Posted by Jeff Johnson, MS

> I love to eat bananas.
> I usually eat about 3 a day
> i know they contain lots of potassium,
> but i don't know what potassium does.
> Do you know anything about potassium
> and its functions?
> I know it relates to sodium somehow.
>
> Also, will eating too many bananas
> make me gain weight? They do contain
> a lot of (natural) sugars. Will these
> sugars be stored if i don't use them?
>
> If you know anything about bananas and potassium
> please e-mail me!!!!!!

Potassium, sodium and chloride are "electrolytes". They are found in
all body fluids including the blood, lymph, fluid outside of cells and
fluid within cells (intracellular fluid). Sodium and chloride are
primarily found in the fluids around cells and potassium is found within
cells. They carry an electrical charge when dissoved in body fluids
and thus help regulate nerve transmissions and many cell membrane
functions.

Potassium, sodium and chloride function to maintain the normal balance
and distribution of fluids throughout the body. They also function in
the maintenance of the normal pH balance, and with calcium and magnesium
in the maintenance of normal muscle contraction and relaxation, and
nerve transmission.

Potassium can help prevent hypertension by regulating blood pressure,
maintaining proper calcium balance, and minimizing the pressure-raising
effects of a sodium rich diet. Inadequate potassium intake increases
blood pressure in those with normal and borderline hypertension.
Potassium-rich foods in the diets of hypertensives reduces blood
pressure and often lessens the need for anti-hypertensive medications.

Potassium is important in the regulation of the heart beat.

Potassium and sodium work together to provide what is called the
"potassium/sodium pump" which enables transport of nutrients and waste
products across cell membranes.

Symptoms of potassium deficiency include slow growth, fragile bones,
paralysis, sterility, muscle weakness, muscle cramps, mental apathy and
confusion, kidney damage and heart damage. Sudden death that can occur
during fasting, anorexia nervosa or starvation is often a result of
potassium deficiency.

Toxicity: Dietary intake in excess of 18,000 mg can cause high serum
concentrations, disturbances in heart and kidney function and
alterations in fluid balance. Excess potassium does not cause muscle
cramps.

A medium sized banana contains 550mg of potassium. Assuming you
absorbed 100% of the potassium available in a banana (which you don't
BTW), you would have to eat 33 bananas a day in order to exceed 18,000mg
of potassium.

Weight gain occurs when you consume (eat) more calories than you
expend. Thus eating too much of anything will make you gain weight. If
weight loss is a goal, I would not recommend eating three bananas a
day. If you're satisfied with your present weight, it's not a problem.

How about some variety? Apples, cantelope, grapefruit, oranges, etc.
Don't forget the vegetables too! You should get a minimum of 5 servings
of a combination of fruits and vegetables daily. I recommend setting 7
servings as a goal. With three bananas a day, you're well on your way!

I wouldn't be concerned about your banana consumption unless you start
feeling an urge to swing from trees .

Jeff Johnson, MS
Performance Fitness & Nutrition

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