Do Alkaline Diets Really Work?
Do Alkaline Diets Work?
Many practitioners link a chronic state of acidity (acidosis) within the fluids, cells and tissues of the body to poor health and the development of a wide variety of diseases including osteoporosis, kidney stones, arthritis and even cancer. This leads us to suggest that pH (or the acid-alkaline state) of the body is one of the critical factors that determine our state of health and well-being.
But this is where controversy begins to arise – is subclinical low-grade metabolic acidosis in the cells and tissues of the body a real phenomenon underlying many chronic disease states and in need of addressing to restore and maintain optimal health; or is the orthodox view that the body is capable of maintaining pH balance whatever challenges it faces, and pH changes only manifest as severe metabolic acidosis in a number of discrete health conditions, e.g. renal disease?
Why is the body acid-alkaline balance important?
We can all agree that the body must, at all costs, operate at a stable pH, so any increase in internal acid load, for whatever reason, must be neutralized by one of several homeostatic base-producing mechanisms. It’s a well-researched and documented set of highly intelligent physiological and biochemical pathways that determine the exquisitely sensitive homeostatic mechanisms crucial to governing cell and tissue acid-alkaline levels in the body.
Firstly, we have bicarbonate, phosphate, and protein buffer systems that neutralize acids, for example by combining acids with alkaline minerals like magnesium, potassium, calcium and sodium. This prevents strong acids from building up and causing damage in the blood, lymph and tissue cells.
The kidneys take centre stage in neutralizing acids by combining them with bicarbonate and other alkalis before eliminating them via the urine. It is also well documented that when acidosis is triggered, the body responses elicited to correct the pH creates a measurable increase in renal net acid secretion. Breathing also helps us to alkalize, as we inhale oxygen and exhale acidic carbon dioxide. Finally, our skin eliminates acids through the action of sweating. All these systems, especially the kidneys, keep a tight rein on controlling body pH, especially the blood.1
However, many factors in our lives, including diet, toxins (e.g. cigarette smoke, city pollution) and the environment, challenge our homodynamic pH systems daily, leading to what many health practitioners recognize as a low-grade chronic metabolic acidosis, blighting many industrialized societies. This subtle sub-clinical rise in acidity within the body cells in turn negatively impacts and perturbs biochemical and physiological pathways, including important enzyme pathways and production of cellular energy (ATP). This problem remains undiagnosed and even unrecognized by many in the medical profession but the established alternative view of a subtle state of sub-clinical low grade metabolic acidosis, suggests that if left unchecked could contribute to chronic disease pathways.2
So what links low grade metabolic acidosis to chronic disease and what can we do about this sub-clinical condition?
Let’s start by looking at the science…
Raised acid levels in the body tissues may lead to hypercalciuria (high concentrations of calcium in the urine). Since calcium is a strong alkaline mineral and bone contains the body’s largest calcium store, metabolic acidosis has been suggested to cause a release in calcium from bones, as well as reduce renal tubular calcium resorption. Some studies have also shown that in humans, metabolic acidosis can increase 1,25-(OH)2 Vitamin D and decrease parathyroid hormone (PTH) levels, proposed to be part of the early homeostatic mechanisms
employed in response to calcium imbalances.4 This suggests that subtle, low-grade changes towards metabolic acidosis may alter calcium levels and bone response in the body with some studies showing that the net result of these tissue acid changes is a reduction in bone density in order to neutralize the acidic environment of the body and bone structure may be weakened as a result.5,6,7,8
Arthritis & Joint Problems
According to classically trained practitioners, another type of calcium misplacement in the body can occur when acidic toxins (including those derived from cellular metabolic waste, gut bacterial endotoxins or environmental toxins) accumulate in the joints such as fingers and toes, i.e. extremities in the body far away from the vital soft tissue organs including the heart. The understanding is that the body uses calcium to buffer the increasing acidity within the joints (i.e. calcium misplacement) leading to stiffness and arthritic changes often starting with the fingers and toes, leading onto wrists, ankles, elbows, knees and other joints.
