Body pH: Acid-base Balance and Alkaline diet
Written by Millie Lytle, ND, MPH, CNS
Your blood is made up of acids and bases which are measured using a pH scale. PH stands for the “potential of Hydrogen” and inversely measures the concentration of hydrogen ions per cubic area of a substance. A lower pH means more hydrogen. Keeping it simple, the pH scale measures acidity (below 7) and alkalinity (above 7) with neutral pH being 7. Acid-base balance is important for your health. Here's why -
Pure water has a pH of 7, which is neutral. The human blood is slightly alkaline with a constant pH of 7.4. If blood pH goes up then the person will suffer from metabolic alkalosis, when the body has too many bases or loses too much acid. If the blood pH goes down, then metabolic acidosis will result, a medical condition whereby the body either makes too much acid or does not clear acid from the kidneys. If the blood pH falls below 7.35 then acidemia, a potentially fatal condition, results.
Acid-base balance is maintained by complex mechanisms called human homeostasis.
Homeostasis is a sophisticated multi-tasking system whereby the body’s chemical
and hormonal interactions work to maintain a balance, above all else, by continually
correcting for and returning functioning within a normal range. Fluid regulation
and osmolality are key functions of homeostasis that affect body’s acid-base balance,
blood pressure, blood volume, extracellular volume and more. The primary organs
responsible for homeostasis are the liver, kidneys, brain and endocrine system,
which auto-correct for changes that support physical and psychological health. If
the body suffers homeostatic imbalance, then death or disease may occur, such as
heart attack, osteoporosis, diabetes, dehydration or gout. If the body cannot clear
harmful substances from the bloodstream, such as infection or sepsis, this may be
considered a result of homeostatic imbalance, as well. At certain times, the body
will compensate for physical or nutritional deficiencies in order to preserve the
life of the individual. Homeostasis, in prioritizing survival, may sacrifice the
health of one or several body systems. In fact, some organs may suffer over time
as a result of normal homeostasis and disease can still result.
While the body works to maintain homeostasis, it is continually influenced by various
factors such as medications, heavy metals, chemical exposures and nutrition. Nutritional
deficiencies can interrupt homeostasis mechanisms and lead to inadvertent disease.
Diet-induced metabolic acidosis, as a result of mineral deficiencies, has been theorized
to be largely responsible for causing many common chronic diseases due to their
effect on the body’s homeostasis1. What’s more, the Standard American
(SAD) diet is considered acidogenic due to the high dietary acid load from meat,
refined wheat and other grains, sugar and low in alkalizing dietary minerals such
as potassium, magnesium and calcium2. The SAD diet sets many Americans
up for illness over their lifetime, but the good news is many of these diseases
are preventable with nutrition and lifestyle changes.
Blood pH and Antacid Medication
Although the blood needs to be alkaline, the stomach needs to be acid. An acid stomach
with a pH of 1-3 is in a normal and healthy state. Stomach acid is required in order
to breakdown proteins, produce B12 and prevent bacterial illness, such as food poisoning,
H. Pylori and intestinal parasites. Acid reflux or GERD is a result of acid being
irregularly produced away from food due to stress, cigarettes, or acidic foods, such
as alcohol, soda, and coffee. Acid, then, splashes up into the esophagus from a
weak or faulty esophageal sphincter; a muscle that acts like a valve but is not
actually a valve.
Many people take over-the-counter and prescription acid reducers
to soothe reflux pain and lesions. New studies show, however, that long-term use
of strong acid-lowering medications (cimetidine, ranitidine, omeprazole) may cause
a host of problems including osteoporosis and higher chances of hip and thigh fractures,
even when taking medications to reduce bone loss called bisphosphonates (Fosamax,
Boniva, Actonel, Reclast, etc.)4. Although antacids produce an alkaline
environment in the stomach, they ironically contribute to metabolic acidosis. Antacids
contain aluminum that increases calcium excretion in the urine and lead to mineral
deficiencies. In order to maintain pH in the blood, the bones respond by releasing
calcium into the blood to balance the loss of calcium through the urine. Over time,
the bones thin and weaken. In this study, those who used antacids regularly but
less than once a day had a 12% higher fracture risk, a pill a day caused a 30% increased
chance of fracture and most significantly, those who took more than one antacid
per day had an increased risk of fracture of 41% over those who do not take any
Suggestions for a natural approach to heartburn (that maintains proper calcium levels in the bone)
- Demulcents herbs such as DGL, plantain, marshmallow and slippery elm to sooth mucous membranes and promote healing before meals and prior to lying down
- A handful of raw almonds as a source of acid buffering calcium carbonate as needed,
- Digestive enzymes with papain and bromelain to digest protein food and support normal stomach acid production to eliminate gas and bloating after a meals.
