Let’s start with talking about why it is that milk can cause problems in the first place? Here’s my Laymen’s understanding of the process. Milk contains a sugar called lactose. This lactose is broken down and used by the body by an enzyme within us called lactase. The only problem with that is that lactase stops being produced by the body after infancy, and so usually only exists in us when we are babies. This, in theory, makes every adult on the face of the planet unable to digest lactose (in other words lactose intolerant) and can cause some fairly serious (and embarrassing) consequences for those who consume it.
And now for the ‘But’. Clearly some people can consume milk with no problems and the benefits of consuming milk are very advantageous for those who can (good source of usable protein and calcium). Why is this so? The theory is that about 7000-8000 years ago, the people living in the Northern European/Scandinavian region developed a genetic mutation that allowed them to tolerate milk consumption. This added source of nutrients gave them an evolutionary advantage and thus the gene was passed down.
This is reflected in the fact that today approximately 90% of people with a northern European background are considered to be tolerant to lactose, as opposed to only 10% in equatorial populations (although the news is not all bad for people of equatorial heritage where almost the opposite can be said for their ability to tolerate fructose, the sugar found in fruit).
Not all in the paleo community think that milk should even be off the menu. Notably Mark Sisson, author of ‘The Primal Blueprint’ has stated (on Robb Wolf’s ‘The Paleo Solition Podcast) that he believes that milk should be part of the modern diet, as it was probably introduced into the human diet long before the onset of agriculture. He reasons that Paleolithic cavemen would have used as much of an animal they had killed as possible, including the udders of milk bearing mammals.
So the question is to consume milk or not to consume milk. I still believe that the best protocol to follow for this situation is Robb Wolf’s 30 day exclusion diet, where you take diary, grains and legumes out of the diet for 30 days (after which you can begin to reintroduce them). Most of us don’t have genealogical records or DNA analysis telling us what exact lineage we have, so the safest way is exclude all potentially problematic foods and then reintroduce them (one at a time) after the 30 days to see the effect.
At the end of the day lactose tolerance is not a black and white thing. There is a small percentage of the population that are totally intolerant and a small percentage who are super tolerant. The rest of the population sit on scale from fairly intolerant to fairly tolerant. Knowing what foods you can and can’t tolerate is really an essential part of tailoring your eating habits. We are all different, so why should our gastrointestinal tracts be any different.
In the interest of full disclosure I should divulge that I am a milk drinker, so I am a bias towards having it in the diet. However I have gone without it and I found that benefits of having it in my diet far outweigh any possible problems (although for me there are none. Good Viking heritage I guess). as I was alluding to before though, your diet is exactly that – Yours, so you should take the time and effort to see if things like milk work for you.