Is Dairy Bad For You?

Humans have been drinking other animal’s milk for roughly 12,000 years or so. Dairy is touted for its ability to build strong bones. Yet, dairy is becoming more and more scrutinized for being a food designed to feed baby cows, and not human beings. Regardless of whether you believe one should be drinking milk from the utters of another animal, you should determine if dairy foods are the right choice for your body.

We all know that milk is a good source of calcium, protein, vitamin D, and other nutrients. In that sense, dairy is good for you. We can get those nutrients from other food sources, though.  Which is why people can survive and thrive without dairy foods, as long as they are getting adequate nutrition. Calcium and vitamin D may be the protective nutrients against cancer, inflammation, hypertension, and decreased bone health. (R)

That being said, let’s look at some of the studies about dairy foods and health.


Bone Health

A randomized controlled trial found that 10 year old girls who received milk on school days for 2 years had higher gains in height, body weight, bone mineral content and bone mineral density than the control group. Many other studies have found that dairy products increase bone health during childhood and adolescence, which is important for peak bone mass. (R)

One study found children who consume less milk have less bone mass in adulthood and have a greater fracture risk. It’s probably not the lack of dairy that causes this, it’s the lack of nutrients. Again, these nutrients can be found in other foods, so don’t be worried if you cannot tolerate or don’t want to drink dairy. (R)

Two large cohorts of men and women that were followed up after roughly 20 years found that higher milk intake was associated with higher mortality and increased fracture incidence in women. However, the study also found that fermented milk products were associated with decreased rates of mortality and fracture. There are some possible confounding factors, and the study itself recognizes and states this. One possible explanation is that those who were more likely to have osteoporosis drank more milk in order to try and offset it. (R)

Dairy products are also scrutinized for their fat content, particularly saturated fat content. However, dairy foods are also nutrient dense, which may “balance” out the possible negative effects of saturated fat. (R) (R)

Fermented dairy products may be better since they contain low amounts of lactose, and may have probiotic antioxidant and anti-inflammatory effects, as well as favorable effects on gut bacteria. (R)

High intakes of fermented dairy foods have been found to be associated with decreased risks of cardiovascular disease. (R)

Non-fermented dairy products contain high amounts of D-galactose, which when give to lab animals, has been shown to cause premature aging and shorten life span by causing oxidative stress and inflammation. (R)


Lactose Intolerance

Most people stop producing the lactose digesting enzyme lactase after weaning, which means most people are lactose intolerant.  It’s estimated that about 75% of the entire world’s adult population is lactose intolerant. Which means, only about 25% of people can digest lactose. It appears that it is natural to be lactose intolerant as an adult, because we don’t need to drink milk.  Our bodies naturally stop producing lactase, because we don’t need it.

Percentage of those with lactose intolerance:

  • Native Americans: 80-85%
  • Some Asian Populations: >90%
  • Africans and African Americans: 65-75%
  • Hispanics: 50%
  • Whites: 7-20%

Lactose intolerance commonly cause the following symptoms:

  • Diarrhea
  • Abdominal pain
  • Flatulence
  • Bloating

The cause of these symptoms are from gut bacteria eating the undigested lactose.

Some dairy foods are fairly safe for people with lactose intolerance, because the lactose is either removed or digested by microbes. Dairy foods that are considered safe are fermented dairy products like hard cheeses and greek yogurt, and lactose free milk (which has lactase added to it). (R)

A lot of persons with IBD find that dairy products make their symptoms worse. (R)

Some studies have shown that dairy foods may be associated with increased risk of IBD, while other studies have shown that dairy foods actually have a protective effect, or no effect at all on risk of IBD. Which usually means that some are able to tolerate dairy foods, while others cannot.  It could also mean that there other factors to consider in the studies, such as what else are the participants consuming, and what other lifestyle choices do they make. (R)

The studies on how dairy affects a person’s symptoms once they have IBD are also mixed. It’s really a case by case situation. Also, if a person has IBS and IBD, then lactose will likely increase symptoms of IBS. (Lactose is the disaccharide in FODMAPs)


Heart Disease

A very large meta-analysis of 29 cohort studies found no association between dairy and health outcomes of mortality, coronary heart disease or cardiovascular disease. Actually, fermented dairy foods like cheese and yogurt were found to be inversely associated with cardiovascular disease risk and mortality. (R)

Dairy foods have been found to improve hypertension and weight management, and also reduce the risk of colorectal cancer, and improve bone health. (R)


How I Feel About Dairy

Strictly looking at dairy from a health standpoint, I’m not a huge fan of milk, but I believe that fermented foods may provide the health benefits without the negative effects from lactose.  Children can usually tolerate dairy foods quite well, but many have problems with lactose or the proteins in dairy sometime in early adulthood. If you find that you react to dairy, it’s important to know that you can get those nutrients in other foods if you don’t consume dairy, and it’s also important to ensure that you are getting enough of them.