Meet Our Team

Founder & CEO

Dr. Jeffrey Gladden,MD, FACC

Battling fatigue, anxiety, and depression, he embarked on a transformative journey to uncover answers to his own health challenges. Fueled by the question, “How good can I be?” Dr. Gladden transitioned from a conventional healthcare approach to championing peak human performance. Today, his life is a testament to this transformation, exemplifying boundless vitality through activities like running, surfing, mountain biking, and music. Dr. Gladden’s journey beckons us to embrace our ageless potential and embark on a path to Live Young for a Lifetime.

Dr. Jeffrey Gladden’s story is one of remarkable transformation and pioneering vision. With a background in interventional cardiology, he founded Gladden Longevity + Advanced Performance Center, recognized by many as the best longevity clinic in Dallas, and a leader in advanced age optimization. Graduating from Temple University with Honors and being elected to the AOA medical society, he went on to explore multiple domains of cardiology, leaving an indelible mark on the field.

Dr. Gladden held the position of Director of Heart Attack and Stroke Prevention and Cardiac Rehabilitation for several years at The Heart Hospital Baylor Plano, which he co-founded in 2004. Additionally, he was founder and played a pivotal role as CMO at Scientia Cardio Access which was acquired by Scientia in 2024. He served as a board member of Scientia Vascular, which is currently being acquired. Despite these achievements, both his personal and professional life encountered a pivotal shift in his mid-fifties — one that ultimately led him to build what many consider the best anti-aging clinic in Dallas.

Physician

Luke Sorrell, MD

From an early age, Luke Sorrell was drawn to the medical field, driven by a passion for science and a deep desire to help others. His journey began with a degree from Abilene Christian University, followed by medical school at The University of Texas at Houston and an internal medicine residency at Baylor University Medical Center in Dallas. Initially, Luke worked as a hospitalist before transitioning to primary care, believing it would be his long-term path.

While he valued the relationships he built with patients in primary care, Luke became frustrated with the reactive nature of traditional medicine. Late diagnoses of serious conditions, unchecked progression of pre-diabetes, and inadequate management of cardiovascular disease highlighted the need for a more proactive approach.

This realization led Luke to functional and longevity medicine, focusing on early detection, comprehensive interventions, and addressing root causes. Joining Dr. Gladden and Gladden Longevity felt like a perfect fit, aligning with his dedication to helping people “Live Young for a Lifetime” through what many consider the best personalized health program in Dallas and a leading age management clinic in Dallas.

Doctor of Acupuncture

Tammy Sorenson Besher, DAc, IFMCP

Dr. Tammy Sorenson Besher is an integrative health practitioner specializing in the intersection of Eastern medicine philosophy and Western clinical modalities. Her work bridges ancient healing systems with modern longevity and performance medicine, creating a precise and personalized approach to human optimization.

At the core of Dr. Tammy’s methodology is helping individuals understand and regulate how their body responds to stress, environment, and internal patterns—translating complex biological, emotional, and behavioral dynamics into clear, actionable strategies. Through this work, she supports clients in restoring balance, increasing energy, and building sustainable, long-term health.

Her approach is both intuitive and highly structured, grounded in the belief that optimal performance and healing require alignment across internal state, biology, and behavior. Drawing from Eastern principles of harmony and connection to nature, alongside Western frameworks of measurement and intervention, she guides individuals toward greater resilience, clarity, and capacity.

Dr. Tammy integrates this work within private practice and collaborative care settings, supporting individuals who are seeking not just symptom resolution, but precision, ownership, and mastery of their health.

Physician Assistant

Jason Gourlas, MPAS, 
PA-C

From an early aspiration to be a detective, Jason Gourlas found his true calling in medicine while serving as an Army medic — a perfect fusion of investigative rigor and scientific passion. A member of the Texas Army National Guard, he graduated summa cum laude from the U.S. Army Physician Assistant Program in 1996 and later earned his Master’s in Physician Assistant Studies from the University of Texas.

With more than 29 years of clinical practice, Jason has broad experience in military medicine, family practice, emergency medicine, neurotology, and surgical/trauma critical care.

In 2006, personal health challenges unmet by the conventional medical paradigm led him to integrative and functional medicine. By applying root-cause principles and lifestyle medicine, he restored his own health, which was an experience that redefined his approach to patient care. He went on to complete advanced training with the Institute for Functional Medicine and earned board certification from the American Academy of Anti-Aging Medicine.

Jason is deeply committed to translating the latest evidence-based integrative and functional strategies into personalized plans that resolve underlying drivers of disease and promote lasting vitality and longevity, contributing to the reputation of Gladden Longevity as a leading regenerative medicine clinic in Dallas.

RN

Emilie Brown

Emilie earned her Bachelor of Science in Nursing from Auburn University and brings a unique combination of critical care experience and regenerative medicine expertise.

She previously served as a nurse in the Pediatric Cardiac Intensive Care Unit at Medical City Dallas Children’s Hospital, where she managed complex, high acuity patients requiring constant monitoring and precise clinical decision making.

Most recently she served as a Nurse Manager in a regenerative medicine clinic where she oversaw clinical operations and supported therapies including IV infusions, ozone therapy, peptide protocols, hormone optimization, and regenerative treatments.

Her expertise includes advanced infusion therapy, peptide and hormone therapy support, regenerative treatments such as microneedling with exosomes, and personalized patient education and follow up.

Medical Assistant

Abigail Buentello

Abigail Buentello is a dedicated and compassionate Certified Medical Assistant with a strong clinical foundation and a passion for delivering exceptional patient care. She brings a combination of hands-on medical experience, outstanding communication skills, and a warm, personable approach that helps clients feel supported from the moment they arrive.

