For generations now, we have all been told that we must get our daily fix of cow's milk in order to get our required dose of calcium and build ourselves some strong bones. The 15$ billion-dollar Canadian Dairy Industry's marketing campaigns work hard to teach the public that if you're not drinking enough milk, you're not looking out for your own health. And while there's no excusing the truth that calcium is a key mineral in the makeup of your bones and that milk is a rich source of it, it gets a little more complicated than that. What most of us don't know is that milk itself may not be the best food source for our bodies to utilize all that calcium. In fact, it may be working against you...
first things first...
Let us start by pointing out an obvious fact - we are the only species known to drink milk past infancy, and more importantly, it's not even our own milk. The fat-filled, hormone-rich, mineral-dense cocktail a mother cow produces is intended to take her roughly 65 lb infant calf to a whopping 700 lbs in just under a year. That ratio in comparison to human development seems a little off to me...
That infant then grows to a healthy size, develops dentition, and takes on solid food, leaving the milk behind. Yet we as North Americans never seem to really outgrow milk, and I say North Americans because there are numerous cultures around the world that have never tasted a drop of bovine syrup and have lived healthy ever after.
Furthermore, there's a concern with the drug called rBST (recombinant bovine growth hormone) used to increase the milk yield from cattle. And much like the name suggests, growth hormone leads to the proliferation of cells in the body. Unfortunately, cancer cells from ovarian, breast, and prostate cancer are very receptive to this hormone, causing them to grow and spread at an alarming rate.
Now the plus side is, no dairy cows within Canada are approved for the use of this hormone. However, that's not to say that Canada does not import dairy products from the US. In 2011, more than 102 million kilograms of dairy products were imported into Canada from the US, all of which were not rBST free. So if you've just got to have some of that creamy white nectar, look for this emblem on the packaging to ensure it's 100% Canadian.
the sour facts...
To summarize what's out there, plenty of older research supports the fact that calcium prevents bone loss, and milk is rich in calcium. Studies looking at fracture incidence in North American women conclude that a lower intake of milk in adolescence has an increased risk of fracture later on in life (1). However, according to the authors of the Save Our Bones program, the vast amount of research is often misinterpreted, with the underlying truth being that very little evidence actually shows a positive relationship between calcium and bone health, with an almost non-existent relationship between milk and bone health.
A famous Harvard study in the late 90s followed a large group of women for 12 years, and concluded that drinking milk once or more daily actually increased fracture risk compared to those women who only drank milk once per week (2).
An excerpt from the study: "These data do not support the hypothesis that higher consumption of milk or other food sources of calcium by adult women protects against hip or forearm fractures.”
Furthermore, when you dig into the demographics, data shows that the countries that consume the most amount of milk actually have the highest incidences of osteoporosis and loss of bone mass. How is that so, when milk saves our bones? On the same subject line, similar results are seen regarding calcium when you compare African tribes who consume less than 350 mg of calcium a day and almost zero incidences of broken bones with the Eskimo tribes who survive on fish bones loaded with calcium and have one of the highest incidences of osteoporosis in the world (3). That being said, I think it's also very important to recognize other factors involved here, as the lower incidence populations also have higher amounts of vitamin D exposure and greater amounts of daily exercise - hint hint.
what the dairy industry doesn't tell us...
There's some evidence out there to suggest that milk may increase the risks of certain types of cancer for both men and women.
The sugar in milk, called galactose, which is digested to the well-known allergenic sugar, lactose, may have some effects on ovarian cancer risk. While not all studies suggest this, one Harvard study pooled results of multiple trials to conclude that with a high intake of lactose (unspecific to which type of dairy it came from) there was a modestly higher risk of ovarian cancer. It's not to be ignored that this may actually correlate more so to the hormonal compositions of today's milk, as ovarian cancer is hormone sensitive.
With regards to males, a prospective study suggests men who consume high amounts of calcium (nearly 2000 mg/day or 3 cups of milk) may have anywhere between 39% to almost double the increased risk of developing fatal prostate cancer than those who consume low amounts (4,5).
the take-home message...
#1 substitute Scrap the belief that milk is needed to breed strong bones. Theres some fantastic alternatives out there that do the trick, and aren't squeezed from a cow's udder. Almond and Coconut milk are very tasty, they make for a delicious latte, and they can replace milk in any recipe (my favourite brand is Silk, as it contains no carageenan - a stabilizing agent linked to endocrine problems). Coconut yogurt is a delicious alternative. Stick to goat-based cheeses to avoid lactose. #2 balance What's important to know is that milk actually contains some ingredients, protein is the most prominent, that can have acidifying effects on our bodies. The problem lies in the fact that our body maintains an ideal pH to function properly, and the only way to neutralize acid is to add an alkaline substance or base. And where are the most basic minerals stored in our bodies? You guessed it - our bones. Now I haven't come across any HARD evidence to say this happens in humans, but mouse trials support this hypothesis. Offset things that acidify your body with the most basic, mineral-rich food group known to man, VEGETABLES! Mom did know best. Ditch the coffee (I know, I was devastated too), alcohol, sugar, cheeses and animal proteins for some mineral-dense, alkalinizing items like Spinach, Sprouts, Cucumber, Apples, Zucchini, and so on.
#3 don't leave anyone out Vitamin D, vitamin K (found in dark leafy greens), magnesium, and phosphorus are ALL just as essential to bone health as the ever-popular calcium. Leaving one out throws off the whole matrix. Again, vegetables are the best sources of all these nutrients, as well as some healthy, safe, sun exposure. Evidence shows that a little daylight (up to 15 mins/day) actually increases vitamin D serum levels more effectively than supplementing with it. In the winter months, however, 2000-4000 mg/day of liquid (in a fat solution) vitamin D may be an easier option. And let's not forget the role of exercise - particularly the weight-bearing kind. There's no question that increased stresses on the bones from weight-bearing activity leads to a better, stronger, and thicker depositing of minerals into that beautiful white matrix. Park your car at the end of the parking lot and carry your groceries. Walk around the house with the baby, or puppy, or your husband if you have to, in your arms. Engage in some fun interval training, using your own body weight as the resistance. Get out and move. And most of all, don't stress if you haven't been drinking your milk... you may have done yourself a favour.