Salt: How much, how often, and why?

Julie Matel, MS, RD, CDECF Center Dietitian

Salt

Salt = NaClSodium + Chloride Essential minerals Must be supplied in the

diet

Why is salt important for people who have CF?

Na CL lost in the sweat (2-5 x normal amounts) Skin tastes salty Sweat chloride test used to

diagnose CF Normal = less than 40 mmol/L

NaCl CF = at least 60 mmol/L and

usually more than 100 mmol/L NaCl

Functions of Salt in the Body

Salt helps to… maintain the body’s fluid balance maintain muscle contractions Salt is a vital component of blood,

plasma, and digestive secretions

Consequences of Increased Salt Loss in CF

More rapid onset of heat prostration (heat stroke)

Reduced appetite Abdominal pain Weakness Nausea Headache Poor growth

Who is at risk for having low sodium levels?

Breast fed infants with CF Anyone with CF experiencing

vomiting and diarrhea Anyone with CF living in a hot

environment or exercising vigorously

Acid Base and Electrolyte Disturbances in Infants with CF

103 infants diagnosed with CF prior to 1 year (1990-2000)

Evaluated for acid base and electrolyte disturbances

Fustik et al. Ped Inter (2002) 44, 289-292.

Macedonia

Results

16% of the infant CF population had electrolyte and acid base disturbances

Age 2 to 6 months No seasonal occurrence was found All infants breast fed Most not previously diagnosed with CF All infants had history of some loose stools

and failure to thrive prior to admission 94% of infants presented with vomiting All infants were pancreatic insufficient Only 60% showed mild to moderate signs

of dehydrationFustik et al. Ped Inter (2002) 44, 289-292.

The Bottom Line….

Early infant age Breast-feeding Delayed diagnosis Heat exhaustion The presence of CFTR mutations

associated with severe disease… are predisposed factors for development

of electrolyte and acid base abnormalities in CF patients

Exercise Study

Objective:To determine how much salt is required to increase voluntary fluid intake

Exercise study

11 subjects with CF (6 girls, 5 boys) Ages 11-20 years Attended 3 sessions of

intermittent moderate exercise

(4, 20 min bouts of cycling) 95 degrees F

(50% humidity)

Exercise Study

One of the following beverages wasassigned in each session… Water Flavored water Flavored water with 690 mg/L of Na

and 6% carbohydrate Additional session in 6 subjects with

flavored drink with 1150 mg/L of Na and 6% carbohydrate

Gatorade = 452 mg/L of Na

Bottom Line…

Children and adolescents with CF underestimated their fluid intake and became dehydrated when exercising in the heat

When given a higher sodium beverage (1150 mg/L), fluid intake increased sufficiently to prevent dehydration

Add 1/8 tsp to every 12 oz of Gatorade

How much salt do I need?

No one is sure!For people without CF… 120 mg for infants less than 6months 1500 mg for adults

People with CF need more

Sodium Recommendations for CF

Eat salty foods Use salt shaker freely at meals and

snacks Add 1/8 tsp of salt to 1 ½ cups (12 oz) of sports drink during

outdoor exercise (especially on hot days)

Add 1/8 tsp daily to breast milk or formula for infants

What are the best sources of salt?

Table salt Salted nuts Bacon Pickles Canned soup Salted crackers/chips Canned vegetables Frozen dinners

Food Labels

Food Sodium (mg)Ramen, Noodles 1430Salt ¼ tsp 580Dill Pickle 570Canned Soup (1 cup) 480Hard pretzels (1 oz) 385Pedialyte (1 cup) 245Cheerios (1 cup) 204Bacon 1 slice 185Gatorade 1 cup 200

Can I get too much salt?

Very unusual for someone with CF to get too much

At risk for too little!