Drinking Milk is Dangerous

December 15, 2014

Milk Consumption and the Risk of Mortality 

 Reference: British Medical Journal October 2014 

 Milk is incredibly valuable nutrition for growing humans. It helps us grow taller and stronger. That’s the conventional argument and what we are taught. It has been argued to have been a key contributor to human successful survival on planet earth. But wait, all is not well. This study is a pretty disturbing study, suggesting that milk might have a dark side not completely elucidated yet. 

The study was conducted in Sweden with 61,433 women (ages 39-74) and 48,850 men over 20 years. In that interval, 15,541 women died and 4,259 had hip fractures. Food consumption studies were done with questionaires about what had been eaten over the last year. In women, the adjusted mortality ratio for drinking three glasses of milk a day compared to less than one glass was 193% (basically double) higher.   Ouch. For every glass of extra milk a day, the extra hazard was 15% higher. Double ouch. No reduction in fracture risk was found, regardless of how much milk they drank. 

 What’s going on? Explain this one to me! Well, milk is the main dietary source of D-galactose.   The sugar, lactose, that’s in milk is a disaccharide of glucose and D-galactose. D-galactose is known to accelerate aging, and is used for that in animal studies. Even low doses of d-galactose shortens life span by inducing oxidative stress damage, chronic inflammation, neuro-degeneration, decreased immune response, and gene transcriptional changes.   The animal degenerations studies use about what you get in two glasses of milk a day for a human. The increase in oxidative stress with aging and chronic low grade inflammation are the touted mechanisms for cardiovascular disease and cancer, as well as muscle and bone loss. 

 Now, what is really interesting is that this study found lower rates of trouble with fermented milk products.   Less fractures and less mortality were both associated with yogurts and cheese.   In fermented products, the sugars are used up by the bacteria doing the fermenting.   In the study they found positive associations between milk and urine 8-iso-PGF2α, a known marker of oxidative stress, but not with fermented products.   Intake of cheese and fermented milk products is related to higher HDL cholesterol levels, less insulin resistance, and a lower risk of myocardial infarction. One glass of milk has 5 grams of galactose, far and away the highest source of galactose in our food supply. Cheese doesn’t have that much galactose, it’s fermented out. 

 It’s the positive associations of whole milk with bone trouble but not cheese or yogurt that seems to be the smoking fun identifying galactose as the enemy. Primitive folks benefited hugely from milk and had an advantage from it.   And most of what they ate was fermented “stuff” – yogurt, kefir and other mixes. 

 WWW. What will work for me? I wasn’t aware of the particularly toxic effect of galactose. Now that we can measure oxidative stress and have the ability to look at “Big Data”, we can see patterns.   I thought the effect of milk on increase fracture rate was because of its acidifying effect on your bones, forcing you to excrete calcium in an effort to balance the extra acid from the animal protein.   Maybe it’s both. Clearly, plain milk is not a health food. Cheese, yogurt, kefir? Another matter.   

 Pop Quiz

  1. Milk contains the sugar lactose which is a combination of two sugars: fructose and galactose? T or F                        Answer:   False. It’s glucose and galactose
  1. Galactose appears to stimulate inflammation and oxidation, both of which contribute to accelerated aging? T or F                   Answer:   True. That’s the nugget of this study
  1. Cheese and yogurt, both fermented products of milk, have the same bad effect? T or F Answer:             False. They actually have a beneficial effect – and don’t contain much galactose.
  1. Food frequency research is pretty reliable. T or F                       Answer:  False. That’s the conundrum of this study. It’s sure easier to do but folks' memories are notoriously inaccurate. This study tried to take that into account with several cross related strategies, but the caution remains. That makes the findings interesting, but not conclusive.
  1. With what you know now, you would encourage your kids to drink more that two glasses of milk a day? Y or N                              Answer:     Not me.