Why Is Milk Consumption Associated with More Bone Fractures?

Why Is Milk Consumption Associated with More Bone Fractures?.jpg

Milk is touted to build strong bones, but a compilation of all the best studies found no association between milk consumption and hip fracture risk, so drinking milk as an adult might not help bones, but what about in adolescence? Harvard researchers decided to put it to the test.

Studies have shown that greater milk consumption during childhood and adolescence contributes to peak bone mass, and is therefore expected to help avoid osteoporosis and bone fractures in later life. But that's not what researchers have found (as you can see in my video Is Milk Good for Our Bones?). Milk consumption during teenage years was not associated with a lower risk of hip fracture, and if anything, milk consumption was associated with a borderline increase in fracture risk in men.

It appears that the extra boost in total body bone mineral density from getting extra calcium is lost within a few years; even if you keep the calcium supplementation up. This suggests a partial explanation for the long-standing enigma that hip fracture rates are highest in populations with the greatest milk consumption. This may be an explanation for why they're not lower, but why would they be higher?

This enigma irked a Swedish research team, puzzled because studies again and again had shown a tendency of a higher risk of fracture with a higher intake of milk. Well, there is a rare birth defect called galactosemia, where babies are born without the enzymes needed to detoxify the galactose found in milk, so they end up with elevated levels of galactose in their blood, which can causes bone loss even as kids. So maybe, the Swedish researchers figured, even in normal people that can detoxify the stuff, it might not be good for the bones to be drinking it every day.

And galactose doesn't just hurt the bones. Galactose is what scientists use to cause premature aging in lab animals--it can shorten their lifespan, cause oxidative stress, inflammation, and brain degeneration--just with the equivalent of like one to two glasses of milk's worth of galactose a day. We're not rats, though. But given the high amount of galactose in milk, recommendations to increase milk intake for prevention of fractures could be a conceivable contradiction. So, the researchers decided to put it to the test, looking at milk intake and mortality as well as fracture risk to test their theory.

A hundred thousand men and women were followed for up to 20 years. Researchers found that milk-drinking women had higher rates of death, more heart disease, and significantly more cancer for each glass of milk. Three glasses a day was associated with nearly twice the risk of premature death, and they had significantly more bone and hip fractures. More milk, more fractures.

Men in a separate study also had a higher rate of death with higher milk consumption, but at least they didn't have higher fracture rates. So, the researchers found a dose dependent higher rate of both mortality and fracture in women, and a higher rate of mortality in men with milk intake, but the opposite for other dairy products like soured milk and yogurt, which would go along with the galactose theory, since bacteria can ferment away some of the lactose. To prove it though, we need a randomized controlled trial to examine the effect of milk intake on mortality and fractures. As the accompanying editorial pointed out, we better find this out soon since milk consumption is on the rise around the world.

What can we do for our bones, then? Weight-bearing exercise such as jumping, weight-lifting, and walking with a weighted vest or backpack may help, along with getting enough calcium (Alkaline Diets, Animal Protein, & Calcium Loss) and vitamin D (Resolving the Vitamin D-Bate). Eating beans (Phytates for the Prevention of Osteoporosis) and avoiding phosphate additives (Phosphate Additives in Meat Purge and Cola) may also help.

Maybe the galactose angle can help explain the findings on prostate cancer (Prostate Cancer and Organic Milk vs. Almond Milk) and Parkinson's disease (Preventing Parkinson's Disease With Diet).

Galactose is a milk sugar. There's also concern about milk proteins (see my casomorphin series) and fats (The Saturated Fat Studies: Buttering Up the Public and Trans Fat in Meat and Dairy) as well as the hormones (Dairy Estrogen and Male Fertility, Estrogen in Meat, Dairy, and Eggs and Why Do Vegan Women Have 5x Fewer Twins?).

Milk might also play a role in diabetes (Does Casein in Milk Trigger Type 1 Diabetes, Does Bovine Insulin in Milk Trigger Type 1 Diabetes?) and breast cancer (Is Bovine Leukemia in Milk Infectious?, The Role of Bovine Leukemia Virus in Breast Cancer, and Industry Response to Bovine Leukemia Virus in Breast Cancer).

In health,

Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Image Credit: Sally Plank / Flickr. This image has been modified.

