According to a new study published in the peer-reviewed Nutrients journal, researchers at Flinders University have uncovered evidence that suggests a connection between negative changes in bone mineral density (BMD) and excessive drinking of coffee in older women. Additionally, the researchers have found that, on the contrary, drinking tea may provide positive effects on BMD.
To set the stage for this study, one of the concerns with a worsening BMD is due to it being an important measure used to assess risk of osteoporosis — a major health problem across the world that affects roughly one in three women aged 50 and above, and is responsible for millions of bone fractures yearly. Women in particular are of higher risk due to having generally lower base bone mass and accelerated bone loss after menopause. As a result of the fact that billions of people around the world drink coffee daily, even little effects on bone health could mean important implications. While previous research on the subject between the connection of coffee and bone health has produced mixed findings, relatively little has followed subjects for as long as this recent one has.
Speaking of, this most recent study was conducted by following 9,704 women aged 65 and older over a 10-year period who drank coffee and tea to see what effects they would have over a prolonged period of time. During the decade, the women would regularly report to the researchers the amounts of coffee and tea they consumed, and the researchers themselves would use data from the Study of Osteoporotic Fractures as well as advanced imaging methods to monitor changes in the bone density of participants.
What the researchers found was that the women who drank tea had a slightly higher total hip BMD than the ones who didn’t — a small but statistically significant difference that may matter across larger populations. Coffee, on the other hand, demonstrated a more complicated yet potentially converse effect of the tea. While those who consumed about two to three cups a day showed no association with harm to bone health, those drinking more than five daily demonstrated lower BMD — drawing a possible connection between excessive coffee consumption and adverse effects to bone density. Additionally, negative healthstyle factors such as a higher lifetime alcohol consumption presented greater, negative BMD effects — opposite of women with obesity who experienced more pronounced apparent benefits suggested by tea.
Reflecting upon the study, co-author Ryan Liu of Flinders University suggested that compounds called catechines found abundantly in tea could be the culprit for promoting bone formation and slower bone breakdown, while “coffee’s caffeine content, by contrast, has been shown in laboratory studies to interfere with calcium absorption and bone metabolism, though these effects are small and can be offset by adding milk.” He would additionally note that “our results don’t mean you need to give up coffee or start drinking tea by the gallon, but they do suggest that moderate tea consumption could be one simple way to support bone health, and that very high coffee intake might not be ideal, especially for women who drink alcohol.”
On the other side of it, Adjunct Associate Professor Enwu Liu added that the findings of the study suggest that regular consumption of tea may offer a simple and accessible way to support bone health for later in life, focusing on the potential positive effects this study may indicate over the more negative, extreme cases of coffee consumption in excessive settings.
