What is dairy?
Any food made from the milk of mammals is considered a dairy product. Cow’s milk is naturally packed full of nutrients and minerals to help a baby cow grow into an adult. Although most dairy products in the world are made from cow’s milk, dairy products may also feature milk from other animals, like goats.
In addition to milk, some common dairy products consumed by humans include:
- Whey protein powder
Dairy has become a hot topic in recent years. Its legacy as a healthy source of protein and calcium has been unquestioned until only recently. There have been new studies on its negative effects on health, especially in light of the growing trend favouring plant-based over animal-based sources of protein. There are also ethical concerns over the treatment of cows, as well as environmental sustainability of the cattle industry. In this article we look at the evidence supporting the health benefits of dairy products in the diet and ask: Is it worth it?
Is it natural to eat dairy?
Almost every aspect of modern human life is unnatural; from our lifestyles to our environments. Why should our diets be an exception? What we should be asking is if dairy is actually good for us.
But to really address how natural dairy is, we have to look at our biology. Humans are able to produce their own milk for their offspring, just like any other mammal. However, they are only able to produce milk up till a certain point after birth (usually a year). The baby will eventually wean off its mother’s milk and consume other food products. In fact, most people naturally stop producing the digestive enzyme responsible for breaking down milk sugar in adulthood (lactose intolerance). Hence, it can be argued that dairy is unnatural for adults to consume as most people cannot digest it properly.
Before the first agricultural revolution about 10,000 years ago, almost nobody drank milk. The first people to drink milk regularly were the early farmers in Western Europe. They were some of the first people to live with domesticated farm animals, including cows. Today, drinking milk is common practice in Europe and North America as people of these civilisations have adapted to be able to digest lactose well into adulthood.
These cultures have been consuming milk for thousands of years. Milk is embedded into their diets. You could argue that humans have indeed evolved to include dairy in their diets as lactose tolerance is a genetic trait.
What are the health benefits of dairy?
Whether or not dairy is natural to eat, it is still important to look at the actual benefits of having it in your diet.
1. High nutrient content
Milk is rich in key vitamins and minerals needed to keep the body healthy such as:
- Vitamin A
- Vitamin B1, B2, B6 & B12
- Vitamin D
Milk is also high in protein and fatty acids including
- Conjugated linoleic acid (CLA)
- Omega 3 fatty acids
Milk is also known as a ‘complete protein’; it has all 9 essential amino acids needed in the human body. Protein is one of the most important nutrients as it is required for normal bodily functions, such as repairing cells, muscle development and regulating the immune system. A diet rich in protein will help minimise the effects of muscle loss and improve the body’s muscle repair mechanisms after exercise.
2. Improved bone health
Dairy is one of the best sources of calcium you can get in your diet. The main mineral in your bones is calcium and consuming dairy can help improve the health of your bones. A diet rich in calcium, combined with regular weight-bearing exercise, will lead to stronger bones and a lower likelihood of developing osteoporosis.
3. Lower risk of obesity
Dairy consumption has been associated with a lower risk of obesity in some studies. This is thought to be due to the effect of protein making you feel fuller so that you are less likely to overeat and exceed your daily calorie intake.
CLA in milk is also able to accelerate weight loss as it helps break down fat and inhibits fat production. Early reports have also shown a link between increased intracellular levels of ionised calcium and improved fat metabolism.
4. Reduced risk of type 2 diabetes
Dairy is able to reduce your chances of developing type 2 diabetes. It improves insulin sensitivity, improving your body’s ability to regulate your blood sugar levels. It is can also be a healthy option for those who are already diabetic. If the source of dairy has a low glycaemic index, it can be a good source of nutrients without affecting overall blood sugar control.
Are there health complications associated with dairy?
Dairy can cause adverse reactions in some people if they cannot digest it. Additionally, excess consumption of dairy can lead to over nutrition, with excess calcium being especially unhealthy for you.
1. Lactose intolerance
Approximately two-thirds of the Earth’s population are lactose intolerant. Lactase enzymes in the digestive system break down lactose into soluble molecules called glucose and galactose. For people with lactose intolerance, these enzymes are not produced by the body in adulthood. This prevents the lactose in milk from being digested, leading to gut symptoms such as bloating and abdominal pain.
There have been some studies suggesting a link between dairy intake and acne breakouts. However this finding has not been consistently proven, and the underlying mechanism is not clear. One theory is that dairy products stimulate the hormone insulin-like growth factor, IGF-1, which is associated with acne. However this appears to be related to the glycaemic load of the product more than its dairy component. Other studies have found the milk protein lactoferrin can actually improve acne by decreasing sebum and exerting anti-inflammatory effects.
3. Overconsumption of calcium
As with anything, moderation is the key and calcium is no exception. Prolonged high levels of calcium in the blood can cause constipation, kidney stones, calcium deposition in the arteries and even kidney failure. The recommended amount of calcium per day is 1,000 mg for adults aged 19 – 50 years old (around 3 cups of milk or equivalent), so there is no need to take supplements if you are getting adequate intake through your diet.
What are the best dairy products?
The healthiest dairy products come from cows that are grass-fed and raised on free-range farms. A healthy cow will produce more nutritious milk. Including fermented dairy products in your diet like yoghurt can offer probiotic benefits to your digestive system and reduce your chances of falling sick. If you can afford it, opt for these types of dairy products.
Are there dairy alternatives?
There are many non-dairy and lactose-free alternatives on the market if you can’t or don’t want to drink cow’s milk. They can have just as many nutrients and as much protein content, but do be mindful of the sugar content, as some may have natural or artificial sweeteners added which may reduce their nutritional benefit. Some of these alternatives include:
- Almond milk
- Coconut milk
- Cashew milk
- Soy milk
- Oat milk
- Rice milk
Article reviewed by Dr Joy Lim, acting medical director at IHH Healthcare Singapore
6 Reasons to Get Your Dairy. Retrieved on 02/06/2019 https://www.webmd.com/diet/features/6-reasons-to-get-your-diary#2
All about milk. Retrieved on 02/06/2019 https://www.medicalnewstoday.com/articles/273451.php
5 Ways That Drinking Milk Can Improve Your Health. Retrieved on 02/06/2019 https://www.healthline.com/nutrition/milk-benefits
What is the best milk for people with diabetes? Retrieved on 02/06/2019 https://www.medicalnewstoday.com/articles/311107.php
Is there a link between acne and milk products? Summary of evidence. Retrieved on 03/02/2020 https://www.dairynutrition.ca/scientific-evidence/roles-on-certain-health-conditions/is-there-a-link-between-acne-and-milk-products-summary-of-evidence
Dougkas, A., Barr, S., Reddy, S., & Summerbell, C. (2019). A critical review of the role of milk and other dairy products in the development of obesity in children and adolescents. Nutrition Research Reviews, 32(1), 106-127. doi:10.1017/S0954422418000227