Original Link

Why Is Milk Consumption Associated with More Bone Fractures?

Why Is Milk Consumption Associated with More Bone Fractures?.jpg

Milk is touted to build strong bones, but a compilation of all the best studies found no association between milk consumption and hip fracture risk, so drinking milk as an adult might not help bones, but what about in adolescence? Harvard researchers decided to put it to the test.

Studies have shown that greater milk consumption during childhood and adolescence contributes to peak bone mass, and is therefore expected to help avoid osteoporosis and bone fractures in later life. But that's not what researchers have found (as you can see in my video Is Milk Good for Our Bones?). Milk consumption during teenage years was not associated with a lower risk of hip fracture, and if anything, milk consumption was associated with a borderline increase in fracture risk in men.

It appears that the extra boost in total body bone mineral density from getting extra calcium is lost within a few years; even if you keep the calcium supplementation up. This suggests a partial explanation for the long-standing enigma that hip fracture rates are highest in populations with the greatest milk consumption. This may be an explanation for why they're not lower, but why would they be higher?

This enigma irked a Swedish research team, puzzled because studies again and again had shown a tendency of a higher risk of fracture with a higher intake of milk. Well, there is a rare birth defect called galactosemia, where babies are born without the enzymes needed to detoxify the galactose found in milk, so they end up with elevated levels of galactose in their blood, which can causes bone loss even as kids. So maybe, the Swedish researchers figured, even in normal people that can detoxify the stuff, it might not be good for the bones to be drinking it every day.

And galactose doesn't just hurt the bones. Galactose is what scientists use to cause premature aging in lab animals--it can shorten their lifespan, cause oxidative stress, inflammation, and brain degeneration--just with the equivalent of like one to two glasses of milk's worth of galactose a day. We're not rats, though. But given the high amount of galactose in milk, recommendations to increase milk intake for prevention of fractures could be a conceivable contradiction. So, the researchers decided to put it to the test, looking at milk intake and mortality as well as fracture risk to test their theory.

A hundred thousand men and women were followed for up to 20 years. Researchers found that milk-drinking women had higher rates of death, more heart disease, and significantly more cancer for each glass of milk. Three glasses a day was associated with nearly twice the risk of premature death, and they had significantly more bone and hip fractures. More milk, more fractures.

Men in a separate study also had a higher rate of death with higher milk consumption, but at least they didn't have higher fracture rates. So, the researchers found a dose dependent higher rate of both mortality and fracture in women, and a higher rate of mortality in men with milk intake, but the opposite for other dairy products like soured milk and yogurt, which would go along with the galactose theory, since bacteria can ferment away some of the lactose. To prove it though, we need a randomized controlled trial to examine the effect of milk intake on mortality and fractures. As the accompanying editorial pointed out, we better find this out soon since milk consumption is on the rise around the world.

What can we do for our bones, then? Weight-bearing exercise such as jumping, weight-lifting, and walking with a weighted vest or backpack may help, along with getting enough calcium (Alkaline Diets, Animal Protein, & Calcium Loss) and vitamin D (Resolving the Vitamin D-Bate). Eating beans (Phytates for the Prevention of Osteoporosis) and avoiding phosphate additives (Phosphate Additives in Meat Purge and Cola) may also help.

Maybe the galactose angle can help explain the findings on prostate cancer (Prostate Cancer and Organic Milk vs. Almond Milk) and Parkinson's disease (Preventing Parkinson's Disease With Diet).

Galactose is a milk sugar. There's also concern about milk proteins (see my casomorphin series) and fats (The Saturated Fat Studies: Buttering Up the Public and Trans Fat in Meat and Dairy) as well as the hormones (Dairy Estrogen and Male Fertility, Estrogen in Meat, Dairy, and Eggs and Why Do Vegan Women Have 5x Fewer Twins?).

Milk might also play a role in diabetes (Does Casein in Milk Trigger Type 1 Diabetes, Does Bovine Insulin in Milk Trigger Type 1 Diabetes?) and breast cancer (Is Bovine Leukemia in Milk Infectious?, The Role of Bovine Leukemia Virus in Breast Cancer, and Industry Response to Bovine Leukemia Virus in Breast Cancer).

