DISCUSSION
Salt is sodium chloride. Food labels list sodium rather than salt content.
When reading a Nutrition Facts Panel on a food product, look for the sodium
content. Foods that are low in sodium (less than 140 mg or 5 percent of the
Daily Value [DV]) are low in salt.
Common sources of sodium found in the food supply are provided in
figure 4.
On average, the natural salt content of food accounts for only about 10
percent of total intake, while discretionary salt use (i.e., salt added at the
table or while cooking) provides another 5 to 10 percent of total intake.
Approximately 75 percent is derived from salt added by manufacturers. In
addition, foods served by food establishments may be high in sodium. It is
important to read the food label and determine the sodium content of food,
which can vary by several hundreds of milligrams in similar foods. For
example, the sodium content in regular tomato soup may be 700 mg per cup in
one brand and 1,100 mg per cup in another brand. Reading labels, comparing
sodium contents of foods, and purchasing the lower sodium brand may be one
strategy to lower total sodium intake (see table 15 for examples of these
foods).
An individual's preference for salt is not fixed. After consuming foods
lower in salt for a period of time, taste for salt tends to decrease. Use of
other flavorings may satisfy an individual's taste. While salt substitutes
containing potassium chloride may be useful for some individuals, they can be
harmful to people with certain medical conditions. These individuals should
consult a healthcare provider before trying salt substitutes.
Discretionary salt use is fairly stable, even when foods offered are lower
in sodium than typical foods consumed. When consumers are offered a lower
sodium product, they typically do not add table salt
to compensate for the
lower sodium content, even when available. Therefore, any program for reducing
the salt consumption of a population should concentrate primarily on reducing
the salt used during food processing and on changes in food selection (e.g., more fresh,
less-processed items, less sodium-dense foods) and preparation.
Reducing salt intake is one of several ways that people may lower their
blood pressure. The relationship between salt intake and blood pressure is
direct and progressive without an apparent threshold. On average, the higher a
person's salt intake, the higher the blood pressure. Reducing blood pressure,
ideally to the normal range, reduces the risk of stroke, heart disease, heart
failure, and kidney disease.
Another dietary measure to lower blood pressure is to consume a diet rich
in potassium. A potassium-rich diet also blunts the effects of salt on blood
pressure, may reduce the risk of developing kidney stones, and possibly
decrease bone loss with age. The recommended intake of potassium for
adolescents and adults is 4,700 mg/day. Recommended intakes for potassium for
children 1 to 3 years of age is 3,000 mg/day, 4 to 8 years of age is 3,800
mg/day, and 9 to 13 years of age is 4,500 mg/day. Fruits and vegetables, which
are rich in potassium with its bicarbonate precursors, favorably affect
acid-base metabolism, which may reduce risk of kidney stones and bone loss.
Potassium-rich fruits and vegetables include leafy green vegetables, fruit
from vines, and root vegetables. Meat, milk, and cereal products also contain
potassium, but may not have the same effect on acid-base metabolism. Dietary
sources of potassium are listed in K sources.
Considerations for Specific Population Groups
Individuals With Hypertension,
Blacks, and Middle-Aged and Older Adults. Some
individuals tend to be more salt sensitive than others, including people with
hypertension, blacks, and middle-aged and older adults. Because blacks
commonly have a relatively low intake of potassium and a high prevalence of
elevated blood pressure and salt sensitivity, this population subgroup may
especially benefit from an increased dietary intake of potassium. Dietary
potassium can lower blood pressure and blunt the effects of salt on blood
pressure in some individuals. While salt substitutes containing potassium
chloride may be useful for some individuals, they can be harmful to people
with certain medical conditions. These individuals should consult a healthcare
provider before using salt substitutes. |
