Study Finds Blood Pressure Drug Losartan May Enhance Metabolism and Brain Health by Stimulating Brown Fat Activity

New research indicates that losartan, a common antihypertensive medication, may stimulate brown adipose tissue (BAT) activity, potentially linking improved metabolism to better cardiovascular and psychiatric health outcomes.

In a groundbreaking study published in the journal Nature, a team of researchers from Rockefeller University and Memorial Sloan Kettering Cancer Center (MSKCC) has uncovered evidence suggesting that losartan, an angiotensin receptor blocker (ARB) widely prescribed for hypertension, can enhance the metabolic activity of brown adipose tissue (BAT) in mice. This discovery opens up new avenues for potential therapeutic applications of losartan, given its established safety profile and the growing interest in the health benefits associated with BAT.

Led by Dr. Paul Cohen, the research team analyzed extensive medical records, revealing that the presence of brown fat is linked not only to lower rates of cardiometabolic diseases but also to improved mental health. The study builds on earlier research from Cohen’s lab, which indicated that individuals with higher levels of brown fat had significantly reduced incidences of conditions such as coronary artery disease and type II diabetes.

Research Context and Methodology

The findings stem from an analysis of medical records from over 100,000 patients at MSKCC. The researchers expanded their previous work, which had focused primarily on cardiovascular disease, by examining a broader range of health conditions related to brown fat. “We only looked for a few diagnostic codes in that study, mainly focusing on cardiovascular disease since that’s what this tissue has historically been associated with,” Dr. Cohen stated. The current study took a more comprehensive approach, analyzing more than 500 diagnostic codes to uncover new insights about the health implications of brown fat.

The methodology involved a reverse translational approach, which seeks to elucidate the molecular mechanisms underlying clinical observations. The researchers utilized PET/CT scans performed for cancer surveillance, identifying the presence of BAT in six anatomical regions, including the neck and armpit. Nicolás Gómez-Banoy, the first author of the study and an endocrinologist at Cohen’s lab, applied a machine learning tool developed by MSKCC colleagues to quantify BAT activity across these regions. The study found that the location of brown fat is significant; for example, increased brown fat activity in the axillary area was linked to a reduced risk of high blood pressure.

Key Findings on Losartan and Brown Fat

The researchers observed that patients taking ARBs like losartan exhibited a higher prevalence of brown fat in their scans. To further investigate the relationship, experiments were conducted to test the direct impact of losartan on cultured brown fat cells. The results indicated that losartan indeed enhances the metabolic activity of these cells, and importantly, the pathways responsible for this effect differ from those that mediate the drug’s antihypertensive properties. “The fact that its different effects are mediated by different molecular pathways is advantageous,” Gómez-Banoy explained, suggesting that future therapies could isolate these effects to specifically stimulate brown fat in individuals with normal blood pressure.

Additionally, healthy mice treated with losartan exhibited various markers of enhanced metabolism, such as increased energy expenditure, oxygen consumption, and carbon dioxide production, while maintaining stable body weight—further supporting the potential metabolic benefits of the drug.

Connections to Mental Health

The study also uncovered intriguing links between brown fat activity and mental health outcomes. Researchers found that individuals with more brown fat experienced lower rates of anxiety and depression. “We know that metabolically healthy people tend to have lower incidence of psychiatric diseases, so it could be that having brown fat makes you more metabolically healthy, and this correlates with fewer psychiatric issues,” Gómez-Banoy noted. Conversely, the study revealed that selective serotonin reuptake inhibitors (SSRIs), commonly prescribed for depression, appeared to suppress brown fat activity, suggesting a complex relationship between metabolic health and psychiatric treatments.

Implications for Future Research

The findings of this study open several promising avenues for future research. Investigators are encouraged to explore the genetic factors influencing individuals with high levels of brown fat, the potential psychiatric implications associated with BAT, and possible adverse effects, such as increased osteoporosis and skin conditions among those with elevated BAT levels. Dr. Cohen emphasized the importance of this research as a starting point, stating, “There were plenty of other medications associated with brown fat activity in our large cohort. This is just a start.” The potential for further exploration of additional pharmacological agents alongside losartan could yield significant insights into the therapeutic modulation of brown fat and its associated health benefits.

As researchers continue to investigate the complexities of brown fat and its implications for health, losartan’s dual role as both a blood pressure medication and a potential enhancer of metabolic and psychiatric health remains a topic of great interest. This study not only contributes to the understanding of brown fat’s role in human health but also paves the way for future clinical applications that could improve the quality of life for individuals dealing with metabolic and psychiatric disorders.