High coffee consumption may be associated with lower bone mineral density (BMD) in older, postmenopausal women, according to a study published in the journal Nutrients. Researchers from Flinders University analyzed the coffee and tea consumption of 9,704 women aged 65 and older over a decade, measuring their BMD at the femoral neck and hip.
The study found that drinking more than five cups of coffee per day was associated with lower BMD. In contrast, tea consumption was linked to higher total hip BMD. Moderate coffee intake, defined as two to three cups daily, did not show negative effects on bone health.
Factors Influencing Bone Density
The research also identified interactions between beverage consumption and other health and lifestyle factors. Coffee consumption was associated with lower femoral neck BMD among women with higher alcohol intake. The positive association between tea and bone density was more pronounced in women with obesity.
Osteoporosis, a condition characterized by low BMD, is a significant global public health concern. According to the study, approximately one in three women and one in five men aged 50 and older worldwide experience osteoporosis-related fractures. Women are at a higher risk due to generally lower bone mass and accelerated bone loss after menopause.
In the United States, the number of adults aged 50 and older with low BMD is projected to increase, contributing to healthcare costs and long-term disability.
Understanding the Beverage Impact
Scientists investigated the relationship between coffee, tea, and bone health because dietary factors play a crucial role in preventing noncommunicable diseases and can influence bone health. Coffee and tea are among the most widely consumed beverages globally.
Compounds called catechins, abundant in tea, may promote bone formation and slow bone breakdown. Conversely, caffeine in coffee has been shown in laboratory studies to interfere with calcium absorption and bone metabolism. However, these effects can be small and potentially offset by adding milk.
Researchers emphasized that the findings do not necessitate giving up coffee or drinking excessive amounts of tea. Instead, they suggest that moderate tea consumption could support bone health, while very high coffee intake might not be ideal, particularly for women who also consume alcohol.
Dietitian Lisa Young, an adjunct professor of nutrition at New York University, advised interpreting the findings with caution. She noted that the study, which observed women over time without assigning specific beverage intakes, can only show associations, not prove causation. Limitations include variations in participants' lifestyles, a focus on bone density rather than fractures, and relatively small effects observed primarily in older women.
While moderate coffee intake appears acceptable for bone health, proven methods for protecting bone health include adequate calcium and vitamin D intake, regular physical activity, and avoiding smoking and excessive alcohol consumption. Young added that too much of any one thing is generally not beneficial for health.