Dr. Zava has devoted his 40 year professional career to exploring the role of hormones in aging and disease. After completing his Ph.D. in biochemistry at the University of Tennessee in 1974, Dr. Zava spent much of his time doing basic research on hormones and breast cancer in Texas, Switzerland, California and Oregon. In 1998, he established ZRT Laboratory, a CLIA-certified laboratory that is a frontrunner in the innovative development of test methods to identify hormonal imbalances that can lead to debilitating symptoms, diminished quality of life, and increased risk for cancers and many of the diseases of aging, such as diabetes, cardiovascular disease, and senile dementia. ZRT Laboratory was one of the first laboratories to develop and commercialize noninvasive (saliva and dried urine) and semi-invasive (dried blood spots) methods for testing hormones as an alternative to conventional serum testing. Using these unique methods of body fluid collection, ZRT is actively engaged in hormone research studies with Universities, Government (NIH, CDC) and Military agencies, private physicians, and Professional Sports teams. In addition to his innovations in clinical laboratory testing and development, and numerous scientific publications over the past 40 years, Dr. Zava coauthored a landmark book, What Your Doctor May Not Tell You About BreastCancer: How Hormone Balance Can Help Save Your Life. In this book Dr. Zava and coauthors describe how breast cancer can be caused by hormonal imbalances that occur naturally as we age, but can be prevented if the types of hormonal imbalances are identified with testing and restored to optimal healthy levels with bioidentical hormone replacement therapy and improved lifestyle (diet, exercise, stress reduction).