Wednesday, March 26, 2014

The Calcium Myth - More Is Not Better


Adopting a healthier lifestyle leads to a lot of questions. Adopting a whole foods, plant-based diet as part of a healthy lifestyle leads to even more questions. Aside from the question of, How do you get enough protein?, the question of How do you get enough calcium? is usually next on the minds of others.

Getting enough calcium without consuming dairy products can seem like an impossible feat for those unfamiliar with the science behind calcium and human nutritional needs. It's not as complex or difficult as it may seem though. Unfortunately, the dairy industry has marketed immense fear into the minds of both healthcare professionals and lay people that a severe calcium deficiency will unfold if you don't consume their products. This is not true. Allow me to explain.

The Role of Calcium in the Human Body

Calcium plays several roles in the human body besides its responsibilities in maintaining strong, healthy bones. Calcium helps regulate muscles contractions, blood clotting, cell to cell signaling, and proper functioning of the nervous system (nerve impulse transmissions) [1,2]. While less than one percent of calcium is used for non-skeletal functions, greater than ninety-nine percent of calcium can be found hard at work in the bones. Calcium provides our skeletal system with the strength it needs to support the human frame. Without it, we'd be limp noodles unable to stand up and walk around upright. Calcium is definitely a vital mineral.

How Much Calcium Do You Need?

Calcium requirements are a controversial subject in the medical, nutritional, and political fields. The science, however, is not controversial. The most pressing concern of both experts and the general public is in getting enough calcium to prevent osteoporosis.

However, most experts, and certainly the general public, do not truly understand how calcium regulation works in the human body leading to osteoporosis in the first place. Therefore, current recommendations require people to load up on dairy products as well as calcium supplements to prevent later-life fractures. This approach is unnecessary. Not only is it unnecessary, it is harmful in many cases and is the reason many chronic diseases develop in the first place due to the consumption of unhealthy foods.

The Institute of Medicine sets the current calcium Recommended Dietary Allowance (RDA) for calcium requirements in the United States. The RDA is defined as the average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy individuals. The RDA for calcium in adults in the United States is dependent on age and gender [3]:

Females (age 19-50) - 1,000 mg/day
Females (age > 50) - 1,200 mg/day
Males (age 19-70) - 1,000 mg/day
Males (age > 70) - 1,200 mg/day

These values are quite generous, going over and above what the scientific evidence calls for in achieving a neutral calcium balance in the human body (that is, to allow for the same amount of calcium coming into the body as is being lost from the body on a daily basis). These recommendations are based on a 2007 study published in the American Journal of Clinical Nutrition (AJCN) which found a "neutral calcium balance at calcium intakes of 741 mg/day for healthy individuals regardless of age or sex." [4] The government came up with the above RDA values by rounding up and allowing for a 'safety net' without any scientific reason to support this higher intake of calcium.

The 2007 AJCN study went on to say that "homeostatic mechanisms for calcium metabolism seem to be functional across a broad range of typical dietary calcium intakes to minimize calcium losses and accumulations" and "that saturation of the active transport component of calcium absorption occurs at an intake of  500 mg/day." In other words, the human body has compensatory mechanisms in place to properly regulate calcium balance no matter how much calcium you consume or don't consume in your daily diet. This is done by the gut, kidney, and bone [2].

Let's take a look at what this means. As an example, if you consume a low amount of calcium (let's say 400 mg/day) then your body is going to tell your kidneys to retain calcium instead of filtering it out into the urine, your gut is going to work to absorb more calcium from the food you eat, and your bones are going to release calcium from their built up stores into bloodstream, thereby increasing serum calcium levels. If you consume too much calcium in your diet (let's say 2,000 mg/day) then the opposite takes place. The kidneys filter more calcium out in the urine, the gut doesn't readily absorb as much calcium from the foods you eat, and the bones hold on to the calcium already stored in them.

In 2011, another calcium balance study was conducted in adult men. This study was published in the American Journal of Clinical Nutrition as well. The results mirrored the previous 2007 study and found that a neutral calcium balance was achieved at an intake of 750 mg/day of calcium [5]. Keep in mind that the two different neutral calcium balance values of 741 mg/day and 750 mg/day were found in the general population eating a typical, unhealthy diet of animal-based (meat, dairy, and eggs) and processed foods.

