Should We drink cow’s milk?

It is said that the average person consumes 144 pints of cow’s milk a year, but 40% of that is poured on to cereal. The definition of what an average person is seems to include 60% who are children. But what was once touted as the one-stop supplier of most nutrients is going out of fashion – Americans drink 37% less milk than they did in the 1970s, and in the UK dairy consumption overall has fallen by a third in the past 20 years.

Milk is increasingly getting a bad press. What gluten intolerance did for bread, lactose intolerance is doing to milk. A recent blog suggested: “Maybe people are drinking less milk because it is poisonous to many of us.”
The solution

Lactose is the sugar found in milk and dairy products and it needs the enzyme lactase to break it down. Without enough lactase, the lactose is broken down by bacteria in the small bowel, causing bloating, flatulence, stomach cramps, diarrhoea and nausea. Globally, around 70% of us don’t continue producing lactase after we have finished breast or formula feeding. Genetically, babies need milk – adults not so much. But northern Europeans, who thousands of years ago got into cattle farming, have adapted to cow’s milk and have a genetic mutation so that only between 2 and 15% have a degree of lactase deficiency. This rises to 23% in central Europeans and 95% in Asian populations.

So is lactase deficiency the normal state? Not really – it made sense to drink milk at one time, so we adapted to do so. And cow’s milk is nutritious – it contains calcium, vitamins A and D and riboflavin, as well as protein and isn’t heavy on calories. Dr Miranda Lomer, senior consultant dietitian in gastroenterology at Guy’s and St Thomas’ NHS Foundation Trust, says our bodies may find the calcium in cow’s milk easier to extract than from the supplements in almond and coconut milks (which are generally less nutritious). Lomer also points out that lactase deficiency does not equal intolerance and even people with lactase intolerance can still usually drink milk in tea (around 50ml) or on cereal – between 250 to 375ml a day.

You can see your GP for a lactose breath test, but Lomer suggests drinking a large glass of milk. If you get bloating, gurgling and diarrhoea within the next 24 hours, you should consider yourself intolerant. But you may still be able to have milk in cereal and tea. People may have ethical issues about exploiting cows for their milk, but it isn’t true to say we aren’t meant to drink it – because in northern Europe, we are genetically modified to do so.