You only have one life. Make the most of it.


Dr. Chris Renna

Dr. Renna graduated from University of Texas, earned his medical degree cum laude from the University of North Texas Health Science Center and completed a residency in family medicine. In his initial years of practice, he learned that medical school prepared doctors to diagnose disease but did not prepare them to create health.

Dr. Renna decided to truly help his clients improve health, he needed to create an entirely new system and approach.  This was the beginning of LifeSpan medicine.  LifeSpan provides comprehensive and focused medical evaluations specializing in preventing disease, resolving symptoms and improving health.  These programs are delivered through personalized concierge support, access to your medical team 24/7 and exceptional follow up. 

Since founding LifeSpan medicine in 1992, Dr. Renna has maintained a small practice focused on optimal health with two rules. 

Everything is about you.
Everything is about your health.

Over the years his passion and dedication to clients as well as his unique approach has earned him an exceptional reputation as the nation’s premiere preventive medicine provider. He is a published author, popular public speaker and lecturer to audiences across the United States and abroad.

“Dr. Renna changed my life. All of the injuries from my athletic youth were starting to add up and the constant pain from arthritis seemed to be something I was going to have to live with. Since having the injections I have been able to ski..and to live my active life without having to manage pain.”


Dr. Moshe Ben-Roohi

Moshe Ben-Roohi, M.D. specializes in advanced non-surgical orthopedics and regenerative treatments for sports injuries, degenerative joint disease, and conditions of the spine. He often works with clients who have tried everything else and failed. 

He is board certified in Physical Medicine and Rehabilitation (PM&R). He obtained his medical degree at Tel-Aviv University’s Sackler School of Medicine and residency at NYU Medical Center and Hospital for Joint Diseases where he served as Chief Resident. After residency he completed a fellowship in Interventional Spine and Sports Medicine. 

Dr. Ben-Roohi maintains his role in academic medicine through his continued pursuit of ongoing research. He has published numerous scientific papers in PM&R and other peer reviewed journals. He is a frequent speaker on the subjects of Sports Medicine, Pain Management and Molecular Orthopedics. Dr. Ben-Roohi is a member of the American Medical Society for Sports Medicine (AMSSM), North American Spine Society (NASS), International Spine Intervention Society (ISIS), International Cellular Medicine Society (ICMS), American Academy of Orthopedic Medicine (AAOM), Institute for Functional Medicine (IFM) and the American Academy of Physical Medicine and Rehabilitation (AAPMR).

Dr. Jared Greenberg

Dr. Jared Greenberg is a leading specialist in regenerative and non-surgical orthopedics and recognized by his peers as a top doctor in spine medicine. Dr. Greenberg is board-certified in PM&R, and a fellow of the American Academy of Physical Medicine and Rehabilitation. He has performed over 12,000 spine, joint and bursa injection procedures in his career and has an expertise utilizing top technologies including fluoroscopic X-ray or ultrasound guidance for added accuracy and precision.

Dr. Greenberg attended the University of Pennsylvania in Philadelphia, PA for medical school. After completing his M.D. degree, he began an Orthopedic Surgery residency at the University of Wisconsin in Madison, WI. During his surgical training, Dr. Greenberg realized that he was more interested in non-operative treatments of musculoskeletal conditions, rather than operative. In 2006, Dr. Greenberg then returned to Philadelphia for a second residency, in Physical Medicine and Rehabilitation (PM&R). He completed this program at the Hospital of the University of Pennsylvania in 2009, and served as a Chief Resident for two consecutive years.

Dr. Greenberg then received subspecialty training as an Interventional Spine Fellow / Clinical Lecturer in the PM&R Spine Program at the University of Michigan Health System in Ann Arbor, MI. Dr. Greenberg was also selected to serve as a National Board Examiner through the American Board of Physical Medicine and Rehabilitation.


Tracey Thomas, ND, FABNO, CNS

Dr. Thomas is a board certified Naturopathic Doctor, Fellow of the American Board of Naturopathic Oncology and a Certified Nutrition Specialist. Dr Thomas has had a broad and accomplished medical career ranging from private practice internal medicine to specialized integrative care in cancer treatment.  

Her passion and focus is providing the best individualized medicine to clients all over the world.  She is dedicated to improving the quality of care and life for each of her clients by solving complex health issues through leading edge, translational medicine and individualization of recommendations and programs.  She is adept in building relationships and known for her ability to cultivate a scientific bridge between clinical information and implementation of this information in clinical treatment programs.

