Three a Day Dairy: Helpful or Harmful? April 10, 2009Posted by Katelyn Mack in Nutrition.
Dr. Walter Willett spoke this week to a packed classroom at Harvard School of Public Health. The topic: what is up with the three servings of dairy a day recommendation? Is it based on science (…or based on good science) or might it have been influenced by (ahem) the huge and ever-expanding dairy industry?
In true research fashion, Dr. Willett did not actually touch on the last point. He focused singly on the science in order to sway his critical-minded audience.
The 3-a-day dairy recommendation likely results from the DRI (Dietary Reference Intake) indicating adults consume 800-1000mg of calcium daily. However, these nutrition guidelines vary widely worldwide. In fact, the recommended intake for calcium in the US is much higher than is recommended in Europe or by the WHO.
He gave a great deal of evidence showing that it is unlikely that we benefit from consuming excessive (>800 mg) amounts of calcium a day. Indeed, it may actually result in harm due to the release of growth factor and possible links to colorectal cancer. The 3-a-Day recommendation actually fits that bill and result in a dietary intake of calcium well over 1000mg/day.
So why am I blogging about this here? What does it have to do with social determinants of health?
Well, dairy is a huge industry. Milk consumption has been influenced by the Got Milk? campaigns (their website boasts: boost your calcium with a latte!). And we all can recall the slogan “Milk — it does the body good” (see video above). Even Yoplait has a website: “Calcium every day – the easy way.” The National Dairy Council has been incredibly successful in promoting dairy products in the US and has shaped norms around milk and dairy consumption for decades.
What is needed is a strong understanding by public health organizations (government, NGOs, and for-profits) that these suggestions are not based on strong scientific evidence. It is a marketing tool used to promote a product.
Who needs to know this?
- Nutritionists need to know in order best guide their clients to a health-promoting diet.
- Clinicians need to know this because otherwise they (like my current primary care doctor) might insist on their patients getting 3 servings of dairy a day.
- Policymakers need to be aware of this because they are making decisions about what to fund in school lunches and guidelines for WIC recipients. These decisions should be informed by the best current evidence that we have.
My take-away message: limit milk intake and get my calcium from other sources (e.g. dark leafy greens, almonds, salmon). Make sure I am getting enough Vitamin D in my diet (or better yet – through outdoor physical activity) to build muscles and increase calcium absorption.
What are your thoughts on the milk Ads and dairy marketing? Is this good for peoples’ health? Bad for health? Or is it a wash?