Why do people follow this diet?
A low-salt diet is beneficial for certain people with cardiovascular disease. Preliminary evidence has
linked salt consumption with increased cardiovascular disease incidence and death among overweight people. Low-salt diets seem to be
especially important for people with
hypertension (high blood pressure). Salt intake has been definitively linked to
hypertension in Western societies, and minimizing salt consumption lowers blood pressure in
Research studies consistently find that increased dietary salt aggravates asthma symptoms, especially in men. In a small,
preliminary trial, men with asthma who doubled their salt intake for one month experienced a
worsening of their lung function. Although not all of the observed effects were conclusive,
several double-blind trials have provided evidence of clinical improvement following a period
of salt restriction.
Other conditions that may benefit from a low-salt diet include Ménière’s
disease, migraine headaches, kidney stones, gastritis, and ulcers caused by H. pylori infection.
Preliminary evidence also suggests that restricting dietary salt may play a role in the
prevention of certain types of cancer,
including stomach, colorectal, and head and neck cancers.
Restricted levels of salt may help to preserve bone density. Short-term increases in
dietary salt result in increased urinary
calcium loss, which suggests that over time, salt intake may cause bone loss. Increasing dietary salt has increased
markers of bone loss in post- (though not pre-)
Lower salt intake may also help to protect against the development of reduced insulin
sensitivity, a physiological process that can lead to blood sugar regulation problems in
certain people. Preliminary studies suggest that high salt intake decreases insulin
sensitivity in young, healthy people, but not in older people with hypertension. Moderate
restriction of salt, however, also decreased insulin sensitivity in one preliminary study of
healthy people, but had no effect in other studies of people either with or without
Salt restriction also may be helpful in reducing edema in some people. High salt intake tends to lead
to water retention that may promote the further accumulation of fluid beneath the skin.
Pregnant women who are experiencing hypertension of pregnancy should not follow a
low-salt diet. A low-salt diet has not been shown to have a significant effect in reducing
blood pressure during pregnancy, so salt restriction is not recommended to women with
gestational hypertension and preeclampsia.
Additionally, unlike other conditions that cause high blood pressure, salt restriction (and
use of diuretics) can worsen preeclampsia by
reducing blood flow to the kidneys and placenta. In preeclampsia, unrestricted use of salt and
an increased consumption of water are needed to maintain normal blood volume and circulation
to the placenta.
People with certain conditions have been found to benefit from salt intake and should not
follow a low-salt diet. Children with cystic
fibrosis lose a large amount of salt in their sweat and thus should be encouraged to salt
their food liberally. Chronic fatigue syndrome
sufferers who have a form of low blood pressure triggered by changes in position (called
orthostatic hypotension) have been reported to be helped by additional salt intake.
Additionally, people with goiter or
hypothyroid condition should not restrict intake of iodized salt if it is their only major
source of iodine.
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