I’ve been fretting that the paleo diet may not provide enough calcium to keep aging bones strong. On the other hand, the writer(s) at the Joslin Diabetes Blog point out that too much calcium may promote cardiovascular disease.
The February, 2013, issue of British Medical Journal has a pertinent research report. The Joslin blogger writes:
Participants were women from a mammography cohort who were asked about their calcium consumption, using a food frequency questionnaire, at baseline and seven-to-ten years later. The 61, 433 women were followed for a period of 19 years. During that time, 6894 participants died of cardiovascular disease or stroke. The researchers found that the women taking over 1400mg of calcium per day had a higher incidence of cardiovascular disease. Participants whose calcium consumption remained within suggested bounds, between 600mg and 1000mg per day, did not appear to have a greater vulnerability to cardiac disease.
I confess I haven’t read the BMJ article.
I always wonder about overall death rates when I see results like this. A group may have higher or lower rates of cardiovascular disease, and yet live longer than the comparison group. An intervention could prevent cardiovascular disease and cardiovascular death, yet increase the incidence of death from infection, cancer, accidents, or suicide, etc.
I bet a lot of adults eating a paleo-style diet approach or exceed 600 mg a day of calcium. I’m feeling better about the calcium in paleo diets. But I don’t want to have to depend on feelings.
The Joslin blogger notes that, “Perhaps it is time to have a conversation with your health care provider to determine what the best dose of calcium is for you.” Problem is, I’m not sure any healthcare provider really knows the best “dose” of calcium for the average person, whether supplemental or dietary calcium.
Sorry, men. These findings may or may not apply to you. At least you don’t have to worry about osteoporosis nearly as much as women.
Steve Parker, M.D.
PS: In case you hadn’t run across it elsewhere, note that taking a calcium supplement without a concomitant vitamin D supplement may be more harmful than taking calcium with vitamin D.