"If you care about your bone health and preventing fractures, don't drink the milk, but take your cow for a walk! The bones that are the strongest are the ones we put stress on.
Calcium and dairy are definitely not the solution to osteoporosis. Countries consuming the most calcium have the highest rates of fracture. Looking at the Nurses' Health Study & the Health Professions Follow-up Study, there was no relationship in the amount of calcium or milk consumed by women and men and their risk of fractures.
It's true we do need some calcium in our diet--it's absolutely essential for bone health, but 500-700 mg of calcium a day is probaby right. (Note: the DRI for calcium for people age 50+ is 1200 mg; ages 19-50 is 1000 mg) Most people are already getting enough and just adding more isn't going to be helpful."
-Walter Willett, MD, DrPH, is Chairman of the Department of Nutrition and the Frederick John Stare Professor of Epidemiology and Nutrition at Harvard University's School of Public Health. Click here for source of quotes-
If you received this post via email, click here to get to the web version with all the links.
OK, I admit it--this post is ridiculously long. I apologize!
Bone health and calcium have definitely been on my radar screen this week. Here's why:
- Can calcium supplements increase cardiovasuclar events? I know, it doesn't seem plausible--for years we've been told to dutifully take our calcium supplements! But the authors of this article think there are good reasons to seriously reconsider the widespread use of calcium supplements. "Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis," Bolland, MJ, Reid, IR et al. BMJ 2010 Jul 29;341:c3691. doi: 10.1136/bmj.c3691 Click here for article.
This provocative New Zealand "meta-analysis of trials looked at studies totalling 12,000 people who took calcium supplements (without vitamin d) and found they increased the risk of myocardial infarction by 30%. Given the modest benefits of calcium supplements on bone density and fracture prevention, a reassessment of the role of calcium supplements in the management of osteoporosis is warranted," the authors write. What could be the cause? The proposed mechanisms for the higher risk include increased blood coagulability and decreased blood vessel compliance due to calcium buildup in the arterial wall.
- If the BMJ article is correct, & calcium supplements do have risks, what should physicians advise their patients? From Medscape's Internal Medicine Stay Well series, published 10/25/10, "Rethinking Calcium: Bone Health or Heartache?" by Dr. Sandra A. Fryhofer, Clinical Associate Professor of Medicine, Emory University School of Medicine, American College of Physicians Past President. As a result of the BMJ study Fryhofer is rethinking calcium supplementation. Although previous studies have shown them to be safe, they may be problematic from a cardiovascular standpoint. She's recommending her patients look primarily to dietary sources of calcium in order to get 1000 mg of calcium a day; she's discouraging the use of calcium supplements & advising their use only for patients who can't get enough dietary calcium--and advising they take 1000 IU of vitamin D daily. She's also recommending non-dairy sources of calcium like vegetables, fruits, nuts, and fish; and encouraging adequate intake of vitamin D.
- Hot Off the Press! Even calcium supplements with vitamin D may also increase the risk of myocardial infarctions. As soon as I finished writing this post I received a press release of Dr. Ian Reid's (he's the BMJ primary author of the calcium supplement article) recent presentation to the Annual Meeting of the American Society for Bone and Mineral Research. It turns out that Reid recently looked at a subgroup of 16,000 women in the Women's Health Initiative (WHI), half of whom took 500 mg of calcium + D a day, and half of whom took a placebo. According to Reid, the calcium group had a significant 22% relative increased MI rate, compared to the placebo group. "We calculate that for every 1,000 people treated with calcium for 5 years, it will lead to four additional myocardial infarctions, four additional strokes, and two additional deaths, while preventing three fractures," Dr. Ian R. Reid said. Click here for the press release.
According to Reid, a professor of medicine at the University of Auckland, New Zealand:
"I don’t prescribe calcium supplements to anyone anymore for preventing bone fractures. People should get calcium from their diet. We believe there is a fundamental difference between dietary calcium and supplemental calcium." He speculated that a calcium supplement, even at a relatively modest dose of 500 mg, produces a "borderline hypercalcemia" that persists for several hours and raises the risk for MI or stroke, the same way that people in the highest quartile for normal blood calcium levels have an increased risk for cardiovascular disease events.
Full Disclosure: The researchers who ran the Women’s Health Initiative (WHI) study questioned the legitimacy of the new analysis beyond a hypothesis-generating exercise. Stay tuned. This new analysis is not without its critics.
- This weekend I'm traveling to Columbus, Ohio to hear Dr. Amy Lanou speak on "Building Bone Vitality". I'm interested to hear what she has to add to this discussion. I've posted about her book and research previously, in: "Preventing Bone Loss & Osteoporosis Through a Plant-Based Diet & Weight-Bearing Exercise--Dr. Amy Lanou & Michael Castleman's Research-Backed Case for Building Bone Vitality".