In health,

Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Image Credit: Sally Plank / Flickr. This image has been modified.

Original Link

Hummus for a Healthy Heart

NF-Mar3 Beans Beans They're Good For Your Heart.jpeg

I've talked previously about the anti-diabetic and anti-obesity effects of various phytonutrients in beans, but beans have protective effects on the cardiovascular system as well. As one academic review suggested, plant-specific compounds can have a remarkable impact on the health care system and may provide therapeutic health benefits, including the prevention and treatment of diseases and disorders. Plants have antioxidant effects, anti-inflammatory effects, protect our livers, lower cholesterol and blood pressure, and help prevent aging, diabetes, osteoporosis, DNA damage, heart disease and other disorders. Those without legumes in their daily diet, for example, may be at quadruple the odds of suffering high blood pressure.

Legumes such as chickpeas have been used to treat high blood pressure and diabetes for thousands of years. And they can also lower cholesterol levels. Researchers placed people in Northern India on high fat diets to raise their cholesterol levels up to that of the Western world (up around 206 mg/dL) and swapped in chickpeas for some of the grains they were eating. In five months, their cholesterol levels dropped to about 160, almost to the target of around 150. Cholesterol was reduced more than 15 percent in most of the subjects. In a randomized crossover trial, highlighted in my video, Beans, Beans, They're Good for Your Heart, two servings a day of lentils, chickpeas, beans, or split peas cut cholesterol levels so much that many participants moved below the range for which statin drugs are typically prescribed.

In the India study, although the subjects' cholesterol levels were comparable to the Western world at the start of the treatment with chickpeas, before the studym the participants were eating a low-fat diet. So low that their cholesterol levels started out at 123, well within the safe zone. Only after packing their diets with saturated fat were the researchers able to boost their cholesterol up to typical American levels, which could then be ameliorated by adding chickpeas. So it would be better if they just ate healthy in the first place. Or even better, healthy with hummus: a healthy diet with lots of legumes.


Beans dips like hummus are among my favorite go-to snacks. I like to dip snap peas and red bell pepper slices in them. I'd love to hear everyone's favorite recipe. You show me yours and I'll show you mine :)

Canned Beans or Cooked Beans? Click the link to find out!

Beans can help us live longer (Increased Lifespan from Beans), control our blood sugars (Beans and the Second Meal Effect), and help prevent and treat diabetes (Preventing Prediabetes By Eating More and Diabetics Should Take Their Pulses).

What about the purported "anti-nutrient" phytates in beans? You mean the Phytates for the Prevention of Cancer, the Phytates for Rehabilitating Cancer Cells, and the Phytates for the Treatment of Cancer? Phytate-containing foods may also help protect our bones (Phytates for the Prevention of Osteoporosis).

Why not just take cholesterol pills every day for the rest of our life? See my videos Statin Muscle Toxicity and Statin Cholesterol Drugs and Invasive Breast Cancer.

In health,
Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: homami / Flickr

Original Link

Exercise as Medicine

NF-Sep24 Longer life within walking distance.jpg

Physical inactivity has been called the biggest public health problem of the 21st century. Of course just because someone calls it that doesn't mean it's true, in fact physical inactivity ranks down at #5 in terms of risk factors for death, and #6 in terms of risk factors for disability. Diet is by far our greatest killer, followed by smoking.

But, there is irrefutable evidence of the "effectiveness of regular physical activity in the prevention of several chronic diseases--cardiovascular disease, diabetes, cancer, hypertension, obesity, depression, osteoporosis, and premature death"--helping to add years to our life, and above all, "life to our years." It truly may be survival of the fittest.

How much exercise do we need? In general, the answer is the more the better. Currently, "most health and fitness organizations advocate a minimum of a thousand calories of exercise a week," which is equivalent to walking an hour a day five days a week. Seven days a week, though, may be even better in terms of extending one's lifespan.

Exercise is so important that not walking an hour a day is considered a high risk behavior, alongside smoking, excess drinking, and being obese. Having any one of these effectively ages us three to five years in terms of risk of dying prematurely, though interestingly those who ate green vegetables on a daily basis did not appear to have that same bump in risk. Even if broccoli-eating couch potatoes live as long as walkers, there are a multitude of ancillary health benefits to physical activity that doctors are encouraged to prescribe it, to signal to the patient that "exercise is medicine."

