Who doesn’t love a cheese board? Or a quintessentially British Ploughman’s lunch? Gooey melted mozzarella on pizza? A thick wedge of mature cheddar and pickle sandwich? What about a glass of milk and a chocolate digestive? Dairy can feature heavily in our diets but is it actually bad for us?
Should we be jumping on the nut-milk bandwagon, shunning all forms of dairy, and having a drizzle of olive oil on our toast instead of a pat of butter (some may consider that suggestion sacrilege)?
When it comes to food and health, there is nothing quite as controversial or divisive as dairy. Depending on the latest diet trend or recent study, milk products have either been touted as essential for health or as a one-way ticket to hell and heart disease. It’s not surprising then that the inconsistent info has left a lot of us scratching our heads.
We’re the only species that drinks another animal’s milk and the only one that carries on drinking it as adults. For this reason, some people claim that consuming dairy isn’t natural. If we come to think about it though, we’re the only species that wears clothes or drives and you won’t catch any of the Beingwell family walking to work in the nud (sorry to disappoint).
So, what’s the truth — is dairy healthy, or a health risk?
First, let’s talk about lactose. Milk is the basis of every mammal’s diet after birth when our digestive system is immature and small. At that point in our lives, it’s a superfood to kick start our bodies to develop and grow. Milk is rich in fat, vitamins, minerals, and milk sugar (lactose). On top of that, for a while after birth, breastmilk contains proteins and antibodies that protect us from infections and support our young immune systems in developing. It’s a powerhouse of goodness!
But and there is a but, for the last (roughly) 6 million years humans and our ancestors stopped drinking milk in infancy. Milk is technically and biologically meant for infants to nurture them as they grow until they can eat the same diet as adults. It was only about 11,000 years ago (a teeny, tiny speck of time in the grand scheme of millions of years) that our ancestors settled down in the first agricultural communities that we started drinking the milk of other animals and continued drinking it as adults.
As babies, we have an abundance of lactase, a specialised enzyme, that helps to break down milk sugar (lactose) and digest it easily. The older we get the fewer lactase enzymes our bodies produce.
Worldwide its estimated that a staggering 70% of the population don’t produce enough of this enzyme after infancy .
That means we’re unable to properly digest milk and many other dairy products. This is known as ‘lactose intolerance’, and it usually doesn’t manifest before 5 years of age . If lactose doesn’t get broken down during digestion, we might end up with nausea, stomach cramps, excess gas, general discomfort, or diarrhoea. Not pleasant.
And whether lactose intolerant or not, skimmed milk has been shown to increase the risk of acne by 24% .
Does that mean 70% of people shouldn’t be eating dairy?
Not necessarily, dairy contains varying levels of lactose and we also might individually stomach certain ones better than others. One of our Beingwell family members would violently chuck up if she drank a glass of cow’s milk but is perfectly fine with a bit of feta (feta is made from sheep or goat milk). Yoghurt is an interesting option as the live bacteria within it naturally gobble up some of the lactose, and hard cheeses like parmesan contain little to no lactose. More and more shops are stocking lactose-free products, and people may choose to take lactase tablets when chowing down on cheese.
Also, lactose intolerance isn’t spread evenly around the world. In some parts of Asia, for example, it’s as high as 90%, whereas in Europe and North America the rates are the lowest in the world. Likely because we’ve been eating dairy for much longer and it features much more heavily in our diet.
Will drinking milk increase my risk of breast cancer?
This is a tricky one to answer. There's currently not enough conclusive research into the link between dairy and breast cancer. A 2020 study  found that dairy milk is associated with a greater risk of breast cancer. The author of the paper, Dr Gary Fraser, said a possible explanation for this is the sex hormone content of dairy milk, as often about 75% of the herd is pregnant to be able to produce milk.
"Dairy milk does have some positive nutritional qualities," Fraser said, "but these need to be balanced against other possible, less helpful effects. This work suggests the urgent need for further research."
Whilst genetics plays a part, for many people lifestyle factors, such as being overweight or drinking excessive amounts of alcohol, are big influences on developing breast cancer. More research is needed to draw solid conclusions about a possible link with breast cancer.
If I stop drinking milk will my bones crumble?
We all know that dairy is a great source of calcium so if we swap our milky coffee for an oat latte instead and lay off the white stuff are we risking our bone health? According to a recent review , milk may not be a magic bullet when it comes to strong and healthy bones. Researchers concluded that while milk contains tons of essential nutrients for humans, those nutrients can all be found elsewhere.
If we decide to go dairy-free or cut back, it’s important to make sure we up any nutrients we might miss out on. Tofu, almonds, beans, fatty fish, leafy greens, eggs, fortified plant-based milk can be healthy substitutes – there are plenty. As long as the gaps are filled, eliminating dairy doesn’t mean compromising our health.
What about the planet? Is dairy bad for the world?
We’re not gonna sugar coat it - dairy has a massively significant impact on our global climate. Dairy production is responsible for 3.4% of greenhouse gas emissions which is close to every single aeroplane and ship in the world combined . The United Nations' Food and Agricultural Organisation (FAO) calculated that between 2005 and 2015, the dairy cattle industry's greenhouse gas emissions increased by 18% as demand for milk grows . A 2018 study showed that an immense 628 litres of water are needed to produce just 1 litre of milk! Say what!? 
If we want the lowest negative impact on the planet chose soya or oat milk.
Final thoughts: As it turns out, there’s no definitive winner in The Great Dairy Debate. There are some legit reasons to avoid or cut down on dairy: allergies, intolerances, tummy issues, possible breast cancer risks, environmental or ethical concerns. On the flip side if we can’t imagine life without a thick, creamy Greek yoghurt, cold milk on our cereal, or the gloriousness of a gooey cheesy pizza, then we don’t need to give up dairy just because “everyone” else is doing it (which they’re not). Our advice? Go with your gut!
1. Country, regional, and global estimates for lactose malabsorption in adults: a systematic review and meta-analysis (2017). The Lancet.
2. Lactose intolerance and gastrointestinal cow’s milk allergy in infants and children – common misconceptions revisited (2017). World Allergy Organisation Journal.
3. The effect of milk consumption on acne: a meta-analysis of observational studies (2018). JEADV.
4. Dairy, soy, and risk of breast cancer: those confounded milks (2020). International Journal of Epidemiology.
5. Sector by sector: where do global greenhouse gas emissions come from? (2020). Our World in Data.
6. Climate change and the global dairy cattle sector (2019). FAO.
7. Milk and Health (2020). New England Journal of Medicine.
8. Volume of milk to produce a liter of milk by type (2018). Statistica.