Calcium needs of people eating a healthy diet are likely much lower, closer to 500 mg/day. This was also pointed out in the 2007 AJCN article which stated "that individuals with low, but nutritionally adequate, intakes of sodium and protein may have calcium requirements as low as 500 mg/day." [4]. Low, but nutritionally adequate, intakes of sodium and protein are exactly what a whole foods, plant-based diet is. To the nutritionally uninformed consumer or medical professional (though not their fault because of current-day advertising and marketing efforts of the dairy industry), this nutritional terminology is almost impossible to decipher in a practical manner, so the status quo remains. Inappropriate advice is given to consumers to consume large amounts of calcium by increasing their dairy consumption and to take calcium supplements.

Can Too Much Calcium Cause Harm?

Consuming too much calcium, in and of itself, doesn't necessarily lead to harmful effects depending on where the calcium is coming from (think dairy vs. green leafy vegetables). Remember if the kidney, gut, and bones are working in harmony everything is tightly regulated to maintain calcium balance in the human body.

However, there are negative health effects of eating a diet consisting mostly of animal-based and processed foods, and also with taking calcium supplements. First, let's take a look at osteoporosis rates around the world.

Dairy consumption and osteoporosis

One would think as dairy consumption went up, osteoporosis and bone fracture rates would go down. Not so. Milk consumption in the rural Chinese averages 0.6 kilograms (approximately 21 ounces) per person per year. That's less than a 24 ounce bottle of soda! Yet, the Chinese have one of the lowest rates of hip fractures in the the entire world, with Chinese women having six-fold fewer fractures than their American counterparts [6].

In an AJCN article titled, Fractures, calcium, and the modern diet, researchers stated "Western diets are also high in protein, especially animal protein. The international epidemiological data show an association between protein consumption and osteoporotic fractures ... There are now considerable data indicating that high intakes of fruit and vegetables protect against fractures." [7]

You may have heard that the consumption of animal protein produces an acidic effect in the human body, and that this acid-forming effect would need to be buffered by the body in order to return to a state of alkalinity (the body's preferred metabolic state). This buffering effect would consist of calcium being leeched from the bones in order to neutralize these acid-forming animal proteins.

This theory has been proven to have little, if any, validity to it in multiple studies over the past decade. [15,16,17] Any calcium loss from the bones due to animal protein consumption is insignificant. Rather, what has been proven is that diets high in meat (and other acid-forming animal proteins) cause an increase in calcium absorption from the foods being consumed. This, in turn, leads to excess calcium levels in the blood that the kidneys then have to filter out of the body (refer back to the explanation of calcium balance in the human body above). The result is an increase in urinary calcium levels.

So what's going on then? How does consuming milk, dairy, and other animal foods increase the risk of osteoporosis? The answer may still be unfolding for all we know. Osteoporosis, and bone health in general, is a disease with multiple dimensions to its complexities. Food is only part of the picture. Other lifestyle, genetic, and environmental factors can also play a role in this disease.

Having said that, there are some studies now implicating a role for animal-based and processed foods leading to excessive dietary phosphorus intake. Excess dietary phosphorus intake has subsequently been shown to increase bone loss and the risk for osteoporosis. [18,19] It just so happens that phosphorus comes in a more absorbable form when it comes packaged in animal foods compared to unprocessed (whole) plant foods; cheese and processed meats are especially known for high amounts of absorbable phosphorus. [20,21] Soda is also loaded with phosphorus in the form of phosphoric acid. Adopting a whole foods, plant-based diet and eliminating or reducing your consumption of animal-based and processed foods will help ensure a diet that contains low, but adequate amounts of dietary phosphorus.

The take-home message is that higher calcium, phosphorus, and protein intakes from dairy (and meat) increase your risk of bone loss over time and, consequently, lead to higher rates of osteoporosis.

Calcium consumption and prostate cancer

Prostate cancer is the most common cancer in men in the United States, aside from skin cancer. Higher dairy and calcium intakes in men are linked to increased rates of prostate cancer.

In the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial researchers found that "greater dietary intake of calcium and dairy products, particularly low-fat types, may be modestly associated with increased risks for nonaggressive prostate cancer." [8] Low-fat dairy products include skim milk and yogurt. Nonaggressive prostate cancer is what most men have in the United States. It is a slow growing cancer that is often detected in men in their fifties and sixties.