Researchers at the London School, Harvard, and Stanford compared exercise to drug interventions in study highlighted in my video, Longer Life Within Walking Distance, and found that exercise often worked just as well as drugs for the treatment of heart disease, stroke, and diabetes. There's not a lot of money to fund exercise studies, so one option would be to require drug companies to compare any new drug to exercise. In cases where drug options provide only modest benefit, patients deserve to understand the relative impact that physical activity might have on their condition.

Exercise is just one of four lifestyle behaviors found to significantly extend our lifespan. See my video, Turning the Clock Back 14 Years.

Other longevity videos include:

More videos on exercise:

What about the stress it can put on our bodies? See:

In health,
Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: Dominic Alves / Flickr

Original Link

Phytates in Beans: Anti-Nutrient or Anti-Cancer?

NF-May28 Phytates for the Treatment of Cancer.jpg

In my videos, Phytates in the Prevention of Cancer and Phytates for Rehabilitating Cancer Cells, I described how phytates in beans may be the reason why legumes are so successful in preventing cancer and re-educating cancer cells. What about phytates for the treatment of cancer?

Colorectal cancer is the second leading cause of cancer death in the United States. It arises from "adenomatous polyps," meaning that colon cancer starts out as a benign little bump called a polyp and then grows into cancer that can eventually spread to other organs and kill. So the National Cancer Institute funded the Polyp Prevention Trial, highlighted in my video, Phytates for the Treatment of Cancer, to determine the effects of a high-fiber, high fruit and vegetable, low-fat diet.

Researchers found no significant associations between polyp formation and overall change in fruit and vegetable consumption. However, those with the greatest increase in bean intake only had about a third of the odds of advanced polyps popping up. It could have been the fiber in the beans, but there's lots of fiber in fruits and vegetables, too. So it may have been the phytate.

If the tumors develop from polyps, they still need to spread. Tumor growth, invasion, and metastasis are multistep processes that include cell proliferation, digestion through the surrounding tissue, and migration through barrier membranes to reach the bloodstream so the tumor can establish new proliferating colonies of cancer cells. A critical event in tumor cell invasion is the first step: the tunneling through the surrounding matrix. To do this, the cancer cells use a set of enzymes called matrix metalloproteinases. This is where phytates might come in. We've known that phytates inhibit cancer cell migration in vitro, and now perhaps we know why. Phytates help block the ability of cancer cells to produce the tumor invasion enzyme in the first place (at least for human colon and breast cancer cells).

So what happens if you give phytates to breast cancer patients? Although a few case studies where phytates were given in combination with chemotherapy clearly showed encouraging data, organized, controlled, randomized clinical studies were never done--until now. Fourteen women with invasive breast cancer were divided randomly into two groups. One group got extra phytates; the other got placebo. At the end of six months, the phytate group had a better quality of life, significantly more functionality, fewer symptoms from the chemo, and did not get the drop in immune cells and platelets chemo patients normally experience.

What are the potential side effects of phytates? Less heart disease, less diabetes, and fewer kidney stones.

Because cancer development is such an extended process--it can take decades to grow--we need cancer preventive agents that we can take long-term. Phytates, which naturally occur in beans, grains, nuts, and seeds, seem to fit the bill.

In the past, there were concerns that the intake of foods high in phytates might reduce the bioavailability of dietary minerals, but recent studies demonstrate that this co-called "anti-nutrient" effect can be manifested only when large quantities of phytates are consumed in combination with a nutrient poor diet. For example, there used to be a concern that phytate consumption might lead to calcium deficiency, which then led to weakened bones, but researchers discovered that the opposite was true, that phytates actually protect against osteoporosis (See Phytates for the Prevention of Osteoporosis). In essence, phytates have many characteristics of a vitamin, contrary to the established and, unfortunately, still existing dogma among nutritionists regarding its 'anti-nutrient' role.

As one paper in the International Journal of Food Science & Technology suggests:

"Given the numerous health benefits, phytates participation in important intracellular biochemical pathways, normal physiological presence in our cells, tissues, plasma, urine, etc., the levels of which fluctuate with intake, epidemiological correlates of phytate deficiency with disease and reversal of those conditions by adequate intake, and safety - all strongly suggest for phytates inclusion as an essential nutrient, perhaps a vitamin."