I Used to Take Calcium Supplements & Drink Milk with Double the Calcium - Not Anymore!
Three years ago I was following my doctor's orders to get 1500 mg of calcium a day, in divided doses. I drank a glass of Lactaid milk with 500 mg of calcium per 8 oz. serving every day. I took 2 Citracal calcium supplements a day to get 630 mg of calcium, and topped off my tank with 220 mg of calcium from a Centrum multiple vitamin.
Grand total: 1350 mg, and I figured I picked up another 150 mg a day from other calcium-containing foods.
Taking a calcium supplement is something I only do occasionally--and now I'm going to seriously rethink that practice. I take care of my bones by ditching animal protein--in favor of a diet high in dietary calcium in the form of kale, broccoli, arugula chard, other greens, beans, calcium-enriched non-dairy milk, tofu, dried fruits, kiwi, and soy yogurt.
I strengthen my bones with a regular yoga practice (click here to find out how yoga benefits bones), twice a week weight-training, and lots of walking.
What We Eat Affects Bone Quality - Is There a Connection Between Animal Protein & Bone Loss?
I first learned about how animal protein adversely affects bone in March 2008, when Dr. T. Colin Campbell spoke at a Wellness Grand Rounds at the medical center where I work. Yes, I was skeptical at first. But, when I read a research study in the Journal of Clinical Endocrinology & Metabolism (JCEM), authored by Dr. Bess Dawson-Hughes, the past president of the National Osteoporosis Foundation, it started to sound more plausible.
- Higher intake of animal protein (dairy/milk) = a higher rate of bone fractures. Cornell University nutrition professor emeritus Dr. T. Colin Campbell explains this counter-intuitive situation best. An animal protein diet creates an acidosis state in the body that diminishes vitamin D, which is needed to build strong bones. In addition, when acidosis exists, the body pulls out calcium from the bones in an attempt to neutralize the acid state.
- Dr. Bess Dawson-Hughes, a former President of the National Osteoporosis Foundation, Professor of Medicine at Tufts University and Director of the Bone Metabolism Laboratory at the Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University explains that when older adults eat diets high in protein & grain, acid is produced, and as we age our bodies are less able to excrete this acid. Read more here.
"One way the body may counteract the acid from our diets is through bone resorption, a process by which bones are broken down to release minerals such as calcium, phosphates, and alkaline (basic) salts into the blood. Unfortunately, increased bone resorption leads to declines in bone mass and increases in fracture risk."
Exercise - Strength-Training Has a Profound Effect of Strengthening Bones
This comes from Randy Raugh, MPT, the author of Prime for Life - Functional Fitness for Ageless Living. Raugh is a physical therapist and the fitness director of Canyon Ranch. The prevention of osteoporosis through exercise is a chief concern of his.
The BEST Study of Bone Density
The BEST Study (which stands for Bone Estrogen Strength Training study) was conducted in Arizona betwen 1995 and 2001 and is considered to be a seminal study in osteoporosis. The study looked at 266 sedentary postmenopausal women, ages 44-66, all in relatively good health. The subjects were all nonsmokers. About half of them were on hormone replacement therapy, the others were not. Every participant took a daily calcium supplement--making an equal playing field. The subjects' bone density was measured prior to the test using the Bone Mineral Density (BMD) test.
Participants in the BEST study were divided into two groups, half taking hormone replacement therapy and half not. The object of the study was to determine what effect weight-bearing exercise had on bone mineral density (BMD) when the only variable was exercise. So one group on each team (those taking hormones, and those not) undertook a strength-training program, while the others had no regular strength training at all.
Exercisers performed supervised aerobic, weight-bearing, and weight-lifting exercises, three times per week in community-based exercise facilities. To encourage and maintain interest in exercise for one year, the women in the strength-training group participated in social support programs resulting in a high level of adherence.
The findings were startling. The participants in both groups who exercised--whether they were taking hormones or not--had markedly improved bone density in their hips and low backs, the areas of focus for the study. (The hormone-raking group showed a slightly higher, but not significant, level of improvement.)
Among non-exercisers, the hormone-taking group showed a slight increase in bone density while the other group showed no improvement at all--or, even worse, showed a decrease in bone density.
The study powerfully showed that a dramatic increase in bone density and strength can occur with regular, weight-bearing exercises.
The BMJ Study Explained - The Effect of Calcium Supplements on the Risk of Myocardial Infarction and Cardiovascular Events: A Meta-Analysis
From Dr. Sandra A. Fryhofer's article for Medscape, 'Rethinking Calcium: Bone Health or Heartache?' What the BMJ study discovered about calcium supplements.
