Milk and other dairy products like cheese and yogurt have been a key component of the human diet around the globe for thousands of years and have become a main recommended dietary category by many governmental agencies worldwide. It is clear that the benefits of consuming dairy are strong, tested by time, and backed by research.
Dairy products contain a wide range of macro- and micronutrients which are often difficult to obtain on diets that restrict or eliminate dairy products. Dairy is known for being rich in calcium, but it is also a major source of protein, potassium, and vitamins A and D, among others. In fact, dairy products are the single largest source of calcium for up to two-thirds of the population in Western countries. Milk and other dairy products contain a high percentage of these nutrients, meaning people need to consume less of them to reach the recommended daily minimum nutritional values.
The nutrients found in dairy products, most importantly calcium and vitamin D, play a vital role in maintaining health and lowering the risk for certain conditions. According to the United States Department of Agriculture (USDA) guidelines, dairy intake has been linked to better bone health, which can decrease the risk for osteoporosis, a condition where bone density goes down and bones are more likely to break. Dairy intake is particularly important for children and adolescents as their bones are developing at a faster rate than adults. Women in menopause should also monitor their calcium intake as menopause is known to affect bone density levels.
Calcium is a micronutrient required for proper formation and maintenance of bones and teeth. Over 99 percent of all the calcium in the body is stored as calcium hydroxyapatite and is found in bones and teeth where it is vital to the strength of these tissues. The remaining calcium circulates in the body and is part of muscle function, nerve signal transmission, signaling, and more. Therefore, dietary calcium intake is important to maintaining not only bone and tooth health but also overall body health.
The recommended daily intakes provided by the National Institutes of Health for adults is around 1,000 mg of calcium per day with higher requirements of up to 1,300 mg per day for children and adolescents. As calcium is so important to proper bodily functioning, it is also important to consider the best sources of dietary calcium. Dairy products provide the richest natural source of calcium, particularly as many milk options are additionally fortified with calcium. For example, a single serving of plain yogurt provides almost half of the daily requirement for calcium.
An important factor to consider when looking for dietary calcium sources is the bioavailability of each source. While non-dairy foods like spinach do contain high levels of calcium on a molecular level, this calcium is not easily accessed by the digestive system. This is because these non-dairy calcium sources contain compounds that bind calcium and limit its digestibility by the body. One such compound is oxalic acid, which is high in spinach, collard greens, and beans. Moreover, studies have also demonstrated that consuming foods high in oxalic acid together with dairy products limits the bioavailability of calcium from the dairy as well.
Altogether, dairy products provide the best source of calcium. Milk and other dairy products have been shown to have a positive impact on bone mineral density, no correlation with fractures, and improved dental health, particularly in children and growing adolescents. Studies also noted that while plant-based alternatives may objectively have similar amounts of calcium, there is not enough research to conclude that they have similar bioavailability or positive impact in the body.
Recent research has revealed new benefits to dairy products, however. A study conducted at the University of Kansas found that adults who regularly consumed milk had higher levels of glutathione in their brains. Glutathione is an antioxidant and its levels are negatively affected by the oxidative stress that results from aging or neurodegenerative disorders. Thus, the study linked older adults who consumed milk to better overall brain health. The researchers suggested that this link may be due to the nutritional makeup of milk, providing the building blocks for the creation of glutathione in the brain.
Ultimately, it is clear that dairy has a wide range of benefits. From simply providing an easy way to reach the daily recommended value of vitamins, nutrients, and minerals to potentially working against aging in the brain, there is a lot of research that supports the consumption of dairy products for people of all ages.
About the author
Nuria García is the President at the Dairy Knowledge Center, LLC. She holds a DVM and a PhD in Biological Sciences (specialization in Dairy Manufacturing) and has extensive experience with veterinary diagnostics and antimicrobial susceptibility testing. She has conducted research studies on molecular diagnostics, antimicrobial resistance genes, and the use of enzymes in cleaning biofilms on dairy separation membranes. Nuria@dairykc.com