The paper concludes that inclusion of phytates in our diet for prevention and therapy of various ailments, cancer in particular, is warranted.

More on preventing tumor invasion and metastasis in:

Other foods that can help stop the progression of precancerous lesions (like the adenomatous polyps) are profiled in Strawberries versus Esophageal Cancer and Black Raspberries versus Oral Cancer.

There's a substance in mushrooms that's also another "essential" nutrient candidate. See Ergothioneine: A New Vitamin?

-Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: The Ewan / Flickr

Original Link

Three Things to Know About Bone Health

Bone health…an issue that many of us take for granted until, perhaps, it is too late. 54 million U.S. adults age 50 and older (a large chunk of the population) are affected by osteoporosis and low bone mass. Here are Three Things To Know about bone health….in collaboration with Vegan Street… Resources: 5 Ways to Optimize …

Original Link

5 Ways to Optimize Bone Health

Cray cray for calcium? Indeed! The dairy industry has brilliantly distorted the idea that the more of its products you consume, the better off your bones will be for the long haul. If only it were that simple…. Dairy products do indeed deliver a dose of calcium and fortified vitamin D, but that is not the …

Original Link

How Beans Help Our Bones

NF-Nov20 How Beans Help Our Bones.jpg

Health authorities from all over the world universally recommend increasing the consumption of whole grains and legumes--beans, split peas, chickpeas, and lentils--for health promotion. But what about the phytates?

Phytate is a naturally occurring compound found in all plant seeds (like beans, grains, and nuts) that over the decades has been maligned as mineral absorption inhibitors. That's why, for example, one hears advice to roast, sprout, or soak your nuts to get rid of the phytates so we can absorb more minerals, like calcium.

The concern about phytates and bone health arose from a series of laboratory experiments performed on puppies published in 1949, which suggested that high phytate diets have a bone softening and anti-calcifying effect. Subsequent studies on rats, in which they fed them the equivalent of ten loaves of bread a day, "confirmed" phytate's status as a so-called anti-nutrient. But more recently, in the light of actual human data, phytate's image has undergone a makeover.

A recent study published in the Journal of Medicinal Food asked a simple question: Do people who avoid high phytate foods--legumes, nuts, and whole grains--have better bone mineral density? No. Those that consumed more high-phytate foods actually had stronger bones, as measured in the heel, spine and hip. The researchers conclude that dietary phytate consumption had protective effects against osteoporosis and that low phytate consumption should actually be what's considered an osteoporosis risk factor.

A follow-up study, measuring phytate levels flowing through women's bodies and following bone mass over time, found the same thing: women with the highest phytate levels had the lowest levels of bone loss in the spine and hip. Those who ate the most phytates were also estimated to have a significantly lower risk of major fracture, and a lower risk of hip fracture specifically.

This is consistent with reports that phytate can inhibit the dissolution of bone similar to anti-osteoporosis drugs like Fosamax. Phytates don't have the side effects, though, such as osteonecrosis (bone death) associated with that class of drugs. People take these drugs to protect their bones, but by doing so may also risk rotting them away (See Phytates for the Prevention of Osteoporosis).

Eating healthy can help us avoid other drugs as well. See, for example:

Beans might not just help our skeleton last longer, but the rest of us as well. See Increased Lifespan From Beans.

How might one boost mineral absorption? See New Mineral Absorption Enhancers Found.

Alkaline Diets, Animal Protein, & Calcium Loss is another surprising video on bone health.

And more on the benefits of phytates can be found in my videos:

-Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Asja Boros / Flickr

Original Link

What Do Meat Purge and Cola Have in Common?

NF-Oct9 Phosphate Additives in Meat Purge and Cola.jpg

In my video, Treating Kidney Failure Through Diet, I profiled research suggesting that the use of a plant-based diet for patients with kidney failure would be beneficial. An important function of our kidneys is to filter out excess phosphorus from our bloodstream, so a decline in kidney function can lead to the build-up of phosphorus in our bodies. This in turn can cause something called metastatic calcification, where our heart valves and muscles and other parts of the body can buildup mineral deposits, eventually potentially resulting in bad things like skin necrosis, gangrene, and amputations. Therefore, controlling dietary phosphorus intake is the lynchpin of successful prevention of metastatic calcification. While both plant foods and animal foods have phosphorus, our bodies seem better able to handle phosphorus excretion from plants, so a plant-based diet may help protect against this dreadful condition.

