Finally, a randomized, double-blind, placebo-controlled intervention study in 3,365 subjects from the Shandong province of China found that supplementation with aged garlic extract and steam-distilled garlic oil for 7.3 years did not reduce the prevalence of precancerous gastric lesions or the incidence of gastric cancer (85)
Adaptive Responses Involved in the Control of Immune Reactions Melatonin has been investigated in the therapy of several autoimmune diseases, including systemic lupus erythematosus, MS, type 1 diabetes mellitus, rheumatoid arthritis, and inflammatory bowel disease, with controversial results

Digestive Symptoms In a 2-week study in 14 people with histamine intolerance and symptoms that included abdominal pain, bloating, or diarrhea, 93% of participants reported a resolution of at least one digestive symptom after taking 4.2 mg of DAO twice daily ( Migraine Attacks and Headaches A 1-month study in 100 people with previously diagnosed DAO deficiency observed that participants who supplemented daily with DAO experienced a 23% reduction in the duration of migraine attacks, compared to the placebo group ( Skin Rash A 30-day study in 20 people with chronic spontaneous urticaria (skin rash) and DAO deficiency noted that participants who received the supplement twice daily experienced significant relief in symptoms and required less antihistamine medication ( Although these studies suggest that supplementing with DAO may eliminate or improve symptoms of deficiency, theres no guarantee that its effective for everyone
Kimple and Sondek, 2004)