You're probably
aware that bananas contain lots of potassium. What
you may not know is the potassium in fruits and
vegetables can help you toward a healthy blood pressure.
Potassium has the opposite
effect of sodium. Potassium lowers your blood pressure
while sodium chloride, found in table salt, raises
it.
And according to a recent
study from Loyola University Health System in Chicago,
not getting enough potassium may be just as important
a risk factor for cardiovascular disease as getting
too much sodium.
Design of study
In the study, researchers
looked at about 3,000 men and women aged 30 to 54
with blood pressure readings just under levels considered
high. The scientists accurately determined intake
of sodium and potassium based on the amount of the
minerals excreted in each participant's urine.
Previous studies of the relationship
between sodium or potassium and hypertension had
used less reliable means of estimating mineral intake.
Most relied on people's memory of foods they had
eaten.
The new study is "a quantum
leap in the quality of the data compared to what
we have had before," says Dr. Paul Whelton, an epidemiologist
and senior author of the study.
Research findings
After collecting the initial
data, the researchers followed participants for
10 to 15 years to see whether or not they developed
cardiovascular disease. Results of the study, published
this year in the Archives of Internal Medicine,
are as follows:
Participants with the highest
sodium levels in their urine were 20 percent more
likely to suffer heart attacks, strokes, or other
cardiovascular complications of high blood pressure
compared to participants with the lowest sodium
levels. But most interestingly, participants with
the highest sodium-to-potassium ratio in urine were
50 percent more likely to experience cardiovascular
disease than those with the lowest sodium-to-potassium
ratios.
What it all means
"Potassium seems to be effective
in lowering blood pressure," explains Whelton, "and
the combination of a higher intake of potassium
and lower consumption of sodium seems to be more
effective than either on its own in reducing the
risk of cardiovascular disease."
Expert guidelines
The Institute of Medicine
(IOM) has set dietary recommendations for salt and
potassium. The IOM advises healthy 19-to-50-year-old
adults to consume no more than 2,300 milligrams
of sodium in a day—equal to one teaspoon of table
salt. Currently, more than 95 percent of American
men and 75 percent of American women in this age
range exceed this amount.
And what about potassium?
Well, most Americans consume only half the 4.7 grams
of dietary potassium that IOM recommends daily.
Where to find it
Potassium is found in a wide
variety of fruits and vegetables. I usually encourage
eating at least four to five servings of vegetables
each day, plus three to four servings of fruit.
Some of the best plant sources
of potassium include orange juice, bananas, avocados,
prunes, tomatoes, white and sweet potatoes, beans,
and leafy greens. Low-fat dairy products and fish
are other good sources.
Ask your doctor if you have
a health condition or medication need that would
interact adversely with increased potassium intake.
For most folks, more dietary potassium and less
salt is a combination that equates with better blood
pressure and better cardiovascular health.
For more information:
American Heart Association,
www.americanheart.org.
Practical Prevention Banner
