The Paleo Diet, Calcium, and Bone Health: The Myth of Dairy

A lot of people, when switching over to eating a Paleo diet, are concerned with a decrease in their overall calcium intake with the elimination of dairy.  This would be a valid concern if A) Veggies didn't provide just as much if not more calcium than dairy and B) Overall calcium intake was the only thing that mattered for bone health.

Calcium is one of the most abundant minerals in our diet and in the US we consume more of it than almost anywhere else in the world, but somehow we also have one of the highest rates of Bone Demineralization (Osteoporosis) in the world.  This should confuse you because we have always been told that we need more calcium and calcium is "King" if you want strong bones.  Remember the commercials- "Milk: It does a body good".  Well I hate to say it but they neglected to mention a few other things that are just as important.  It is true that milk has a good amount of calcium in each serving, however there are more factors involved with bone health than just overall calcium intake.

To understand why drinking an absurd amount of milk might not be the best way to increase bone health, you have to understand a few things.

1. We don't just consume calcium, we also excrete it.
2. When food is eaten, the kidneys determines whether it is an acid(acidic) or a base(alkaline).
3. Our body doesn't like being acidic.
4. The are other minerals and hormones involved with maintaining bone health.
5. Certain things can block calcium absorption and retention.

So what does all that mean in terms of the Paleo Diet, calcium intake, and bone health.  Well hold on to your butts, because here we go.

The pH balance of your body doesn't like being acidic, so when you consume a bunch of acidic foods, i.e. fatty meats, processed meats, hard cheeses, grains, legumes, and (believe it or not) dairies,  your body tries to find a way to bring you back into a more alkaline state, back to the pH balance it loves.  The easiest way and the most abundant source for doing this is taking the calcium salts from your bones and shoving them into your bloodstream.  They are then sent to your kidneys and you literally piss away your calcium and bone health.  To keep this from happening you would need to keep your body at the pH it yearns for.  How could someone accomplish such an impossible feet?  It may surprise you, but by eating lots of yummy veggies and fruit, which also are LOADED with calcium and magnesium (I'll explain why that's important in a bit) you can easily keep your body at the pH it thrives at.  The truth is by relying on dairy products for calcium you are forcing your body to take in WAY more calcium than necessary because the acid load of dairy is just going to turn around and make you pee the calcium right out.  If you add in the fact that most people eat grains, legumes, and highly processed and fatty meats along side of dairies, you are basically telling your body that you hate your bones.  And that's not nice because your bones have always been super supportive of you. (ha anatomy jokes are awesome)

Now if we are peeing out a lot of the calcium we take in, I think the best way to obtain better bone health is to concentrate on how to keep calcium in our bodies and out of our tinkles.  On average we only absorb about 10% of the calcium we ingest (1), so figuring out way to maximize your body's use and retention of calcium might be a better idea than just continually dumping more in just to be excreted, which can cause problems down the road, i.e. calcium kidney stones, age-related muscle wasting, hypertension, stroke, asthma and exercise-induced asthma (2).  So the question is not "Are you getting enough calcium?" it's "Are you absorbing and retaining as much calcium as you need from what you ingest".  So here is a shortish list of things that effect calcium absorption and retention that I found, modified, and shortened for your benefit from http://paleodiet.com/losspts.txt :

1.   Parathyroid hormone moves calcium from bone to bloodstream and signals kidneys to conserve calcium and other minerals from the urine.  It also signals kidneys to produce calcitriol, which is the hormonally active form of Vitamin D, which among other functions signals the small intestine to absorb more calcium, which also reduces the loss of calcium in the urine.
   
2.   Calcitonin, which is secreted by the thyroid and increases bone mineralization, and decreases the rate at which the bone is broken down.  Calcitonin production is increased by impact stress on the bones (in other words doing things that oppose gravity), i.e. walking, jogging, lifting, etc.  This leads to increased deposition of calcium in the bones.  Important note swimming and cycling don’t seem to have the same effect on calcitonin production.
3.   Phytic Acids from grains.  It is an acid that binds to a variety of minerals during digestion including calcium,that forms insoluble salts (phytates) that are excreted from the body.  This obviously is bad because it prevents our bodies from even having a chance at absorbing these minerals.
4.   Inadequate levels of vitamin D prevent proper absorption of calcium. And since we have been told to stay out of the sun by "Health Experts" almost all of us could use a little more vitamin D.  So getting some sensible sun on your skin will help you build your bones stronger than drinking milk will.
5.   Magnesium deficiency is probably the most overlooked aspect of bone health. 1:1 ancestral ratio of calcium/magnesium is what our bodies are adapted to have.  Dairy has a 12:1 ratio, and since most Americans drink milk for their calcium it has caused an average modern ratio of 4:1.  Getting our ratio back to where it should be is where that magnesium loaded veggies I mentioned earlier come in handy.  Calcium and magnesium compete for the same absorption mechanisms, and the modern imbalance will lead to a magnesium deficiency. The problem with a magnesium deficiency is that it will lead to inhibition of osteoblast, which are cells that build and maintain bones.  One could increase bone density by an increase of or supplementation of magnesium, not calcium.  (This could also help with sleep quality but that's another post all together)
   
6.   Phosphoric acid(soft drinks) can also cause problems.  In order to utilize calcium well, we need 1.5g of phosphorus and .5g of magnesium for each gram of Calcium.  Phosphorus is very abundant in our modern diets and the increase that comes from soft drink consumption drives up our need for magnesium and calcium, which as you might guess just makes it much harder on your body to keep your skeletal system healthy.

  Here are a few suggestions to help improve calcium absorption, retention and overall bone health: 

1. Get your calcium from vegetables and fruits;

2. Minimize your salt intake;

3. Spend regular time in the sun, or supplement with vitamin D;

4. Get plenty of anti-gravity exercise;

5. Make damn sure you are getting as much magnesium as you are calcium;

6. Reduce or eliminate dairy products from your diet;

7. Avoid processed sugar intake;

8. Avoid soft drinks;

9. Limit coffee and tea consumption to reasonable levels;

10. Do not smoke;

11. Stay away from all grains, legumes, and dairies;

12. Get plenty of quality sleep; 

 Do these suggestions sound familiar, because they should.  These are the exact same 

recommendations that you have been given to optimize not only your health but performance

too. 

So here's the deal, don't worry about "getting enough calcium" on the Paleo diet.  You'll be

fine just eat lots of lean meats, veggies, some fruits, nuts, seeds, and good oils, and run

around and lift things in the sun for reasonable amounts of time, and your bones will 

continue to support you till the day you die. 

Resources:

1) Paleo Diet website by Don Wiss http://paleodiet.com/losspts.txt 

2) The Paleo Diet website by Dr. Loren Cordain http://www.thepaleodiet.com/nutritional_tools/acid.shtml