More data comes from the Health Professionals Follow-up Study looking at calcium intake and prostate cancer risk over a 16-year period in 47,750 males with no history of prostate cancer. Researchers stated, "Our findings suggest that calcium intakes exceeding 1,500 mg/day may be associated with a decrease in differentiation in prostate cancer and ultimately with a higher risk of advanced and fatal prostate cancer." [9]

A 2014 article published in the European Journal of Cancer Prevention states, "Epidemiological studies have shown that, overall, the habitual consumption of a diet high in saturated fat, well-done meats, and calcium is associated with an increased risk for advanced prostate cancer." [10]

This data should serve as a huge red flag if you are a man. Milk, cheese, yogurt, and other dairy products are not doing you any favors when it comes to your prostate health. Heed this as a warning to avoid a dairy-rich diet altogether.

Negative health effects of calcium supplementation

So why not just supplement with calcium to prevent osteoporosis? That's what pharmacists and doctors tell you to do right? This is what I told patients right after graduating pharmacy school, until I learned better.

It turns out that calcium supplementation carries its own risks. Recent data have now been surfacing over the past several years showing a number of negative health effects from calcium supplementation. The most alarming effect is the link between calcium supplements and cardiovascular events.

In 2008, the British Medical Journal (BMJ) reported that there was an increased risk of heart attacks, stroke, and sudden cardiac death in postmenopausal women taking calcium supplements compared to women taking a placebo [11].

In 2010, BMJ again heeded warnings against calcium supplementation based on a comprehensive review of the scientific data. They concluded, "Calcium supplements (without coadministered vitamin D) are associated with an increased risk of myocardial infarction [heart attacks] ... A reassessment of the role of calcium supplements in the management of osteoporosis is warranted." [12]

A year later, in 2011, the BMJ once again looked at more data regarding calcium supplementation and found that, "Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction [heart attacks] ... A reassessment of the role of calcium supplements in osteoporosis management is warranted." [13]

In 2013, the Journal of the American Medical Association (JAMA) Internal Medicine found that calcium supplementation (> 1,000 mg/day) in men significantly elevated the risk of cardiovascular deaths, including both heart attacks and stroke [14]. Researchers stated in this study that previous data had shown calcium supplementation increasing vascular calcifications which can lead to blood clots, causing heart attacks and strokes.

The more time goes on, the more data that surfaces linking calcium supplementation to harmful cardiovascular events. If you want to do your heart a favor maybe it's time to put down the calcium supplements.

In Summary

Excellent bone health is achieved through eating a healthy, plant-based diet comprised of whole foods and exercising (strength/resistance training). Think fruits and vegetables! This eating style provides protection against osteoporosis and negates the need for harmful calcium supplementation. Avoiding meat and dairy products will further improve bone health as pointed out in the studies above. Milk, sour cream, cheese, yogurt, and other dairy products only succeed in providing excess calcium, phosphorus, and protein above and beyond the body's needs. Consequently, it puts an additional workload on your kidneys to remove these excesses.

Do your body a favor and don't believe the dairy industry's promotional marketing hype to get you to buy more of their products. They only wish to increase their bottom line, not your health. The dairy industry has duped the general public and healthcare professionals into believing that a calcium-deficient diet will lead to a major healthcare crisis of broken bones. They spend millions of dollars per year lobbying the federal government to create dietary guidelines and marketing campaigns to promote their harmful foods. These efforts have nothing to do with improving human health.

By doing your homework and educating yourself on the scientific evidence on calcium and its role in human health, you will find that a whole foods, plant-based diet offers the greatest amount of benefits and absolutely no side effects. Throw in a little exercise on the side and you have yourself a winning game plan. If you haven't given this lifestyle a try, you should. Only positive things will come from it.

Ditch the dairy, love your bones!







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by Dustin Rudolph, PharmD
Clinical Pharmacist

Check out Dustin Rudolph's book The Empty Medicine Cabinet to start your journey towards better health. This step-by-step guide leads you through many of today's common chronic diseases (heart disease, obesity, diabetes, cancer, and more), giving you the facts on foods versus medications in treating these medical conditions. The book also contains an easy-to-follow guide on how to adopt a whole foods, plant-based diet as a part of an overall lifestyle change, producing the best possible health outcomes for you and your family. Hurry and get your copy today!


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References:
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Washington (DC): National Academies Press (US); 2011.
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