Is the Alkaline Diet Good for Your Health?

The proponents of the Alkaline Diet are urging you to eat the right foods, but for the wrong reasons. The Alkaline Diet is based on the idea that you should eat foods that have an alkalinizing (pH-raising) effect on the body, while avoiding foods that have an acidifying (pH-lowering) effect on the body. The proponents of the Alkaline Diet often make claims that are clearly nonsense. For example, some of them claim that the diet will cause your blood pH to rise to 8.5, thus killing cancer cells while allowing ordinary cells to survive. That is clearly false. On the other hand, some detractors of the Alkaline Diet also say some things that are false. Some of them are simply against vegan diets, for ideological reasons. Others fail to grasp how an acidic food, such as lemon juice, could end up having a net alkalinizing effect on the body, as I’ll explain below.

If you eat the kind of diet that the promoters of the Alkaline Diet recommend, your health will almost certainly improve. The foods that have the strongest acidifying effect on the body come from animals: dairy foods, meats, fish, and eggs. Grains and beans have only a small acidifying effect. In contrast, nearly all fruits and vegetables have a net alkalinizing effect. For this reason, people who avoid the most acidifying foods will end up eating a vegan diet, including lots of fruit and vegetables.

A vegan diet is great for your health, as long as you don’t eat too much fat (from oils, nuts, or avocadoes) or too much refined sugar (empty calories) and as long as you take a vitamin B12 supplement. A low-fat vegan diet provides plenty of fiber and carbohydrate. It provides no cholesterol or animal protein. As a result, a low-fat vegan diet will stabilize your blood sugar, help you lose weight, and reduce your risk of heart attack, stroke, and many cancers and autoimmune diseases. Yet even if you are eating a lot of alkalinizing fruits and vegetables, your blood pH will not change. It will stay at almost exactly 7.4, unless you get really sick. Nevertheless, the alkalinizing effect of a vegan diet does provide a few benefits: a decrease in the risk of gout, kidney stones, and osteoporosis.

The Alkaline Diet has come under fire from skeptics who point out (correctly) that this diet does not really alter the pH of your blood. Unfortunately, many of these skeptics are unaware of (or in denial about) the health benefits of a low-fat vegan diet. Some of them even fail to understand how an acidic food like lemon juice (pH of 2.0 to 3.0) could have a net alkalinizing effect on the body.

All foods are mixtures of organic and inorganic compounds. If you burn a piece of food in a laboratory, most of the organic compounds will be oxidized to form carbon dioxide and water. After the food is completely burned, you will be left with an ash that contains inorganic compounds. The ash will contain some important cations (pronounced cat-eye-ons), including the alkaline metals (sodium and potassium) and alkaline earth metals (calcium and magnesium), and some important anions, including sulfates and phosphates. If you dissolve that ash in water, the pH of the water could go up or down. If the ash is richer in the alkaline metals and alkaline earth metals than in sulfates and phosphates, the pH of the water will go up (alkalinizing effect). If the ash is richer in sulfates and phosphates than in the alkaline and alkaline earth metals, the pH of the water will go down (acidifying effect).

When you metabolize your food, you burn up most of the organic compounds, including many (but not all) of the organic acids. You will be left with an alkaline or acidic ash, plus the organic acids that your body cannot metabolize. These acidic and alkaline byproducts of metabolism will circulate in your bloodstream until they are lost in your urine. In the meantime, they will seem to have little or no effect on the pH of your blood. Instead, they will mainly affect the pH of your urine. You can make a reasonably accurate prediction of how much of an effect a serving of any food will have on the pH of urine by measuring the amounts of protein (a source of sulfur), phosphorus, calcium, potassium, and magnesium that are in the food and plugging the results into an equation.

The pH of your blood must stay at almost exactly 7.4 (slightly alkaline) all the time, or you will die. To keep the blood pH at 7.4, the body has an elaborate system of buffers. The main buffer is derived from carbon dioxide. The body uses an enzyme called carbonic anhydrase to speed up the conversion of carbon dioxide and water to carbonic acid (H2CO3) and vice versa. Carbonic acid is a weak acid, which means that when it is dissolved in water, only a small percentage of its molecules get pulled apart into hydrogen ions (H+) and the acid’s conjugate base (bicarbonate, HCO3). An even smaller percentage of the bicarbonate ions get pulled apart into H+ and carbonate ions (CO3–2).

The pH of an aqueous solution is a measure of the concentration of H+ ions. In pure water, the H+ concentration is about 1 ten millionth of a mole per liter, or 1 × 10–7 M, which is a pH of 7 (the negative of the base-10 logarithm of the H+ concentration). If you added enough acid to make the H+ concentration go up to one millionth of a mole per liter (1 × 10–6 M), the pH would go down to 6. In other words, more H+ means lower pH. (That explains why sea water is becoming more acidic as the amount of carbon dioxide in the atmosphere rises!) In contrast, when the concentration of H+ in an aqueous solution goes down, the pH of the solution goes up.

