Milk plays a vital role in the life of all mammals - it is the major source of nourishment from birth.
But dairy consumption has become a controversial topic.
On one hand, you have a number of studies linking dairy products with overall healthy bodies and good, strong bones.
On the other hand, opponents point to the cost of producing dairy products (such as agricultural costs and GHG emissions) as well as studies showing negative health impacts of dairy - which is fueling the growth in non-dairy alternatives.
Dairy is, undoubtedly, a good source of calcium, vitamin D, and other nutrients that are integral to strong bones.
In this blog post, we'll be breaking down the science behind why you need dairy for strong bones.
Why Calcium is Important
Your bones serve a structural role, but they also store calcium. This is because your body relies on this mineral for multiple functions like maintaining an appropriate blood level and preventing fractures.
One of the main ways that you lose bone mass (a condition known as osteoporosis) is if you aren’t getting enough calcium from your diet.
Other problems can arise from a lack of calcium such as an increased risk of hypertension, colon cancer, and cardiovascular disease.
It's easy to see how significant calcium is to our health! So what does this mean for dairy? Dairy products such as cheese and milk are excellent sources of calcium, making them essential foods for bone health.
Why Dairy is Important
Dairy, in its many forms, is a key source of calcium and vitamin D in the diets of many New Zealanders. In fact, for many people it is difficult to achieve the recommended daily intake of calcium with dairy-free diets.
Studies have shown that people who consume three servings or more per day of dairy products have higher bone mineral density (BMD), which means stronger bones.
Then of course you start to layer in the benefits of the different types of milk. For example, our A2 jersey milk has a range of benefits that can only be provided by A2 proteins. Some of these include less digestive pain amongst those with dairy intolerance, decreased risk of diabetes and improved heart function. You can read all about the health benefits of A2 milk here.
Of course, there are many other sources of both calcium and vitamin D - including leafy greens like kale and spinach, certain types of fish like salmon, fortified foods like cereal, orange juice, yogurt, soy milk- but these foods don't offer quite as much calcium or vitamin D as dairy does.
The Science Behind Why You Need Dairy For Strong Bones
When it comes to the link between dairy consumption and bone health the evidence is clear: dairy consistently leads to improved bone health in randomised controlled trials (considered the gold standard for scientific study) in every age group. Let’s dive into this deeper and unpack what the studies have to say.
In children and teenagers, multiple studies (from around the world) have shown that dairy consumption, and the resulting calcium intake, leads to increased bone growth, helping develop a strong foundation for later life.
One study found that high calcium intake from calcium-enriched foods (such as milk) significantly increased bone mass in prepubescent girls after a double-blind trial for one year.
A second study found similar results, but also found that the increase in dairy products, which provided the boost to calcium, did not have any impact on fat intake or weight gain, meaning the girls in the study improved bone density but didn’t gain excess weight.
In adults, the science also supports dairy intake for bone health, but in a different way.
One study involved premenopausal women, who were given a modified diet consisting of dairy products. The results showed that dairy consumption can help maintain bone density and strength when estrogen levels are depleted. Over 3 years, women involved in the study maintained bone density levels, while the women in the control group saw a decrease in bone density.
A similar study looked at postmenopausal women and found the results to be the same. In this study they used calcium tablets and milk tablets, and found that in both groups there was a cessation in the loss of bone density, while the control group (who were taking a placebo) had a reduction in bone density.
Calcium intake is an important aspect of bone health - both in building density as we grow, and preventing loss as we get older. Dairy is a great source of calcium and has been proven by a range of scientific studies to be beneficial in developing strong bones.