However, we're beginning to realize that absorbing too much phosphorus isn't good for anyone, even those with healthy kidneys. Having high levels in our blood has been found to be an independent predictor of heart attacks and mortality in the general population, increasing the risk not only of kidney failure, but also of heart failure, heart attacks, coronary death, and overall death. Dietary intake of phosphate is an important matter not just for persons with kidney disease, but for everybody. It's thought to cause damage to blood vessels, to accelerate the aging process, and even, potentially, to hurt our bones by contributing to osteoporosis via a disruption of hormonal regulation. The estimated average requirement of phosphorus is less than 600 mg a day, but the estimated average intake in the United States is nearly twice that. How do we stay away from too much of the stuff?

In the video, Phosphate Additives in Meat Purge and Cola, we can see the different levels of phosphorus in different foods. It looks like many plant foods have as much phosphorus as many animal foods. So why are plant-based diets so effective in treating kidney failure patients? Because most of the phosphorus in plant foods is found in the form of phytic acid, which we can't digest. Therefore, while plant and animal foods may have similar phosphate contents, the amount that is bioavailable differs. In plant foods, the bioavailability of phosphates is usually less than 50%, while the bioavailability of most animal products is up around 75%.

So when we adjust for how much actually gets into our system, plant foods are significantly better. It's like the absorption of heme and non-heme iron: our bodies can protect themselves from absorbing too much plant-based iron, but can't stop excess muscle and blood-based (heme) iron from animals slipping through the intestinal wall (see my video Risk Associated With Iron Supplements).

The worst kind of phosphorus is in the form of phosphate additives (which are absorbed nearly 100%) that are added, for example, to cola drinks. Why is phosphate added to cola? Without the added phosphate, so many glycotoxins would be produced that the beverage would turn pitch black (see my video on Glycotoxins). Thus, cola drinks owe their brown color to phosphate.

Phosphate additives play an especially important role in the meat industry, where they are used as preservatives for the same reason: to enhance a meat product's color. Just like the dairy industry adds aluminum to cheese, the meat and poultry industries "enhance" their products by injecting them with phosphates. If one looks at meat industry trade journals and can get past all the macabre ads for "head dropping robots for the kill floor," you'll see all ad after ad for injection machines. Why? Because of "increased profitability." Enhanced meats have better color and less "purge."

Purge is a term used to describe the liquid that seeps from flesh as it ages. Many consumers find this unattractive, so the industry views phosphate injection as a win-win. When chicken is injected with phosphates, the "consumer benefits through the perception of enhanced quality," and the processor benefits from increased yield because they just pump it up with water and they sell it by the pound. The problem is that it can boost phosphorus levels in meat nearly 70%, a "real and insidious danger" not only for kidney patients, but for us all.

Another toxic addition to alter the color of meat is arsenic-containing drugs fed directly to chickens (see my video Arsenic in Chicken). Carbon monoxide is used to keep red meat red, anthoxanthins keep salmon pink (Artificial Coloring in Fish) and titanium dioxide is used to whiten processed foods (Titanium Dioxide & Inflammatory Bowel Disease). I'm amazed by the risks the food industry will take to alter food cosmetically (more on this in Artificial Food Colors and ADHD).

There are other harmful additives in soda as well (Is Sodium Benzoate Harmful? and Diet Soda and Preterm Birth).

What else is in poultry purge (chicken "juice")? Find out in my video, Phosphate Additives in Chicken.

-Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Images thanks to Michael Scheltgen / Flickr

Original Link

Does Animal Protein Cause Osteoporosis?

NF-July29 Alkaline Diets, Meat, and Calcium Loss.jpg

For most of the last century, a prevailing theory within the field of nutrition was that by eating acid-forming foods such as meat, we were, in essence, at risk of peeing our bones down the toilet. And no wonder! Experiments dating back to 1920 showed over and over that if we add meat to our diet we get a big spike in the amount of calcium being lost in the urine.

