Saturday, November 18, 2006

Drink Lots and Lots of Milk!

Dairy is big business in Canada.

Last year's Canadian farm receipts from dairy totaled $4.8 billion which means as an industry, it likely contributes $15-20 billion dollars to the Canadian economy which definitely means we can refer to them as Big Dairy.

As noted in a prior post, Big Dairy takes their marketing very seriously and there's no disputing the fact that they're very good at it. Certainly if you were to ask folks on the street if milk was good for you, I imagine they would almost certainly say "Yes", that is unless you happen upon the chair of Nutrition at Harvard, Dr. Walter Willett.

Dr. Willett, when asked to review the draft Canada's Food Guide, seemed quite taken aback by its dairy recommendations. Here are his thoughts (I've added hyperlinks to pertinent research):

"Like the US Guideline, the draft Canadian guidelines advocate large amounts of dairy products. There is really not a credible scientific basis for this. The usual justification is that this will reduce osteoporosis and fractures, but large prospective studies (Study #1, Study #2), consistently show no benefit of high dairy consumption on fracture incidence.

The high dairy intake would not be a major issue if it were clearly safe. However, the US Guidelines completely ignored a very substantial body of data showing increased risks of aggressive and fatal prostate cancer with high dairy consumption (review article). Also, many studies have found increased risks of ovarian cancer with high dairy consumption. Although the findings for ovarian cancer have not been entirely consistent, a recent meta-analysis of prospective studies found about a 25% increase in ovarian cancer with lactose intake equivalent to three glasses of milk per day (in fact two meta-analyses concluded risk with high dairy intake, you can find the other study here).

Thus, there is actually more evidence to suggest harm than benefit from high dairy consumption. The exact amount that might be consumed with little risk is still not clear, but suggestion of three or four servings per day seem excessive given what we do know."
Health Canada was questioned in the House of Commons on Dr. Willett's Dairy comments. Here's what Health Canada officials had to say,
"We actually had somebody go through to do a review this morning, based on those quick notes that came to us. I feel very confident that the pattern we're putting forward absolutely does not create a risk for either of those diseases."
Fastest researcher in the West!

Let me ask you, which would you rather trust, the quick notes of a researcher with a clear conflict on interest (Here the Health Canada researcher has a clear conflict of interest because he or she would not want to report Health Canada's recommendations as being wrong the day Health Canada was summoned to the House of Commons to defend themselves), or the word of the man who actually conducted the studies, the second most cited scientist in the history of clinical medicine, arguably the world's leading nutritional epidemiologist and a man who has no vested interest whatsoever in what Health Canada recommends?

So why does the Food Guide love dairy so much? It's a strange love affair given the medical evidence showing more evidence of risk than benefit. It's a strange love affair given that dairy contributes over one third of the total amount of saturated fat in our diets. It's also a strange love affair given that roughly 10% of the population is lactose intolerant.

Good thing for Big Dairy that to counter the wealth of evidence that suggests we're recommending too much dairy, they've got representatives on virtually every level of the Food Guide's decision making process including the Guide's 12 member advisory committee. Imagine what might have happened to the recommendations if they didn't!

Monday: A Match NOT Made in Heaven - The 1997 Nutrient File and Canada's Food Guide working together to increase obesity

Yesterday: Eat Less Fruit and Vegetables - Amazingly that's part of Health Canada's new recommendations