I’m still seeing a lot of stuff written about balancing out our blood ph levels in an effort to reduce acidity, and therefore improve health, disease markers, and reduse bone loss, etc.
The premise is that consuming too many acid causing foods (I’m not going to list them because there’s many arguments on both sides of the field) causes the ph of our blood to become too acidic, and to compensate our bodies have to leech calcium from our bones in an effort to reduce that acidity and increase alkanine balance. The health consequences of which are said to be cancer, osteoperosis, heart disease, and a host of other problems.
It’s also said that you can measure this change in ph by buying those little ph strips from the pharmacy and checking the levels in your urine or saliva.
The origination of the acid-base theory is often epidemiological studies, which we all know are incapable of determining cause and effect relationships. I talked about that already here. They still try to do it, nonetheless, and everyone gets all excited and starts pointing fingers.
Of couse, the promoters of these “ph balance” diets are predominantly meat-haters (you know who you are), but occasionally I see arguments coming from the Paleo realm. This strikes me as odd. But oh well. I smell bullshit, so I’m going to take a swing at dispelling this acid-base diet myth once and for all.
The science of ph balance
Here’s the scale:
Right, so our blood generally likes a ph of 7.4, right in the middle. Any large variation on that towards acidic or basic results in certain death. This is homeostasis. Luckily we have a series of buffers and mechanisms that regulate this ph. For example, carbon dioxide is the most abundant acid in our bodies, and is a product of regular cellular activity. Our lungs do their job and expell CO2 when we breathe. The kidneys also provide natural acid elimination through the urine. And our blood is constantly circulating to help provide homeostasis.
Now lets look at the digestive process. Everything we eat has to pass through the stomach first. Our stomach environment is highly acidic. It’s full of hydrochloric acid, after all. Almost everything that enters the stomach is broken down by this hydrochloric acid, and therefore takes on the same ph as the stomach. A nice acidic ph of 3.
Once this digested food enters the intestines, digestive enzymes and liquids immediately bring the acidity back down to the same level as the intestines. This means that, after entering the stomach, then the intestines, the initial ph of anything we eat is irrelevant.
The ph of the urine varies naturally as a function of the waste that is being eliminated. But this is unrelated to the ph of the rest of your body. Excess acidity is eliminated in the kidneys, and will vary depending on what you eat, but that’s it. If your blood ph actually correlated to your urine ph, you would easily be dead already.
But cancer only survives in an acid environment, right?
This is a common claim. But does it hold water? Again, our bodies can only survive within a narrow window of ph near 7.4. This is tightly regulated by homeostasis. Leukemia and lymphoma thrive in a blood ph of 7.4. So the claim that cancer only survives in an acid environment is totally bunk, and claims that acidity is the root of all disease is bunk.
But why do we see calcium secretion in the urine of populations eating [insert various food here] diets?
Calcium leeching from the bones happens due to nutrient deficient diets. Certain nutrients play a very crucial role in calcium metabolism, and a defficiency can cause calcium to go where we don’t want, like our teeth as plaque, or our arteries, and not into bones where it’s suposed to. We already know that vitamin D plays a crucial role in making sure calcium is used properly. We can get plenty of calcium from green leafy veggies, and a little bit of gool ol’ sun exposure gives us a great source of D.
“Alfred Wallace hypothesized that hypocalcemic tetany from low levels of calcium and vitamin D underlied a phenomenon of hysteria found among Eskimos called pibloktok. Wallace noted that tetany was common among Inuit who did not have year-round access to fatty fish and fish bones, but that bone diseases were incredibly rare among the Inuit even when they faced seasonal malnutrition.
So much for the idea that acid-producing diets lead to bone disease among the Inuit.”
“Studies conducted by Jane Kerstetter’s group at the University of Connecticut, however, showed that an even larger increase in dietary protein from 0.7 g/kg to 2.1 g/kg did, in fact increase urinary calcium, but not by leaching it from bone. Instead, they found that consuming more protein increased calcium absorption from the intestines.”
Then there’s this intervention trial, that shows very clearly how protein intakes far beyond the minimal requirement actually improve bone health.
Vitamins K , A and D.
“Vitamin K-2 is the substance that makes the vitamin A- and vitamin D-dependent proteins come to life. While vitamins A and D act as signaling molecules, telling cells to make certain proteins, vitamin K-2 activates these proteins by conferring upon them the physical ability to bind calcium. In some cases these proteins directly coordinate the movement or organization of calcium themselves; in other cases the calcium acts as a glue to hold the protein in a certain shape. In all such cases, the proteins are only functional once they have been activated by vitamin K…”
“…Vitamin K-2 may also be required for the safety of vitamin D…”
“…Vitamin K1 supplements produce modest decreases in bone loss in the elderly. A number of Japanese trials, on the other hand, have shown that vitamin K2 completely reverses bone loss and in some cases even increases bone mass in populations with osteoporosis…”
“…The balance of the evidence, however, suggests that vitamin K2 is essential to skeletal health and that it is a key substance that modern diets do not adequately provide…”
So it’s obvious that these nutrients are crucial for proper calcium metabolism, they work in synergy. Without enough of one, we have problems with the other potentially forming.
With a poor diet, as is often looked at in epidemiological health studies, we see instances of poor bone health. Attempts to link one type of diet (particularly high protein or high fat or high acid or whatever) to weak bones usually results in weaker correlations. But a closer look reveals stronger associations with diets that are deficient or cause deficiencies in vitamins A, D, and K. Such diets are usually very high in nutrient-void processed foods, and high grain diets also contribute to deficiencies by way of phytates. Avoiding nutrient dense animal foods doesn’t help matters either.
So again. Acid-base ph blood balance vs calium and bone health etc etc. Bullshit. It was a nice theory, but science doesn’t support it. Let’s move on, shall we?
“As long as you are eating properly, and not just downing protein powder as your only source of food, you will be consuming adequate calcium and fat soluble vitamins, like K2, which support proper calcium metabolism.”