And this made total sense. We had known since 1912 that meat was acid-forming within the body, and how do we buffer acid? What are in antacid (anti-acid) pills like Tums? Calcium compounds.

Meat and eggs have a lot of sulphur-containing amino acids (two to five times more than grains and beans) that are metabolized into sulphuric acid, which the body buffers with calcium compounds. And where is calcium stored in the body? The skeleton. So the thinking was that every time we ate a steak, our body would pull calcium from our bones, bit by bit, and over time this could lead to osteoporosis. Based on 26 such studies, for every 40 grams of protein we add to our daily diet, we pee out an extra 50 mg of calcium. We only have about two pounds of calcium in our skeleton, so the loss of 50 grams a day would mean losing close to 2% of our bone calcium every year. By the end of the 20th century, there was little doubt that acid-forming diets would dissolve our bones away.

But if we actually look at the studies done on protein intake and bone health, that's not what we find. So, where's the flaw in the logic? Meat leads to acid, which leads to calcium loss, which leads to bone loss, right?

Well, it's uncontroversial that protein results in greater calcium excretion, but we've just been assuming it's coming from the bone--where else could the extra calcium dumped in our urine be coming from but our bones?

One study appeared to solve the mystery. An intrepid group of researchers tried feeding a group of volunteers radioactive calcium and then put them on a high protein diet. What happens when we put people on a high protein diet? The amount of calcium in their urine shoots up, and indeed that's just what happened. But here's the big question, was that extra calcium in their urine radioactive or not? To everyone's surprise, it was radioactive. This meant that the excess calcium in their urine was coming from their diet, not from their bones.

What seemed to be happening is that the excess protein consumption boosted calcium absorption, from down around 19% up to 26%. All of a sudden there was all this extra calcium in the blood, so presumably the kidneys are like "whoa, what are we going to do with it all?" So they dump it into the urine. 90% of the extra calcium in the urine after eating a steak doesn't appear to be coming from our bones but from our diet. We're not sure why protein boosts calcium absorption. Maybe protein increases the solubility of calcium by stimulating stomach acid production? Whatever the reason, there was indeed more calcium lost, but also more calcium gained such that in the end, most of that extra calcium is accounted for. In effect, more calcium is lost in the urine stream, but it may be compensated by less loss of calcium through the fecal stream.

This was repeated with even more extreme diets--an acid-forming five-burgers-a-day-worth-of-animal protein diet that limited fruits and vegetables versus an alkaline diet emphasizing fruits and vegetables. More calcium in the urine on burgers, but significantly greater calcium absorption, such that at the end it was pretty much a wash.

Other studies have also since supported this interpretation. Here's an ingenious one: Feed people a high animal protein diet but add in an alkali salt to neutralize the acid. The old thinking would predict that there would be no calcium loss since there is no excess acid to buffer, but no, even though the acid load was neutralized, there was still the excess urinary calcium, consistent with the radioactive isotope study, challenging the "long-standing dogma that animal protein consumption results in a mild acidosis promoting the increased excretion of calcium."

So if our body isn't buffering the acid formed from our diet with our bones, how is it neutralizing the acid? Maybe with our muscles. Alkaline diets may protect our muscle mass! I cover that in my video Testing Your Diet with Pee and Purple Cabbage.

Now the boost in calcium absorption can only compensate if we're taking enough in. For example, dietary acid load may be associated with lower bone mineral density in those getting under 800mg a day. Plant Protein is Preferable to animal protein for a variety of reasons (tends to have less methionine, is less IGF-1 promoting, etc.), but it's not clear how much of an advantage it has when it comes to bone health.

I previously touched on this topic in my video Is Protein Bad to the Bone? But I promised I'd take a deeper dive, hence my video Alkaline Diets, Meat & Calcium Loss.

-Michael Greger, M.D.

Note to chemistry geeks: Yes, I know it's the calcium salt anions that actually do the buffering (carbonate in Tums and phosphate in bones), but I'm trying my best to simplify for a largely lay audience. I'll make it up to you with some kitchen chemistry (actually bathroom chemistry!) in my Testing Your Diet video.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death and More Than an Apple a Day.

Image Credit: PD Art / Wikimedia Commons

Original Link