The alkaline diet is also known as the acid-alkaline diet or the alkaline ash diet. It is based around the idea that the foods you eat leave behind an "ash" residue after they have been metabolized. This ash can be acid or alkaline.
Proponents of this diet claim that certain foods can affect the acidity and alkalinity of bodily fluids, including urine and blood. If you eat foods with an acidic ash, they make the body acidic. If you eat foods with an alkaline ash, they make the body alkaline.
Acid ash is thought to make you vulnerable to diseases such as cancer, osteoporosis, and muscle wasting, whereas alkaline ash is considered to be protective. To make sure you stay alkaline, it is recommended that you keep track of your urine using handy pH test strips.
For those who do not fully understand human physiology and are not nutrition experts, diet claims like this sounds rather convincing. However, is it really true? The following will debunk this myth and clear up some confusion regarding the alkaline diet.
But first, it is necessary to understand the meaning of the pH value.
Put simply, the pH value is a measure of how acidic or alkaline something is. The pH value ranges from 0 to 14.
- 0-7 is acidic
- 7 is neutral
- 7-14 is alkaline
For example, the stomach is loaded with highly acidic hydrochloric acid, a pH value between 2 and 3.5. The acidity helps kill germs and break down food.
On the other hand, the human blood is always slightly alkaline, with a pH of between 7.35 to 7.45. Normally, the body has several effective mechanisms (discussed later) to keep the blood pH within this range. Falling out of it is very serious and can be fatal.
Effects Of Foods On Urine And Blood pH
Foods leave behind an acid or alkaline ash. Acid ash contains phosphate and sulfur. Alkaline ash contains calcium, magnesium, and potassium.
Certain food groups are considered acidic, neutral, or alkaline.
- Acidic: Meats, fish, dairy, eggs, grains, and alcohol.
- Neutral: Fats, starches, and sugars.
- Alkaline: Fruits, vegetables, nuts, and legumes.
Foods you eat change the pH of your urine. If you have a green smoothie for breakfast, your urine, in a few hours, will be more alkaline than if you had bacon and eggs.
For someone on an alkaline diet, urine pH can be very easily monitored and may even provide instant gratification. Unfortunately, urine pH is neither a good indicator of the overall pH of the body, nor is it a good indicator of general health.
Foods you eat do not change your blood pH. When you eat something with an acid ash like protein, the acids produced are quickly neutralized by bicarbonate ions in the blood. This reaction produces carbon dioxide, which is exhaled through the lungs, and salts, which are excreted by the kidneys in your urine.
During the process of excretion, the kidneys produce new bicarbonate ions, which are returned to the blood to replace the bicarbonate that was initially used to neutralize the acid. This creates a sustainable cycle in which the body is able to maintain the pH of the blood within a tight range.
Therefore, as long as your kidneys are functioning normally, your blood pH will not be influenced by the foods you eat, whether they are acidic or alkaline. The claim that eating alkaline foods will make your body or blood pH more alkaline is not true.
Acidic Diet And Cancer
Those who advocate an alkaline diet claim that it can cure cancer because cancer can only grow in an acidic environment. By eating an alkaline diet, cancer cells cannot grow but die.
This hypothesis is very flawed. Cancer is perfectly capable of growing in an alkaline environment. In fact, cancer grows in normal body tissue which has a slightly alkaline pH of 7.4. Many experiments have confirmed this by successfully growing cancer cells in an alkaline environment.
However, cancer cells do grow faster with acidity. Once a tumor starts to develop, it creates its own acidic environment by breaking down glucose and reducing circulation. Therefore, it is not the acidic environment that causes cancer but the cancer that causes the acidic environment.
Even more interesting is a 2005 study by the National Cancer Institute which uses vitamin C (ascorbic acid) to treat cancer. They found that by administering pharmacologic doses intravenously, ascorbic acid successfully killed cancer cells without harming normal cells. This is another example of cancer cells being vulnerable to acidity, as opposed to alkalinity.
