Lactose intolerance is the inability to digest, without discomfort, normal amounts of lactose. Lactose could be called ‘milk sugar’. The symptoms that appear after a milk intake greater than the tolerated level occur because your body has a low amount of lactase, the enzyme that digests milk sugar or lactose.
Symptoms occur when unabsorbed lactose in the small intestine – where most nutrients are absorbed – reaches the colon, where it is fermented by intestinal bacteria. This produces flatulence, swelling, cramping, and in individuals with very low tolerance, diarrhea.
Seventy percent of the world’s population is lactose intolerant. This is so because the human being, throughout its evolution of millions of years, never needed to digest milk. He was a hunter, and until he became a shepherd and a herdsman, he did not start milking cows. This happened relatively recently in terms of evolution, just 11,000 years ago.
It was in Northern Europe where the man began to consume milk; he could ferment it but also consumed it raw. This fact produced an adaptation of the organism, a genetic alteration and a natural selection of individuals able to digest lactose by being better nourished, which helped their survival. And so the human being was evolving towards adult tolerance to milk.
From the nutritional point of view, it is not advisable to eliminate consumption of milk and dairy products. Dairy foods are the most concentrated in calcium. An adult person needs 1000 to 1500 milligrams of calcium to keep a good bone health. Calcium intake at early ages, especially in girls, provides additional protection against osteoporosis after menopause.
Some ways to eliminate the annoying symptoms of dairy consumption are to look for tolerated dairy products or to ingest other foods high in calcium and consume them in a varied diet to maintain a healthy state.