While some of you may have never heard of the alkaline diet others may know it quite well or possibly even have tried it. Although there may be slight variations, the basic concept is similar, the foods we consume leave behind an ash residual after being metabolized. This ash will either be acidic or basic (alkaline) depending on what food-group it falls under.
But, before we go any further, let’s do a little brush-up in high school biochemistry for those of you who may not remember the basis behind acid and alkalinity in relationship to pH. Perhaps you may recall that pH is a measure of the acidity or basicity (alkalinity) of a solution. If a solution is 7, it’s considered neutral, less than 7, its pH is acidic; over 7, and it becomes basic or alkaline.
Based on those measures, the foods we consume fall into one of three basic categories:
- Acidic
- Alkaline
- Neutral
For example, foods that fall into the acidic camp are meat, poultry, fish, dairy, eggs, grains and alcohol while foods that fall into the alkaline camp are fruits, nuts, legumes and vegetables, with natural fats, starches and sugars being neutral due to the fact that they don’t contain protein, sulfur, or minerals.
According to the Alkaline Diet theory, it’s been proposed that if we eat an alkaline based diet, thereby leaving behind an over-all alkaline load on our body, we can supposedly protect ourselves from the many modern diseases that society struggles with today, whereas if we eat a diet rich in foods that leave an over-all acidic load on us, we will become highly susceptible to everything from cancer and autoimmune disorders to allergies and arthritis.
The Alkaline Diet and Health
First, unlike millions of other diets on the market today the alkaline diet is actually quite healthy. It encourages a significant consumption of fruits, vegetables and healthy plant foods, while eliminating almost all processed foods, which is a good thing.
However, the claims about the means behind the diet are not at all supported by human physiology. If fact, many foods that leave an over-all acid load on the body are some of the most important foods for us. These include meat, poultry, fish, dairy, eggs, which are all protein bearing foods, supplying the body with the necessary building blocks (amino acids) vital in the development, maintenance and repair of our hair, skin, eyes, muscles, and organs, not to mention an array of metabolic processes. (1 , 2, 3)
Cracks Within the Hypothesis
I think we can all agree that it’s very calming to see concrete improvements in health risk factor numbers. In fact, these parameters established when it comes to things like blood pressure, cholesterol, triglycerides, and blood sugars have become our set standards in relationship to the state of our health.
Therefore, because it’s very easy to measure the pH of our urine, which is probably one of the major draws of the alkaline diet, the urine pH test gives proponents of this diet a sort of instant gratification which helps them believe that they’re in a healthful state.
But, while it’s true that different food types do have an effect on the pH of our urine, what is the significance in relationship to the over-all state of our health?
For example, say you have mixed berries and nuts for breakfast, if you were to test your urine a few hours later, your residual would most likely be much more alkaline than that of someone who had scrambled eggs and toast. (4)
However, as you’ll soon learn, urine pH is not a substantially good indicator of the overall pH of the body, nor is it a good indicator of the over-all state or our general health. (5)
Can Food Really Influence Blood pH?
Although we’ve established that food does have an over-all affect on the pH of our urine, the more important question becomes, can food really alter the pH of our blood? This is a warranted question, because at the end of the day what’s happening within the blood will ultimately determine the over-all state of our health.
According to advocates of the Alkaline Diet if we change our diet from acid forming foods to alkaline forming foods we can subsequently change the pH of not only our body, but more importantly, our blood, thus creating an environment where disease is unable to incubate.
However, the body already has many built-in mechanisms that continuously regulate the pH balance in our body, which is known as Acid-based homeostasis. (6)
In fact, the body’s acid/alkaline balance is tightly regulated by buffering agents, the respiratory system, and the renal system, keeping our blood pH constantly hovering between 7.36 and 7.42 respectively. If we were to fall outside of this tightly regulated operating range, our cells would stop functioning properly, and left untreated, would send us into a serious life threatening situation. (7)
So, fortunately for us, these mechanisms make it near impossible for any outside influences, particularly the type of foods we eat, to change the pH value of our blood. And if this wasn’t true, we would surely be at risk for many major health consequences.
Therefore, food simply cannot change our blood pH…Period! (8)
Acid Forming Foods and Bone Health
Many alkaline diet enthusiasts are convinced that if we eat a diet rich in acid forming foods the body will leach minerals, such as calcium, from our bones to buffer the acids in order to maintain a constant blood pH.