Before joining Gladden Longevity, Abigail served at WellMed Medical Management, where she gained extensive experience in both clinical and administrative roles. Her responsibilities included taking vitals, administering injections, performing point-of-care testing, assisting with minor procedures, monitoring Medicare measures, handling prescription refills, completing documentation, managing insurance-related tasks, and providing phlebotomy services.

Earlier in her career, Abigail strengthened her customer service and leadership skills through roles in retail and hospitality, where she learned to navigate fast-paced environments, resolve issues quickly, and maintain a positive, service-driven mindset.

Abigail is CPR-certified and is currently pursuing her Bachelor of Science in Psychology at Western Governors University, furthering her knowledge of human behavior, communication, and patient support. She is passionate about whole-person care and thrives in environments where excellence, empathy, and continuous growth are valued.

RN

Nancy Davis BS RN

With over 20 years of experience in the nursing field, Nancy has built a dynamic and well-rounded career across multiple specialties. Her extensive clinical background is matched by a deep commitment to patient-centered care and a reputation for unwavering empathy and compassion.

Throughout her career, Nancy has prioritized strong communication—fostering trust with patients, collaborating effectively with multidisciplinary teams, and mentoring junior staff with professionalism and warmth. Her holistic approach ensures that every patient feels seen, heard, and supported throughout their healthcare journey.

Client Experience & Optimization Consultant

Linda Downey

Linda Downey is a transformational expert specializing in functional health, nervous system regulation, optimization, and behavioral change.

She is also an Exercise Physiologist, with a deep understanding of how the body adapts, performs, and breaks down under stress.

With over 37 years of experience, Linda helps clients uncover and address the root causes of stress, overwhelm, and self-sabotaging patterns that drive burnout and chronic health challenges. Her work integrates neuroscience, transformational psychology, mindfulness, and energy-based healing to restore calm, resilience, and alignment so lasting change is not only possible, but inevitable.

Linda is a Functional Diagnostic Nutrition Practitioner, HeartMath Practitioner, Whole Life Coach, and Transformational Coach. She brings these disciplines together in a singular, highly personalized approach to becoming your best self.

At Gladden Longevity, she ensures that optimization is achieved biologically and becomes fully embodied in the nervous system.

Nutrition & Fitness Director

Zack Jenkins, MS, CPT

Zack Jenkins is an accomplished Fitness Director with a distinguished academic background, holding a Bachelor of Science in Kinesiology from East Carolina University and a Master of Science in Kinesiology, specializing in Biomechanics, from the University of Tennessee. As a NASM-Certified Personal Trainer (NASM-CPT), Zack is deeply committed to helping individuals achieve their fitness goals through evidence-based training methods. His approach emphasizes both peak performance and long-term health, ensuring clients not only reach their objectives but maintain them sustainably.

Director of Operations

Holly Dickinson

With a strong foundation in operations, management, leadership, and entrepreneurship, Holly Dickinson brings a rare blend of strategic oversight, organizational excellence, and hands-on execution to every aspect of the business. She is known for her ability to bring structure to complexity, build efficient systems, support high-performing teams, and ensure that both daily operations and long-term initiatives move forward seamlessly.

Holly has completed advanced professional development in operations and business leadership, including coursework through MIT in Operations Management and Harvard Business classes, further strengthening her expertise in process improvement, organizational strategy, and executive-level decision support. She is also trained and experienced in multiple leading assessment and team-development tools, including Kolbe, Culture Index, Wonderlic, and CMOM, allowing her to support hiring, team alignment, communication, and performance optimization at a high level.

Holly’s experience spans virtually every operational area of a growing business and medical practice, including operations management, team leadership, HR, payroll, accounts payable, accounts receivable, vendor relations, compliance coordination, and executive support. She is known for her ability to step into any area that needs attention and bring order, efficiency, and forward momentum. In her current role, she serves as a central force behind the clinic’s infrastructure, supporting both the organization as a whole and Dr. Jeffrey Gladden directly with whatever is needed to keep the practice operating at a high level.

Chief Growth Officer

Kelli Calabrese

Kelli Calabrese serves as Chief Growth Officer for Gladden Longevity, leading the clinic’s business development, membership strategy, and signature client experience. With more than 30 years of expertise in health, fitness, and high-performance transformation, Kelli bridges advanced longevity science with world-class service to create a seamless, elevated journey for every client.

At Gladden Longevity, Kelli oversees strategic expansion, brand development, and the full lifecycle of client engagement, ensuring that each individual receives personalized, concierge-level care from their first inquiry through their advanced optimization plan. She partners closely with Dr. Jeffrey Gladden and the clinical team to design programs, systems, and experiences that reflect the innovation, precision, and luxury associated with the best longevity clinic in Dallas.

Before joining the organization, Kelli built a distinguished career as a wellness expert, consultant, author, and international speaker. She has been featured across major media, coached thousands toward transformation, and co-hosts the Fit Over 50 Life Podcast, inspiring people to live younger, longer, and stronger.

Store Fulfillment and Management

Debra Weatherford-Slatton

Debra Weatherford-Slatton joins Gladden Longevity® as a Store Associate, bringing more than 20 years of experience supporting patients, providers, and healthcare teams. With a strong background in EMR charge compliance, patient support, scheduling, and cross-department coordination, she has built a reputation for staying calm under pressure and keeping busy environments running smoothly.

Debra is known for her friendly personality, clear communication, and genuine care for the people she serves. She’s excited to bring her customer service strengths and passion for wellness to the Gladden Longevity team.