Why Religious Fasting Could Be Good for Your Brain

Ramadan is in its third week now, and the required dawn-to-dusk fasting often feels like a daily mini–marathon. By late afternoon, hunger and thirst have sucked me dry, leaving me sleepy, slow-minded, and sometimes short-tempered.

I know that the purpose of fasting is spiritual—God will reward us in the next life—but in this lifetime, fasting sometimes makes me an ineffective, irritable person. So I was excited to learn that Harvard psychiatrist John Ratey, MD, had spoken at a recent Renaissance Weekend event about how caloric restriction can improve brain function.

I emailed Dr. Ratey to find out if those benefits might extend to religious fasting, and he sent me a 2006 paper on the brain functioning of men during the Ramadan fast. The researchers studied a small group of healthy men during and after the holy month, looking at their brain activity via functional magnetic resonance imaging (fMRI). They concluded that “all individual results showed consistent and significant increase of activity in the motor cortex during fasting.”

Other research shows similar results
That research builds on the work of other scientists, including Mark Mattson, PhD, who heads a neuroscience lab at the NIH’s National Institute on Aging. Mattson has done important research on how dietary restrictions can significantly protect the brain from degenerative diseases like Alzheimer’s or Parkinson’s.

In a 2003 article, Mattson and others reported that rats who were deprived of food every other day, or restricted to a diet at 30% to 50% of normal calorie levels, showed not only decreased heart rates and blood pressure, but also “younger” brains, with “numerous age-related changes in gene expression.”

Mattson and his colleagues also shared data from research on humans, which shows that populations with higher caloric intakes—such as the United States and Europe—have a greater prevalence of Alzheimer’s than do populations that eat less—such as China and Japan. The authors speculate that humans may have adapted to conditions of feast and famine; the stress of having little food, they write, “may induce changes in gene expression that result in adaptive changes in cellular metabolism and the increased ability of the organism to reduce stress.”

Although this research is relatively new, with many questions left unanswered, the authors conclude that “it seems a safe bet that if people would incorporate a spartan approach to food intake into their lifestyles, this would greatly reduce the incidence of Alzheimer’s, Parkinson’s and stroke.” (Of course, how this recommendation translates for individual people remains almost a complete unknown; consult with your own doctor before restricting your diet in dramatic ways.)

Next page: Finding motivation from on high