Nov. 6, 2003 -- Need yet another good reason to eat your vegetables? The cruciferous kind -- including broccoli, cabbage, and cauliflower -- are believed to protect against a host of human cancers. Now, early animal studies suggest they may also prevent -- and even treat -- the autoimmune disease lupus.
A compound found in abundance in cruciferous vegetables, known as indole-3-carbinol (I3C), delayed the onset of lupus and reduced its severity in mice genetically bred to develop the disease. Mice fed a diet supplemented with I3C lived significantly longer than diseased mice fed a normal diet in the study, conducted by investigators at the North Shore-Long Island Jewish Research Institute.
The findings have not been confirmed in human studies, but researchers say the hope is that eating a diet rich in cruciferous vegetables or taking I3C in supplement form may benefit lupus patients and those at risk for the disease.
"My feeling is that this compound could be very useful for delaying the disease and for keeping people in remission once they have it," lead researcher Karen Auborn, PhD, tells WebMD. "It is also possible that it could be given along with the current treatments."
Current Treatments Have High Price
Approximately 1.5 million Americans suffer from lupus, with roughly 90% of cases occurring among women. Steroids such as prednisone are the most commonly prescribed treatment for the chronic inflammatory disease. The steroids suppress inflammation and slow disease progression, but this delay often comes at a high price. Osteoporosis and joint deterioration are common side effects of long-term use, and the treatment is associated with an increased risk of heart disease and diabetes.
I3C is believed to act as an anti-estrogen and is also under investigation for the prevention and treatment of breast cancer. Earlier research showed that women with lupus metabolize estrogen differently from women without lupus, and this is what led the North Shore researchers to investigate its activity in the genetically altered mice.
Newly weaned mice fed an I3C-supplemented diet and those introduced to the diet at five months of age were compared with mice fed a regular diet without I3C supplementation. At 12 months of age, 80% of the mice fed the I3C diet from soon after birth were alive, compared with only 10% of the non-supplemented mice. Normal mice live from one to two years. The findings are published in the latest issue of the Journal of Nutrition.
I3C-fed mice had far fewer kidney problems than the mice whose diets were not supplemented, and researchers say this is the reason that they lived much longer. Kidney disease is one of the main, life-threatening complications of lupus.
While Auborn says there is probably little harm in taking I3C supplements, which are sold in health-food stores, she adds that it is too soon to recommend them for lupus patients and those at risk. The North Shore investigators hope to begin human trials soon.
"Obviously we can't make recommendations to patients based on animal studies, but it is probably a good idea for everyone to eat cruciferous vegetables at least three times a week," she says.
Rheumatologist Richard A. Furie, MD, who is planning the human trials but was not involved in the animal study, agrees that it is too soon to know whether I3C will benefit lupus patients.
"I think the benefits will be modest at best," he says. "But right now we are using the same drugs to treat lupus that we used 20 years ago. There is a real need for new therapies."