Food for thought
Fasting fans have long hailed the diet’s weight-loss powers. Now research is exploring the role it can play in mind maintenance, too. Dietitian Tai Ibitoye stress-tests the claims
Much like TV spoilers, it’s hard to miss the chat around fasting – or the hype around the health benefits. Its most popular incarnation? Intermittent fasting (IF) – restricting your calories for a set time period. In terms of physical health, research suggests it can speed up metabolism, reduce LDL (aka ‘bad’) cholesterol levels and support weight loss.
Recently, the research focus has shifted from physical to mental health, with different theories emerging. It’s been suggested that fasting causes an increase in brain-derived neurotrophic factor (BDNF) – atype of protein in the brain that’s involved in the regulation of serotonin metabolism. BDNF increases the number of neurons in the brain, which is linked with dysfunction and degeneration. One study* found that BDNF levels were lower in those with depression, so if fasting can increase your BDNF levels, it could improve your mental health, too.
Building on this, a review of 11 studies (published in the journal Nutrients in 2021) determined the effectiveness of fasting on stress, anxiety and depression. While IF, time-restricted eating and one-day-a-week fasts were addressed, most studies focused on the Islamic holy month of Ramadan. Researchers found that fasting during Ramadan was linked with a significant improvement of symptoms related to stress, anxiety and depression. But here’s the caveat: researchers didn’t address how fasting and mental health are related. They also noted that the improvement in depressive symptoms could be explained by other lifestyle modifications, such as not smoking or sleep quality.
It’s worth noting that most people struggle to get all the nutrients they need while fasting, increasing the risk of deficiencies that will, in turn, affect mental health. Observational studies show th
