Dear Alice,
If you do not have salt sensitive hypertension, do you need to worry
about salt consumption levels? If so, what would be safe daily amounts?
Dear Reader,
It's difficult to know who is and who isn't salt-sensitive. In addition,
research gives us conflicting ideas about the effect of salt intake on hypertension.
Two recent studies regarding salt intake and high blood pressure have
had conflicting results. One study showed a direct relationship between
salt intake and high blood pressure. The other showed that decreased salt
intake resulted in mildly reduced blood pressure levels, but only in older
patients previously diagnosed with hypertension. Cutting back on salt appeared
to have no effect on younger people with "normal" blood pressure.
The problem is that these results were based on numerous short studies,
many involving children, who aren't thought to respond to salt in the same
way that adults do.
So, what is the right answer? Well, the evidence strongly suggests that
salt does play a role in blood pressure regulation. For one thing, salt
affects the volume of blood circulating throughout our bodies. The more
salt we eat, the more water is drawn into the bloodstream. This raises total
blood volume, which leads to increased blood pressure. High blood pressure
puts a greater strain on blood vessels. On the other hand, high blood pressure
is sometimes treated with medications whose function is to remove salt and
water from body tissues.
On average, evidence has shown that as people age, those who use more
salt have higher blood pressure. In countries where the population eats
a low-salt diet, little hypertension exists. While Americans are thought
to be heavy-handed with the salt shaker, the truth is that the majority
of the salt in our diets comes from processed foods (i.e., frozen entrees,
canned goods, snack goods, snack food, and fast food) and not from the salt
shaker.
The government has recommended that adults consume no more than 2,400
milligrams of sodium, or six grams of salt (equal to
one teaspoon), daily. This is due to the fact that as many as 50 million
people a year suffer from hypertension (high blood pressure). Hypertension
is instrumental in 700,000 yearly deaths due to heart disease, kidney disease,
and stroke. Excessive salt intake is thought to increase blood pressure.
In addition, whether or not you are salt-sensitive, salt could also increase
your risk of osteoporosis, particularly in women. Regardless of how much
calcium is in your diet, researchers have found that a high sodium intake
can lead to calcium loss (excreted out in urine). This loss in calcium is
exacerbated with increasing amounts of sodium in the diet, and/or if intake
of calcium is low. This finding is important because continued urinary calcium
loss, caused by a high intake of sodium, will translate to decreased bone
density and increased risk for fractures in the later years. Young women
and men beware: since you continue to increase bone mass until your early
30s, it's particularly important for you to watch your sodium intake now.
The more sodium you eat, the more calcium you will need to maintain your
bones.
So, Alice recommends that whether or not you are salt-sensitive, male
or female, young or old, it pays to watch your salt intake. Pay attention
to processed foods. Try to salt your food after it's cooked, as opposed
to during and after (your food will lose the salty flavor in the process
of cooking, but the sodium content remains -- so you wind up using more
salt). It will most likely be worth your while to keep your daily salt intake
close to one teaspoon per day.
- Alice
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