Is dairy bad for your health? Discover the truth behind the headlines

4 min read

Dairy, particularly cows milk, is the latest food source to provoke the fury of the masses. Scan the internet and you'll stumble across a ton of articles demonising milk and it's 'cancer-causing hormones'.

Milk and dairy foods are full of essential nutrients: calcium, vitamin D, phosphorus, ... not to mention being a fantastic source of protein. So, why the backlash?

Is this bitter criticism validated by the evidence? Are we risking our lives with every coffee that we add a splash of milk to?

The answer to both questions is a resounding no.

If you can comfortably consume dairy, there is no need to avoid it. In fact, the evidence suggests it could offer a whole host of health benefits!

In this article we're going to address the two most common arguments thrown around on the internet when it comes to dairy:

  1. Dairy is bad for your bones
  2. Excess calcium = increased risk of cancer

'Dairy is bad for your bones'

The basis of people's arguments that dairy is bad for bones is taken from the notion that higher protein-based diets contribute to a high level of acidity within the body (Nicoli, Mclaren Howard, 2014).

In order to counter this acidic environment, our bones step into the breach and leach calcium from themselves in order to stabilise the acidic environment. Bones are weakened and become brittle because of the loss of calcium, therefore, dairy = bad bones.

Easy, right? Well, let's pump the brakes for a minute.

A study from Fenton and Lyon (2011) put this idea more or less to bed. According to the authors, who reviewed all the data in this area, milk and other dairy products do not produce acid upon consumption and metabolism.

They don't influence systemic pH (the body’s acid-base balance) within the body either. This is the big answer to this idea: If food was able to alter our systemic pH as easily as it is suggested, we would be dead many, many times already.

One more thing. Before you throw the 'well, alkaline diets change urinary pH and that is measurable' argument at me. Urinary pH has the ability to be changed, yes, BUT it is not a marker of systemic pH or else, again, we would be dead (Movassagh, Vatanparst, 2017).

THE TAKEAWAY
Drinking milk is not linked to brittle bones. Milk is a great source of calcium which is crucial for strong bones.

Calcium and cancer risk

This one follows on nicely from some of the points made above.

It has been said by people on the internet (so called gurus), that calcium is a major cause of cancer. It is then concluded that a diet that contains a lot of calcium (ie dairy products) will be cancer promoting.

This stems from the fact that high levels of calcium in the blood is observed in various forms of cancer. Case closed, gurus say that diary and calcium are cancer causing agents.

But it's not so black and white.

Here’s the part that the gurus don’t know themselves or don’t want you to know:

According to Cancer Research UK, you can’t reduce the level of calcium in your blood by reducing the calcium content of your diet. Equally, the calcium content of your diet has nothing to do with the calcium content of your blood (Calvez et al, 2012).
The fact that it is seen in cancer diagnoses is related to the action of cancer on the body and bones, not the action of dairy on the body leading to cancer.

There are in fact oodles of data on the role of dairy products in cancer prevention with plenty of research concluding that it is associated with a lower risk of breast cancer.

This is slightly different. Whilst the evidence supporting the link between dairy and prostate cancer is not particularly strong (some is inconclusive), it is enough for the American Cancer Society to advise that if you are at a high risk of prostate cancer, it could be a good idea to reduce the amount of dairy in your diet.

THE TAKEAWAY
Research concludes that dairy is not linked to breast cancer but if you have a  family history of prostate cancer, it might be worth decreasing dairy consumption.

What is dairy good for then?

Interestingly enough, dairy products are fairly robust for health. There is strong evidence for its protective effects in Type 2 Diabetes and cardiovascular disease risk (Alexander et al, 2016, de Goude et al, 2016).

Equally as important is the evidence for a positive role in the prevention of childhood obesity and long-term healthy body composition management. However, this is likely to do with the overall nutritional quality and protein content of dairy products

Dairy products generally have a positive influence on overall health due to its high nutrient quality. Whey addicts rejoice! Your gains are pure and likely contributing to your overall quality of life! (Devries, Phillips, 2015)

Wrapping it up:

  • The key takeaway from this is that dairy is ultimately safe to consume as part of a balanced diet and the known data-backed benefits outweigh any alleged negative effects. You won’t lose bone mineral density through consumption of dairy products. You cannot modify the body's pH through diet.

  • When it comes to excess calcium, the amount that you’re eating will not contribute to cancer risk. It’s a byproduct of the disease state, not a causative agent.

  • Dairy and milk products can be handled by the body perfectly fine (unless otherwise clinically advised). While our ability to tolerate the colossal amounts we once did as kids does lessen, that doesn’t mean we still can’t have it. Just be smarter with your dairy amounts at each sitting.

  • From an overall health point of view, milk and dairy products can absolutely be part of your everyday routine. They are safe to consume and can have protective measure on your health.

I would just say that downing a litre of milk probably doesn't make anyone feel good.

It’s a good party piece though.


Rabin Das

Rabin Das

An MNU Certified Health and Performance Nutritionist and musclefood advisor with an MSc in Human Nutrition and Metabolism. Rabin is passionate about all things health and nutrition related.