In short, there is no scientific link between eating an acidic diet and cancer. Cancer cells can grow in both acidic and alkaline environments.
Acidic Diet And Osteoporosis
Osteoporosis is a progressive bone disease characterized by a decrease in bone mineral content, leading to lowered bone density and strength and higher risk of a broken bone.
Proponents of the alkaline diet believe that in order to maintain a constant blood pH, the body takes alkaline minerals like calcium from the bones to neutralize the acids from an acidic diet. As discussed above, this is absolutely not true. The kidneys and the respiratory system are responsible for regulating blood pH, not the bones.
In fact, many studies have shown that increasing animal protein intake is positive for bone metabolism as it increases calcium retention and activates IGF-1 (insulin-like growth factor-1) that stimulates bone regeneration. Thus, the hypothesis that an acidic diet causes bone loss is not supported by science.
Acidic Diet And Muscle Wasting
Advocates of the alkaline diet believe that in order to eliminate excess acid caused by an acidic diet, the kidneys will steal amino acids (building blocks of protein) from muscle tissues, leading to muscle loss. The proposed mechanism is similar to the one causing osteoporosis.
As discussed, blood pH is regulated by the kidneys and the lungs, not the muscles. Hence, acidic foods like meats, dairy, and eggs do not cause muscle loss. As a matter of fact, they are complete dietary proteins that will support muscle repair and help prevent muscle wasting.
What Did Our Ancestors Eat?
A number of studies have examined whether our pre-agricultural ancestors ate net acidic or net alkaline diets. Very interestingly, they found that about half of the hunter-gatherers ate net acid-forming diets, while the other half ate net alkaline-forming diets.
Acid-forming diets were more common as people moved further north of the equator. The less hospitable the environment, the more animal proteins they ate. In more tropical environments where fruits and vegetables were abundant, their diet became more alkaline.
From an evolutionary perspective, the theory that acidic or protein-rich diets cause diseases like cancer, osteoporosis, and muscle loss is not valid. Half of the hunter-gatherers were eating net acid-forming diets, yet, they had no evidence of such degenerative diseases.
It is worth noting that there is no one-size-fits-all diet that works for everyone, which is why Metabolic Typing is so helpful in determining your optimal diet. Due to our genetic variances, some people will benefit from an acidic diet, some an alkaline diet, and some in between. Thus the saying: one man's food can be another man's poison.
It is true that many people who have switched to an alkaline diet see significant health improvements. However, do bear in mind that other reasons may be at work:
- Most of us do not eat enough vegetables and fruits. According to the Center for Disease and Prevention, only 9% of Americans eat enough vegetables and 13% enough fruits. If you switch to an alkaline diet, you are automatically eating more vegetables and fruits. After all, they are very rich in phytochemicals, antioxidants, and fiber which are essential to good health. When you eat more vegetables and fruits, you are probably eating less processed foods too.
- Eating less dairy and eggs will benefit those who are lactose-intolerant or have a food sensitivity to eggs, which is rather common among the general population.
- Eating less grains will benefit those who are gluten-sensitive or have leaky gut or an autoimmune disease.
One last point worth mentioning is that many people believe that drinking alkaline water (pH of 9.5 vs. pure water's pH of 7.0.) Is healthier based on similar reasoning as the alkaline diet. Anyhow, it is not true. Water that is too alkaline can be detrimental to your health and lead to nutritional disequilibrium.
If you drink alkaline water all the time, it will neutralize your stomach acid and raise the alkalinity of your stomach. Over time, it will impair your ability to digest food and absorb nutrients and minerals. With less acidity in the stomach, it will also open the door for bacteria and parasites to get into your small intestine.
The bottom line is that alkaline water is not the answer to good health. Do not be fooled by marketing gimmicks. Instead, invest in a good water filtration system for your home. Clean, filtered water is still the best water for your body.