Salt: How much, how often, and why?

Salt:How much, how often, and why? Julie Matel, MS, RD, CDE CF Center Dietitian

Salt Salt = NaCl Sodium + 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 dehydration Fustik 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 was assigned 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 1430 Salt ¼ tsp 580 Dill Pickle 570 Canned Soup (1 cup) 480 Hard pretzels (1 oz) 385 Pedialyte (1 cup) 245 Cheerios (1 cup) 204 Bacon 1 slice 185 Gatorade 1 cup 200

Can I get too much salt? • Very unusual for someone with CF to get too much • At risk for too little!

Salt: How much, how often, and why?