"In the past, calcium concerns have focused on bone health and on how to get enough calcium. Adequate calcium intake recommendations developed by the Food and Nutrition Board at the Institute of Medicine say that children and teens 18 years of age or younger need 1300 mg daily, and adult men and women 19 to 50 years of age need 1000 mg daily. After age 50 years, the Institute of Medicine recommends even more calcium, and daily adequate intake increases to 1200 mg. Now, a study in BMJ raises concern that supplemental calcium may have an inadvertent adverse outcome: It could hurt your heart.
Calcium and Heart Woes
In this meta-analysis of 15 randomized blinded placebo-controlled trials. Dr. Mark Bolland (and Dr. Ian Reid) from the University of Auckland in New Zealand and colleagues evaluated calcium supplement use (at least 500 mg daily) in more than 12,000 patients older than 40 years of age. The findings were surprising: The pooled results linked calcium supplement intake to a significant 30% increased risk for heart attack. A tendency to increased risk for stroke and sudden death was also seen, but this result was not significant. Of note, cardiovascular outcomes were not a primary endpoint in any of the individual trials. Proposed mechanisms for the higher risk include increased blood coagulability and decreased blood vessel compliance due to calcium buildup in the arterial wall. On the basis of these findings, the authors postulate that treating 1000 people with calcium for 5 years would prevent 26 fractures but cause an additional 14 heart attacks.
This is not the first time that Dr. Bolland has studied calcium intake and cardiovascular outcomes. Two years ago, results of a randomized placebo-controlled study of 1471 postmenopausal women were published that linked calcium supplements with greater cardiovascular risk. That 2008 study by Bolland and colleagues was included in their 2010 meta-analysis.
No Trials of Calcium Plus Vitamin D Were Included
The type of calcium supplement did not seem to matter, but the current meta-analysis looked at calcium supplements alone. Researchers did not include any trials looking at calcium plus vitamin D. (Note: Since Fryhofer's article, the BMJ authors have looked at 16,000 participants in the WHI who took calcium with vitamin D & also found an increased risk of myocardial infarction.)
An accompanying BMJ editorial questions the role of calcium in bone health in reducing fractures. It even goes so far as to say that only patients with osteoporosis who are also taking medication for it should take calcium supplements, alone or with vitamin D, and calls for further research on calcium supplement safety and efficacy.
The Women's Health Initiative evaluation of combined calcium and vitamin D found no effect on heart attack and stroke. A recent systematic review in the Annals of Internal Medicine suggests that moderate to high doses of vitamin D may reduce cardiovascular risk, whereas calcium alone had no significant effect. (Note: the BMJ authors recently looked at a subgroup of the Women's Health Initiative (WHI) who had not taken calcium with D prior to the start of the WHI study. They felt analysis of this group would provide a more accurate measure of the risk or lack of risk of calcium supplements. When they looked at this group they found a 22% relative increased myocardial infarction rate, as compared to the placebo group.)
Q & A with Dr. Walter Willett on Bone Health & Calcium
When I heard Dr. Walter Willett's interview about bone health on Joe and Terry Graedon's People's Pharmacy he turned my view about calcium & bone strength upside down. Willett is one of the country's most-esteemed and cited nutrition experts. He leans on the conservative side nutritionally, so to hear him say that calcium isn't a big player in bone health--and that the U.S. recommendations for calcium intake are based on poor science--was shocking to me.
Back in May 2010 Dr. Mark Hyman also weighed in on dairy, and presented a good case for looking to other sources to get our calcium. Dr. WiIlett was also his go-to expert when it came to rethinking dairy as a key player in bone health. It's worth taking a look at, and he references his claims. Among Hyman's reasons to avoid dairy: it's linked to prostate cancer, it aggravates irritable bowel syndrome, digestive disorders from lactose intolerance and more. Click here to read more.
If you just increase your calcium intake and eat more dairy will you keep your bones strong?
Calcium and dairy are definitely not the solution to preventing osteoporosis. It's true we do need some calcium in our diet--it's absolutely an essential for both bone health and other physiological requirements. But how much--and are there many people in the U.S. who are deficient, is the real question. From many lines of research over the past 10 years have made it clear that not very many people will benefit by getting more calcium in their diets. Consumed the wrong way, it's even possible to be harmful. There is even risk of fracture from too much calcium intake.
Please explain this. It's so embedded in our thinking that we need calcium to avoid fractures.
Several decades ago Dr. D. Mark Hegsted looked at the fracture rates & calcium intake around the world and he found that the countries consuming the most calcium & drinking the most milk had the highest rates of fracture. This doesn't prove that calcium & milk cause fractures--but it certainly questions whether calcium is strongly protective. To read his eye-opening article in the Am J Clin Nutr, "Fracture, Calcium, and the Modern Diet" click here.
