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Alkaline Water
By Markus MacGill
Reviewed by Natalie Butler, RD, LD
Alkaline
water is the opposite of acidic water. It has a higher pH level than plain
water.
Claims
that it has various health benefits have helped increase the popularity of
alkaline diets and sales of machines that turn water alkaline.
Ionizing
machines are one example of these products. These can cost over a thousand
dollars.
But what
scientific evidence lies behind drinking alkaline water? Are there any proven
health benefits?
What is
alkaline water?
The pH of
water is neutral, around pH 7. Chemicals and gases can change this to make it
more acidic or more alkaline.
Rainwater's
pH is slightly below neutral, because there is carbon dioxide from the air, and
this increases acidity.
· Acidic substances have a pH of below 7.0, down to zero. The pH of
vinegar is around pH 3, lemon juice around pH 2, and battery acid around pH 1.
· Alkaline substances have a pH up to 14. Baking soda's pH is between pH
8 and 9, and milk of magnesia is between pH 10 and 11.
Water can
be high or low in pH, but if it is too high or too low, it can have adverse
effects.
Water
that is too alkaline has a bitter taste. It can cause deposits that encrust
pipes and appliances.
Highly
acidic water may corrode metals or even dissolve them.
Benefits
Alkaline
water has become popular in recent years due to a belief that it may benefit
health.
Bone
health and osteoporosis
Some
research has been done on the effects of alkaline intake on bones.
A study
published in Bone found an effect on
bone resorption. Bone resorption is the process where old bone cells are broken
down and replaced by new ones.
Less bone
resorption and more mineral density result in better bone strength.
The authors concluded that "a bicarbonate- and
calcium-rich alkali mineral water decreased bone resorption more than a
calcium-rich acidic mineral water."
However,
this was a small effect.
The
scientists called for more research, to see if the benefit of less bone
resorption was long-term and could improve bone mineral density.
Another
study, published in Nutrition Journal, compared the impact of an
acidic diet, rather than alkaline water, on osteoporosis,
a disease marked by weak and brittle bones.
Reviewing
the background to the study, the authors noted a high number of claims being
made on the Internet.
These claims suggested "that alkaline diets and related
commercial products counteract acidity, help the body regulate its pH, and thus
prevent disease processes."
The
review used high-quality evidence to conclude that
acid from the modern diet does not cause osteoporosis.
It also
concluded that an alkaline diet or alkaline supplements or salts do not prevent
osteoporosis.
A review
of studies published in 2012 found that an alkaline diet resulted in
urine that was more alkaline, and possibly less calcium in the urine.
However,
the researchers did not expect this to reflect total calcium levels, and they
found no evidence that this would improve bone health or help prevent
osteoporosis.
Cancer
A review
of the effects of alkalis on cancer was
published by Dr. Tanis Fenton and colleagues in the journal BMJ Open.
The
review assessed thousands of studies, but the authors found only one proper, randomized
test of acid in the diet and cancer of the urinary bladder.
They
found no studies about alkaline water and cancer in humans.
The researchers note: "In our experience, patients with
cancer are approached by salespeople who are promoting water alkalinizers as a
way to treat their cancer."
They
conclude:
"Despite the promotion of the alkaline diet and alkaline water by
the media and salespeople, there is almost no actual research to either support
or disprove these ideas."
One study
has suggested that an alkaline diet, but not specifically alkaline water, may enhance the action of some chemotherapy drugs
used to treat cancer.
Acid
reflux
Acid reflux disease
is when the contents of the stomach, which are acidic, splash back up the food
pipe.
Acid
reflux that keeps happening for a long time can cause damage and a disease
known as gastroesophageal reflux disease, or GERD.
A study
published in Annals of Otology, Rhinology & Laryngology found that drinking alkaline water might be
worth further study as a supplement to other treatments for reflux disease.
It found
that alkaline water at pH 8.8 stops an enzyme that is connected to reflux
disease. It also appeared to reduce the acidity of the stomach contents.
The work
was done in a laboratory rather than in humans. More research would be needed
to support these findings.
Moreover,
stomach acid exists for a purpose. It kills bacteria and other pathogens, and
it helps our bodies to digest food and absorb nutrients.
Blood
pressure and diabetes
Scientists
in Shanghai found that 3 to 6 months after drinking alkaline water, people
with high
blood pressure, high blood sugar, and high blood lipids had lower measures in each
of these factors.
In
2016, researchers found that
a high-pH electrolyte water reduced blood viscosity in 100 adults, after
exercising. This may help reduce cardiovascular strain due to dehydration.
