Could reducing someone’s calorie intake before or immediately after a heart attack help protect their brain function?
UCI Health neurologist Dr. Yama Akbari thinks it may.
“Cardiac arrest affects over 500,000 people annually in the U.S.,” Akbari says.
“For 80 percent to 90 percent of the survivors, the most serious complication is poor neurological outcome, including coma, caused by reduced blood flow to the brain during cardiac arrest.”
He and the team of neurocritical care specialists in the UCI Health Neurosciences ICU see patients weekly that suffer from global anoxic brain injury, that is, brains deprived of oxygen during cardiac arrest. This complication can lead to severe disability or death.
Tests show benefits of caloric restriction
“It’s a major problem,” he says. “There’s a lot of research published on caloric restriction and longevity, stroke, and cancer, but not cardiac arrest. Additionally, chronic caloric restriction is heavily studied while the potential benefits of very short-term caloric restriction are not.”
So he and his lab set up tests to determine whether restricting caloric intake might confer neurological benefits. A rodent model showed that restricting food intake for just 12 hours prior to cardiac arrest significantly improved recovery from coma after cardiac arrest.
Akbari and his team presented these findings this month at the 2015 Neurocritical Care Society meeting.
“While this doesn't ‘solve’ the problem, it lays the foundation for potential treatments to be investigated further,” Akbari says.
“By understanding the mechanism of how caloric restriction provides neuroprotection from cardiac arrest, we can attempt to define those pathways and investigate their role and applicability in people.”
Akbari emphasizes that much more basic research is necessary, though these very preliminary findings potentially have implications for people at high risk of cardiac arrest. The next step, he says, is to test in rodent models whether caloric restriction after, rather than before, cardiac arrest might be beneficial. Eventually, it may be possible to show in people that reducing caloric intake, even a short-term reduction, could one day be either a recommended preventative measure or treatment, like taking an aspirin is today.
Akbari’s abstract, “Short Term Caloric Restriction Before Cardiac Arrest and Resuscitation Improves Neurological Outcome,” was recognized as one of the Top 20 Posters from among the more than 350 abstracts submitted.