Studies have shown that high acid levels in the body contribute to negative nitrogen balance (i.e. high concentrations of nitrogen in urine) contributing to skeletal muscle protein breakdown as the body ages (i.e. sarcopenia).9 Glutamine in skeletal muscle is responsible for binding hydrogen ions to form ammonium. Since hydrogen ions are acidic, some believe that glutamine acts much like calcium to neutralize the body’s accumulating acidosis. Skeletal muscle contains the body’s largest glutamine store, therefore low-grade metabolic
acidosis may contribute to muscle breakdown to liberate glutamine from the muscle. The amino acids from this muscle breakdown are then excreted, causing a net loss of muscle protein.10
Clinical studies show that serum insulin growth factor-1 (IGF-1) concentrations are decreased in response to metabolic acidosis. Thyroid hormone secretion (T3 and T4) is also reduced in this cellular state with the underlying potential to induce primary hypothyroidism.11 Chronic metabolic acidosis has also been demonstrated to significantly increase cortisol levels, which may contribute further contribute to protein (muscle) breakdown and increase renal acid load.12
Kidney Stones & Renal Disease
Clinical evidence demonstrates that many forms of kidney stones are calciferous, so in classical health terms this is another example of calcium misplacement. Organic citrates, used as carriers in some high-quality food supplements to bind alkaline minerals like magnesium, may reduce the formation of kidney stones.13,14.Recent clinical studies have shown how manipulating the acid content of the diet and reducing potassium concentrations helps successfully manage cases of chronic kidney disease.15
Low grade metabolic acidosis and chronic disease
Low-grade metabolic acidosis may well worsen with age (potentially contributing to development of one of the conditions previously described). We could speculate that this is due to an age-related decline in kidney function and therefore ability to excrete acids. Some practitioners may also consider the increasing levels of acidic toxins (e.g. cellular metabolic waste and related dietary metabolites) that accumulate with advancing age, coupled with reduced detoxification capacity and increased dehydration, which may contribute to age-related body acid load.
Many of the studies we’ve just discussed investigated cases of chronic acidosis or clinically induced acidosis. However, we can postulate that the body is most likely to move through preliminary stages of acidosis (i.e. low-grade metabolic acidosis) before entering a deeper level of acidity and pH imbalance – after all:
“We don’t catch chronic diseases, we create them by breaking down the natural defenses according to the way we eat, drink, think and live” (Dr. Bernard Jensen, Natural Health Doctor 1908-2001).
Simply put, this means that by regularly employing a few simple acid-base strategies to help support the optimal cellular function and consequently helps to maintain the health of tissues and organs such as bone, muscle and kidneys.
Managing acid-base balance in the body
One of the most obvious ways to manage the acid-alkaline load of the body is through our diets. But again, controversy continues between understanding the true power of foods to alter pH within the tissues. Let’s start by considering a clinical study that show a direct correlation between animal protein consumption, especially consuming more than five portions of red meat a week and bone fractures in women (due to decreasing bone density), in part due to the higher content of acid forming sulfur-containing amino acids found in animal proteins.16
In fact, a wide range of studies suggests that our diets affect the body’s acid-alkaline balance. Traditional discussion is often centered on the acid or alkaline forming nature of food ash.17 A contemporary (and more accurate) understanding about the effects of different foods and drinks on the acid-alkaline balance in the body tissues assigns scores based on potential renal acid load (PRAL).18 This provides a simple way to determine the acid load of individual foods and entire meals.
However, this is where some confusion may lie. Classical understanding is that the food ash pH may have a direct effect on body tissue pH, i.e. can alkalize acid tissues. What’s important to remember is it’s not the pH of foods or drinks that has a direct impact on reducing metabolic acids and building alkalinity in the body.19 It’s the content of alkalizing minerals (electrolytes) and buffering components such as bicarbonates or hydroxides (i.e. alkalinity) that neutralizes acid.20 Remember, lemons, apple cider vinegar and carbonated water all have acid pH but some research suggest these liquids may have an alkalizing effect on body tissues.
PRAL is a more accurate measure of the effects of foods on body’s pH than comparing food ash. These measurements assess an estimate of the production of endogenous acid that exceeds the level of alkali produced for given amounts of individual foods ingested daily.21 The concept of PRAL calculation is physiologically based and experimentally validated in healthy adults. It also considers different intestinal absorption rates of individual minerals and of Sulphur-containing protein (i.e. bioavailability), as well as the amount of sulphate produced from metabolized Sulphur in proteins, food composition and the obligatory diet-independent organic acid losses. This method of calculation shows that under controlled conditions, acid loads can be reliably estimated from diet composition.22
In layman’s terms, this now means that researchers can analyze a food and, based on its components, determine what the true acid or base load on the body will be. Simply speaking, a positive PRAL score means a food contributes to the acid load whereas a negative PRAL score means a food has an alkaline affect in the body. For a full list of food PRAL scores and to calculate your dietary acid load then please view this table.
