Green Tea Extract in Treating Patients With Stage 0, Stage I, or Stage II Chronic Lymphocytic Leukemia

DISEASE CHARACTERISTICS: * Confirmed diagnosis of chronic lymphocytic leukemia (CLL) * Stage 0, I, or II disease * Previously untreated disease * Splenomegaly, hepatomegaly, or lymphadenopathy are not required for the diagnosis of CLL * Absolute lymphocyte count \> 10,000/mm\^3 * Lymphocytosis must consist of small to moderate size lymphocytes, with ≤ 55% prolymphocytes, atypical lymphocytes, or lymphoblasts morphologically * Phenotypically characterized B-CLL defined by all of the following criteria: * A population of leukemic cells that co-expresses the B-cell antigen CD23 as well as CD5 in the absence of other T-cell markers (CD3, CD2, etc.) * Dim surface immunoglobulin expression * Exclusively κ or λ light chains * Mantle cell lymphoma must be excluded by demonstrating the absence of the t(11:14) by FISH testing * Patients who require chemotherapy for treatment of CLL, based on any of the following criteria, are excluded: * CLL-related symptoms requiring treatment, including any of the following: * Unintentional weight loss ≥ 10% body weight within the previous 6 months * Extreme fatigue * Fevers \> 100.5°F for 2 weeks without evidence of infection * Night sweats without evidence of infection * Evidence of progressive marrow failure due to CLL involvement of bone marrow as manifested by the development of worsening anemia (hemoglobin \< 11 g/dl) and/or thrombocytopenia (platelet count \< 100,000/mm\^3) * Thrombocytopenia due to immune phenomena (ITP) is permitted as long as platelet count is ≥ 100,000/mm\^3and the patient is not on active pharmacologic therapy * Massive (i.e. \> 6 cm below left costal margin) or progressive splenomegaly * Massive nodes or clusters (i.e., \> 10 cm in longest diameter) or progressive adenopathy * Progressive lymphocytosis with an increase of \> 50% over 2 month period, or an anticipated lymphocyte doubling time of \< 6 months PATIENT CHARACTERISTICS: * Platelet count ≥ 100,000/µL * ANC ≥ 1500/µL * Hemoglobin ≥ 11 g/dL * Total or direct bilirubin ≤ 1.5 x upper limit of normal (ULN) * AST (SGOT) and ALT (SGPT) ≤ 2 x ULN * Creatinine ≤ 1.5 x ULN OR creatinine clearance ≥ 40 mL/min * May have a history of autoimmune hemolytic anemia (AIHA) and positive Coombs test provided there has not been active hemolysis requiring transfusion or steroid treatment ≤ 10 weeks prior to registration * ECOG performance status 0, 1, or 2 * Life expectancy of ≥ 6 months * No uncontrolled infection * No myocardial infarction within the past 6 weeks * No New York Heart Association class III or IV congestive heart failure * Not pregnant or nursing * Negative pregnancy test * Must employ adequate contraception (condoms, diaphragm, birth control pills, injections, intrauterine device \[IUD\], or abstinence, etc.) prior to study entry and for the duration of study participation * No other severe medical or psychiatric illness * No active hemolysis requiring transfusion or other pharmacologic therapy PRIOR CONCURRENT THERAPY: * At least 8 weeks since prior and no other concurrent over the counter green tea or green tea extract * No prior daily use of over the counter green tea products for medicinal purposes for \> 4 weeks (phase II only) * No other concurrent chemotherapy, immunotherapy, radiotherapy, or any ancillary therapy considered investigational (utilized for a non-FDA-approved indication and in the context of a research investigation) * No concurrent combination anti-retroviral therapy for HIV positive patients * No concurrent oral steroid preparations