Here in the UK, we collectively purchase around 5.2 billion litres of liquid cow’s milk from the supermarkets and milkman each year (1) – that’s roughly 75 litres of milk per year, per person, if we are including all 70 million of us. On top of that, 6,072 million litres go towards dairy products such as cheese, butter and dried milk powder (1) – staple components of many favourite dishes and traditional home-comfort foods.
Like the majority of people born and raised in the UK, I was raised to believe that cow’s milk was a nutritious source of vital micronutrients such as calcium, vitamin D and the B-vitamin complex – calcium in particular, has enjoyed a long and fruitful reign as the sole beneficiary of cow’s milk.
Now, we already know that calcium is an essential and obligatory micronutrient – it’s the most abundant mineral in the human body (2), and is responsible for numerous biological functions including bone density maintenance, cell-signalling and regulation of protein function (2). Calcium is vital to our well-being, and we must safeguard calcium stores through sustained consumption of calcium-rich foods, or risk some major negative health outcomes. (The average* adult should be consuming approximately 1000mg per day, in case you were wondering).
It’s great to see the emergence of research papers that strike against popular belief, and open-up the minds of those who are willing. Traditional thinkers will know that cow’s milk and its derived products such as yogurt and milk, have long been recommended as excellent sources of calcium that have the potential to maintain bone density and aid growth during childhood. However, increasing evidence is beginning to emerge in regards to the cow’s milk-calcium connection, and the results aren’t what popular culture would have us believe…
A study published in the British Medical Journal in October 2015 examined whether high cow’s milk consumption was associated with mortality and fractures in both women and men, and found that high milk intake was associated with higher mortality in one cohort of women and in another cohort of men, and with higher fracture incidence in women.
Because of the high content of lactose in milk, the researchers hypothesised that high consumption of milk may increase oxidative stress, which in turn affects the risk of mortality and fracture. The paper notes that a high intake of milk might, however, have undesirable effects, because milk is the main dietary source of D-galactose. Even a low dose of D-galactose induces changes that resemble natural aging in animals, including shortened life span caused by oxidative stress damage, chronic inflammation, neurodegeneration, decreased immune response, and gene transcriptional change.
You can read the full article here: http://www.bmj.com/content/349/bmj.g6015
I think this article highlights the importance of having an open mind, as a human sciences student or consumer in general, as traditional teachings may not always provide a complete answer. A cautious interpretation of the results in this paper were recommended, however there are many studies elsewhere that support similar claims – wider reading is certainly recommended.
The shift in attitude towards food products, especially contentious ones such as animal products (meat, dairy and eggs), superfoods and health-related supplements is especially fascinating – and an area I am keen to keep an eye one. I would encourage anyone with an interest in nutrition to do the same, it speaks volumes about societies incentives and values.
All in all, the UK buys enough dairy products fill nearly 4,500 Olympic-size swimming pools every year – but, is it really doing us any good?
Charlotte Harbour – 2nd Year Nutrition Student
*Average is depicted as an 18 years + male or female with a healthy/normal body fat percentage and no chronic disease or health implications that would influence or dictate calcium absorption and/or consumption.
**(Immunoglobulin G (IgG), the most abundant type of antibody, is found in all body fluids and protects against bacterial and viral infections)
DISCLAIMER – this article is intended for information only and should not be considered to be nutritional advice. If you would like to change your diet please see a qualified registered practitioner for professional advice.