Lifestyle approaches are also important, such as avoiding spicy and acidic foods, practicing stress relief and smoking-cessation.
Urine pH and Alkaline Diets
While metabolic acidosis is concerned with the pH of the blood, it is not a necessarily
a good measurement of body mineral level because homeostatic mechanisms work to
ensure a constant pH. Urinary pH has been shown to be a good indicator of nutritional
mineral status both in population studies as well as clinical trials. Alternative
health providers have been testing urinary pH as an indicator of physiological health
and correcting it through diet and supplementation for the last century. As urine
pH relates to dietary acid-base load, it has been proven as a useful tool to monitor
change in consumption of fruit and vegetables in individuals.2,6 Population-based research started investigating these areas of nutrition after 2001, with the Framingham
Osteoporosis Study (2001)1 and the European Prospective Investigation
into Cancer and Nutrition (EPIC, 2002)2. Results of both epidemiological
studies showed an alkaline-generating diet with higher fruit and vegetable and lower
meat intake are related to more alkaline urine.1,2 A Dutch clinical study
also showed that ingestion of a multi-mineral supplement is associated with both
a significant increase in blood and urinary pH.3 Read more below.
Urinary pH and Bone Mineralization
Bone is an example of a body tissue that can suffer in order to maintain normal levels of minerals in the blood (to maintain proper pH). In cases of nutritionally-related metabolic acidosis, there are not enough available minerals in the blood from the diet so the pH falls between 7.4 and 7.35. This type of metabolic acidosis has been targeted as a key etiology in the onset of many nutritionally related chronic diseases such as osteoporosis.3 When the pH falls, the blood pulls calcium and magnesium out of the bones to normalize and correct the acidic pH. When bone cannot maintain normal levels of minerals, if suffers from chronic degenerative change over time, such as demineralization, bone loss and ultimately osteoporosis. Calcium and vitamin D are both approved by the FDA as necessary for bone health.
“Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis.” - FDA
Other nutrients have also been identified as necessary for proper calcium utilization and bone quality such as protein, vitamins K, K2, C and B complex, magnesium and silica. While vitamins C and B complex, zinc, selenium, boron and copper and strontium have also shown research promise for bone strength5.
Evidence exists that a more acidic diet is detrimental to bone health. A large population
study (22,034 men and women aged 39-78 years old) first proved a relationship between
urine pH and dietary acid-base load as influenced by servings of food groups. A
sub-study done on 363 people compared pH in casual and 24 hour urine samples to
food intakes from a 7 day diary and the Food Frequency Questionnaire. A more alkaline
diet (high fruit and vegetable intake and lower consumption of meat) was significantly
associated with a more basic urine pH. When adjusted for age, Body Mass Index (BMI),
physical activity and smoking habit, high fruit and vegetables intake and low meat
intake still predicted alkaline urine. Also excluded were the following variables;
urinary protein, glucose, ketones, diagnosed high blood pressure and diuretic medication6.
The 7 day diet diary and a 24 hour urinalysis was the best combination indicator
of pH. Although more precise methods exist for measurement of acid-base balance,
urine pH reflects acid-base balance and is readily measurable at home.
If you want to test your urine pH then measure all urine collected over a 24 hour
period. In order to increase the pH, eat over 6 servings of mineral-rich fruits
and vegetables per day, as well as dietary supplements, for 7 days and measure the
pH of all urine collected over a 24 period.
Urinary pH and Electrolytes
Electrolytes are minerals that help maintain alkaline pH and hydration first in
the intestines and then in the rest of the blood and tissues. Electrolytes include
magnesium, potassium, calcium, sodium and bicarbonate. Previous investigations have
reported beneficial effects of dietary potassium and potassium-rich foods and mineral
water on bone health. In some rat studies, it has been shown that supplementation
with alkaline minerals neutralizes diet-induced metabolic acidosis and is related
to higher bone density7. In addition, potassium bicarbonate has been
shown to reduce calcium excretion in the urine of postmenopausal women8.
Another study indicated that bone resorption (loss) was reduced and bone formation
was increased following potassium bicarbonate intake in post-menopausal women9.
An acid pH destroys bone by increasing the number of osteoclasts (cells that destroy
bone), as well as inhibits bone matrix mineralization10. High fruit and
vegetable intake and dietary supplements containing alkalizing minerals have been,
in contrast, shown to increase the pH of the blood and urine (and saliva) when taken
acutely as well as over a long period of time. Taking a multi-mineral dietary supplement significantly increases the pH of the blood and urine. Adequate levels of magnesium,
potassium and calcium in the blood are beneficial to address muscle cramping by
reducing neuropathy and nerve pain.
