If you're a woman of a certain age (like me) you've probably been brainwashed when it comes to calcium intake, and most likely (like me) have a bottle of supplements in your kitchen cabinet. You may even have taken a calcium-based antacid in hopes of killing two birds with one stone, and if you're really obsessive-compulsive, and as Rick would opine, like me, you have probably adopted a program of weight-bearing exercise, all in the hopes of avoiding osteoporosis, hip fracture, and that downward death trajectory. Now, as we discuss on PodMed this week, and as published in the British Medical Journal or BMJ, it's time to reconsider calcium supplementation in light of an increased risk of cardiovascular disease and death in women, just as we've seen emerging in men these last few years.
The study crunched data from a huge (90, 303) cohort of Swedish women born between 1914 and 1948 and invited to participate in a study of routine mammography. In addition to mammography a questionnaire was administered to those who agreed, with a food assessment and other dietary and lifestyle practices such as supplement use. Over 60,000 women enrolled and baseline data was obtained; about 40,000 of them remained in the study for follow up about 10 years later.
Calcium intake was calculated for study participants and included both estimates of dietary calcium as well as supplement use, including calcium as part of a multivitamin. The long and short of the analysis was that the highest cardiovascular risk as well as all cause mortality was seen in the women with the highest calcium intake, in the group taking greater than 1400 mg/day of calcium. A dose response was seen regarding calcium intake and cardiovascular and all-cause mortality. The risk for all cause mortality among the group with the highest calcium intake was over 2.5 times that of women who did not use calcium supplements.
Well. Yet again something that flies in the face of established opinion and renders us all wondering just how much damage we may have done to ourselves with regard to tossing down those supplements. Rick points out in the podcast that this is merely an association at this point, with no smoking gun on the scene. Yet it seems prudent to stop taking calcium supplements if you're still doing so, perhaps to get a DEXA scan of your bones to find out where you are with regard to calcium stores in your skeletal system, and if you're really worried, maybe a coronary calcium scan to assess your heart health. While the definitive study on this matter won't likely ever be done, since randomizing large numbers of women to take calcium supplements or not over decades of life and then examining causes of death would be prohibitively expensive and maybe even unethical, it sure does seem once again that moderation, prudent diet, exercise, and avoidance of now, even supplements may prove the best strategy for a long and healthy life.
Other topics this week include two in JAMA: folic acid and autism, and risk of recurrent Helicobacter pylori infection in Latin America, and in JAMA Internal Medicine a look at consumer pricing of hip replacement surgery. Until next week, y'all live well.
Calcium No More!,6 Comments