Too much protein is bad??

If you're an older woman, too much animal protein (especially meat and dairy) can contribute to osteoporosis. I took a course in nutrition a few years ago, and the way they described it was that the body releases acids to digest animal protein. Too much protein will cause acid levels to rise on a continuous level in your body. To neutralize and buffer the acidity, your body will release calcium phosphate, which it pulls from the bones. So obviously too much calcium pulled from the bones will increase the risk of weaker bones, and eventually osteoporosis.

It may explain why the countries in the world that have the highest meat and dairy consumption, also have the highest levels of osteoporosis. It should be the opposite.

Hmmmm, Asians have a pretty high rate of osteoporosis and most of the Asian countries have a diet high in vegetables, fish, seafood, and chicken, and very low in dairy calcium. I always thought it was related to overall bone density hence why races of lighter bone density Caucasian and Asian have a greater risk for osteoporosis. Also, it's probably somewhat related to vitamin D as you look again at people those in higher northern climates with less sunlight also have problems with osteoporosis such as Scandinavians. I'd be curious to see the literature of your nutrition class.

And just for giggles if we really wanted to prevent osteoporosis obesity is a great prevention

If you're an older woman, too much animal protein (especially meat and dairy) can contribute to osteoporosis. I took a course in nutrition a few years ago, and the way they described it was that the body releases acids to digest animal protein. Too much protein will cause acid levels to rise on a continuous level in your body. To neutralize and buffer the acidity, your body will release calcium phosphate, which it pulls from the bones. So obviously too much calcium pulled from the bones will increase the risk of weaker bones, and eventually osteoporosis.

It may explain why the countries in the world that have the highest meat and dairy consumption, also have the highest levels of osteoporosis. It should be the opposite.

This is a myth & has been proven wrong. In fact, the opposite is true! Abstract from articles below:

Dietary protein and skeletal health: a review of recent human research.
Kerstetter JE, Kenny AM, Insogna KL.

Department of Allied Health Sciences, University of Connecticut, Storrs, Connecticut, USA. jane.kerstetter@uconn.edu
Abstract

PURPOSE OF REVIEW:
Both dietary calcium and vitamin D are undoubtedly beneficial to skeletal health. In contrast, despite intense investigation, the impact of dietary protein on calcium metabolism and bone balance remains controversial. A widely held view is that high intakes of animal protein result in increased bone resorption, reduced bone mineral density, and increased fractures because of its ability to generate a high fixed metabolic acid load. The purpose of this review is to present the recent or most important epidemiological and clinical trials in humans that evaluated dietary protein's impact on skeletal health.

RECENT FINDINGS:
Many epidemiological studies have found a significant positive relationship between protein intake and bone mass or density. Similarly, isotopic studies in humans have also demonstrated greater calcium retention and absorption by individuals consuming high-protein diets, particularly when the calcium content of the diet was limiting. High-protein intake may positively impact bone health by several mechanisms, including calcium absorption, stimulation of the secretion of insulin-like growth factor-1, and enhancement of lean body mass. The concept that an increase in dietary protein induces a large enough shift in systemic pH to increase osteoclastic bone resorption seems untenable.

SUMMARY:
Recent epidemiological, isotopic and meta-analysis studies suggest that dietary protein works synergistically with calcium to improve calcium retention and bone metabolism. The recommendation to intentionally restrict dietary protein to improve bone health is unwarranted, and potentially even dangerous to those individuals who consume inadequate protein.


***

Dietary protein: an essential nutrient for bone health.
Bonjour JP.

Service of Bone Diseases, University Hospital, Rue Micheli-Du-Crest, 1211 Geneva, Switzerland. Jean-Philippe.Bonjour@medecine.unige.ch.