Urinary pH, Uric Acid Levels and Electrolytes
Uric acid is a metabolic result of the breakdown of purine nucleotides. A high blood
concentration is associated with gout, kidney stones and diabetes. An alkaline diet
that results in alkaline urine facilitates the excretion of uric acid11.
Though this may read counter-intuitive, it is so because foods containing high levels
of alkalizing minerals have fewer purine bodies than acidifying foods. A study was
conducted for the Japanese government health promotion program whereby acid diet
and alkaline diets were given to healthy female students in a 5-day crossover study.
The study collected urine volumes and measured pH, uric acid, creative and all mineral
levels (alkaline cations and acidic anions). After 3 days on either the acidic or
alkaline diet, urinary pH stabilized to indicate acidic or alkaline. Results showed
that the amount of organic acid generated consistent with the pH of the diet, indicating
that hydrogen ions in urine is generated by the metabolic breakdown of food materials.
The more uric acid excreted, the higher the urine pH. Uric acid in the blood was
higher in the acidic group than the alkaline group, pointing towards metabolic acidosis.
There were noticeable differences between acidic and alkaline diets in the uric
acid concentration in serum as well as in urine; uric acid in the serum was higher
in the acidic group than in the alkaline group, while urinary uric acid was lower
in the acidic than the alkaline group. These changes of uric acid in acidic urine
and in serum were reflected in the reduction of its clearance. From these observations,
it is considered that uric acid may be reabsorbed in the bloodstream of those with
more acidic urine than alkaline urine. Whereas an acidic diet raises uric acid in
the blood and decreases output in the urine. The researchers thus proved that alkalization
of urine by eating nutritionally well-designed alkaline diet, such as diets high
in vegetable and fruit and less animal protein, is effective for removing uric acid
from the body12. Patients with uric acid calculus, calcium oxalate and
those without urinary calculus were compared for their metabolic status. In addition
to low fruit and vegetable intake, low urinary pH, low daily water intake, eating
more salted and animal food, were very closely associated with uric acid calculus
and calcium oxalate patients. Blood potassium and magnesium were higher in the control
group than in the calculi groups13. Novel drug research has studied the
effects of dietary seaweed extracts on the levels of urinary calcium oxalate in
inhibition of calcium oxalate stone formation and excretion14.
Muscle pH; Brief Muscle and Heart Pathophysiology
The University of Mississippi Medical Center lists that the cellular pH in resting
skeletal muscle is typically 7.15. During exercise, as alkalizing minerals are utilized,
pH falls in proportion to the intensity of the exercise. Lactic acid concentrations
along with carbon dioxide contribute to the lower pH. Minerals are required to normalize
the pH following exercise. If a balance of magnesium, potassium, sodium and calcium
are not replenished adequately this leaves electrolyte deficits that can contribute
to abnormal muscle function. Based on the normal physiology of the skeletal muscles
as well as the heart muscle, muscles require a substantial concentration of available
alkalizing minerals to fire and function smoothly, maintain regular blood flow to
the cell and reduce tension. In an acidic environment, muscular inflammatory response
can lead to lack of recovery and other symptoms including pain, numbness, and even
paralysis (tetany). Increasing potassium and magnesium levels through supplementation can reduce muscle pain and tension in people with Gitelman’s Syndrome, a genetic
metabolic alkalosis characterized by low blood potassium, low urinary calcium and
low blood magnesium15 as well as people with normal mineral physiology.
Thiazide diuretics can also cause these same muscle symptoms15.
Blood pressure physiology involves the mineral balance of minerals sodium, potassium,
magnesium, chlorine and calcium. Health promotion efforts from public health departments
have highlighted the importance for the population to eat a low salt diet, but have
not emphasized the importance to balance salt intake with more alkalizing minerals
such as potassium, calcium and magnesium. When these minerals are relatively low
in the diet, the negative effects of sodium chloride (salt) become dire. In an acidic
environment blood pressure rises, heart beat becomes irregular and cardiac events
can result. Increasing potassium and magnesium levels through supplementation can
nutritionally support the over-excitability of the heart15. Men who die
of a sudden ischemic heart attack may have the very low levels of magnesium and
potassium in the heart muscle as compared to others who did not die16.
