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A study sponsored by the National Institutes of Health and the American Association of Retired Persons finds that men are at greater risk of death from cardiovascular disease when they take too many calcium supplements. But a bone-friendly remedy exists.

Many people like to consume calcium supplements for the health benefits it comes with, but did you know some people who take too many of these have a greater risk of death?

If you live anywhere in the United States, or even in other places, you have almost certainly heard the famous advertising slogan, "Milk does a body good." One of the reasons millions believe milk does a body good is its content of calcium needed for healthy bones, but not everyone likes to drink (or even can drink) milk on a daily basis.

To fill the gap, the supplements industry has promoted  all sorts of calcium supplements for bone health for over 20 years now. Calcium supplements do indeed offer many health benefits and actually do help your bones stay strong and healthy, but that might not be true for everyone. Unfortunately for men, a new study sponsored by the NIH (National Institutes of Health) and the AARP (American Association of Retired Persons) found out that taking more than 1,000 mg of calcium per day raises the risk of death from a cardiovascular disease in men by approximately 20%.

Is Calcium a Killer?

The NIH-AARP study, which was published in the Journal of the American Medical Association on 4 February 2012, reported a study of 388,229 American men and women aged 50 to 71 who were first contacted in the years 1995 and 1996. These Americans were simply asked whether they usually took calcium supplements, and if they did, how much on a daily basis. Then researchers followed the AARP volunteers for the next 12 years, noting deaths which they recorded in the National Death Index.

In both men and women, there was a trend for more deaths from heart attacks, stroke, and vascular disease with greater consumption of calcium supplements, although there was no apparent additional risk from consuming calcium-rich foods.

Among the women who participated in the study, taking more than 1,000 mg of calcium supplements per day was associated with a 5 percent greater risk of dying of heart disease, a 6 percent greater risk of dying of other kinds of chronic cardiovascular disease, or an 8 percent greater risk of dying from stroke. In women, however, the relationship between the calcium intake and cardiovascular disease was only a trend. It was not shown to be statistically significant. (That is, the researchers could not state with 95 percent certainty that there wasn't an off chance that women's taking calcium's supplements actually lowered the risk of developing heart disease).

Among the men in the study, taking more than 1,000 mg of calcium supplements per day was associated with a 19 percent greater risk of dying of a heart disease, a 20 percent greater risk of dying of other kinds of chronic cardiovascular disease, and a 14 percent greater risk of dying from stroke. Only the 19 percent greater risk of dying from heart disease, however, was statistically significant.

The study also made several interesting findings that didn't make most of the news reports about it.

The men at greater risk of death from heart disease, the researchers found, were less likely to smoke, more likely to exercise, better educated, and ate more fruits and vegetables.

Assuming that not smoking, exercising more, knowing more, and eating more fruits and vegetables don't cause heart disease, it appears that taking calcium cancels out other healthy lifestyle choices.

Only Supplements Seem to Make a Difference

It is worth repeating that this study did not find that consuming high-calcium foods such as milk, cheese, yogurt, fish, and leafy green vegetables was not associated with greater risk of any kind of cardiovascular disease. Only supplements seem to make a difference.

And it is also helpful to understand that previous studies have not suggested this problem. A study published in the same journal in 1996, for example, found that taking calcium supplements slightly lowered blood pressure (systolic blood pressure, the first number, but not diastolic blood pressure, the second number). And a study published just a few months earlier in the American Journal of Medicine just a few months earlier reported that the link between calcium supplements and heart disease risk was unclear.

Making Calcium Safe For Your Heart With Vitamin K2

 

What the studies of calcium supplements and heart disease have not taken into account is that how calcium works in the body depends on its co-factors, especially vitamin K2. With vitamin K2, calcium goes into bones where it is needed.

Without vitamin K2, calcium can accumulate in the cholesterol-laden plaques that block arteries.

What Is Vitamin K2?

