Raw milk proponents claims it's healthier and safe when hygiene standards are followed, but opponents point to microbiological risks. Jane Carstens investigates.
Pasteurisation is feted as one of the pillars of public health, alongside sanitation and clean drinking water. It was invented by French scientist Louis Pasteur in the mid-19th century after he discovered that heating beer and wine prevented them from turning sour by killing most of the bacteria that caused spoilage. This process, called pasteurisation, has been most effective from a public health perspective when applied to milk. Pasteurised milk is heated to a particular temperature for a short time (usually 72°C for 15 seconds) to destroy disease-causing microorganisms. It’s been compulsory in Australia since the 1940s.
It’s illegal to sell unpasteurised (raw) cow’s milk for human consumption in Australia. This contrasts to the UK, some states in the USA, and New Zealand, where it’s legal to sell it, but under very strict conditions. Raw cow’s milk can be sold as bath milk, pet milk or cosmetic milk, and it’s an open secret that some people drink these products. In some cases, the side effects of drinking raw cow’s milk have been life-threatening and occasionally fatal. Proponents of raw milk claim that it’s healthier, tastes better and is safe when strict standards of hygiene and storage are adhered to. Opponents mostly point to the microbiological risks. For every claim there’s a counter claim, but unlike a rotten egg or meat that’s off, you can’t tell if fresh raw milk is carrying harmful bacteria – only a laboratory can do that.
“Nationally and internationally, raw milk products account for a small proportion of sales but a very large proportion of outbreaks,” explains NSW Food Authority CEO Dr Lisa Szabo. “Unpasteurised milk could contain harmful bacteria, such as E.coli, salmonella and listeria, that can cause illness or even death.” Szabo adds that claims raw milk has superior nutritional value are unfounded, and that it is a high food safety risk. “I recognise and appreciate that people are increasingly conscious of the effect good nutrition has on their health; however, pasteurisation is important as it kills dangerous pathogens but has minimal effect on milk's nutritional value or flavour.”
New Zealand legalised raw cow’s milk for sale in 2016. It can be sold directly from the farmer to consumers either at the farm or via home deliveries, provided suppliers meet strict food safety criteria. Before this change, New Zealand’s Ministry of Primary Industries evaluated the benefits claimed for consuming raw cow’s milk, and the potential detrimental effects of pasteurisation (often the biggest ‘con’ cited). They found:
* Heating milk modifies the structure of milk proteins with the changes related to their functional properties (e.g. solubility and emulsifying), but found no significant effect on their digestibility and nutritional properties.
* There was no significant effect on the concentration of vitamins B1 or B6, although concentrations of B2, folate and vitamin C were lower.
* Pasteurisation does not significantly affect the amount or bioavailability of calcium, and there is no impact on milk mineral content and bioavailability.
* Pasteurisation does not affect milk fats, with the main determinant being what the cows ate and seasonal variations.
A further report on microbiological risks associated with consuming raw milk stated that its “… safety is influenced by a combination of management and control measures along the entire dairy chain and no specific husbandry practices can ensure freedom from pathogens.” Lydia Buchtmann, spokesperson for Australia’s Food Safety Information Council, is blunter: “The cow’s udder is very close to where it poops, and it’s very hard to stop contaminants from getting onto it. Even a tiny amount of E.coli in milk can multiply very quickly. Vulnerable people, such as pregnant women, should not consume raw milk or raw milk cheeses as they can get seriously ill if they get food poisoning from it.”
Buchtmann adds that studies overseas consistently show risks related to raw milk. One noted the risk of outbreaks linked to raw cow’s milk is at least 150 times greater than the risk of outbreaks linked to pasteurised cow’s milk. To add to the complexity of this debate, research published in the Journal of Allergy and Clinical Immunology also suggests a protective effect of farm life, including drinking raw cow’s milk, related to asthma and/or atopy (the genetic tendency to develop allergic diseases). “Certainly, research shows a protective effect for children living on a farm, but that’s due to the entire environment, because children are far more likely to be exposed to animals and mud rather than drinking raw milk if they have dairy cows. There are still food poisoning cases on farms from raw cow’s milk, including people camping on the farms,” Buchtmann explains.
Blessed are the cheesemakers
Food Standards Australia New Zealand changed the Food Standards Code, first in 2012 to allow production and sale of some hard cheeses, and again in 2014 to allow production and sale of some semi-hard cheeses, made from raw milk in Australia. “Cheese made from raw milk is, generally speaking, safer than raw drinking milk, as it is a fermented food involving conversion by lactic acid bacteria of lactose in milk into lactic acid. However, it must be made with care and skill to ensure it's safe,” explains Alison Lansley, secretary of the Australian Specialist Cheesemakers’ Association (ASCA). “These new standards include very specific and stringent requirements for the dairy producing the raw milk as well as for the cheesemaker processing it. The final product must also undergo sampling and testing to check for pathogens.”
So, there are arguments for and against pasteurisation, but one fact stands. Unpasteurised cow’s milk may contain bacteria that can cause serious illness and death. This is the main sticking point for health authorities, no matter how many health claims are attached to raw milk. It’s been said that pasteurisation masks milk from sick cows, so knowing how animals are treated and what they're fed will influence milk quality. Research where the milk you drink comes from. One tip: organic milk is produced without pesticides and usually with higher animal welfare standards.