enough research has been done.
One more thing: beer and other alcohol intake. For that, we have to go back to another paper based on the Framingham Study I mentioned earlier. They examined the alcohol intake of men and women and BMC. Men tended to drink more beer while women preferred wine. Men that drank two servings of beer or less per day had higher BMC while more than 2 servings was associated with a decrease in BMC. For women, fewer than two servings of alcohol or wine per day was also associated with an increase in BMC. The difference was that greater than two servings of alcohol per day did not result in a loss of BD like it did in men. There has been limited research since then to elaborate on other factors that may be bone protective. It doesn’t mean any adult should increase their alcohol intake or begin drinking if they don’t. It’s just another open question left to be studied at some point.
So where does this leave you on whether or not you should drink soda and all the new carbonated beverages with or without alcohol? We don’t have the definitive answers yet and at the rate this type of research progresses, we may never have it. I think a conservative approach is the correct one. Don’t overconsume any soda containing beverages with or without alcohol and make sure you perform weight bearing exercise every day. As someone who has osteoporosis due to radiation for prostate cancer, that’s what my approach is. If you do those things, soda or other carbonated beverages will more than likely have a limited impact on your bones or anything else. Eat less. Eat better. Move more.
Let me leave you with some words of wisdom found in the lyrics of a song that was in a BBC program Paula and I watched. “I’d rather remember memories then dreams.” Think about it for a while. Being closer to the end of my life—not anytime soon I hope—I’d rather be thinking about the memories I’ve created than remembering the things I didn’t get done.
That’s all the time I have for this episode. If you like this podcast, please hit the share button and tell your friends and colleagues about it. Until next time, this is Dr. Chet Zelasko saying health is a choice. Choose wisely today and every day.
——
Am J Clin Nutr. 2001 Sep;74(3):343-7.doi:10.1093/ajcn/74.3.343.
Am J Clin Nutr, 2002https://doi.org/10.1093/ajcn/84.4.936
Curr Dev Nutr. 2023 Oct 18;7(11):102020. doi: 10.1016/j.cdnut.2023.102020
Nutr J 20, 41 (2021). https://doi.org/10.1186/s12937-021-00698-1
Am J Clin Nutr. 2009 Apr;89(4):1188-96.doi: 10.3945/ajcn.2008.26765.
