Researchers led by Professor Karl Michaelsson of Uppsala University in Sweden found that the high levels of lactose and galactose sugar in milk mean the drink in large quantities could have a negative effect. Up till now a diet rich in dairy products, milk included, was thought to reduce the possibility of osteoporotic fractures. It was earlier recommended by the United States Department of Agriculture (USDA) that a daily dose of 3 cups of dairy are good for health and improvement of bone mass. 3 to 4 glasses of milk per day were also suggested to cut at least 20 % of health care costs linked to osteoporosis.
“Our results may question the validity of recommendations to consume high amounts of milk to prevent fragility fractures,” said lead researher Karl MichaAlsson from Uppsala University in Sweden. The researchers set out to examine whether high milk intake may increase oxidative stress, which, in turn, affects the risk of mortality and fracture.
Two large groups of 61,433 women (aged 39-74 years in 1987-1990) and 45,339 men (aged 45-79 years in 1997) in Sweden completed food frequency questionnaires for 96 common foods including milk, yoghurt and cheese. Women were tracked for an average of 20 years, during which time 15,541 died and 17,252 had a fracture.
Furthermore, women who drank more than three glasses of milk a day had a higher risk of death than women who drank less than one glass of milk a day. Men were tracked for an average of 11 years, during which time 10,112 died and 5,066 had a fracture.
Men were tracked for an average of 11 years, during which time 10,112 died and 5,066 had a fracture. Men also had a higher risk of death with higher milk consumption, although this was less pronounced than in women.
There is a bit of hope for dairy lovers, though. Although higher consumption of milk was found to be associated with negative health consequences, a high intake of fermented milk products with low lactose content, such as cheese and yogurt, was found to lower the risk of bone fracture and death. This observation was especially prominent for women.
“As milk consumption may rise globally with economic development and increasing consumption of animal source foods, the role of milk and mortality needs to be established definitively now,” said lead researcher Karl Michaëlsson.