Ask the experts: Raw milk
It has its fans, but is raw milk as good as supporters claim? HFG senior nutritionist Rose Carr investigates.
Q: Is raw milk really healthier for us? I read online that it has enzymes, vitamins, probiotics and healthy fats that regular processed milk doesn’t have?
A: There is no evidence to support claims that raw milk is healthier than regular pasteurised milk.
Pasteurisation involves briefly heating milk and it does inactivate some enzymes. For others such as lactoperoxidase and lysozyme, enzymatic activity is reduced to 70-75 per cent. There is also a slight reduction in the amount of some vitamins, such as up to 10 per cent loss of vitamin C. There is potential for probiotic strains of bacteria to be present in raw milk, but their actual presence, probiotic activity, and any particular health benefit are unknown.
A Food Standards Australia New Zealand (FSANZ) assessment of the evidence concerning the difference in health and nutrition between pasteurised and raw milk concluded there was not a significant difference (apart from the potential for the presence of harmful bacteria in raw milk).
Pasteurised milk which has had any disease-causing bacteria removed is a nutritious food containing protein, calcium and many other nutrients.
At Healthy Food Guide we recommend using low-fat (pasteurised) milk to reduce saturated fat intake. There is a wealth of evidence to support the links between saturated fat and heart disease.
Q: Is it really true that people who are lactose intolerant can tolerate raw milk?
A: It’s entirely possible that raw milk is more well-tolerated by people with lactose intolerance as pasteurisation does destroy any lactase-producing bacteria that might be present. People with lactose intolerance have little of the enzyme lactase which helps break down lactose.
Q: Can raw milk help cure diseases (such as infections, asthma, allergies) as I have read online?
A: We’re really waiting on the science to confirm or deny some of these claims. The FSANZ review concluded that a specific association between raw milk consumption and protection against allergy sensitisation has not been fully established in currently available scientific literature.
Q: What is the argument against raw milk? Is it really that dangerous?
A: The immediate risk to your health comes from food poisoning which is potentially dangerous. This is especially the case for young children, older people, pregnant women or anyone with a compromised immune system due to other health problems. For these people the consequences are more likely to be more serious than for a healthy adult. We strongly recommend not giving raw milk to anyone in this group. Between March 2011 and April 2013 at least 57 people in New Zealand are believed to have become sick from drinking raw milk. In a campylobacter outbreak in the Manawatu, nine cases of food poisoning were linked to drinking raw milk from ne farm and several of the affected people were hospitalised. In the US, two deaths have been directly linked to drinking raw milk. Fortunately, that has not yet happened here.
Even extremely good hygiene measures on a farm will not 100% ensure that dangerous pathogens are not present in milk, which is why pasteurisation is routinely used.
The US Centre for Disease Control and Prevention reported that unpasteurised milk is 150 times more likely to cause foodborne illness and results in 13 times more hospitalisations than illnesses involving pasteurised dairy products.
In addition to food poisoning, the longer-term risk is from adding saturated fat to your diet, risking elevated blood cholesterol levels and heart disease. One cup of full-fat milk has around 6g saturated fat, over one-quarter the amount recommended in an average 8700kJ day.
Q: What does pasteurisation and homogenisation do to milk? Are these really harmful processes?
- Pasteurisation: Milk is heated to around 74°C for about 15 seconds. This kills the harmful bacteria and helps increase the life of the milk barely affecting the flavour or nutrient content. Rather than being harmful, pasteurisation has been a huge boon to public health.
- Homogenisation: Milk is passed through a valve under pressure. By doing this the fat globules are broken into smaller particles and mixed into the milk so they no longer separate out. Because this alters the size of the fat particles, homogenisation has been the subject of much speculation about possible health effects. All the negative-effect theories so far have been debunked, so we can only say there is no evidence that homogenised milk is harmful.
Low-fat ‘trim’ milk is not homogenised, so if you’re worried, that’s another good reason to choose trim milk.
Q: What about goat’s milk? Is it better for us if we can’t tolerate cow’s milk?
A: The composition of goat’s milk has similarities and differences to cow’s milk. However, the relevance of these differences to human nutrition has not been widely studied. It’s often said goat’s milk is more easily digested than cow’s milk and while a recent laboratory study appears to support this, there is currently little scientific evidence. Note that children allergic to cow’s milk are usually allergic to a number of proteins present in dairy products. As similar proteins are present in other animal milks, such as goat’s milk, these milks can also trigger an allergic reaction and should be avoided.
Buying raw milk
The sale of raw milk is not permitted in stores but you can purchase up to five litres a day at the farm gate if it’s for personal and direct family use. This restriction is to protect the more vulnerable people in our community, who may not be aware of the risks associated with unpasteurised milk. If you purchase raw milk, ensure it is always kept at 4°C or less (the standard guideline for fridge temperature). Higher temperatures increase the potential for growth of any pathogens present in the milk. A longer storage time also increases risk.
The bottom line
- There is no current evidence that raw milk is healthier than pasteurised milk. It is possible raw milk is more easily tolerated by people with lactose intolerance, although there’s not enough evidence to say for sure.
- Pasteurisation does destroy or reduce some of the enzymes and vitamins in milk. However, this makes little ifference to the overall nutrition of the milk.
- Raw milk presents a serious risk of food poisoning. We advise to consume it at your own risk, and don’t give it to children, older people, pregnant women or immune-compromised people.
- Raw milk is higher in saturated fat, which we recommend limiting in the diet.