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Drinking milk may be bad for your bones
For years, if not decades, we have been told to drink our milk in order to build strong bones. Milk is a good source of calcium, Vitamin D, and phosphorus, all important nutrients for bone formation and maintenance, so many people are told that they should drink at least three glasses a day to help prevent fractures and osteoporosis.
Breast Cancer and Calcium Supplements
You may have heard that certain vitamin supplements can help you reduce your risk of breast cancer. One in particular that you've probably heard about is calcium supplements with vitamin D.
Need to improve your cholesterol profile? Make sure you get enough calcium
One recent study involving weight loss appears to show that high calcium intake, whether in pill or dairy food form, will help reduce blood pressure and improve one's cholesterol profile. So was it the weight loss that did it, or the calcium in the dairy?
Health & Nutrition Bites
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Calcium & Vitamin D Supplements:
The Risk/Benefit Ratio
Not long ago I got an email from a Dr. Gourmet reader who was frustrated by some of my answers to Ask Dr. Gourmet questions. For example, the question about whether drinking diet soda is linked to obesity. There isn't a lot of evidence, and it certainly doesn't show that drinking diet soda will cause obesity, but it doesn't look like drinking soda of any kind is all that great an idea, especially when coffee, tea and water is definitely great for you.
That's the trouble with evidence-based medicine: sometimes there just isn't enough evidence (yet) to say simply yes or no, and sometimes later research contradicts earlier research. I want you, our readers, to know what evidence there is so that you can be informed consumers.
Today's Health and Nutrition Bite is a case of conflicting research. In the British Medical Journal a team of researchers in Scotland and New Zealand published a reanalysis of data that had previously been reported on (2011;342:d2040). A large-scale, long term study known as the Women's Health Initiative (WHI), a study of women and calcium and Vitamin D supplementation, had concluded that taking calcium and Vitamin D did not increase the participants' risk of heart attack, stroke, or other cardiovascular event.
The more recent research, using the same data, concludes otherwise. Why? The women who had been participating in the study had been given either calcium and vitamin D or a placebo, and the analysis was based on a comparison of those women who took the placebo with those who took the supplement. The problem is that the majority of the participants were already taking a calcium supplement on their own: the research wasn't comparing some supplementation with none, it was effectively comparing high supplementation with lower supplementation.
Not only did the researchers reanalyze the data from WHI, they also incorporated that information into a meta-analysis of multiple other studies of calcium supplementation. The results are very different: they conclude that taking calcium, with or without Vitamin D, increased one's risk of heart attack by 25% and risk of stroke by about 15%.
What this means for you
A lot of people take calcium to help prevent osteoporosis. Should you? This is where the uncertainty of evidence-based medicine comes in and where we as physicians have to weigh the risks and benefits, as there's no yes or no answer. The researchers state, "treating 1000 patients with calcium... for five years would cause an additional 6 [heart attacks] or strokes... and prevent only 3 fractures." It may be that your doctor feels that for you, the risks outweigh the benefits - or vice versa. Discuss calcium supplementation with your doctor.
First posted: May 30, 2012