Most of you will be very familiar with lactose intolerance but may not have heard of milk protein intolerance. So, what is milk protein intolerance? And how does it affect cheese consumption?
SEE ALSO: What does lactose intolerance mean and why does it matter? →
What is the cause of milk protein intolerance?
The causative agents for milk protein intolerance are usually 2 proteins found in milk called casein and whey. They are present in varying amounts in all types of milk and products that are made from milk e.g. cheese.
Before I delve further into this topic, I need to make a very clear and important distinction. Cow’s milk protein intolerance is different to cow’s milk protein allergy.
Allergy vs Intolerance
Milk protein allergy
Cow’s milk allergy affects around 2% of people at birth and the vast majority of cases resolve as the child grows up.
This type of allergy is what we call anaphylaxis and signs and symptoms include noisy breathing or wheeze, tongue swelling, throat swelling or tightness. These typically occur within minutes of consuming milk.
How to treat allergies
Allergies are a life-threatening reaction and require urgent medical treatment with adrenaline (epinephrine).
If you have milk protein allergy, you need to avoid all food products that contain any type of milk, including cheese.
Moderate symptoms of an intolerance
On the other hand, milk protein intolerance causes more mild to moderate symptoms such as skin rashes (urticaria), swelling of the lips, face or eyes, stomach pain, vomiting and diarrhoea.
Whilst it is still caused by your body’s immune system reacting to casein, it is much less severe than an allergy and is not life-threatening. Moreover, this type of reaction tends to be more delayed and can appear a few hours after consumption.
Casein and whey protein levels in different milks
So, where does that leave people with milk protein intolerances when it comes to cheese.
Even though cow’s milk is the most common culprit, other milks such as goat, sheep, buffalo and camel still contain casein and whey. As such, about 90% of people who are intolerant to cow’s milk will also be intolerant to other milks. And, by extension, all cheeses that are made with said milks.
The effect of heat on milk proteins
But this is where it gets very interesting. Heating milk will actually denature most of the whey protein and a small amount of the casein protein. As a consequence of this, cheeses that are made with cooked curds will actually have a different protein content to uncooked ones.
How about pasteurisation?
A quick word on pasteurisation. This process invented by Louis Pasteur involves heating milk to 71.7°C (162°F) for 15 to 25 seconds. Unfortunately, this process denatures only 2-3% of the whey protein in milk and, as such, is unlikely to make a difference for people with milk protein intolerance.
Cooking the curds
However, there are a large number of popular cheeses that are made by cooking the curd formed upon addition of rennet to milk. Examples of fabulous cheeses made from cooked curds include Parmigiano Reggiano, Gruyère and Mozzarella.
In the case of Parmigiano Reggiano, the curds are cooked at 55°C (130°F) for one hour. Unsurprisingly, this leads to a much more pronounced reduction in the whey protein content.
Examples of cooked curd cheeses
Some other semi-hard to hard cheeses like Morbier, Cheddar and Manchego are made from larger curds that have been more gently heated. Overall, this process, coupled with a long maturation period, will reduce the whey protein content as well.
Does this mean that you won’t get any reaction to the cheese? Not necessarily because the extent of the sensitivity varies from one person to the next. What it does mean though is that there are options that you can try in small amounts if you are craving cheese.
Do you have milk protein intolerance? Or know someone who does? Leave me a comment below.
References
All the advice in this article relating to what cheeses you can eat if you have milk protein intolerance is based on the recommendations by health authorities in Australia. If you are unsure about what you can or cannot eat, please consult your doctor.
ASCIA: Cow’s Milk Dairy Allergy
Parmigiano Reggiano Consortium: The Making of Parmigiano Reggiano
Science Direct: Effect of Pasteurisation on milk protein
Jonah is a a hipster, eco-warrior and slow food afficionado. Coming from a scientific background, Jonah has a particular interest in cheese science. And yes, he loves a good cheese pun!