According to this theory, acid forming diets such as the standard American diet (SAD) cause a loss in bone mineral density, increasing the risk for fractures and osteoporosis, particularly in postmenopausal women. This theory is what is known as the acid-ash hypothesis of osteoporosis. (9)
However, this theory completely overlooks one of the major functions of our kidneys. One of the fundamental roles of our kidneys is to remove acid and regulate body pH. When we digest acid forming foods like meats or grains, the kidneys produce bicarbonate ions that rapidly neutralize acids in the blood. This defensible process creates a sustainable cycle which enables the body to tightly regulate blood pH, with no involvement from our bones whatsoever. (10)
In addition, our respiratory system is also involved in controlling blood pH. When bicarbonate ions from the kidneys bind to acids in the blood, they form carbon dioxide, in which we exhale, and water and salt which are excreted through urination.
In fact, no observational studies have found any correlation between dietary acid load and bone mineral density or higher risk for fracture, nor have they found any correlation between urine pH and bone mineral density or risk for fracture. (11, 12, 13)
Additionally, higher protein intake is actually correlated with better bone health in multiple studies, even though high protein diets are generally net acid forming. In fact, according to studies, protein, particular animal protein, which happens to be one of the most acid-forming food of all, has been associated with better bone health by increasing calcium retention and activating the hormone Insulin-like growth factor 1 (IGF-1) (14), which stimulates the repair of muscle and bone. (15, 16, 17, 18)
Therefore, our understanding of acid-base physiology does in no way support the theory that net acid-forming load causes loss of bone minerals leading to fractures and osteoporosis.
Acid Forming Foods and Muscle Wasting
There is some research that suggests that acid forming foods cause muscle wasting, declaring that the proposed mechanism is similar to that of the acid-ash hypothesis of osteoporosis. The assumption is that in order to eliminate excess acid and maintain homeostasis (19), the kidneys will steal amino acids from muscle tissue. (20)
But, just as higher acid load increases calcium in the urine, it also increases nitrogen in the urine, leading proponents of the Alkaline Diet to believe that acid forming food causes a loss in nitrogen. However, this is simply not true, and in fact, studies show that a higher acid diet actually improves nitrogen balance. (21)
In addition, this theory also does not acknowledge that protein bearing foods, although acid forming actually helps increase the body’s ability to excrete acid. (22)
Acid Forming Foods and Cancer
One of the more popular claims of the alkaline diet is that it has the ability to cure cancer. Advocates of this diet theory say that because cancer can only grow in an acidic environment, by eating foods that leave a net alkaline load on the body can prevent cancer cells from growing, and also eliminate existing cancer cells.
First, in order for this to happen the foods you consume would have to substantially change the pH of the blood, which I’ve already established is not possible. (23, 24)
Second, cancer cells are not only restricted to acidic environments and are perfectly capable of growing in an alkaline environment. In fact, the pH of normal body tissue is 7.4 respectively, which is already slightly alkaline and in almost every experiment done with cancer cells, they are grown in an environment at that pH. (25)
And, although cancer cells do tend to grow better in an acidic environment, the cells actually create this acidity themselves. Therefore, once a tumor develops, it’s not the acidic environment that creates the cancer, but the cancer that creates the acidic environment. (26)
Conclusion
While I don’t deny that many people will see significant health improvements when switching to an alkaline diet, there are a number of reasons why that has nothing to do with pH balance.
As discussed earlier, the Alkaline Diet encourages a significant consumption of natural whole foods from fruits, vegetables and plants while eliminating almost all processed foods.
This will help significantly reduce the consumption of many grain products, which could cause dramatic health improvements for somebody with gut issues like IBS, leaky gut, or even gluten sensitivity.
Dairy would also be minimized, which would help those struggling with dairy sensitivities. And although sugar isn’t an acid-forming nutrient, many would benefit from the elimination of an over-abundance of added sugar that’s normally associated with the Standard American Diet (SAD).
Nevertheless, current research does not support the claim that a net alkaline load on the body, like the one presumed by supporters of the Alkaline Diet Theory will prevent any modern disease any more than a net acid load will create disease.