However,
the scientists point out that participants had different measures of whole
blood viscosity at the outset, which could have affected the results.
It is
worth noting that the study was sponsored by Essentia Water, who also provided
the alkaline water used.
Recommended
daily intake
As there
is no evidence to support the health benefits of alkaline water, there is no
recommended amount that improves health.
However,
if you wish to start drinking alkaline water, start with a low intake and increase
it gradually. This can reduce the corrosive effects of highly alkaline water.
What is
the alkaline diet?
The alkaline diet, said Fenton's study, is promoted to correct "the
acid state that the modern diet creates."
It
includes more fresh fruits and vegetables and reduced protein intake.
"The marketing of the alkaline diet promotes not only a diet, but
also the sale of related supplements and water alkalinizer machines through
almost every media medium, including websites, books, and videos," the authors wrote.
A review
published in the Journal of Environmental and Public Health concluded
that an alkaline diet may have some benefits.
Fruits
and vegetables, say the researchers, have a negative acid load that could improve the balance between sodium
and potassium,
with possible benefits for bone and muscle health.
This
could help prevent high blood pressure, strokes,
and other chronic diseases.
Children
with severe metabolic acidosis tend to have low levels of growth hormone, and this can
lead to short
stature.
An
alkaline diet may help to reduce problems related to low growth hormone in
those who are susceptible.
An
alkaline diet also appears to increase magnesium in
cells. Magnesium, in turn, helps activate vitamin
D.
However,
none of these findings relate specifically to alkaline water.
Longevity
A study
published in 2016 looked at the effect of consuming alkaline water on 150 mice
over a period of 3 years.
Results suggested that those who drank alkaline
water had signs of greater longevity, in other words, they aged less and were
more likely to live longer.
No
significant differences were seen in the heart, liver, kidneys, brain, or
intestine of the groups studied, and no damage occurred, but there were
differences in how the mice and their organs aged.
Does
alkaline water promote weight loss?
Alkaline
water has shown no benefits for general health and metabolism.
While it
will not add calories as
part of a balanced or managed diet, there is no research that supports alkaline
water as a standalone weight loss remedy.
Risks
Drinking
water that is too alkaline may have adverse effects.
Researchers
who looked into the link between alkaline water, an alkaline diet, and cancer
said that an alkaline diet could be harmful, as it encourages people to
avoid foods that contain important nutrients.
They concluded that "Promotion of alkaline diet and
alkaline water to the public for cancer prevention or treatment is not
justified."
Possible
problems
The World
Health Organization (WHO) note that, just as too much
acid is corrosive, so is too much alkali.
In 2001,
scientists published findings following a study in which rats at different
stages of life consumed alkaline water of pH 11.2 or pH 12 for a year.
At
the end of the experiment, the
rats had lost weight or experienced delayed growth, and female rats had fur
that was thin in patches and appeared dull.
Some of
the rats had discoloration in the oral mucosa.
The review that was published in the BMJ found that, among the studies of alkaline water
they reviewed, "none [...] supported the promotions that suggest
alkaline water supports good health."
How to
make alkaline drinking water
Machines
called ionizers make water alkaline, but they are expensive.
Bottled
mineral water tends to be neutral or slightly alkaline. Some manufacturers may
state the pH level of their bottled waters.
Sparkling
waters are acidic. Carbonation introduces carbon dioxide, which lowers the pH
and increases acidity.
Takeaway
The website alkalinewatersionizers.org promotes
water ionizers. It says that "Because ionized water contains so
many active hydrogen molecules, it is able to act as a powerful antioxidant that searches out and destroys
free radicals."
However,
the site also emphasizes the message:
"You must understand that there are no benefits to drinking
alkaline water."
It is
only the ionizing, they say, that brings the benefits, yet there is little to
no published research to support ionized water for health.
The Cleveland Clinic, meanwhile, in their article, "Alkaline
water: Don't believe the marketing hype," advise people to drink
water, but make it plain water, because too much acidity or too much alkalinity
can cause problems.
They point out that the
human body is designed to find its own balance.
People
should think carefully whether it is worth investing in expensive equipment
that is unlikely to make a difference.
Natalie Butler, RD, LD, is a foodie
at heart and passionate about helping people discover the power of nourishing,
real food. She graduated from Stephen F. Austin State University in
Nacogdoches, Texas. She is a corporate dietitian for Apple, Inc. in Austin,
Texas and also manages her own private practice. Her happy place is her
kitchen, and she loves teaching her two kids to cook, garden, be active, and
enjoy a healthy life.
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