Is drinking milk good for you?

Is milk bad for adults?

​​Milk consumption is a debated topic regarding its effects on health, with often conflicting opinions and scientific results. Some say it can increase the risk of cancer, while others see it as a protective factor. However, the truth probably lies somewhere in the middle and consuming milk has no significant effect on your health unless you are severely allergic or intolerant to lactose. An innovative perspective to evaluate the effects of milk on health could be the analysis of our genome.

With advanced genomic analysis, we can identify the genes that have undergone positive selection and those that are harmful to our organism. In this way, we can examine whether the gene that allows us to digest lactose in adulthood has a positive or negative effect on our health.

Haplotypes, which are specific combinations of alleles on a chromosome, can provide important information about the presence of signs of positive selection in the genome of populations. Because haplotypes shorten during sexual reproduction, generating new combinations of genetic variants, haplotype length analysis can help identify regions of the genome that have been subjected to positive selection.

What does the human genome and the lactase gene have to do with anything?

The enzyme lactase digests lactose, which is milk sugar, in the small intestine, but most adults do not produce it after weaning. This means that adult men tend to no longer produce lactase in the quantities necessary for this process and are no longer able to physically digest lactose.

However, some human populations have continuous production of lactase throughout their lives, primarily those who traditionally practice livestock farming as their primary source of livelihood. Indeed, the consumption of dairy products has been beneficial, providing important proteins and nutrients and allowing populations to thrive.

We are talking about European populations, almost all African populations (Eastern, Southern and Middle Eastern) and South Asians. The ability to digest lactose in adulthood of these peoples was an advantage for populations that practiced livestock farming, since milk and its derivatives are a rich source of proteins and nutrients. This has allowed these populations to thrive in regions with few food alternatives and to develop dietary practices based on dairy products, also contributing to the creation of specific culinary cultures.

So are some people able to tolerate lactose?

In summary, populations that have not had a strong tradition of livestock breeding, and therefore constant consumption of derived products, such as East Asian populations, Native American populations and many West African populations, generally have a lower frequency of the gene of lactase.

However, the frequency of the lactase gene is undergoing changes in many parts of the world, due to factors such as migration, urbanization and the adoption of different dietary practices. This is why many people are now able to manage lactose and benefit from milk consumption.

Is drinking a lot of milk bad for you?

Drinking milk in balanced quantities, as suggested by expert nutritionists (2-3 portions per day), does not represent any health risk. In contrast, milk consumption has been associated with protection against one of the most common cancers in our society, colon cancer, second only to breast cancer. However, as with all foods and drinks, excessive consumption of milk can cause gastrointestinal disorders such as heartburn, gastroesophageal reflux and stomach ulcers, as it can increase the production of gastric juices in the stomach. In summary, milk can be beneficial for those who have the right mutation and consume it in the appropriate quantity, but excess is never recommended.