Bicarbonate's Importance to Human
Health
CONTENTS
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From the Health Library
The Health Library's explanation of why the blood level of
bicarbonate is important:
Bicarbonate
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Bicarbonate has beneficial effects on
health
(News vol 3, no 1, May 2001)
Bicarbonate is a major element in our body. Secreted by the
stomach, it is necessary for digestion. When ingested, for
example, with mineral water, it helps buffer lactic acid
generated during exercise and also reduces the acidity of dietary
components. Finally, it has a prevention effect on dental
cavities.
Bicarbonate is present in all body fluids (see table) and
organs and plays a major role in the acid-base balances in the
human body. The first organ where food, beverages and water stay
in our body is the stomach. The mucus membrane of the human
stomach has 30 million glands which produce gastric juice
containing not only acids, but also bicarbonate. The flow of
bicarbonate in the stomach amounts from 400 µmol per hour
(24.4 mg/h) for a basal output to 1,200 µmol per hour (73.2
mg/h) for a maximal output. Thus at least half a gram of
bicarbonate is secreted daily in our stomach. This rate of
gastric bicarbonate secretion is 2-10% of the maximum rate of
acid secretion. In the stomach, bicarbonate participates in a
mucus-bicarbonate barrier regarded as the first line of the
protective and repair mechanisms. On neutralization by acid,
carbon dioxide is produced from bicarbonate. A study has
underlined that a dose of 6.17 g of sodium bicarbonate rapidly
leaves the stomach with the liquid phase of the meal.
Effects of ingested bicarbonate
For digestion, bicarbonate is naturally produced by the
gastric membrane in the stomach. This production will be low in
alkaline conditions and will rise in response to acidity. In
healthy individuals this adaptive mechanism will control the pH
perfectly. To modify this pH with exogenous doses of bicarbonate,
some clinical experiments have been conducted with sodium
bicarbonate loads as high as 6 g. Only a transient effect on pH
has been obtained. It is quite possible that bicarbonate in water
may play a buffering role in the case of people sensitive to
gastric acidity. Thus bicarbonate may be helpful for
digestion.
The most important effect of bicarbonate ingestion is the
change in acid-base balance as well as blood pH and bicarbonate
concentration in biological fluids. It has been studied
particularly in physically active people. Among the types of acid
produced, lactic acid generated during exercise is buffered by
bicarbonate. In a study on sports, a dose of 0.3 g per kg of body
weight of sodium bicarbonate was given (15.25 g bicarbonate for a
man of 70 kg) to subjects before performing 30 minutes cycling.
While blood pH was increased and then maintained constant with
this bicarbonate load due to the changes in blood bicarbonate
concentrations, increased acidity and decreased bicarbonate blood
concentration were observed in controlled subjects. Mineral water
which contains bicarbonate (>600 mg/l) may have an effect on
acid-base balance. It is the case of Qu zac. The daily
consumption of 1.5 liter of Qu zac in healthy subjects has
produced a significant increase in the urinary pH due to the
ingested bicarbonate (1685 mg/l).
Prevention of renal stones
Bicarbonate also reduces the acidity of dietary components
such as proteins. As an example, adding sodium or even more
potassium bicarbonate to subjects on a high protein diet known to
acidify urine and leading to hypercalciuria (high level of
calcium in urine) has been shown to greatly reduce calcium
urinary excretion. The effect has been observed with 5.5 g of
bicarbonate supplement received daily for two weeks. A recent
study presented in the review of literature highlights that a
bicarbonate-rich mineral water could be useful in the prevention
of the recurrence of calcium oxalate and uric acid renal
stones.
Many oral hydration solutions contain bicarbonate showing the
usefulness of bicarbonate to control water absorption in patients
at risk of dehydration.
Sodium intake is restricted in patients with hypertension, but
it is demonstrated that the accompanying anion, such as
bicarbonate or chloride, plays an important role. It is now well
established that sodium bicarbonate as well as citrate and
phosphate salts do not raise blood pressure to the same extent as
do the corresponding amounts of sodium chloride. A study on
mineral water containing sodium bicarbonate has confirmed the
absence of effect on blood pressure in elderly individuals.
Bicarbonate has been shown to decrease dental plaque acidity
induced by sucrose and its buffering capacity is important to
prevent dental cavities. Other studies have shown that
bicarbonate inhibits plaque formation on teeth and, in addition,
increases calcium uptake by dental enamel. This effect of
bicarbonate on teeth is so well recognized that sodium
bicarbonate-containing tooth powder was patented in the USA in
October 1985. Sodium bicarbonate has been suggested to increase
the pH in the oral cavity, potentially neutralizing the harmful
effects of bacterial metabolic acids. Sodium bicarbonate is
increasingly used in dentifrice and its presence appears to be
less abrasive to enamel and dentine than other commercial
toothpaste.
