By Karen Kaplan, Los Angeles Times
Got milk? If you’re drinking it to prevent bone fractures or to boost your overall health, you might want to go back to the fridge and opt for a yogurt or a slice of cheese instead.
A study in the journal BMJ casts doubt on the widely held view that milk can help adults ward off hip fractures and broken bones. After tracking more than 100,000 Swedish men and women for up to 23 years, the study authors saw no link between milk consumption and fracture risk. However, they did find that avid milk drinkers were more likely to die at younger ages than their counterparts who drank little to no milk.
The Dietary Guidelines for Americans advise everyone over the age of 8 to consume three cups of milk per day or the corresponding amount of yogurt, cheese or other dairy products. Many European countries offer similar suggestions. After all, milk is a convenient source of calcium, vitamin D and phosphorus, three nutrients that are important for bone growth.
However, the researchers — from the Uppsala University, the Karolinska Institute and the Swedish National Food Agency — wondered whether this advice was scientifically valid. No randomized clinical trials have shown that drinking milk causes the risk of fractures or premature death to fall, and observational studies that might reveal an association between milk and better health have had mixed results.
The research team cited another reason for their skepticism: D-galactose. This is produced by the body as it breaks down lactose, the sugar in milk. Studies in animals have shown that chronic exposure to the nutrient causes “oxidative stress damage, chronic inflammation, neurodegeneration, decreased immune response, and gene transcriptional changes,” they wrote. In fact, when scientists want to mimic the effects of aging, they give animals shots or food containing D-galactose.