----- Original Message -----
From: "Joseph Berne" <[log in to unmask]>
> I'm sorry to intrude, but can anybody point me to a decent source for
> basic (no pun intended) information about acid- base issues with
> nutrition?
Hi. I know that not everyone on the list agrees w/ Dr. Loren Cordain re.
fat/low fat, but the following may be of some interest to you. It is from
the Paleo Diet Update dated October, 2008.
Kath
Dear Dr. Cordain,
Q - I recently read an article pertaining to Acid/Alkaline balance of foods.
It said you should not believe that it matters whether foods are acidic or
alkaline, because no foods change the acidity of anything in your body
except your urine. Your stomach is so acidic that no food can change its
acidity, and foods (citrus fruits, vinegar, and vitamins such as ascorbic
acid or folic acid) do not change the acidity of your stomach or your
bloodstream. So does it really matter?
Thank you,
Mike Hoover
Novi, MI
A - Thank you for your question Mike. It is a common misunderstanding that
because the food you eat does not change the pH of your blood or stomach
acid, it is inconsequential to your health.
Bone mineral content is based upon net calcium balance. This is the amount
of calcium you take in minus the amount of calcium you excrete. This helps
explain why the U.S. has one of the highest rates of osteoporosis in the
world despite having one of the highest calcium intakes worldwide.
All digested food ultimately reports to the kidneys as either acid or base.
If the diet yields a net acid load, the acid must be buffered by the
alkaline stores of base in the body. The highest acid-producing foods are
hard cheeses, cereal grains, salted foods, meats, fish and eggs. The only
alkaline, base-producing foods are fruits and vegetables. Because the
average American diet is overloaded with grains, cheeses, salted processed
foods, and fatty meats at the expense of fruits and vegetables, virtually
everyone in the U.S. has chronic low-grade metabolic acidosis.
Many nutritionists think the degree of this metabolic acidosis is mild and
inconsequential since it does not affect blood pH. However, this
perturbation of systemic acid-base balance is, in part, responsible for the
age-related loss of bone and skeletal muscle mass. To buffer the excess
acid, alkaline calcium salts are released from bone. Glutamine is released
from the muscles and utilized for the generation and excretion of ammonium,
gradually leading to sarcopenia.
Many studies with kidney patients have shown that a chronic metabolic
acidosis leads to bone loss1 and muscle loss2. For most folks, the
dietary-induced damage to the skeleton, skeletal muscle, and kidneys is
cumulative over a lifetime and appears later in life.
Studies by Dr. Anthony Sebastian's team have shown that when healthy people
were given potassium bicarbonate (a base) in order to reverse metabolic
acidosis, it improved biomarkers of bone health3 and reduced muscle loss4.
Likewise in 2006, an intervention study found that fruits and vegetables (as
opposed to grains) improved bone health5.
Among Eskimos, age related bone loss starts earlier in life and is more
pronounced than it is among Westerners due to the combination of an almost
exclusively animal diet and very low calcium intake in the Eskimo diet.
It's also important to mention that some studies have shown that
hypertension could also result from a disturbance in the acid-base balance.
Further evidence of this link comes from the fact that chloride seems to be
a major determinant of the diet's net acid load6, and from the fact that old
studies show that chloride raised blood pressure to a significantly higher
level than did sodium7.
Normal adult humans eating the typical Western diet, whose metabolism yields
more acids (sulphuric acid from meat, fish, eggs, dairy and cereal grains)
than base (bicarbonate from fruits and vegetables), have chronic, low-grade
metabolic acidosis. This is aggravated by the normal age-related decline in
overall renal function.
To correct this low-grade metabolic acidosis, focus on eating a high amount
of fruits and vegetables, and lower consumption of grains, hard cheese, and
chloride. This will bring the body back into acid/base balance, which
naturally brings it back into calcium balance, and has numerous other health
benefits. Remember, the goal is to avoid a net acid load on your kidneys.
References are available at www.ThePaleoDiet.com/v4n13.shtml.
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