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| Stroke Prevention
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The idea that high potassium
intake may help prevent a stroke is an old one, but a new study has given it
added strength.
Nearly 44,000
men aged 40 to 75 were tracked for 8 years, during which time they
completed questionnaires on their diet and gave particulars of their medical
history and lifestyle. The questionnaires asked about the average frequency of
intake of 131 specified food items, as well as vitamins and mineral
supplements; the men were also asked about their blood pressure, and whether
they had been diagnosed by their physicians as having hypertension.
Fatal and non-fatal strokes occurring
during the 8-year period were recorded. Non-fatal stroke information was
obtained from the questionnaires, and confirmed from hospital records. Deaths
were reported by the next-of-kin, coworkers, or the National Death Index, and
the diagnosis of stroke confirmed by medical records or death
certificates.
For
analysis, the intake of potassium and other nutrients were adjusted to a
diet of 2,000 calories/day. The subjects were grouped into five classes of
equal size (i.e. each comprising 20%), depending on the amount of potassium
they consumed, according to their first questionnaire.
Similar classes were created for the other
nutrients and supplements. Then the relative risk for increased potassium
intake was calculated by dividing the incidence of stroke in the top 20% of
potassium consumers by the incidence in the lowest 20%.
Similar calculations were done for the
other nutrients. Relative risks were
calculated for the other nutrients. It seems that increased intake of
potassium, magnesium, fiber and calcium was commoner in men with a healthy
lifestyle - the top 20% in each case were less likely to smoke, were more
physically active, and took less alcohol and fat than men in the bottom 20%.
Results of the relative
risk calculations showed that men in the top 20% for potassium consumption had
38% fewer strokes than those in the bottom 20%. For total fiber 2, magnesium
and calcium the decreased frequencies of stroke were 30%, 30% and 12%,
respectively. Only in the case of potassium were the results "statistically
significant" i.e. they could not have been caused by chance under virtually any
circumstance.
The
protective benefits of increased potassium, cereal fiber and magnesium were
greater in subjects diagnosed as having hypertension. Hypertensive patients
taking diuretics (water pills) and potassium supplements showed even greater
benefits - 64% fewer strokes. Surprisingly, low salt intake was not associated
with any protective action on t he occurrence of stroke.
The practical consequences of this study are
fairly clear - we should ensure that our daily intake of potassium is high
enough. But how much is enough? The men in the high-potassium 20% ate an
average of 9 potassium-rich servings a day, compared with the lowest 20% who
consumed less than 4 servings daily. The difference is only about 2 grams of
potassium.
Potassium-rich
foods include bananas, tomatoes, spinach, and other fruit and vegetables.
And cereals rich in fiber are readily available.
It should not be a problem to help ward off the
likelihood of a stroke by increasing potassium intake with a change in eating
habits. The use of potassium supplements on the other hand, should be avoided,
unless prescribed by a physician; they can be harmful, especially to people
with kidney problems.
Thefore, do what your mother said - eat your fruit and veggies!
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