Up until the agricultural revolution a few thousand years ago, humans survived on breast milk in infancy and then followed on with a staple diet of meat, fish, fruit and vegetables. Then came the introduction of cattle farming and dairy specific farms and the high consumption of dairy began. The average person in Australia now consumes over 100 litres of milk each year!
The argument for dairy
Many studies have shown that as humans we’ve adapted genetically to be able to digest dairy products, despite much of the world still being lactose intolerant. There are also many proven health benefits of regularly consuming milk, yogurt and cheese.
A cup of milk contains calcium, vitamin D, vitamin B2, B12, Potassium, Phosphorus, vitamin A, B1, B6, Selenium, Zinc and Magnesium. It’s also relatively high in protein and omega 3 fatty acids (particularly grass fed cows).
As dairy is such a good source of calcium, it is often touted as a way to ensure good bone health and Nutrition Australia recommend eating some foods from the dairy group each day to provide calcium, Iodine, protein and the B vitamins.
Benefits of dairy on weight and heart health
Numerous studies have found that people who regularly consume dairy products find it easier to lose weight than those who don’t consume dairy. In addition to this, other studies have shown that people who eat dairy rather than take calcium supplements have been shown to have greater weight loss, indicating that it’s not simply the calcium that helps with the weight loss but another factor, possibly related to the protein or fat content of dairy.
There was also a well-respected study run by Harvard University which looked at the amount of trans-palmitoleic acid (a fat found in dairy products) in the participants’ bloodstream. In this study, those who consumed the most full-fat dairy had less abdominal fat, less inflammation, lower triglycerides, improved insulin sensitivity and a 62% lower risk of type 2 diabetes.
But not everyone is so convinced of the nutritional benefits of the white stuff - in fact more and more people are now shunning dairy in favour of dairy-free alternatives. These people would argue that it’s not natural for adults to drink dairy, and that we’re the only animal in the world still consuming milk past infancy.
Lactose intolerance is one of the prime reasons that people avoid dairy - and with 74% of the world being lactose intolerant this is not surprising. Yet, the majority of people with lactose intolerance are Asian, South America and African whilst the prevalence in Caucasians is closer to 15%. Symptoms of lactose intolerance include gas and flatulence, bloating, abdominal pain, and or diarrhea.
Dairy and IGF
Some studies have shown that intake of dairy products may increase the production of a growth factor in the body called IGF or Inflammatory Growth Factor. Whilst some IGF is natural and indeed helpful in the body, too much of this factor has been linked to increase risk of heart attacks, inflammation in the body and skin conditions such as acne and eczema - one of the reasons that many people find that a dairy-free diet helps with skin conditions.
Dairy and bone health
Despite milk, yogurt and cheese all being good sources of calcium and vitamin D, it has been argued that the calcium in dairy products is not well absorbed and may even increase calcium loss from bones. The much quoted book entitled the China Study argues that osteoporosis is linked to the consumption of animal protein because animal protein, unlike plant protein, increases the acidity of blood and tissues. While there is some evidence that very high protein diets may lead to reduced bone density, there is little evidence to suggest that dairy intake per se has this affect.
So the overall verdict is that while many people across the world can’t tolerate dairy products and appear to thrive, there are also many proven health benefits related to dairy intake. It is advisable to choose organic dairy products to benefit from the best profile of fatty acids and choose semi-skimmed or full-fat milk to benefit from the fat soluble vitamins.
Written by Ruth Tongue