Women who drank more than three glasses of milk a day were actually found to be more likely to break bones than those who drank less.
Milk had been recommended for years as a good source of bone-strengthening calcium, but studies that looked into the link between milk and fewer fractures had conflicting results.
The research, conducted in Sweden, examined the dietary habits of more than 60,000 women between 1987-1990 and 45,000 men in 1997 as well as their general health for years afterwards.
Participants were asked about how frequently they consumed common foods such as milk, yoghurt, and cheese over a year period. The study’s authors then tracked down how many of these participants developed fractures and died in the years afterwards.
Twenty years on, the women monitored who drank more than three glasses, or 680ml, of milk a day were more likely to develop fractures than those who consumed less milk. They also had a higher risk of death too.
Men surveyed showed a similar, but less pronounced, trend, 11 years after the initial survey.
Conversely, those who consumed high levels of fermented milk products such as yoghurt had a lower risk of fractures.
Scientists believe their findings could support the notion that the reason for the difference in findings could be due to the sugars found in milk – which have also been shown to accelerate ageing.
“Our results may question the validity of recommendations to consume high amounts of milk to prevent fragility fractures,” Prof Karl Michaelsson, lead researcher at Uppsala University, said
“The results should, however, be interpreted cautiously given the observational design of our study.”
The researchers cautioned that their work only suggested a trend and should not be interpreted as proof that high milk consumption caused fractures.
Factors such as alcohol and weight were likely to play a role, they said.