Are humans Evolving to Digest Milk !

Most of us don't know the fact that human adults were primarily lactose intolerant. Around ten of thousands years ago, the concept of cattle farming and dairy was not there. At that time human beings just used to feed on their mother's breastmilk during the early years of life. After those early years their body gradually used to stop the production of lactase enzyme, as it was no longer needed. But as humans learned about cattle farming and importance of nutrients found in milk, they started to develop a habit of using milk as a part of their lifelong diet. This practice improved the lactose tolerance capability in our body, and by now most of us can digest cow's milk for our whole life. But some people are there who have not fully developed this ability and are known as lactose intolerant.

Cow's Milk and History of Human Evolution

The history of cow's milk consumption by humans dates back thousands of years, to the domestication of cattle in various parts of the world. Cow's milk was likely one of the first animal milks consumed by humans, and it has been a staple food in many cultures throughout history.

The exact timeline of cow's milk consumption is not well documented, but evidence of dairy farming has been found in archaeological sites in Europe, Asia, and Africa, dating back to at least 7,500 years ago. In many cultures, cow's milk was an important source of nutrition, particularly for those who lived in areas where other food sources were scarce.

Over time, cow's milk has become widely available and is now consumed by people all over the world. In some cultures, it is still an important part of the daily diet, while in others, it is consumed more occasionally or not at all. Despite its widespread use, the consumption of cow's milk continues to be a topic of debate, with some health experts promoting its benefits and others questioning its safety and nutritional value.

Lactose Intolerance among some

The prevalence of lactose intolerance varies widely among different countries and populations, and estimates can vary depending on the methods used to determine lactose intolerance. However, here are some approximate estimates of lactose intolerance by country or region:

• Africa: High levels of lactose intolerance, with estimates ranging from 80-100% in some populations.
• Asia: High levels of lactose intolerance, with estimates ranging from 60-100% in some populations.
• Europe: Lower levels of lactose intolerance, with estimates ranging from 5-20% in some populations. Northern European populations generally have the lowest rates of lactose intolerance, while Southern and Eastern European populations have higher rates.
• Native American populations: High levels of lactose intolerance, with estimates ranging from 60-100% in some populations.
• Middle East: Rates of lactose intolerance vary widely, with some populations having high levels and others having low levels.
• Australia and New Zealand: Low levels of lactose intolerance, with estimates ranging from 5-15% in some populations.

These are general estimates, and the exact prevalence of lactose intolerance can vary within each country or region based on factors such as genetics, ethnicity, and diet. It's important to note that lactose intolerance is not a disease, but rather a normal physiological condition for many people, and it can be managed through dietary modifications or the use of lactase supplements.

Are we Evolving to be Lactose Tolerant ?

The ability to digest lactose into adulthood, known as lactase persistence, has evolved in some populations as a result of natural selection. The evolution of lactase persistence is thought to have occurred in response to the domestication of cattle and the adoption of dairy products into the human diet.

In populations with a long history of dairy farming and consumption of dairy products, individuals who were able to digest lactose without experiencing digestive symptoms had a survival advantage, as they were able to benefit from the additional source of nutrients and energy provided by dairy products. Over time, the frequency of lactase persistence increased in these populations through a process of natural selection.

So, in a sense, some populations have evolved from being lactose intolerant to being lactose tolerant, or at least more tolerant than their ancestors.

It's worth noting that the evolution of lactase persistence is not a linear process, and the frequency of lactase persistence can vary within populations based on factors such as genetics, ethnicity, and diet. Additionally, the exact mechanisms by which lactase persistence has evolved are not well understood, and the process may have been influenced by multiple factors.

Individuals in populations with a long history of dairy farming and consumption, such as northern European populations, are more likely to be lactose tolerant, while individuals in populations with little or no history of dairy consumption are more likely to be lactose intolerant.

Evolution is a slow process that occurs over many generations and is driven by a variety of factors, including natural selection and genetic mutation. Lactose tolerance is simply a genetic variation that has developed in some populations over time. This variation allows individuals to continue to produce the enzyme lactase, which breaks down lactose, into adulthood. This ability to digest lactose can be advantageous in populations where dairy products are a major part of the diet, as it allows individuals to obtain essential nutrients from dairy products.