Looking at the Nurses Health Study--and the Health Professionals Follow-Up Study--it found there was really no relationship in the amount of calcium or milk consumed by women & men, and their risk of fracture.
Most people are probably already getting enough calcium, and just adding more isn't going to be helpful.
How did this happen? Most women over 40 or 50 are told that getting calcium is good for their bones--and many of them are taking 1500 mg of calcium supplements over what they're getting from their diet.
Adding supplements to a diet puts many men & women over 2000 mg of calcium a day. Part of this is driven by the DRI (daily reference intake) that said women & men over 50 need 1200 mg of calcium a day for adequate bone health.
But there's a BIG PROBLEM with this recommendation! It was based on some very short-term studies that looked at how much calcium you can force into the bone temporarily. Unfortunately, these studies only lasted just a few days or weeks--and that doesn't reflect what goes on over the long-term.
If you really up the calcium dose, you can only increase the calcium in the bones by 2%. And that's not much when measured by bone mineral density. But, the researchers erroneously thought, "Great! 2%/year X 10 years, and you'll increase the bone density by 20%." Sure, that would have been a good thing, but it was an incorrect assumption. Bone absorption just doesn't work that way.
If you maintain that high a dose (1200 mg a day) you don't continue to get increases in calcium in the bone! It's just a one time 2% increase that doesn't continue to accumulate--and then if you reduce that high intake you even lose that small 2% increase in a matter of months.
So, this short-term study on which we've based our RDAs or DRIs was very misleading. In the UK, experts looked at this and they came up with 700 mg of calcium/day as being adequate.
A committee for the World Health Organization looked at this and they came up with 500 mg of calcium/day as adequate.
Bottom Line: 500-700 mg of calcium a day is probably about right & you can get that with a decent diet & just one serving of dairy, or soy, or almond milk a day--which is much less than is being recommended. If there is any benefit of higher calcium intake it's very small.
What role do nutrients besides calcium play in bone health?
We need a whole orchestra of minerals & vitamins to maintain healthy bone. The question is, which one's are most of us deficient in? The evidence is strong that many of us are way below adequate levels of Vitamin D.
How much Vitamin D should someone be taking to prevent osteoporosis?
Two-thirds of us have inadequate vitamin D levels because we're so cut-off from the sun. For most of us to get up to adequate levels we would need to supplement at around 3000-4000 IUs of Vitamin D. (my comment: the only way to know for certain your vitamin D level is to be tested with the 25-hydroxyvitamin D test, and although one needs a minimum level 32 ng/mL to absorb calcium, most vitamin D experts recommend reaching levels of 40-50 ng/mL.
What kind of a diet is best for building strong bones?
Clearly, eating plenty of vegetables and moderate amounts of fruit is going to be beneficial. People who aren't eating enough green leafy vegetables aren't getting enough vitamin K--which is needed for bone health. And the green leafy vegetables provide calcium, as well. We do need some calcium, so if you eat a vegetarian diet, it is possible come up on the short side of calcium. But, we don't have the fine detail yet to know exactly where you swing into the short side. The question of whether or not too much animal protein can have a deleterious effect on bone is another interesting question, but not one I'm able to answer.
Dairy is not essential, but we do need some calcium. I think it's fine to have 1 or 2 servings of dairy a day, but with higher amounts, I think are going to start outweighing the benefits.
|Vegetables||Acorn squash (1 cup): 90 mg
Arugula (1 cup): 125 mg
Broccoli (1 cup): 180 mg
Chard or okra (1 cup): 100 mg
Kale, raw (1 cup ): 55 mg
Spinach, cooked (1 cup): 240 mg
|Fruits||Figs, dried uncooked (1 cup): 300 mg
Calcium-fortified orange juice (1 cup [8 oz]): 400 m
Source: USCF Medical Center. Calcium content of selected foods.
What about physical exercise? How important is it?
Physical activity is profoundly beneficial for bone health. Every study that has looked at that has seen a much lower risk of fractures among people who are physically active. The bones that are stressed the most are the strongest.
Walking is good for hip fractures, but it won't do a thing for wrist fractures, so we need exercises to keep the upper body bones strong, too.
What exercises do you suggest for all-around bone strength?
Variety! Just plain walking at a moderate to brisk pace will benefit your heart, prevent diabetes, stroke, and hip fractures. But, the bones that are strengthened are only the ones we put stress on--a few minutes 2-3 times a week with free weights is need to strengthen upper extremities.
So there you have it!
- Reconsider calcium supplements
- Get 500-700 mg of dietary calcium a day
- Be sure to get adequate Vitamin D--consider a supplement--get your level tested.
- Definitely strengthen your bones with yoga, weight-training, and/or walking
- Consider the effects of animal protein on bone quality & density.