Drs. Jay Luthar and Julia Loewenthal, physicians at Lutanen Health in Boston's Back Bay, have been named 2026 Castle Connolly Top Doctors, marking the second consecutive year they have received this honor. Only 7 percent of licensed physicians nationwide are selected annually as Castle Connolly Top Doctors for their specialties in their regions.
Lutanen Health, a bespoke primary care and longevity practice, limits each doctor to no more than 150 patients, allowing for deep, sustained relationships and strategic life-wide health stewardship. The practice is the only academically affiliated primary care practice in Boston that integrates longevity science into routine care. "The Castle Connolly recognition affirms what I believe matters most in medicine: time, trust, and partnership," said Dr. Luthar. "When you understand someone's biology, context, and goals over time, you can offer care that is not only more effective but deeply human."
At Lutanen Health, primary care becomes private health management, focusing on identifying risk before symptoms emerge and allocating interventions across a lifespan to preserve vigor and delay decline. Both physicians are fellowship trained in integrative medicine, bringing mind-body science and holistic approaches to lifestyle optimization. Their newly designed 3,000-square-foot healing space includes a state-of-the-art human performance laboratory.
The practice evaluates and treats a wide range of primary conditions with a focus on metabolic health, cardiovascular risk reduction, cognitive preservation, and healthy aging. The team specializes in managing complex internal medicine cases and addressing the needs of older patients, including frailty risk, medication optimization, and age-related vitality. Advanced diagnostic technologies are employed, such as AI-guided plaque detection, multi-cancer early detection blood testing, VO₂ max testing, biological age tracking, and genetic analysis.
Practice amenities include extended visits, same-day appointments, 24/7 physician access, individualized nutrition counseling, and home visits for select patients. Complimentary valet parking is available. Dr. Luthar completed his medical residency at Cambridge Hospital, a Harvard Internal Medicine Residency Site, and is board-certified in Internal Medicine, Integrative Medicine, and Lifestyle Medicine. Dr. Loewenthal completed her residency at Brigham and Women's Hospital and a geriatric fellowship through Harvard, with board certifications in Internal Medicine and Geriatric Medicine. Both hold academic appointments at Harvard Medical School.
Top Doctors are nominated by peer physicians and selected by the Castle Connolly research team. More information can be found at castleconnolly.com. Doctors do not and cannot pay to be selected as a Castle Connolly Top Doctor.