Boost Your Juice!
One of the best ways to alkalize the body is achieved by regularly drinking ½ liter of fresh green juice with an alkalizing greens powder alongside fresh greens like spinach, kale, cucumber, celery, parsley etc. This will deliver about 2000mg of alkalinity in the form of a variety of alkalizing mineral compounds, as well as the health benefits from all of the other phytonutrients, vitamin, minerals and fibre. But here is the surprise; the pH of ALL fresh green juices, which deliver the most beneficial alkalinity, is acid (pH 5.8 to 6.8). So what neutralizes acid is alkalinity and not pH; that is an acid beverage with the right minerals can be very alkalizing! 23
Organic greens powders are a great way of boosting alkalinity in the diet, with the addition of concentrated powders to your juice including spinach, spirulina and sea-greens.
So the bottom line is yes, we can do a lot to support our tissue acid-alkaline balance through the diet and therefore support long-term health. However, forget about the pH of anything you eat or drink. It’s irrelevant to human physiology. To really determine if a food conveys an alkaline effect look for goods listed by their PRAL scores, the negative foods confer an alkalizing effect and the positive ones an acidifying effect.
As eating is something we do on a regular basis it seems obvious that we can therefore use the diet to become your own pH master!
PRAL foods table - https://www.clinicaleducation.org/documents/revised-summary-pral-list.pdf
1 Wiederkehr et al (2001) Metabolic and endocrine effects of metabolic acidosis in humans. Swiss Med Wkly 10:127-132
2 Richards P, et al (1972) Treatment of osteomalacia of renal tubular acidosis by sodium bicarbonate alone. Lancet 1972/ II:994-997
3 Lee SW, et al (1977) 25-hydroxycholecalciferol: conversion inhibited by systemic acidosis. Science195:994–6
4 Frassetto et al (1997) Potassium Bicarbonate Reduces Urinary Nitrogen Excretion in Postmenopausal Women. J Clin
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6 Wiederkehr M. et al, (2001) Metabolic and endocrine effects of metabolic acidosis in humans. Swiss Med Wkly. 10:127-132
7 Buclin et al, (2001) Diet Acids and Alkalis Influence Calcium Retention in Bone. Osteoporos Int. 12: 493-499
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9 Welbourne, TC, (1994) et al. J Enteral glutamine spares endogenous glutamine in chronic acidosis. PEN 18(3): 243-7
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12 Baum M, et al (1993) Glucocorticoids stimulate Na/H antiporter in OKP cells. Am J Physiol 264:F1027–31
13 Nutrigold blog: https://nutrigold.co.uk/blog/simply-magnesium-part2-bioavailability-supplementation/
14 Nutrigold blog: https://nutrigold.co.uk/blog/simply-magnesium-part1/
15 Scialla, J, et al (2013) Dietary acid load: A novel nutritional target in chronic kidney disease? Adv Chr Kid Dis 20:141-149
16 Willett, W. et al (1996) Protein consumption and bone fractures in women. Am J Epidemiol 143:472-479
17 Aihara, H. Acid and Alkaline. George Ohsawa Macrobiotic Foundation 1986 (5th edition).
18 Remer T, Manz F. (1994) Estimation of the renal net acid excretion by adults consuming diets containing variable amounts of protein. Am J Clin Nutr 59:1356–61
19 Lemann J Jr. (199) Relationship between urinary calcium and net acid excretion as determined by dietary protein and potassium: a review. Nephron 81:18–25
20 Drever, James I. (1988). The Geochemistry of Natural Waters, Second Edition. Englewood Cliffs, NJ: Prentice Hall. pp. 51–58 .
21 Trinchieri A, et al (2001) Effect of potential renal acid load of foods on calcium metabolism of renal calcium stone formers. Eur Urol 39:33–6
22 Remer T, Manz F. (1994) Estimation of the renal net acid excretion by adults consuming diets containing variable amounts of protein. Am J Clin Nutr 59:1356–61
23 Ash, M. (2014) Acid Or Alkali – What Does Food Choice Have To Do With It? Clinical Education. http://www.clinicaleducation.org/resources/reviews/acid-or-alkali-what-does-food-choice-have-to-do-with-it/