Dr Thomas spent 5 years in private practice managing internal medicine issues from weight loss to chronic health conditions before transitioning to Cancer Treatment Centers of America, where she focused her medical expertise on integrative programs .  After spending 5 years in specialty care, she looked for a more comprehensive and preventive approach to health and moved back into a multi-specialty practice focusing on preventive medicine and personalized medical programs.

Dr Thomas has consulted with large scale medical organizations and practices to create effective health programs such as developing Bariatric Nutrition Protocols to the American Society for Metabolic and Bariatric Surgery (ASMBS)  and created and implemented Cancer Treatment Centers of America (CTCA) Residency Training programs, collaborating with physicians and executive management . She is an active member of IFM, A4M and other leading edge organizations.

Dr. Gina Nick

Dr. Nick is a renowned doctor who has been in private practice for 10 years in Newport Beach, CA where she provided concierge, functional, preventive medicine programs to executives in the Newport Beach community and throughout California. She is a California native who completed her undergraduate degree at UCLA and medical school in Tempe, Arizona. 

Dr. Nick specializes in functional, preventive medicine with a focus on executive health including nutrition, microbiome, hormone replacement, brain optimization, immune function and overall health.  Her practice focuses on truly understanding her clients and helping them prevent functional decline and improve health.

She is known for unparalleled dedication to her clients and their health. Her programs and care focus on identifying the principal cause of health issues and use leading edge treatments and customized recommendations to resolve these issues.

Dr. Nick is a published practitioner, an RMD and recognized speaker for ACAM and other medical organizations.  She has published numerous articles on primary care issue, preventive medicine, hormone replacement, detoxification and nutrition. She holds a seat on the board of directors at Angel Light Academy, a Youth Leadership Organization as well as the California Naturopathic Doctors Association. Dr. Nick was also awarded the Emord & Associates Excellence in Integrative Medicine Award for 2013-2014.

“I really do believe that the anti-inflammatory program at Lifespan Medicine changed our lives for the better and I can’t thank you enough as I know that the changes I made helped me with this pregnancy. The lifestyle changes have also given our little girl the best start she could hope for in life!”

Nicole Visnic, CCN

Nicole Visnic, CCN, is the Ambassador of Nutrition at LifeSpan medicine. Nicole is a featured speaker, media consultant and has a wealth of knowledge on nutrition, weight loss, and various other health topics for our clients. Nicole builds all the LifeSpan medicine programs for our corporate health partnerships. She is an expert in customized nutrition plans involving lifestyle modifications, diet, supplementation and exercise. She excels at helping others reach a health goal they may have from weight loss, to more energy, less inflammation or just feeling and looking better overall.

Nicole enjoys cooking, and utilizes her expertise in the kitchen to provide specialized menus and recipes for clients to fit their individual preferences, allergies and food sensitivities, and overall lifestyles. She is currently working with meal delivery programs and restaurants world wide to provide LifeSpan medicine approved meals and menus. 

She earned her Bachelor of Science in Health Education from Winona State University and her Masters in Human Nutrition from the University of Bridgeport. In addition to her Master’s degree, Nicole is a certified clinical nutritionist.  She has directed corporate wellness programs and has also served as an adjunct professor of psychology at Brown Mackie College. She also practices what she preaches, adhering to a nutritious diet, and continually challenging herself by participating in rigorous events such as the LA Marathon, Orange County Duathlon and NPC Figure Competition.


Rachel Swanson, MS, RD

Rachel Swanson is a leading nutritionist at LifeSpan medicine specializing in individualized nutrition programs focused on optimum health, detoxification, weight loss, performance and peak physical function. She holds a masters in nutrition as well as a registered dietetic degree from NYU. Rachel began her accomplished career with the New England Patriots providing team nutrition programs focused on optimization of player health and team performance. She launched her private practice in nutrition consulting for different organizations and projects at Harvard, several nutraceutical companies and private physicians.

Rachel has worked with a broad range of individuals from celebrities, professional athletes to business professionals and moms, dads and families of all ages.  Her experience in dietetics and private practice have provided experience and expertise in a wide range of health issues and nutritional program to optimize health and prevention or manage disease such as cardiovascular disease, diabetes, weight loss/gain, anti-inflammatory diets, gastrointestinal health, chronic disease prevention, skincare/anti-aging, and sports nutrition. 

She is passionate about her work and 100% committed to helping each and every client succeed. Her current practice focuses on nutrition counseling, customized programs and nutritional education.Rachel is a renowned speaker and contributor to media and events like TechCrunch, FounderMade, Huffington Post, Dr Oz and more. Rachel holds memberships in multiple professional organizations such as California Academy of Nutrition and Dietetics, Dietician in Integrative and Functional Medicine, and American College of Sports Medicine.