Abstract
Nutrition plays a major role in the development and maintenance of bone structures resistant to usual mechanical loadings. In addition to calcium in the presence of an adequate vitamin D supply, proteins represent a key nutrient for bone health, and thereby in the prevention of osteoporosis. In sharp opposition to experimental and clinical evidence, it has been alleged that proteins, particularly those from animal sources, might be deleterious for bone health by inducing chronic metabolic acidosis which in turn would be responsible for increased calciuria and accelerated mineral dissolution. This claim is based on an hypothesis that artificially assembles various notions, including in vitro observations on the physical-chemical property of apatite crystal, short term human studies on the calciuric response to increased protein intakes, as well as retrospective inter-ethnic comparisons on the prevalence of hip fractures. The main purpose of this review is to analyze the evidence that refutes a relation of causality between the elements of this putative patho-physiological "cascade" that purports that animal proteins are causally associated with an increased incidence of osteoporotic fractures. In contrast, many experimental and clinical published data concur to indicate that low protein intake negatively affects bone health. Thus, selective deficiency in dietary proteins causes marked deterioration in bone mass, micro architecture and strength, the hallmark of osteoporosis. In the elderly, low protein intakes are often observed in patients with hip fracture. In these patients intervention study after orthopedic management demonstrates that protein supplementation as given in the form of casein, attenuates post-fracture bone loss, increases muscles strength, reduces medical complications and hospital stay. In agreement with both experimental and clinical intervention studies, large prospective epidemiologic observations indicate that relatively high protein intakes, including those from animal sources are associated with increased bone mineral mass and reduced incidence of osteoporotic fractures. As to the increased calciuria that can be observed in response to an augmentation in either animal or vegetal proteins it can be explained by a stimulation of the intestinal calcium absorption. Dietary proteins also enhance IGF-1, a factor that exerts positive activity on skeletal development and bone formation. Consequently, dietary proteins are as essential as calcium and vitamin D for bone health and osteoporosis prevention. Furthermore, there is no consistent evidence for superiority of vegetal over animal proteins on calcium metabolism, bone loss prevention and risk reduction of fragility fractures.

If you're an older woman, too much animal protein (especially meat and dairy) can contribute to osteoporosis. I took a course in nutrition a few years ago, and the way they described it was that the body releases acids to digest animal protein. Too much protein will cause acid levels to rise on a continuous level in your body. To neutralize and buffer the acidity, your body will release calcium phosphate, which it pulls from the bones. So obviously too much calcium pulled from the bones will increase the risk of weaker bones, and eventually osteoporosis.

It may explain why the countries in the world that have the highest meat and dairy consumption, also have the highest levels of osteoporosis. It should be the opposite.

It's called metabolic acidosis. And thank you, somebody who knows what they are talking about is such a breath of fresh air around here.

Maybe you mean someone wearing the same tinfoil hat.

Seriously, do you really want to me to pull up all the medical studies (not paid for by some private lobbying group) that show what I wrote about? Here is one:

A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Study of Osteoporotic Fractures Research Group - Division of Endocrinology, the General Clinical Research Center, and the Department of Epidemiology and Biostatistics, University of California, San Francisco, USA:

Link - http://www.ncbi.nlm.nih.gov/pubmed/11124760

Cornell University Chronicle:
Want to reduce the risk of osteoporosis? Eat less meat, Cornell researchers say. In fact, they say, reducing the amount of meat in the diet may do more to reduce the risk of osteoporosis than increasing calcium intake. A series of studies from the Cornell-China-Oxford Project on Nutrition, Health and Environment, by nutritional biochemist T. Colin Campbell and his colleagues, conclude that reducing meat intake reduces the risk of losing bone density. Osteoporosis is a condition, usually associated with aging, in which bone density decreases, making people susceptible to breaks and fractures.

http://www.news.cornell.edu/stories/1996/11/eating-less-meat-may-help-reduce-osteoporosis-risk

.....and here's another

http://www.ncbi.nlm.nih.gov/m/pubmed/11127216/?i=6&from=/11124760/related

Effect of dietary protein on bone loss in elderly men and women: the Framingham Osteoporosis Study

Abstract

Few studies have evaluated protein intake and bone loss in elders. Excess protein may be associated with negative calcium balance, whereas low protein intake has been associated with fracture. We examined the relation between baseline dietary protein and subsequent 4-year change in bone mineral density (BMD) for 391 women and 224 men from the population-based Framingham Osteoporosis Study. BMD (g/cm2) was assessed in 1988-1989 and in 1992-1993 at the femur, spine, and radius. Usual dietary protein intake was determined using a semiquantitative food frequency questionnaire (FFQ) and expressed as percent of energy from protein intake. BMD loss over 4 years was regressed on percent protein intake, simultaneously adjusting for other baseline factors: age, weight, height, weight change, total energy intake, smoking, alcohol intake, caffeine, physical activity, calcium intake, and, for women, current estrogen use. Effects of animal protein on bone loss also were examined. Mean age at baseline (+/-SD) of 615 participants was 75 years (+/-4.4; range, 68-91 years). Mean protein intake was 68 g/day (+/-24.0; range, 14-175 g/day), and mean percent of energy from protein was 16% (+/-3.4; range, 7-30%). Proportional protein intakes were similar for men and women. Lower protein intake was significantly related to bone loss at femoral and spine sites (p < or = 0.04) with effects similar to 10 lb of weight. Persons in the lowest quartile of protein intake showed the greatest bone loss. Similar to the overall protein effect, lower percent animal protein also was significantly related to bone loss at femoral and spine BMD sites (all p < 0.01) but not the radial shaft (p = 0.23). Even after controlling for known confounders including weight loss, women and men with relatively lower protein intake had increased bone loss, suggesting that protein intake is important in maintaining bone or minimizing bone loss in elderly persons. Further, higher intake of animal protein does not appear to affect the skeleton adversely in this elderly population.

