Austrian researchers report that supplementation with beta-carotene (in addition to vitamin A, vitamin C and vitamin E) is effective in normalizing blood levels of beta-carotene in cystic fibrosis patients and has significant clinical benefits. Cystic fibrosis is characterized by abnormal mucus secretion and chronic lung inflammation. It is postulated that the increased free radical generation from activated neutrophils (killer cells) creates an oxidant/antioxidant imbalance. Supplementation with vitamin E (5-15 mg/kg/day), a powerful antioxidant, is an accepted part of the treatment of cystic fibrosis (CF). The randomized, double-blind, placebo-controlled study involved 24 CF patients (average age of 11 years). Thirteen were randomized to receive supplementation with synthetic beta-carotene at a dose of 1 mg/kg/day (maximum 50 mg/day) for three months followed by a dose of 10 mg/day for a further three months. The remaining 11 patients received placebos. The blood level of beta-carotene increased from an abnormally low level of 0.08 micromol/L to 0.56 micromol/L during the first three months, but dropped back to 0.32 micromol/L during the following three months of the low dose supplementation (10 mg/day). Healthy controls had an average beta-carotene level of 0.27 micromol/L.
The researchers also noted a significant decrease in the number of days the
patients in the high dose supplementation group needed antibiotics to control
their symptoms. Before supplementation antibiotics were required on an average
of 14.5 days in a three-month period; during the high dose period this dropped
to 9.8 days; it increased slightly to 10.5 days in the low dose period. In
contrast, the placebo group needed antibiotics for an average 24.8 days during
the first three months and 18.5 days during the last three months. The trial
period coincided with the cold season.
The concentration of malondialdehyde, a marker of lipid peroxidation, decreased
significantly during the high dose supplementation period, but not during the
low dose period. Supplementation was well tolerated in all the patients. The
researchers conclude that high dose supplementation with beta-carotene may
benefit CF patients. Editor's Note: The benefits could possibly be
enhanced by using beta-carotene from natural sources and by taking it in
combination with a fat-containing meal.