It is important to eat a diet high in vegetables, sea greens and consume dietary
supplements with alkalizing minerals such as calcium, magnesium and potassium in
order to avoid diet-induced metabolic acidosis. Avoiding antacid medications preserves
an alkaline pH in the blood and protects bones from demineralization. Similarly,
eating an alkalizing diet rich in fruits, vegetables and minerals increases the
pH of the blood and preserves bone. A diet rich in mineral electrolytes prevents
inflammation of the nervous tissue as well as maintains strong and flexible muscles.
Maintaining a high blood and urine pH as well as consuming an adequate water intake
prevents high uric acid levels in the blood. Regular and adequate consumption of
green vegetables, seaweeds and alkalizing minerals maintains normal urinary function
and may contribute to disease-reduction in those with diabetes, kidney stones and
gout. Muscle pain and rigidity in the heart and skeletal muscle impedes normal function
when associated with mineral deficiencies; be they congenital, drug-induced, sport-related
or nutritional. Eating a diet rich in alkaline minerals is imperative to homeostasis,
beneficial to many organ systems and can mediate many chronic diseases. One can
measure their own body pH easily with Litmus paper over 24 hour urine collection.
Kiel DP. The acid-base hypothesis: diet and bone in the Framingham Osteoporosis
Eur J Nutr. 2001 Oct;40(5):231-7.
Martínez Garcia C,
Riboli E. Consumption of vegetables, fruit
and other plant foods in the European Prospective Investigation into Cancer and
Nutrition (EPIC) cohorts from 10 European countries. Public Health Nutr. 2002 Dec;5(6B):1179-96.
- König D, Muser K, Dickhuth HH, Berg A, Deibert P. Effect of a supplement rich in
alkaline minerals on acid-base balance in humans. Nutr J. 2009 Jun 10; 8:23.
de Vries F,
van Staa TP,
Cooper C. Fracture risk in patients receiving acid-suppressant
medication alone and in combination with bisphosphonates.
Osteoporosis Int. 2009 Dec;20(12):1989-98.
Faliva MA. Update on nutrients involved in maintaining healthy bone.
Endocrinol Nutr. 2013 Apr;60(4):197-210.
- Welch AA, Mulligan A, Bingham SA, Khaw KT. Urine pH is an indicator of dietary acid-base
load, fruit and vegetables and meat intakes: results from the European Prospective
Investigation into Cancer and Nutrition (EPIC)-Norfolk population study. Br J Nutr.
2008 Jun;99(6):1335-43. Epub 2007 Nov 28.
- Mardon J, Habauzit V, Trzeciakiewicz
A, Davicco MJ, Lebecque P, Mercier S, Tressol JC, Horcajada MN, Demigné C, Coxam
V: Long-term intake of a high-protein diet with or without potassium citrate modulates
acid-base metabolism, but not bone status, in male rats. J Nutr 2008, 138:718-24.
Frassetto L, Morris RC Jr, Sebastian A: Long-term persistence of the urine calcium-lowering
effect of potassium bicarbonate in postmenopausal women. J Clin Endocrinol Metab
- Sebastian A, Harris ST, Ottaway JH, Todd KM, Morris RC Jr: Improved
mineral balance and skeletal metabolism in postmenopausal women treated with potassium
bicarbonate. N Engl J Med 1994, 330:1776-81.
- Arnett TR: Extracellular pH regulates
bone cell function. J Nutr 2008, 138:415S-8S.
- Kanbara A, Seyama I. Effect of
urine pH on uric acid excretion by manipulating food materials. Nucleosides Nucleotides
Nucleic Acids. 2011 Dec;30(12):1066-71.
- Kanbara A, Miura Y, Hyogo H, Chayama K, Seyama I. Effect of urine pH changed by
dietary intervention on uric acid clearance mechanism of pH-dependent excretion
of urinary uric acid. Nutr J. 2012 Jun 7;11:39.
An G. [Percentage of uric acid calculus and its metabolic character in Dongjiang
River valley]. Zhonghua Wai Ke Za
Zhi. 2009 Feb 15;47(4):248-51.
Deng SP, Ouyang
JM. [Modulation of polysaccharide extracted from Laminaria on phase compositions
of urinary crystal calcium oxalate].[Article in Chinese] Guang Pu Xue Yu Guang Pu Fen
Xi. 2007 Nov;27(11):2371-4.
Yildiz M, Yildiz
NB. The effects of serum potassium and magnesium levels
in a patient with Gitelman's syndrome on the timing of ventricular
wall motion and the pattern of ventricular strain and torsion. Echocardiography. 2013
Johnson CJ, Peterson
EK. Myocardial tissue concentrations of magnesium and potassium in
men dying suddenly from ischemic heart disease. Am J Clin Nutr. 1979
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