It seems the take home from most of the protein/calcium and bone loss research I've seen is that a higher than the laughably low RDA intake for protein and exercise/strength training (and reguardless of protein source) helps to preserve bone/muscle mass.

Intakes around say the BroScience 1g/pound may require more dietary calcium to offset mild acidosis, but can overall be beneficial to bone and muscle health.

Total agreement that the western diet is crap because at the RDA and with all animal protein you do get the slight negative of increases acidosis without the benefit of a higher protein diet while consuming a diet that is piss poor in nutrients.

However diets with half a brain overcome all the small negatives highlighted on this thread.

This "metabolic acidosis" theory of calcium depletion is an old 70's and 80's idea and really not something most should worry about even if it were truly a risk, except in certain extreme cases. Its not really an issue from looking at newer studies. And from a logical perspective, when you weight train and eat increased protein, the increased weight loads will cause increased stimulation of bony growth and remodeling to compensate, far outweighing any slight pH factors if they existed. Low protein diets do appear to *reduce* calcium absorption, conversely.

In the same time period there was a large vocal group who spread the ideas that anyone doing an Adkin's diet would have kidney and liver damage from eating almost exclusively protein and fat. This has also shown to be false.

Now gout could be worsened by increased protein, but its relatively rare. And logically, again if you are weight training your protein needs go up. And the risk of metabolic syndrome (increased abdominal fat and linked pre to full diabetes) is a far greater a risk of increasing gout likelihood.

Writers on Yahoo are pretty poorly researched, I would take whatever you see there with a grain of salt. If you are worried still, or are an osteoporotic elderly woman (or have kidney issues already), see your doctor. Not only is there no good evidence for what this writer says, but 110 is not an excessively high number anyways.

If you're an older woman, too much animal protein (especially meat and dairy) can contribute to osteoporosis. I took a course in nutrition a few years ago, and the way they described it was that the body releases acids to digest animal protein. Too much protein will cause acid levels to rise on a continuous level in your body. To neutralize and buffer the acidity, your body will release calcium phosphate, which it pulls from the bones. So obviously too much calcium pulled from the bones will increase the risk of weaker bones, and eventually osteoporosis.

It may explain why the countries in the world that have the highest meat and dairy consumption, also have the highest levels of osteoporosis. It should be the opposite.

It's called metabolic acidosis. And thank you, somebody who knows what they are talking about is such a breath of fresh air around here.

Well for a start the process being described above (calcium release to use as buffering agent) is alkalosis. Metabolic acidosis is often the reverse of this when this buffering fails to occur or there is a build up of acid such as lactate in septicaemia, or ketones following ketosis. Sometimes this occurs when the kidneys fail to excrete a build up of acid due to renal impairment. In the past high protein has been thought to cause renal impairment but this is largely discredited, and protein is only a problem in already impaired kidneys.

I could go on but is this the kind of thing you were looking for in terms of someone who knows what they are talking about?

If you're an older woman, too much animal protein (especially meat and dairy) can contribute to osteoporosis. I took a course in nutrition a few years ago, and the way they described it was that the body releases acids to digest animal protein. Too much protein will cause acid levels to rise on a continuous level in your body. To neutralize and buffer the acidity, your body will release calcium phosphate, which it pulls from the bones. So obviously too much calcium pulled from the bones will increase the risk of weaker bones, and eventually osteoporosis.

It may explain why the countries in the world that have the highest meat and dairy consumption, also have the highest levels of osteoporosis. It should be the opposite.

It's called metabolic acidosis. And thank you, somebody who knows what they are talking about is such a breath of fresh air around here.

Maybe you mean someone wearing the same tinfoil hat.

You guys have been going rounds from one board to the next!

b-U-m-P