The conjugate bases of a weak acid (e.g., bicarbonate and carbonate ions) are unstable. When they meet up with a hydrogen ion in solution, they are likely to react with it. Thus, a carbonate ion is likely to bond with an H+, to become a bicarbonate ion. A bicarbonate ion is likely to bond with an H+, to become carbonic acid. If the carbonic acid content of the solution rises, more of the carbonic acid gets converted back to carbon dioxide and water. The carbon dioxide can then be lost to the atmosphere.

When you mix a weak acid with its conjugate base, such as mixing carbonic acid with sodium bicarbonate, you get a pH buffer. If you add a little bit of acid to blood, the bicarbonate and carbonate ions will immediately bind most of the incoming hydrogen ions. Thus, the number of hydrogen ions in the solution will go up very little (i.e., the pH will not drop by much). The ability of a solution to take in acids or alkalis without changing its pH is called the buffer capacity.

The carbonic acid/bicarbonate buffer system plays an important role in stabilizing the pH of your blood. If you hold your breath, carbon dioxide will start to build up in your blood. As a result, the pH of your blood will drop (respiratory acidosis). Your brain will notice this drop in pH and tell your respiratory system to breathe faster. As you blow off that extra carbon dioxide, your blood pH will rise back to a normal level. If you hyperventilate, you will cause the carbon dioxide levels in your blood to drop to abnormally low levels. As a result, your blood pH will go up. This effect is called respiratory alkalosis. If some process in your body is generating excess acid or alkali, your respiratory system will try to compensate by adjusting your respiratory rate, to adjust the amount of carbon dioxide in your blood. As a result, your blood pH may still stay close to 7.4, even if you have a serious problem with acid-base balance.

The kidneys also play a role in controlling the pH of the blood. If your blood pH drops too low, you will pass more H+ and less bicarbonate in your urine. As a result, your urine will become more acidic. If the pH of the blood rises too high, you will pass less H+ and more bicarbonate in your urine. As a result, your urine will become more alkaline. Because of these and other regulatory systems, the pH of your blood will stay remarkably steady at about 7.4 (slightly alkaline), as long as you are in reasonably good health. Meanwhile, the pH of your urine will change dramatically, depending on what you have been eating.

If you start eating the Alkaline Diet, your blood pH will not change much. However, your body’s ability to buffer an acid load will increase. This increase in buffering capacity explains why vegan diets are useful in the management of gout. Gout results when the blood becomes oversaturated with uric acid. Uric acid is produced when your body breaks down purines, which come from the breakdown of DNA and RNA. Tissue that is highly active metabolically (e.g., organ meats) is rich in purines. So is beer, because yeast is highly active metabolically. When the blood becomes oversaturated with uric acid from the digestion of purines, the uric acid starts to precipitate out as crystals in the joints (especially of the big toe) and the kidneys. The result is gouty arthritis and kidney stones.

Although many vegetables are also fairly rich sources of purines, vegetable foods do not seem to increase the risk of gout, probably because they raise the blood’s acid-buffering capacity. When the blood’s acid-buffering capacity is high, more of the uric acid can remain dissolved in the blood and urine. As a result, fewer urate crystals will form in the joints or in the urinary tract.

Not all kidney stones are made of urate crystals. Many kidney stones are made of calcium oxalate. Calcium oxalate kidney stones are also a common result of an acid-forming diet. When the ordinary buffering systems are not enough to keep the blood pH at 7.4, the body may borrow some calcium from the bones, to use as an antacid. However, the body must also keep the calcium levels in the blood within a narrow range, or the heart will stop. For this reason, the excess calcium is quickly lost in the urine. In the short run, this problem can lead to the formation of calcium oxalate kidney stones. In the long run, it can contribute to osteoporosis.

Osteoporosis is common only where people eat a highly acidifying high-protein diet. Taking calcium supplements may help to correct the metabolic acidosis in the short run, because of the calcium’s alkalinizing effect. But in the long run, the combination of an acid overload and a calcium overload (either from dairy foods or fish bones or from supplements) can undermine the body’s ability to regulate its calcium content. If the blood calcium levels are chronically high, the body may eventually lose the ability to conserve calcium. As a result, the calcium that has been borrowed from the bones is not effectively replaced. So instead of recommending calcium supplements, doctors should be urging patients to avoid eating animal foods and to eat more vegetables and fruit. Doctors should also urge patients to go outside and play: to get exercise and reasonable exposure to sunshine.

You can measure the effects of diet on urine pH within a matter of hours. But to see the effects of diet on health, you often must study a large number of people over a long period of time. For this reason, much of what we know about the effects of diet has been learned from epidemiologic studies. Some of these studies compare different populations at one point in time. Others focus on people who have migrated from one country to another. Still others track the same population over time. Each of these kinds of studies has its own strengths and weaknesses. For example, differences between countries could be due to confounding variables, such as genetic differences. Unfortunately, many “skeptics” dismiss all of these studies as “pseudoscience” because these epidemiologic studies do not follow the same methods as pharmaceutical research. Up until recently, “skeptics” who worked for the tobacco industry used the same kind of arguments to make people doubt that cigarette smoking causes lung cancer.