While "vitamin K" exists in two primary forms, vitamin K1 and vitamin K2, the functions of the two structurally similar chemicals are quite different. Vitamin K1 is phylloquinone, the vitamin found in leafy greens. The body uses vitamin K1 to make blood clotting factors, and the older drugs for preventing blood clots such as Coumadin (warfarin) worked by counteracting vitamin K1. It's almost impossible to get so much vitamin K1 from food or supplements, however, that you would have a vitamin-induced problem with excess clotting.

Vitamin K2 is structurally similar chemical known as menaquinone. This chemical doesn't have anything to do with clotting (at least in the concentrations you can achieve from food and supplements). What vitamin K2 does is to move calcium where it is suppose to go. It activates a protein called osteocalcin that moves calcium into teeth and bones. And it also activates a protein called matrix gla protein (or MGA) that moves calcium out of soft tissues, such as the linings of the arteries.

What Does Vitamin K2 Have to Do with Heart Disease?

Cholesterol is usually called the culprit in cardiovascular disease, but cholesterol is really only part of the problem. Cholesterol by itself is a soft, waxy, fatty substance. Only when cholesterol combines with calcium does it become the artery-clogging plaque that causes cardiovascular disease. If you have cholesterol, but it is not impregnated by calcium, your arteries remain pliable and flexible, less likely to be closed by a blood clot.

Just as cholesterol is only part of the picture of atherosclerotic plaques, calcium is only part of the picture with increased risk of death. It's highly likely that the well-informed, health-conscious, vegetable-eating men at increased risk of death, the same men who tried to protect their bones by taking calcium supplements, did not get enough vitamin K2.

How Can You Be Sure You Get Your Vitamin K2?

Vitamin K2 is not something you get by eating salad greens, tropical fruits, or lean meat. Ironically, this heart-protective vitamin is most abundant in egg yolks, cream, soft cheeses, butter made from milk and cream from grass-fed cows, and a very particular fermented soy food known as natto. Although the report in the Journal of the American Medical Association did not explore this possibility, it is likely that these men most at risk of heart disease did not consume the high-cholesterol foods that, ironically, could help them fight the effects of arterial cholesterol.

So men can fight heart disease by eating more eggs and butter?

If they are the right kind of eggs and butter, yes. Eggs with brilliant orange yolks and butter that is spreadable straight from the refrigerator (with the addition of plant oils) have the vitamin K2 that is needed to keep arteries open.

There is also K2 in goose liver pâté, the animal food with the most K2 per serving, hard cheeses (especially Gouda), soft cheeses (especially Brie), chicken livers, and cheddar cheese.

If you just can't bring yourself to eat these high-cholesterol foods, or you follow a vegan diet, then you can eat a fermented soy food known as natto. (Other fermented soy foods won't work.) Natto contains 3 times more vitamin K2 than goose liver, 20 times more K2 than cheese, and 65 times more K2 than egg yolks. Or you can take a vitamin K2 supplement, which may be labeled as menaquinone, MK-7, or vitamin K2, preferably in a dosage of at least 40 micrograms (40 mcg) per day.

Sources & Links

  • Bucher HC, Cook RJ, Guyatt GH, et al. Effects of dietary calcium supplementation on blood pressure: a meta-analysis of randomized controlled trials. JAMA. 1996.275(13):1016-1022.
  • Reid IR, Bolland MJ, Grey A. Calcium supplements and risk of myocardial infarction: an hypothesis twice tested. Am J Med. 2012.125(4):e15-e17.
  • Xiao Q, Murphy RA, Houston DK, Harris TB, Chow WH, Park Y. Dietary and Supplemental Calcium Intake and Cardiovascular Disease Mortality: The National Institutes of Health-AARP Diet and Health Study. JAMA Intern Med. 2013 Feb 4:1-8. doi: 10.1001/jamainternmed.2013.3283. [Epub ahead of print]
  • Photo courtesy of photos/photo_art on Flickr: www.flickr.com/photos/photo_art/2407080012
  • Photo courtesy of ringai on Flickr: www.flickr.com/photos/ringai/3174655194

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