The complex relationship between cow’s dairy and health: what You need to know

When it comes to its health benefits and potential risks, opinions vary widely. From raw and pasteurised to homogenised milk, each type has unique characteristics that impact health in different ways. Let’s dive into the details and explore whether we truly need cow’s dairy to maintain optimal health. Raw milk is unprocessed and unpasteurised, so it's full of all the natural goodness that it should be! Proponents say that these components, such as lactoferrin and lactoperoxidase, support immune health and offer antimicrobial benefits. But, raw milk must be produced under strict sanitary conditions and sourced from healthy cows to minimise the risk of contamination.

Pasteurised milk is heated to kill harmful bacteria, so it's safer for consumption. However, pasteurisation also destroys some of the beneficial enzymes and decreases the availability of nutrients, which has led some people to believe that pasteurised milk is less beneficial than raw milk.

Homogenised milk: The fat molecules in homogenised milk are broken down to prevent cream from separating, resulting in a uniform texture. This process does not significantly impact the milk’s nutritional content, but it does affect how it is digested and perceived.

The necessity and benefits of consuming cow’s milk are subjects of ongoing debate. It’s pretty unique for humans to drink milk after weaning and regularly consume another mammal’s milk. This unique behaviour has led to questions about the health implications of dairy consumption.

Lactose intolerance: Following weaning, approximately 75% of humans lose the ability to fully digest lactose, the sugar in milk, due to a significant decrease in lactase production. This lactose intolerance can result in digestive issues such as bloating, diarrhoea, and stomach cramps.

Allergies and sensitivities: Dairy is a common allergen and can cause a range of symptoms, including rashes, wheezing, coughs, and digestive issues. For those with a dairy allergy, even small amounts can trigger severe reactions.

Insulin-like growth factors (IGFs): Cow’s dairy is rich in IGFs, which can promote sebum production leading to acne and may also stimulate tumour growth.

Although cow's dairy is rich in calcium, its role in promoting bone health is complex. Despite the high calcium content, there is a clear association between high cow's milk consumption and an increased risk of osteoporosis.

Calcium leaching: The protein component of cow's milk is high in sulphur-based amino acids, such as methionine. These can increase sulphuric acid formation, which may lead to the leaching of calcium from bones to neutralise the acid. This process has the potential to weaken bones over time.

Dietary patterns: Countries with high dairy consumption often also have high intakes of other animal proteins, which contribute to calcium loss from bones. A study by Michaëlsson et al. (2014) found that high milk consumption did not correlate with lower fracture rates and was associated with a higher mortality rate among women (BioMed Central) (SpringerLink).

Recent studies provide a nuanced view of dairy consumption.

Health benefits: Regular consumption of dairy has been associated with important health benefits for children, including improved bone mineral density and reduced risk of fractures. For adults, dairy may offer neutral or slightly favourable effects on cardiovascular health and type 2 diabetes risk.

Sustainability: Increasingly, consumers are turning to plant-based milk alternatives due to concerns about sustainability and animal welfare. Sales of plant-based milks, such as almond and oat milk, have been rising, reflecting a shift in consumer preferences towards more sustainable options​ (SpringerLink)​.

Conclusion

The relationship between cow’s dairy and health is complex and influenced by various factors, including individual tolerance, dietary patterns, and broader health implications. While dairy can provide essential nutrients, it is not strictly necessary for everyone, and alternatives are available for those who are lactose intolerant or prefer plant-based options. As research continues to evolve, it’s important to consider both the benefits and risks of dairy consumption in the context of a balanced diet.

For further reading, you can check out recent studies and reviews on the health impacts of dairy consumption here and here.

References

Milk consumption and multiple health outcomes: umbrella review of systematic reviews and meta-analyses in humans. Nutrition & Metabolism, 2022.

Dairy and Plant-Based Milks: Implications for Nutrition and Planetary Health. Current Environmental Health Reports, 2021.

The potential nutrition-, physical- and health-related benefits of cow’s milk for primary-school-aged children. Nutrition Research Reviews, 2020.

Rozenberg, S., Body, J.-J., Bruyère, O., et al. Effects of dairy product consumption on health: benefits and beliefs – A commentary from the Belgian Bone Club and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases. Calcified Tissue International, 2015.

Bates, B., Lennox, A., Prentice, A., et al. National diet and nutrition survey: Results from years 1, 2, 3 and 4 (combined) of the rolling programme (2008/2009-2011/2012). Public Health England, 2014.

Wilson, T., Temple, N.J. How beverages impact health and nutrition. In: Wilson T, Temple NJ, editors. Beverage Impacts on Health and Nutrition: Second Edition. Cham: Springer International Publishing, 2016.