In other words, the proponents of the Alkaline Diet are urging you to eat a good diet, but for bad reasons. Meanwhile, the skeptics who debunk the Alkaline Diet are often trying to scare you away from eating a good diet, for equally bad reasons.

Photo by blumenbiene

Chronic Fatigue Syndrome Is Not Depression

Many people go to the doctor because they feel tired all the time. Many of these patients are suffering from major depression. These depressed patients often feel better if they get more exercise. However, some patients feel tired because they are teetering on the edge of physical collapse because of some serious circulatory, metabolic, or neurologic disorder. If these seriously ill people try to exercise more, they may end up in big trouble. So it is important for doctors to make the correct diagnosis in these cases. Otherwise, the doctor may offer advice that does more harm than good.

According to the dictionary, fatigue is extreme tiredness, typically resulting from mental or physical exertion or illness. In other words, fatigue is nature’s way of telling you to rest. However, a person may feel fatigue for many different reasons. As psychologist Doug Lisle explained in his book The Pleasure Trap, all animals must balance three conflicting motivations: to feel pleasure, to avoid pain, and to conserve energy. So besides deciding whether an activity is pleasurable or painful, animals must also predict whether a pleasure is worth the energy they would have to expend to obtain it, and whether a pain would be so bad that the effort to avoid the pain would be worthwhile. This estimation that some effort would be either unproductive or dangerous can produce a sensation that is felt as fatigue.

Depression involves a problem with the brain’s ability to predict and feel pleasure. For this reason, the depressed person’s brain concludes that many kinds of physical and mental efforts would not be worthwhile. As a result, depressed people often feel fatigue, even if they are nowhere near their physical limits. (In contrast, people with mania often run themselves into a state of physical exhaustion.) When nondepressed people are approaching their physical limits, their brain warns them that further effort would be dangerous. This warning is also felt as fatigue, even if the person’s activity level is abnormally low. People who push themselves despite this warning can make themselves much sicker. This result is called post-exertional malaise, or the push-crash phenomenon. People who are this sick have a low health-related quality of life. As a result, they may look and feel depressed, which complicates the diagnosis.

Do not assume that someone can exercise his or her way out of a case of a chronic fatiguing illness. Many of these people have an underlying disorder that must be found and corrected. In the meantime, the people may have to avoid exercise, so that they can use their limited supply of energy to do the things that are most important to them.

Many of the problems that cause disabling fatigue fall into two basic, overlapping categories: problems with energy metabolism (cellular respiration) and problems with standing or sitting up (orthostasis).

Many different kinds of problems can interfere with cellular respiration. Lung diseases can limit the flow of oxygen into the bloodstream. Anemia limits the blood’s ability to pick up the oxygen and carry it to tissue. Circulatory disease limits the body’s ability to deliver oxygenated blood to tissue. Nutritional deficiencies or damage to the cells’ mitochondria can interfere with the body’s ability to use oxygen to burn fuel to release energy.

In other words, chronic fatigue can result from a wide variety of serious diseases, many of which are so rare that doctors do not routinely test for them or even know about them. Each of these rare diseases affects only a few people. Yet together, these rare but serious fatiguing illnesses could account for a large number of people, most of whose illnesses never get a proper diagnosis.

Some of these rare problems can be caught if the doctor listens and looks: takes a careful history and does a careful physical examination. For example, to catch cases of spinal fluid leak, doctors must look for patients who have a connective tissue disorder (abnormally tall or abnormally flexible) or a history of spinal injury/surgery or lumbar puncture. They must also listen to the patient’s complaints. Patients with a spinal fluid leak will typically say that they feel better in the morning or after prolonged bed rest but worse in the afternoon or evening or after prolonged sitting or standing. An ordinary MRI might not reveal the leak. Instead, the patient may need magnetic resonance myelography. Yet if the leak is found and patched, the patient can get well.

Low blood volume (hypovolemia) can easily be mistaken for an anxiety disorder. These patients are pale because of poor circulation. The extra norepinephrine that their adrenal glands release to compensate for the shortage of blood can cause tremor and mood disturbance. Their pulse tends to be rapid and weak. In addition to fatigue, hypovolemic patients may complain of dizziness or fainting and an inability to see when they stand up. Yet the results of their complete blood count may be perfectly normal. However, the complete blood count only tells you whether the blood is good. It does not tell you how much blood the patient has. To test for low blood volume, start with a poor-man’s tilt table test: take the pulse and pressure while the patient is lying down, sitting, and then standing. If the pulse goes up a lot or the pulse pressure (systolic minus diastolic pressure) goes down while the patient is standing, the patient probably has low blood volume.

Remember that many vague symptoms, including fatigue, can result from food allergy or intolerances. Doctors can solve many of these problems just by giving the patient a simple handout with instructions on how to follow an elimination diet.

Many patients who are on the edge of physical collapse are mistakenly thought to be suffering from a primarily psychiatric problem. Yet if the patient is on the edge of physical collapse, misguided psychotherapy and the pressure to exercise can do a great deal of harm. If the underlying physical problem cannot be resolved, the patient needs coping skills for living with the disability, as well as help in getting others to understand and accept his or her level of disability.