|
Salt was used long before
recorded history began. One of the earliest known
writings, the Chinese Png-tzao-kan-mu, mentioned
more than 40 types of salt.
This work was written over
4700 years ago. Even older settlements have been
found around the world with various devices such
as pottery used to evaporate water to leave the
salt behind. It is speculated by some that major
civilizations flourished in arid regions at the
edge of vast deserts due to the physiological
need for salt.
Salt, or sodium chloride, is a
chemical compound. Salt occurs naturally in many
areas of the world. Salt crystals are cubic in
form - if you view salt through a magnifying
glass, you will see small "squares" or cubes.
Salt is an essential nutrient -
your body requires both sodium and chloride, and
cannot manufacture these elements on its own.
This is why there is a human gustatory receptor
(taste bud) specifically for salt, forming one
of the basic components of "taste".
Salt
is an electrolyte and has a slight charge. Salt
preserves food by making it difficult for
microorganisms to live - the salt draws water
from the cells of microorganisms and dehydrates
them.
In the body, salt helps to
regulate blood volume and pressure. The
relationship between salt and blood pressure was
known as long as 4,000 years ago, when the
Chinese emperor Huang Ti wrote of the connection
between salt and a "hardened pulse." Many
studies have shown that increasing or
decreasing salt intake for salt-sensitive
individuals can have a direct impact on blood
pressure.
Within the body, salt serves as
part of the ion pump. Just as salt formed a
hostile environment for microorganisms by
dehydrating them, salt controls water balance in
the human body. The sodium/potassium pump is a
prime example of how
electrolytes are
critical to health (sodium and potassium are
both electrolytes).
Two potassium molecules are
pulled into a cell, and three sodium molecules
are pumped out. This is an
endless cycle, with the net result that cells
carry a slightly negative electrical charge.
For many years, controversy has
existed with respect to the optimal amounts of
salt in the diet.
Unfortunately, many studies
focused on the salt content of foods without
taking into account other electrolytes.
Biologically and physiologically, sodium intake
alone does not regulate the sodium/potassium
pump - potassium intake is important as well!
More important than the amount of sodium in the
diet is the ratio of sodium to
potassium.
While food labels are
required to report sodium content, they are not
required to report potassium content, which
makes analyzing potassium intake extremely
difficult.
Recent research suggests that
this ratio is critical.
While many
studies have focused on high sodium content in
the diet, it appears that problems with
hypertension may be related more to an
inappropriate ratio of sodium to potassium.
Processed foods are extremely high in
sodium.
The major sources of potassium
are fruits and vegetables. In recent years, the
typical American diet has increased in the
amount of processed foods and drastically
decreased in the amount of whole, unprocessed
foods such as fruit and
vegetables. This
means that sodium intake is potentially much
higher than potassium intake.
When monitoring sodium in
the diet, it is important to consider two
factors. The first factor already discussed is
the ratio of sodium to potassium. In order to
balance this ratio, it is important to eat whole,
unprocessed foods and not to add excessive salt
to meals. This will lower the amount of sodium
in the diet.
One should also increase
the amount of fruit and vegetables consumed in
order to increase potassium in the diet. The
exact ratio is unknown, but research suggests
that a 1:1 ratio is probably a good target. The
typical American diet is more than a 5:1 ratio
in favor of salt!
The second factor to consider is
fluctuation of intake. Salt sensitivity is not
sensitivity to salt in general. It is
sensitivity to a drastic change of salt intake.
If a person is taking 5 grams of sodium
consistently, then suddenly goes on a low sodium
diet, problems can occur with a radical shift in
blood pressure.
Similarly, someone on a
"low sodium" diet who suddenly increases sodium
intake may experience similar problems. This is
why many people who eat healthy throughout
the week and then treat themselves to a
"splurge" meal sometimes feel nauseous and can
even experience elevated heart rate and blood
pressure: it is the body's reaction to the
sudden increase in salt intake.
The sodium/potassium pump
affects fluid balance. The body monitors the
amount of salt and potassium in the bloodstream,
as the body has no mechanism for storing
electrolytes. Sodium and potassium are typically
filtered in the kidney.
When a shortage of either
exists, the body secretes hormones
that drastically reduce excretion of
electrolytes and fluids. This is why cutting out
sodium too soon before a body building
competition can actually cause the competitor to
retain water - the body is reacting to the
lowered intake by preserving fluids and
electrolytes.
To summarize, the skinny on salt
is as follows:
* Be more concerned with the
ratio of salt to potassium than the actual
amount of salt in the diet
* Do not try to eliminate
salt - it is essential and required
by the body - instead, try to reduce excessive
intake by focusing on whole, unprocessed foods
and minimizing the amount of salt that you add
to meals
* Increase potassium intake by
including 4 - 5 servings of fruit and/or
vegetables in your daily menu
* Focus on restoring
electrolytes post-workout, preferably with a
higher potassium-to-sodium ratio. For example,
Mass Maker from Beverly International has 300mg
of potassium to 140mg of sodium, or
about 2:1.
* Avoid frequent, high
fluctuations in salt and/or potassium intake,
as these may have an adverse effect on your
blood pressure
The lesson here is one of
moderation. Salt is not the enemy, and by no
means should it be eliminated from the
diet. On the other hand, everyone should be
aware of the role that sodium plays in a
balanced nutrition program, to make sure that
excessive salt is not being
consumed.
Balance salt intake with
potassium intake. The preferred source of any
vitamin, mineral, or other nutrient is always
natural, unprocessed foods.
Copyright
2005 Jeremy Likness
| 
