A decade-long study by Flinders University shed new light on two most frequently consumed drinks; tea and coffee and their impact on bone health among women.
The study published in the Journal Nutrients, monitored nearly 10,000 women aged 65 and older for ten years to examine whether regularly drinking coffee or tea was connected to changes in bone mineral density BMD-a central marker used to assess osteoporosis risk.
Osteoporosis affects one in three women over 50 and leads to millions of fractures every year, making bone health an important global issue.
Because coffee and tea are part of daily routines for billions of people, researchers note that understanding their long-term effects on bones is essential.
Moreover, the researchers used information from the study of Osteoporosis Fractures drawing on repeated measures of beverage intake and BMD at the fracture-prone hip and femoral neck.
Throughout the 10-year period, participants regularly reported how much coffee and tea they consumed, while at the same time, their bone density was also assessed using advanced imaging tools.
Results showed that women who drank tea had slightly higher total hip BMD than those who did not.
Although the improvement was small, it was statistically significant and may matter when considering the health of a large population.
Assistant Associate Professor Enwu Liu from the College of Medicine and Public Health expressed, “Even small improvements in bone density can translate into fewer fractures across large groups.”
Researchers found that tea drinkers had slightly stronger bones, while moderate coffee drinking caused no harm.
The research also found that heavy coffee intake over five cups a day was linked to lower bone density, especially in women who consumed more alcohol.
Women with higher lifetime alcohol intake appeared particularly vulnerable to coffee's negative effects, whereas tea showed stronger benefits in women with obesity.
"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," says Ryan Liu from Flinders University.
Ryan Liu, co-author of the study, concluded that Tea’s benefits may stem from catechins that support bone formation.
The researchers say small daily habits could make meaningful difference over time.
Assistant Associate Professor Enwu Liu notes that the research suggests drinking tea daily may be an easy way to support bone health as people grow older.
"While moderate coffee drinking appears safe, very high consumption may not be ideal, especially for women who drink alcohol,” added Enwu Liu.
The study Longitudinal Association of Coffee and Tea Consumption with Bone Mineral Density in Older Women: A 10-Year Repeated-Measures Analysis in the Study of Osteoporotic Fractures was published in the research journal Nutrients.
