It's linked to ovarian cancer. It's only for baby cows. We aren't meant to digest cow's milk. It's linked to bone loss.
It's pretty easy to find anti-dairy sentiment on the internet, and recently I was asked by a colleague if I 'believe' in dairy. "Like I believe in god, ghosts, and washing my face every night?" I replied. Seriously, since when has a glass of milk been so controversial?
I know that since I'm a dietitian, you think I'm going to heavily promote dairy, but you're wrong in that assumption.
The truth is that after almost 20 years of practice, I've fallen into a place where I neither discourage nor encourage dairy. Eat it if you like it. Avoid it if you want. Despite what Canada's Food Guide says, you don't need dairy, but it's not likely to harm you, at least in moderate quantities.
Let's have some fun debunking some myths about dairy:
You need dairy for calcium
Nope, you don't. Dairy is a great source of calcium, but you definitely don't need to get your calcium from dairy. And further to that, the verdict on how much calcium we really need is out anyhow; the actual amount we need may be closer to 500mg than the 1200mg that's currently recommended.
Some inexpensive, yummy plant-based sources of calcium are collards, kale, figs, and tofu. Even oranges have calcium, so don't worry. Avoiding milk doesn't have to mean skimping on calcium.
Dairy increases the risk of cancer
Even though we know that you can definitely affect your cancer risk with your diet, there is no consistent, credible evidence proving that milk increases the risk of cancer. Any type of cancer. Dr. T. Colin Campbell's China Study might have something to do with the 'milk causes cancer' headlines, but the China Study has been roundly criticized and debunked.
For the record, I will never ever dispute that a plant-based diet or mostly-plant-based diet is the healthiest way to eat. I object however to scare tactics and extremism, which I think the China Study basically is.
That being said, if you still want to believe that dairy causes cancer, don't eat dairy.
Dairy causes bone loss and increases fracture risk
We know that it's likely that consuming lots of calcium and vitamin D does NOT prevent bone fractures. But do they do the opposite by making our bodies more acidic? The 'fracture risk' story goes something like this:
You drink milk, and because it's an 'acid-ash' food, it lowers blood pH and causes the body to be acidic. This acidic environment in turn degrades bones because the body will steal alkaline minerals from them to normalize its blood pH.
There are a few issues with this way of thinking.
First off, what we eat doesn't affect our blood pH. Your body regulates its pH so tightly, and if it didn't, you'd die from eating, well, anything.
Also, IF milk did leave acidic metabolites, your kidneys would deal with them.
The truth is, that calcium, even the calcium in milk, builds bone and increases bone density. Do you need to drink milk for this to happen? No. But you should make sure you eat foods that are sources of calcium, and stop listening to people on the internet who don't understand physiology.
Humans aren't made to tolerate dairy
Yes, we are the only animal that consumes dairy into adulthood. And it's also true that up until several thousand years ago, the lactase enzyme 'turned off' when a person reached adulthood - so people actually couldn't tolerate milk.
What happened next is anyone's guess, but perhaps we grew to tolerate milk because it gave us an 'evolutionary edge' in ancient times.
What we know now is that at least 35% of people can tolerate milk without issues. I'm not sure why this 'we can't tolerate dairy' myth persists but it's used a lot. My answer to this one is, if you don't have any issues when you consume dairy, then continue to consume it. No big deal.
People who drink a lot of milk are at greater risk of death
Yes, a study did show this, but the weird part is that this correlation between milk and death -- and correlation doesn't equal causation -- was associated only with milk and not with cheese or yogurt. Actually, the more of these things the people in the study ate, their risk of death (and fractures) went DOWN.
What's up with that?
Researchers believe that D-galactose, which is a sugar present in much greater quantities in milk than in fermented dairy (think cheese and yogurt), may cause oxidative stress and inflammation. Chronic inflammation equals earlier death in a lot of cases. But the people in the study were drinking 3 or more cups of milk a day. As a dietitian, I'd tell you that that is excessive by any standards.
If you like dairy, don't stop eating it because some person on the internet is telling you it's toxic. It's not.
You probably don't need as much calcium as we initially thought, but the jury is out on this one.
People on the internet, even doctors and scientists, can be mighty convincing when they've got an agenda. If someone is preaching diet extremes and using scare tactics, you should take their advice with a grain of salt.
You can get 100% of your calcium needs without consuming one bit of dairy.
The acid/alkaline hypothesis is total malarkey.
I'm sorry to get all dietitian-y on you, but consuming anything in excess -- whether it's carrots, hamburgers, or yogurt - isn't good for you. You don't have to avoid dairy, but don't go nuts on it, either.