Only a few weeks ago, I stopped taking Calcium Supplements because of a recent study published in the BMJ (British Medical Journal) publication Heart that linked these supplements and an increased risk of heart attack (myocardial infarction or MI). The study was called:
Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition study
The crux of their study was this:
Results After an average follow-up time of 11 years, 354 MI and 260 stroke cases and 267 CVD deaths were documented. Compared with the lowest quartile, the third quartile of total dietary and dairy calcium intake had a significantly reduced MI risk, with a HR of 0.69 (95% CI 0.50 to 0.94) and 0.68 (95% CI 0.50 to 0.93), respectively. Associations for stroke risk and CVD mortality were overall null. In comparison with non-users of any supplements, users of calcium supplements had a statistically significantly increased MI risk (HR=1.86; 95% CI 1.17 to 2.96), which was more pronounced for calcium supplement only users (HR=2.39; 95% CI 1.12 to 5.12).
Conclusions Increasing calcium intake from diet might not confer significant cardiovascular benefits, while calcium supplements, which might raise MI risk, should be taken with caution.
I read the thing over and over again trying to find an “out” for my particular situation, but couldn’t. Here’s the dilemma:
- The study showed an marked increase in heart attack risk from a large group of otherwise healthy people who took calcium supplements.
- That same group, if they just had high levels of calcium in their diet (food/dairy) in general, didn’t exhibit an increased risk.
- I stopped taking a calcium/magnesium supplement after I initially read this study.
- Soon after – a few days I guess – I started to notice my sleep degrading. I was initially awake far longer before falling asleep at night, and seemed to wake up even more often. This isn’t documented on my Zeo, unfortunately, because I thought I was doing so well with my insomnia.
As an experiment, and thanks to an “obvious question that I never thought to ask myself” from Hypanogog:
I went back onto the calcium/magnesium supplement as an experiment. And wouldn’t you know it, I started sleeping relatively well again – falling asleep quickly and consciously waking fewer times a night.
So I’m back on the supplements, but suspect there might be some hysteresis effect here – so I’ll take them every second day (so to cut my dosage in half).
Although it seems to me that the greater of the two evils (not sleeping or a heart attack) would be the heart attack I’d still like to hedge my bets as best as I can and get the benefit of both. A small enough dose of calcium (or magnesium, I don’t know which one has the greater effect) to not affect the heart risk, but a big enough dose so I get some sleep.
Once again, I get upset when I see people who “stick with it”, whatever “it” happens to be. When new evidence comes out – either things you’ve discovered on your own, or reputable studies you’ve read about other people, act on it. Sitting on the sidelines until it’s been proven (like “the earth is round” or “germs cause disease”) seems foolish to me. Things change all the time (think about eating eggs – first it’s bad for us, then it’s good, then it’s bad, then it’s good again) … so get used to it.
Moderation in everything – especially moderation!