Comment by Dr Peter Baratosy.
Network: Australian Broadcasting Commission Channel 2 & 20
Series: Ask the Doctor Series 1
Episode: 2 Diet available on iview here.
While I agree that many people do have an intolerance to lactose, many people who think they are intolerant are actually not intolerant to the lactose but may in fact be intolerant to the casein and indeed many people are intolerant to both. Lactose intolerance is quite specific, occurring in the large intestine. A simple test for lactose intolerance is to drink a glass of cows milk then if you get diarrhea two hours later you're probably intolerant to lactose. If you think you may have a lactose intolerance see your doctor and ask to be tested.
However, if you get other more non-specific symptoms such as a rash, groggy feeling, bloating, constipation and so on, you may have an intolerance to casein. Dairy and casein intolerance is more difficult to test. The general principle for testing food intolerance is first elimination, then re challenge - in other words take dairy out of your diet (including dairy products like cheese) for three or four weeks then reintroduce it. If your symptoms abate while off it then return when you have it again, you're probably intolerant to it.
Dairy is a relatively new addition to the human diet. In nature, before civilisation, cows didn't exist as the breed they are now. By artificial human selection (as opposed natural selection) they have been bread. So historically when people say "they drank milk in bible" or the like, they may indeed have done so but it was quite possibly sheeps milk or goats milk or the like which contains the A2 protein. Normal cows milk contains both the A1 and the A2 protein (although there are some companies producing A2 only milk now). Some people can drink A2 milk without the gastric distress they experience with A1 milk.
However, I think the show over states the importance of milk in the diet. While calcium is essential to the body, getting it from dairy is not very efficient as the body spends much more of it's calcium absorber getting the calcium from cows milk than it does from other sources such as bony fish like sardines, nuts, seeds, broccoli and the like which invariably provide significantly less gastric distress.
Gut health and mental health
It's great to see some better content on health being delivered to the Australian public. On the subject of poor gut health being related to some mental health conditions such as depression and anxiety, I can say as a fellow and former lecturer of the Australasian College of Nutritional and Environmental Medicine (ACNEM), we have been educating on this subject for 10 years or more and we even have specific modules on the subject. My book Death by Civilization addresses the mind-gut connection to a degree, it is available at reception.