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Bicarbonate helps physically active people combat
fatigue
(news vol 3, no 1, May 2001)
An ingestion of 300 mg/kg of body weight of bicarbonate before
exercising will help you reduce muscular fatigue and so increase
the performance of short- term physical exercise. Thus drinking
mineral water containing bicarbonate may contribute to this
beneficial intake.
Sportsmen continuously have two problems to solve : the other
athletes to overtake and fatigue to overcome. The causes of
fatigue are multifactorial, either they have physiological or
psychological origins. From the physiological point of view,
fatigue can have a central or peripheral origin. Among the
peripheral causes, fatigue could be due to the accumulation of
metabolites in muscle, such as lactates, hydrogen ions and
ammonia. During prolonged submaximal effort, the major cause of
fatigue is the energy substrate depletion (namely carbohydrates),
but it has been shown that hyperthermia (over 40.1 C) or
dehydration (over 1 or 2 % of body weight loss) could also
contribute to the occurrence of fatigue.
In fact, to optimise performance, it is important to minimise
fatigue and to delay its appearance. Athletes are aware of
substances which could offset fatigue and since the 90s the use
of sodium bicarbonate has become usual among sportsmen to buffer
the acids produced during exercise.
Acid-base balance
The pH is a parameter expressing the acidity of a solution.
Neutral pH is 7. For example, the pH of blood is normally 7.4 and
that of muscle is 7.0. pH under 7 is acid, that is the case of
vinegar (pH =3), orange juice (pH =3.7 ) or cola-drinks (pH
=2.4). pH over 7 is basic or alkaline. Some mineral waters are
alkaline, such as Abatilles (pH = 8.2).
Physical exercise can imply the production of lactic acid,
leading to the acidification of pH in blood and muscle. In order
to buffer this accumulation of lactic acid and to regulate the
acid-base balance, the body uses biological buffers, especially
the bicarbonate buffer system. But under conditions of intense
physical activity (short or long-term), this natural buffer is
limited and accumulation occurs with the risk of fatigue.
Sodium bicarbonate
The ingestion of sodium carbonate as a buffering agent has
been studied in various experimental designs (repeated short bout
exercises or long lasting efforts) and with large dose ranges
(100 to 500 mg per kg body weight, ingested or injected). Plasma
bicarbonate concentrations were shown to increase after oral
ingestion but intracellular concentrations of bicarbonate in
muscle were unchanged. However, recent studies underline that
bicarbonate increases the transport of lactate from muscle.
General considerations can be drawn from the 46 studies showing
enhancements of exercise performance and 37 studies showing no
enhancement : below 200 mg per kg body weight of sodium carbonate
ingested, no effect on performance occurs. The optimum range to
observe an effect seems to be around 300 mg per kg of body
weight. Sodium bicarbonate ingestion is efficient for long
lasting efforts, between 1 to 7 minutes (sprint, 200 m, 400m,
800m and 1500m). When cycling, running, swimming, rowing and
weightlifting exercise performance is increased by sodium
bicarbonate ingestion. Recently, a few studies have shown that
sodium bicarbonate and sodium chloride have the same ergogenic
effect leading to the conclusion that the effect attributed to
bicarbonate buffering may be due to sodium.
Even if the mechanism of the effect of bicarbonate is a matter
of discussion, it is clear that at a dose close to 300 mg per kg
of body weight of ingested bicarbonate increases the buffering
capacity of blood and may decrease the acidity of the muscle pH.
As a consequence, acid accumulation will be attenuated and energy
production or force maintained. The improved acid balance
obtained by this administration produces a reduction of fatigue
and an enhancement of strength recovery.
Mineral water
Natural mineral or spring waters have various contents of
bicarbonates, from some tens to hundreds of mg/litre for still
waters and from several hundreds to thousands of mg/litre for
sparkling waters (see table). Although studies have shown an
effect on acid-base balance of some mineral waters containing
more than 600 mg of bicarbonate per litre, physically active
people need to drink large amounts of water to observe an effect
on fatigue when exercising. In athletes, several authors have
shown a significant increase in blood pH and blood bicarbonate
without improvement of performance.
Moreover, if the optimum content of bicarbonate ingestion is
close to 300 mg per kg of body, this means for a 70 kg sportsman
a dose of about 15 g of bicarbonate. Accordingly, the ingestion
of water alone will help reach an efficient dose of bicarbonate,
if a large volume of water is taken several hours before
exercising. It could contribute to lowering the bicarbonate load
to be ingested and avoiding the possible gastrointestinal
side-effects.
