DAIRY DEBATE

If dairy products make you feel rotten, it could be lactose intolerance — our tummies were never designed for cow’s milk, writes Shanthini Naidoo

If humans were once lactose-intolerant, why do we drink cow’s milk, asks Shanthini Naidoo

SHOULD we ditch dairy? That’s the next question after all the fuss over gluten. Human beings have not always consumed milk from other mammals, but it has become a staple in most parts of the world.

Only since agriculture was invented about 12 000 years ago, have humans been drinking cow’s milk on a regular basis.

Dietician Irene Labuschagne, from Stellenbosch University’s Nutrition Information Centre, explains why many of us don’t digest dairy products well — and why they are still important for good health.

“People with lactose intolerance are unable to fully digest the sugar (lactose) in milk,” she says.

“Lactose intolerance is due to lactase deficiency, which is the lack of the enzyme needed to digest the sugars in milk. As a result, they have diarrhea, gas and bloating after eating or drinking dairy products. The condition is usually harmless, but its symptoms can be uncomfortable.”

When lactose moves through the large intestine without being properly digested, it can cause uncomfortable symptoms.

“Some people who have lactose intolerance cannot digest any milk products,” Labuschagne says.

“Others can eat or drink small amounts of milk products or certain types of milk products without problems. Milk and milk products contain high concentrations of the milk sugars which need help to be broken down.”

People may be lactose intolerant to varying degrees, and there appears to be an evolutionary link.

In northern Europe, 5% of the population is lactose intolerant, in Sicily 70% is, and in some African and Asian countries up to 90% of the population is lactose intolerant. Lactase deficiency has been reported to be common among black South Africans (78%).

The theory is that the more sunlight you get, the less calcium you need from outside sources, because vitamin D — which the skin produces in the presence of sunlight — helps in the absorption of calcium. So people living in the tropics historically would have had less need to drink cow’s milk for its calcium.