Is dairy-free harmful?
We need to talk about dairy. Mainly, because I care deeply about your bone health. I know you can’t really see or feel your bone density. And it is often a conversation left for the latter decades of life. Still, bone health is deeply linked to mortality, independence and quality of life. Let’s put this in perspective:
In 2019, the National Osteoporosis Foundation commissioned a report to investigate the clinical and cost burden of the consequences of osteoporosis. Some statistics are sobering like the fact that 30% of medicare patients who had a hip fracture died within 12 months of the fracture.
Therefore, having strong and healthy bones is a major investment in aging with mobility, independence and high quality of life. And how do we prevent osteoporosis and maintain bone density? Calcium!
We know that calcium prevents fracture risk. For example, one review found that dosing 1200 mg of calcium reduced hip fracture risk by 30% (Manoj, Derwin, & George, 2023).
So, the elephant in the room becomes how do we reconcile the importance of adequate calcium intake with a dairy free diet?
This may surprise you, but I think we can’t. And believe the wellness industry has likely missed the mark in villainizing dairy so strongly. But, before we get into the reasons why, I’d like to make a few caveats to this case.
First, I’m not talking about lactose intolerance. If you have a true lactose intolerance and eating dairy gives you diarrhea and stomach pain, then this conversation becomes how do I still meet adequate calcium levels without dairy? I do not want you to think I’m proposing people eat something that makes them feel badly.
Second, the idea that dairy is inflammatory as you’ll see on many blog posts or social media posts is not conclusive. There’s a mix of data. You’ll often hear that dairy causes tumor growth. A study that saw breast tumor growth with dairy is often cited by critics of dairy (Qin et al., 2007). However, this was a study done in rats that were given a carcinogen and then observed with different dairy consumption. And the same has not been replicated in humans consuming dairy as part of a healthy diet. In fact, as recently as 2021, a meta analysis looking at over a million people found that dairy had a protective effect on the female population and different types of dairy were protective at different stages of a woman’s life. For example, fermented dairy lowered breast cancer risk in postmenopausal women (He et al., 2021).
Third, health discussions are also part of a greater ecological systems and climate change discussion. Perhaps the greatest umbrella for this is the idea that healthier soils produce healthier food which will then be more nutritious to humans. We’re learning more about this connection and the costs of our very industrialized food system to climate and health. I’ll be very clear with my bias here: I think food matters and care deeply about how my food is produced. I, therefore, understand the choice to not consume dairy because of environmental impact. Again, you may choose to not eat dairy, but you still need calcium for your bones.
With all that being said, let’s look at calcium and dairy and bones.
On the one hand, we know that calcium and vitamin D supplementation prevents fracture. Reviewing 7 different studies, researchers found that daily supplementation of 1200 mg of calcium and 800 IU vitamin D was more effective in reducing hip fracture than 1000 mg of calcium plus 800 IU vitamin D (Manoj et al., 2023).
The next question is what results do we get when we supplement with dairy as a calcium source? In a 2022 study, researchers took residents at a long term care facility and observed them over two years. One group was controlled in their dairy servings which equaled 700 mg of calcium and 58 g of protein while the study group added 1.5 servings of dairy to their menu. This moved their totals to 1142 mg of calcium and 69 g of protein. The dairy group had an 11% relative risk reduction in falls; making it harder to get a fracture. The bone in their spines became more dense by 2.1% and then had a 46% reduction in hip fractures (Iuliano et al., 2021). For the record, the group increased their dairy consumption by drinking milk, cheese or yogurt. Not ice cream. I knew you were wondering ; )
We see the impact of calcium fortified dairy repeat itself in various scenarios with benefit to bone mineral density. For example, in 2020, we saw that dairy intake led to a 44% risk reduction in losing bone mineral density in postmenopausal women (Shi, Zhan, Chen, & Jiang, 2020).
In conclusion, I think we need to look at the oversimplified idea that dairy is bad and that therefore everyone should be dairy free in order to be healthy. It’s also worth noting that the Mediterranean diet, for which we have decades of research and a very large evidence base, is notably not dairy free. We can’t deny that dairy is a significant calcium source and that deficiency in calcium could have detrimental effects on bone as well as long term longevity and well-being.
A few final thoughts:
Many of the study participants had some calcium sources in their diet. Low was considered around 700 mg or below 800 mg. Interestingly, this is not an extreme deficiency and may be what we get normally in the diet. Or even on a good day with a serving or two of calcium sources. Which means many of us are likely moving through the world not eating optimally for our bone health or will need to supplement to get closer to the 1200 mg mark.
We can’t forget that dairy is a complex food and not just calcium. It also has protein and other nutrients. And there are studies that reached better calcium levels through dairy versus just a food supplement. Do we know these to be equivalent? Not quite. There exists the possibility that the whole food has a better or different impact.
Take home: pay attention to calcium. Your bones will appreciate it when you're 70 and still dancing comfortably, with ease and healthy bones.
References:
He, Y., Tao, Q., Zhou, F., Si, Y., Fu, R., Xu, B., … Chen, B. (2021). The relationship between dairy products intake and breast cancer incidence: a meta-analysis of observational studies. BMC Cancer, 21(1), 1109. https://doi.org/10.1186/s12885-021-08854-w
Iuliano, S., Poon, S., Robbins, J., Bui, M., Wang, X., Groot, L. D., … Seeman, E. (2021). Effect of dietary sources of calcium and protein on hip fractures and falls in older adults in residential care: cluster randomised controlled trial. BMJ, 375, n2364. https://doi.org/10.1136/bmj.n2364
Manoj, P., Derwin, R., & George, S. (2023). What is the impact of daily oral supplementation of vitamin D3 (cholecalciferol) plus calcium on the incidence of hip fracture in older people? A systematic review and meta‐analysis. International Journal of Older People Nursing, 18(1), e12492. https://doi.org/10.1111/opn.12492
Qin, L.-Q., Xu, J.-Y., Tezuka, H., Li, J., Arita, J., Hoshi, K., & Sato, A. (2007). Consumption of commercial whole and non-fat milk increases the incidence of 7,12-dimethylbenz(a)anthracene-induced mammary tumors in rats. Cancer Detection and Prevention, 31(4), 339–343. https://doi.org/10.1016/j.cdp.2007.04.010
Shi, Y., Zhan, Y., Chen, Y., & Jiang, Y. (2020). Effects of dairy products on bone mineral density in healthy postmenopausal women: a systematic review and meta-analysis of randomized controlled trials. Archives of Osteoporosis, 15(1), 48. https://doi.org/10.1007/s11657-020-0694-y
