Nutrition Science and Everyday Application - beta v 0.1

468 ALICE CALLAHAN, PHD, HEATHER LEONARD, MED, RDN, AND TAMBERLY POWELL, MS, RDN
This slideshow from WebMD, “Sources of Salt and How to Cut Back,” offers some tools for
reducing dietary sodium.
Sodium Deficiency and Toxicity
Deficiencies of sodium are extremely rare since sodium is so prevalent in the American diet.
It is too much sodium that is the main concern. High dietary intake of sodium is one risk
factor for hypertension, or high blood pressure. In many people with hypertension, cutting
salt intake can help reduce their blood pressure. However, studies have shown that this isn’t
always the case. According to Harvard Medical School, “About 60% of people with high blood
pressure are thought to be salt-sensitive — [a trait that means your blood pressure increases
with a high-sodium diet]. So are about a quarter of people with normal blood pressure,
although they may develop high blood pressure later, since salt sensitivity increases with age
and weight gain.” 2 Genetics, race, sex, weight, and physical activity level are determinants
of salt sensitivity. African Americans, women, and overweight individuals are more saltsensitive
than others.
The Dietary Approaches to Stop Hypertension (DASH) is an eating pattern that has been
tested in randomized controlled trials and shown to reduce blood pressure and LDL
cholesterol levels, resulting in decreased cardiovascular disease risk. The DASH plan
recommends focusing on eating vegetables, fruits, and whole grains, as well as including fatfree
or low-fat dairy products, fish, poultry, beans, nuts, and vegetable oils; together, these
foods provide a diet rich in key nutrients, including potassium, calcium, magnesium, fiber,
and protein. DASH also recommends limiting foods high in saturated fat (e.g., fatty meats,
full-fat dairy products, and tropical oils such as coconut or palm oils), sugar-sweetened
beverages, and sweets. DASH also suggests consuming no more than 2,300 mg of sodium
per day and notes that reduction to 1,500 mg of sodium per day has been shown to further
lower blood pressure. 1
Although the updated dietary reference intake (DRI) for sodium does not include an upper
intake level (UL), the updated adequate intake (AI) considers chronic disease risk. 3 There is a
high strength of evidence that reducing sodium intake reduces blood pressure and therefore
reduces cardiovascular disease risk. 4
POTASSIUM
Potassium is present in all body tissues and is the most abundant positively charged
electrolyte in the intracellular fluid. As discussed previously, it is required for proper fluid
balance, nerve transmission, and muscle contraction. 5
Food Sources of Potassium
Potassium is found in a wide variety of fresh plant and animal foods. Fresh fruits and
vegetables are excellent sources of potassium, as well as dairy products (e.g., milk and
yogurt), beans (e.g., lentils and soybeans), and meat (e.g., salmon and beef). 5