I know I said that I wouldn’t address the health concerns associated with dairy consumption, because to be honest, it’s a difficult topic, and in my own little head I find that it is somewhat unnecessary to think about whether or not it is healthy because if I was meant to drink it I would be a calf. Last time I checked, I wasn’t. So I just had almond milk with my cereal this morning, and it was pretty darn good.
Anyway – let’s start with the common statement about dairy consumption and how it is good for bone health since it contains calcium. By consuming dairy, then, it would prevent osteoporosis at older ages (and mind you, this consumption would then have to occur before age ~25, because after that your bones are donesies). Now, as I mentioned in the previous post on dairy, Sweden and the Netherlands are among the top milk consumers in the world. Guess what else they’re winning in? Rates of osteoporosis (Lotters et al. 2013). Interesting.
Other research has instead focused on the role of vitamin D (which is actually a hormone and not a vitamin, but, you know – old habits die hard) in bone health. Indeed, adequate vitamin D status is associated with lower risk of bone fractures related to osteoporosis (Feskanich et al. 2003). Vitamin D is something that we can synthesize ourselves from cholesterol in the skin when we get sunlight shone on it. Forgive me for assuming things, but I do believe that Sweden and the Netherlands score relatively low on sunny days per year. I also believe that both populations score relatively high on activity levels, which is something that promotes bone health.
So, what should be done here? Should these populations simply consume more dairy? Is that even possible? What if… What if there’s something else that affects calcium retention. That was a lame attempt at creating suspense – I know that there’s something else that affects it, and that something is protein consumption. As it happens, protein from animal origins in particular, affects a person’s calcium balance. It increases your urinary calcium losses (Lanou et al. 2005). Which, is slightly amusing since my perception of the way that today’s society tries to stay healthy through diet is via “I have to eat meat to get my protein and I have to consume dairy because it contains like, vitamins and minerals, or something [actually it was my mom and dad that really pushed me to drink it and I never question anything]“.
Well aint’ it time to wake up and smell the coffee! I know that the industry certainly has, because many milk companies now fortify their milk products with vitamin D, so that they can continue to claim that nature’s own beverage is a magic potion for health. It’s not natural anymore, guys! Why do we have to keep discussing this when there are alternatives? Furthermore, why, when there’s such a focus on sustainability, do we keep on raising cattle for milk production, wasting insane amounts of water and feed in the process? I’ve been reluctant to addressing the argument of “well, do you suggest that we just kill all the milk cows then? That’s very animal friendly of you!!!“, because I find it self-explanatory, but since it appears that it is not; I will address it now. First of all, I don’t think dairy production will disappear. Second of all, I do think that dairy production will decrease. When it does, we won’t need to keep these cows lactating non-stop their entire 75%-too-short-lives, but can let them have breaks, which is going to reduce the number of calves born, which is going to, over time, naturally decrease the bovine population of the world.
Now, to return to the calcium. Not only is it the case then, that dairy consumption is related to increased bone resorption or increased fracture risks, but dairy products can often contain as much as 20% of your RDI of sodium (Lanou et al. 2005). This matters, because in your kidneys, there’s a crazy machinery that takes care of your balance concerning electrolytes, minerals, etc. In this machinery, in a part called the renal tubules, calcium and sodium compete for resorption, and as the kidneys excrete sodium, they inevitably also excrete calcium. Is there anyone who has been able to evade all the talk about sodium and how we consume too much of it? Didn’t think so.
The next claim relates tooooo…. cancer! The links have mainly been to cancers of the organs in reproductive system, such as prostate cancer, breast cancer, and ovarian cancer. While soy products can in fact be protective of breast cancer (Pavese et al. 2010), the same does not hold for dairy products. Dairy proteins may, for example, act on the insulin-like growth factor system (IGF), and high levels of circulating IGF-I is a risk factor for many types of cancer (Voskuil et al. 2005). A Swedish cohort found that lactose (milk sugar) contributed to an increased risk of ovarian cancer (Larsson et al. 2004).
I’d love to do more research, but I have a deadline for school. Here’s another little summary (not written by me!).
Lotters FJ, Lenoir-Wijnkoop I, Fardellone P, Rizzoli R, Rocher E, Poley MJ. 2013. Dairy foods and osteoporosis: an example of assessing the health-economic impacts of food products. Osteoporosis Int. 24(1):139-150.
Feskanich D, Willett WC, Colditz GA. 2003. Calcium, vitamin D, milk consumption, and hip fractures: a prospective study among postmenopausal women. American Journal of Clinical Nutrition 77(2):504-511.
Lanou AJ, Berkow SE, Barnard ND. 2005. Calcium, dairy products, and bone health in children and young adults: A reevaluation of the evidence. Pediatrics 115(3):736-743.
Pavese JM, Farmer RL, Bergan RC. 2010. Inhibition of cancer cell invasion and metastasis by genistein. Cancer Metastasis Rev. 29:465-482.
Voskuil DW, Vrieling A, van’t Veer LJ, Kampman E, Rookus MA. 2005. Cencer Epidemiol Biomarkers Prev. 14:195-203.
Larsson SC, Bergkvist L, Wolk A. 2004. Milk and lactose intakes and ovarian cancer risk in the Swedish Mammography Cohort. American Journal of Clinical Nutrition 80(5):1353-1357.