From Family Loss to Brain Research: A Scientist’s Mission to Prevent Cognitive Decline

Growing up, Stefano Tarantini, Ph.D., watched his grandmother lose her independence to cognitive decline. At the same time, he became fascinated with the medical language surrounding her care – terms like ischemia and abnormal vascular function.

Those experiences led him to pursue a research career focused on the cerebrovascular system, the network of vessels that supply blood to the brain. Today, as an assistant professor in the Department of Neurosurgery at the University of Oklahoma College of Medicine, he spends his days in the laboratory searching for answers to the cognitive decline that too often plagues older adults.

“Dementia is one of the major reasons that older adults lose their independence, and it is becoming a bigger problem as our population ages. In the coming decades, more than 30% of our population is projected to be over the age of 65,” Tarantini said. “We are trying to understand what is happening at the cellular level to cause cognitive decline and, ultimately, to prevent or delay its onset.”

The American Heart Association has supported Tarantini’s work since his time as a pre-doctoral student, including funding awarded this year. Although widely recognized for its support of cardiovascular research, the organization also invests in studies of the brain’s blood vessels. Discoveries made with AHA support have helped Tarantini secure additional funding from the National Institutes of Health.

Tarantini’s early research examined how hypertension and aging contribute to micro-hemorrhages – small bleeds in the brain – and how those vascular injuries are linked to cognitive impairment in older adults. As a post-doctoral fellow, he expanded his focus to other mechanisms that could lead to cognitive decline, such as insulin-like growth factor 1 (IGF-1), a circulating molecule that decreases with age and plays a role in maintaining healthy blood vessels.

As an independent faculty member, Tarantini shifted his research toward potential interventions to slow cognitive decline, particularly through diet and lifestyle. One project involves the study of capsaicin, the active compound in chili peppers. Evidence suggests that capsaicin may counteract some of the harmful effects of a high-fat diet, and emerging research indicates it may also help protect against cognitive decline.

“Our goal is to understand the mechanisms of how capsaicin may be affecting cognition. People may not want to eat spicy foods, but perhaps an intervention could be in the form of a supplement,” said Tarantini, who also holds an adjunct faculty position in the Department of Nutritional Sciences at the OU College of Allied Health.

Tarantini’s lab is also investigating the effects of circulating LDL (low-density lipoprotein), or the “bad” cholesterol, on cognition. Over time, LDL can become oxidized, making it even more damaging to blood vessels. Because aging is already associated with chronic, low-grade inflammation – sometimes called “inflammaging” – additional vascular inflammation may further accelerate cognitive decline.

Another study examines the cognitive benefits of intermittent fasting – consuming the same number of calories within a shorter daily time window. Tarantini said periods without food allow the body to perform cellular “housekeeping,” clearing out damaged components that may contribute to cognitive decline. Fasting also allows the liver to produce ketones, a process that converts fatty acids into fuel.

“In today’s culture, we tend to be in a ‘fed’ state from early morning to late at night,” he said. “But increasing the time your body spends fasting really has beneficial effects.”

Although each project examines a different pathway, they share a common goal: protecting the aging brain by preserving the health of its blood vessels.

Finally, Tarantini is studying how the integrity of the brain’s blood vessels influences cognition. As people age, the blood vessels in their brains become “leakier,” which can lead to inflammation in the brain. His research seeks to determine how that vascular “leakiness” drives inflammation and, ultimately, cognitive decline.

In addition to his research, Tarantini mentors graduate students and post-doctoral fellows, several of whom have received their own AHA funding. He credits the AHA not only with advancing his own work but also with helping launch the careers of young scientists in his lab.

“The American Heart Association has been very supportive of younger generations of researchers,” he said.