If dairy gets demoted in the new food guide, does that mean it's bad for you?

Canada’s Food Guide currently lists dairy as an essential food group. Others say milk is making us sick. What does the science say?
(Getty Images/Vetta)

Canada's Food Guide is currently undergoing a major overhaul. While the final version won't be ready for some time, early signs suggest the new guide will make some sweeping changes and may downgrade milk and dairy products, depriving them of their once privileged position.  

The change is going to be Health Canada's attempt to address criticisms that their food guide is dated and unscientific. They have also come under fire for being too willing to appease and accommodate business interests and lobby groups. Case in point, milk is often promoted as necessary for human health but the evidence doesn't quite support the claim.

Milk is certainly a good source of calcium and vitamin D, and children especially need enough vitamin D for healthy bones. But it's not clear that drinking milk will have much of an impact for adults. In children whose bones are still developing, drinking milk does seem to lead to higher bone density and stronger bones. But in adults, a review of the literature found that drinking milk had little effect on osteoporosis and bone fractures.

Of course, there's no reason you need to get calcium and vitamin D from milk. You can easily meet your daily calcium needs by eating foods like broccoli, kale and spinach. You can also get your vitamin D from fish like herring or mackerel. But while adults might see the wisdom in eating these foods, getting kids to eat them might be more difficult.

Difficult, but not impossible. You can get adequate nutrients without milk and dairy products. In fact, most of the world's population is lactose intolerant. Most people of European ancestry drink milk because their ancestors domesticated sheep, goats, and cows millennia ago, and incorporated milk into their diet. However, in many part of Asia and Africa this never happened and milk never made it into people's food habits. Over 70 per cent of the people on the planet can't metabolize lactose, so a food guide that recommends milk as an essential ingredient is ignoring a major reality.

It's worth noting that claims that milk is bad for you seem to be on equally shaky ground. Some studies have suggested that milk increases your chance of dying, others have found that it decreases your chance of dying, while others still have found no difference. In short, anyone can cherry pick the data to prove whatever point they want regarding milk's health effects. Moreover, a recent summary of the data found that there was no consistent evidence showing that drinking milk had any effect on mortality. Studies linking milk with cancer have been equally inconsistent with some showing an increased risk of cancer and others showing a decreased risk of cancer. However, all these associations need to be treated with some skepticism. A 2013 paper highlighted just how conflicted nutrition research can be, by demonstrating that many foods have at one time or another been shown to both cause and prevent cancer.

People who pass on milk because they're lactose intolerant often substitute it for fermented milk products like cheese, yogurt or kefir. Fermented products often have less lactose than milk and some lactose intolerant people can handle them. The potential problem here is that these products aren't governed by the same regulations and might not be fortified with vitamin D as milk is. Some yogurts (particularly flavored yogurts) also contain a lot of sugar, which makes them more like dessert than health food.

Recently, non-dairy plant-based milk products have become popular, especially for people adopting a vegan diet. But here too the wide variety of products means that their nutritional value varies greatly and some products on the market have lower levels of protein and calcium compared to standard cow milk. The other issue is that like yogurt, plant based milk products are not necessarily fortified with vitamin D. Excluding milk from the diets of infants and young children and substituting it with a plant based milk product can cause nutritional deficiencies and medical problems. While this unlikely to happen in adults who have a varied diet, a certain degree of caution is necessary when grocery shopping for young children. Although given that most food labels are near incomprehensible to most people, making sure your milk alternative has enough protein and minerals requires reading some fine print.    

In the end, current research indicates that the benefits and risks of milk consumption have been largely exaggerated. Milk is not a miracle food that cures disease nor is it likely to kill you or hasten your death. It certainly doesn't deserve its own food group, but it doesn't deserve to be vilified as "white poison." It's neither essential nor that harmful. It's just milk.

Christopher Labos is a physician who writes about medicine and health issues. He co-hosts a podcast called The Body of Evidence and tweets at @drlabos.