Friday, July 07, 2006

Milk - It Does a Body Good?

MSNBC reported on a study published in the July issue of Diabetes Care - A prospective study of dairy intake and the risk of type 2 diabetes in women conducted by researchers at UCLA.

The article, Low-fat dairy may lower women’s diabetes risk, opens with "A diet that includes lots of low-fat dairy products may lower the risk of type 2 diabetes in women, new research suggests," and continues with details of the just published study where researchers "looked for the relationship between type 2 diabetes and dietary levels of dairy foods and calcium in 37,183 women in the Women’s Health Study. A total of 1,603 women developed diabetes during an average follow-up of 10 years."

The lead researcher, Dr. Simin Liu, from the University of California Los Angeles School of Public Health noted he and his colleagues undertook the investigation because a series of recent studies suggests that a high level of dairy foods in the diet may lower the risk of being overweight or developing insulin resistance syndrome, studies that have examined the link between these factors and diabetes risk are sparse.

When I first started to read through the data, I was struck by just how many confounding factors they "adjusted" to reach their significant findings!
  • BMI
  • smoking status
  • physical activity
  • family history of diabetes
  • alcohol consumption
  • history of hypertension
  • use of hormones
  • high cholesterol

After "adjusting" for these inconvenient variables, the researchers concluded "A dietary pattern that incorporates higher low-fat dairy products may lower the risk of type 2 diabetes in middle-aged or older women."

They didn't add IF you're normal weight, don't smoke, are active, don't have a family history of diabetes, drink in moderation, don't have a family history of high blood pressure, aren't using hormones and don't have high cholesterol. Basically, they forgot to add the findings apply to those who are in good health!

Which begs the question - was it the inclusion of dairy or was it an overall better dietary and lifestyle pattern that kept these women in good health?

The problem with studies such as this is they're focused only on one particular in a dietary pattern that includes a wide variety of other foods. Add to that lifestyle, genetics and family history and it's impossible to say with any certainty that one particular food or food group is protective against disease. It's a leap of faith to say eating more dairy lowers the risk of type 2 diabetes without considering those confounding variables that were conveniently "adjusted" out of the equation.

I hate to say it, but this isn't science. If you ask me, it seems more like a manipulation of data to promote the dairy industry and the consumption of milk and dairy products.

Hey, I like dairy - I eat natural cheese, whole milk yogurt and occassionally even enjoy some good homemade ice cream - but do I need to include dairy to prevent diabetes? No

Reducing the risk of diabetes comes down to two things - eating a nutrient-rich diet and staying active. Sure, dairy can be part of that equation, but it's not an essential food, holds no magical metabolic protection and is an absolute nightmare for those who are lactose intolerant.


  1. I read this article differently. In population studies like this, more adjustment is better, but requires a bigger population. "Adjustment" is the term for controlling for all the variation between the two groups-

    I think the trouble is that they did not do enough adjustment--in particular they made no adjustment for diet! So we don't know if the two groups ate comparable amounts of carbs, for example. I'm guessing that the group with more dairy consumed less carbs, but since there was no adjustment for carb intake, we don't know!

  2. Excellent post. I love milk and have been focusing on drinking water and milk more than pop and I have lost 10 pounds just from that.

  3. I still think milk is first & formost the food most suited to baby cows, not humans. However I do like the occassional bit of cheese & cream. I certainly don't think it is necessary for any minerals or vitamins which can all be gotten from other sources.
    What the milk industry fail to tell you is that without adequate fat in the milk along with vitamin D & magnesium, your body can't absorb the calcium contained in it anyway. And that the focus on too much Calcium intake with out the balancing of magnesium is bad for your heart - as it is a muscle relaxant & the heart is definitely a muscle you don't want so relaxed it stops!