High levels of leptin, a natural hormone produced by fat cell, have been linked to a lower risk of developing Alzheimer’s. This study, published in the Journal of the American Medical Association, builds on previous studies that show obesity can increase risk of dementia by 80 percent.
“Our study raises the possibility that leptin may actually have a role in the various pathological processes that result in clinical Alzheimer disease,” says senior researcher Dr. Sudha Seshadri of Boston University School of Medicine in an interview with WebMD.
According to Vitals.com, Dr. Seshadri received her medical degree at Madras Medical College and completed her residency at All-India Institute of Medical Sciences and Tufts University.
Leptin created excitement in the 1980’s when research showed that it produced weight loss in mice, reports Bloomberg.com. Unfortunately the hormone didn’t work as well on humans. But further studies on animals showed that leptin improved functioning in the hippocampus, the brain’s main learning and memory center.
In the new study researchers performed brain scans on 198 older volunteers and were followed up for up to 15 years after blood leptin concentrations were measured. Scientists found after over 12 years of follow up the people with the lowest levels were about four times more likely to develop Alzheimer’s disease than people with the highest levels.
“If our findings are confirmed by others, leptin levels in older adults may serve as one of several possible biomarkers for healthy brain aging and, more importantly, may open new pathways for possible preventative and therapeutic interventions,” states Seshadri.
She cautions that further research is needed to confirm that leptin replacement therapy would benefit humans or help protect against the disease. People should wait before running out and getting their levels checked or taking the hormone on their own.
“We need to corroborate this in other studies and understand the possible risks as well as benefits of increasing leptin, since it can affect other areas of the body too. For example, obese people can have high leptin levels but also high levels of leptin resistance.”
Dr. Maria C. Carrillo of the Alzheimer’s Association calls the leptin research promising. Obese people in the study had lower leptin levels, which reinforces the growing recognition that lifestyle-related health issues like obesity and insulin resistance increase the risk for late-life dementia.
Approximately 5.3 million Americans are affected by Alzheimer’s disease and it’s expected to affect 11-16 million by 2050. The benefits of living longer are compromised by the burden of this disease on patients, families and society and have increased the sense of urgency in finding effective prevention and treatment of this illness.
“This gives us more information about how maintaining a healthy weight, staying active, a avoiding diseases like diabetes all come together to help protect our brains as we age,” says Carrillo.