San Pellegrino: 219.6 mg per litre
Perrier: 390 mg per litre
Vittel: 402 mg per litre
Campilho: 1479 mg per litre
Qu zac: 1685.4 mg per litre
San Narciso: 2165.5 mg per litre
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Bibliography of Bicarbonate-related Articles
-- "Normal adult humans eating Western diets have chronic,
low-grade metabolic acidosis ...." Frassetto LA, Todd KM, Morris
RC Jr, Sebastian A(1998) Am J Clin Nutr, 68 (3): 576-83
Estimation of net endogenous
noncarbonic acid production in humans from diet potassium and
protein contents
-- "Previously we demonstrated that low grade chronic
metabolic acidosis exists normally in humans eating ordinary
diets ... and that the degree of acidosis increases with age."
Frassetto L, Morris RC Jr, Sebastian A. (1997) J Clin Endocrinol
Metab, Jan;82(1):254-9
Potassium Bicarbonate Reduces
Urinary Nitrogen Excretion in Postmenopausal
Women
-- "In normal subjects, a low level of metabolic acidosis and
positive acid balance (the production of more acid than is
excreted) are typically present ..." Sebastian A, Harris ST,
Ottaway JH, Todd KM, Morris RC Jr(1994) N Engl J Med, 330 (25):
1776-81
Improved Mineral Balance and
Skeletal Metabolism in Postmenopausal Women Treated with
Potassium Bicarbonate
-- "The lysosome system [acidic denaturing interior] provides
the only intracellular environment capable of performing this
pathological processing, and the recent observations reviewed
here suggest that it lies at the heart of the pathogenesis of
these diseases [Creutzfeldt-Jakob disease, Alzheimer's disease,
neuronal ageing and neuronal cell injury]." Mayer R J, Landon M,
Laszlo L, Lennox G, Lowe J. (1992) The Lancet, Jul
18;340(8812):156-9
Protein processing in lysosomes: the
new therapeutic target in neurodegenerative
disease
-- "Human metastatic breast cancer cells in culture contain
large acidic vesicles ..... large acidic vesicles were associated
with both phagocytosis and invasion ....." Montcourrier P,
Mangeat PH, Valembois C, Salazar G, Sahuquet A, Duperray C,
Rochefort H. (1994) J Cell Sci 1994 Sep;107 ( Pt
9):2381-91
- "Only a narrow pH range is compatible with life because even
a small increase in [H+] [that is, cell acidity] has dramatic
effects on normal cell function." "The major source of H+ [acid]
is ... metabolically produced CO2 [carbon dioxide]." Sherwood, L.
(Third Edition). 1994. Human Physiology. From Cells to Systems.
p. 530
-- "The crux of H+ [acid] balance [in the body] is maintaining
the normal alkalinity of the extracellular fluid (pH 7.4) despite
the constant onslaught of acid." Sherwood, L. (Third Edition).
1994. Human Physiology. From Cells to Systems. p. 531
Fluid and Acid-Base
Balance
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Finding may shed light on causes behind cystic
fibrosis
Researchers found a link between the severity of some forms of
cystic fibrosis and the ability of a key protein to move
particular molecules -- bicarbonate ions -- across cell
membranes.
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Bicarbonate, mineral water, renal stones
Cross-over study of the influence of
bicarbonate-rich mineral water on urinary composition in
comparison with sodium potassium citrate in healthy male
subjects
Kessler T, Hesse A
British Journal of Nutrition, 84, 6, 865-87, (2000)
High fluid intake is the first general recommendation made to
lithiasis patients for the prevention of renal stone recurrence.
The aim of the present study on healthy male subjects aged 23-38
years was to evaluate the influence of bicarbonate-rich mineral
water (1715 mg bicarbonate/l) on urinary-stone risk factors in
comparison with sodium potassium citrate, a well-established
treatment in that case. The results showed that the effect of the
bicarbonate-rich mineral water was similar to that of the sodium
potassium citrate, which suggests that it could be useful in the
prevention of the recurrence of calcium oxalate and uric acid
stones.
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Contraindication for bicarbonate
For people with the rare illnesses of Bartter syndrome or
Gitelman syndrome, bicarbonate may be contraindicated. These rare
sufferers may add a few drops of Real-Lemon juice concentrate to
any bicarbonate-containing beverage to neutralize it.
[Bartter's is listed as an orphan (rare) diseases with
the National Organization of Rare Diseases (NORD); they don't
even list Gitelman's, but include it under
Bartter's.]
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Updated on January 15, 2004
This page was first uploaded to The Magnesium Web Site on
November 14, 2002
http://www.mgwater.com/
Healthy Water
Association--USA