… not to be confused with a milk allergy!
As with all things FODMAP, lactose is a sugar. This one is found in milk, and is digested by the enzyme lactase. If lactase is produced naturally in the body in high enough quantities then the lactose consumed will be digested (broken down into galactose and glucose). If not, this can lead to a list of really undesirable symptoms including pain and discomfort. If you’re not sure whether or not you should be eliminating lactose, talk to your GP - they may be able to arrange Hydrogen Breath testing. This can also be used to determine whether or not you malabsorb Fructose - so it can be a very useful tool in the diagnosis and management of IBS.
As promised, here is a bit of history on lactose intolerance.
It’s all to do with infancy and nursing, weaning, and what’s known as “lactase persistence”, which seems to have developed through evolution and natural selection because of our dietary reliance on milk. Most mammals tolerate lactose only during infancy, because they consume only their mother’s milk - this applies to us humans as well. However, once we discovered that cows were a useful food source and came to rely on their milk in our diets, some human societies developed lactase persistence, meaning that they produce the lactase enzyme beyond infancy to allow them to continue consuming milk as part of their diet. Those with lactose intolerance do not have this lactase persistence and cannot consume products containing lactose with the same joyfully reckless abandon as the lucky few.
Lactase persistence probably originated in Europe where animal husbandry seems to have taken off when we realised that cow’s milk would be a useful secondary food source, and spread from there with the spread of animal domestication. There are many societies for whom milk never became a crucial part of their diet, and so huge swathes of the globe haven’t evolved to tolerate lactose - wherever dairy farming and animal domestication have not been part of agricultural changes, there is no tolerance; think Asia and some African countries, where their reliance tends to be on grains instead.
All of which means that it’s not unusual or scientifically surprising for us to be intolerant to lactose - in fact, you could argue that those with lactose intolerance are “the norm” rather than the exception (although the prevalence of tolerance in Europe is around 80-90% these days!), given that, historically, we would all have been lactose intolerant once weaned off mother’s milk.
Don’t despair - most cheeses have very low levels of lactose, or even none at all. Lactase drops are available online or in health food shops for making your own lactose-free milk and cream, which you can then use to make all of the recipes you’re used to, but without the ill effects.
- Add lactase enzyme drops to ordinary milk. The brand I buy requires 5 drops per pint of milk, but always read the label.
- Shake and leave in the fridge for at least 24 hours before using.