Excessive Caffeine Consumption May Increase Risk of Osteoporosis

In a double-blind clinical study, researchers examined the impact of high-dose, short-term caffeine intake on renal clearance of calcium, sodium and creatinine in healthy adults.

Reuter et al. found that high doses of caffeine (800 mg) consumed over a six-hour period almost doubled the amount of calcium lost in the urine. Image credit: Sci-News.com.

Osteoporosis is a chronic, painful, and debilitating disease which makes bones less dense and more susceptible to fracture.

More common in women, it occurs when bones lose calcium and other minerals faster than the body can replace them.

The consumption of caffeine has been linked to osteoporosis, believed to be due to enhanced bone resorption as a result of increased calcium excretion in the urine.

However, the amount of calcium in the urine may not necessarily reflect the true effect of caffeine on calcium clearance.

“The emergence of an increasing ‘coffee culture’ it’s important for people to understand the impacts of what they are putting into their bodies,” said study co-author Dr. Hayley Schultz, a researcher at the University of South Australia.

“Caffeine is one of the most widely used recreational drugs in the world, with 80% of adults consuming at least one caffeinated beverage per day.”

“It’s a common stimulant, consumed by professionals, parents, shift workers, and teenagers alike to start their day and stay alert — even the military use caffeine to help combat sleepines.”

“But while coffee has its perks, it’s also important to acknowledge its fallbacks — one of them being how our kidneys handle calcium.”

In a double-blind clinical study, participants chewed caffeine or placebo gum for 5 minutes at two-hour intervals over a 6-hour treatment period (800 mg total caffeine).

While the primary research objective was to examine the impact of caffeine consumption on wakefulness and other factors, this sub-study aimed to evaluate the impact of caffeine consumption on the renal clearance of calcium.

“Our research found that people who consume 800 mg of caffeine over a typical working day will have a 77% increase in calcium in their urine, creating a potential deficiency that could impact their bones,” Dr. Schultz said.

“Understanding the long-term impacts of high caffeine consumption is especially important for higher risk groups,” added study first author Dr. Stephanie Reuter Lange, also from the University of South Australia.

“The average daily intake of caffeine is about 200 mg — roughly two cups of coffee. While drinking eight cups of coffee may seem a lot (800 mg of caffeine), there are groups who would fall into this category.”

“People at risk could include teenagers who binge-consume energy drinks are at are at risk because their bones are still developing; professional athletes who use caffeine for performance enhancement; as well as post-menopausal women who often have low blood calcium levels due to hormonal changes and lack sufficient daily dietary calcium intake.”

“Increasingly, we are also seeing high levels of caffeine among shiftworkers who need to stay alert over the night-time hours, as well as those in the military who use caffeine to combat sleep deprivation in operational settings.”

“Caffeine in moderation certainly has its pros. But understanding how excess consumption could increase the risks of a highly preventable disease such as osteoporosis, is important.”

The findings appear in the British Journal of Clinical Pharmacology.

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Stephanie E. Reuter et al. The effect of high-dose, short-term caffeine intake on the renal clearance of calcium, sodium and creatinine in healthy adults. British Journal of Clinical Pharmacology, published online April 14, 2021; doi: 10.1111/bcp.14856

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