Mark Mattson describes his research in the following TEDx talk. Mattson is the current Chief of the Laboratory of Neurosciences at the National Institute on Aging. He is also a professor of Neuroscience at The Johns Hopkins University. Mattson is one of the foremost researchers in the area of cellular and molecular mechanisms underlying neurodegenerative disorders such as Alzheimer's Disease, Parkinson's Disease, and amyotrophic lateral sclerosis.
Arjun Walia, in an article in Collective Evolution, describes and comments on some of the points Mattson makes in the video above. Excerpts from Walia's article are below.
Mattson and his team have published several papers that discuss how fasting twice a week could significantly lower the risk of developing both Parkinson’s and Alzheimer’s disease.
“Dietary changes have long been known to have an effect on the brain. Children who suffer from epileptic seizures have fewer of them when placed on caloric restriction or fasts. It is believed that fasting helps kick-start protective measures that help counteract the overexcited signals that epileptic brains often exhibit. (Some children with epilepsy have also benefited from a specific high-fat, low-carbohydrate diet.) Normal brains, when overfed, can experience another kind of uncontrolled excitation, impairing the brain’s function, Mattson and another researcher reported in January in the journal Nature Reviews Neuroscience.”(source)
Basically, when you take a look at caloric restriction studies, many of them show a prolonged lifespan as well as an increased ability to fight chronic disease.
“Calorie restriction (CR) extends life span and retards age-related chronic diseases in a variety of species, including rats, mice, fish, flies, worms, and yeast. The mechanism or mechanisms through which this occurs are unclear.”
The quote above is from a review of the literature that is more than 10 years old. The work presented here is now showing some of these mechanisms that were previously unclear.
Fasting does good things for the brain, and this is evident by all of the beneficial neurochemical changes that happen in the brain when we fast. It also improves cognitive function, increases neurotrophic factors, increases stress resistance, and reduces inflammation.
Fasting is a challenge to your brain, and your brain responds to that challenge by adapting stress response pathways which help your brain cope with stress and risk for disease. The same changes that occur in the brain during fasting mimic the changes that occur with regular exercise. They both increase the production of protein in the brain (neurotrophic factors), which in turn promotes the growth of neurons, the connection between neurons, and the strength of synapses.
“Challenges to your brain, whether it’s intermittent fasting [or] vigorous exercise . . . is cognitive challenges. When this happens neuro-circuits are activated, levels of neurotrophic factors increase, that promotes the growth of neurons [and] the formation and strengthening of synapses. . . .”
Fasting can also stimulate the production of new nerve cells from stem cells in the hippocampus. He also mentions ketones (an energy source for neurons), and how fasting stimulates the production of ketones and that it may also increase the number of mitochondria in neurons. Fasting also increases the number of mitochondria in nerve cells; this comes as a result of the neurons adapting to the stress of fasting (by producing more mitochondria).
By increasing the number of mitochondria in the neurons, the ability for nerons to form and maintain the connections between each other also increases, thereby improving learning and memory ability.
“Intermittent fasting enhances the ability of nerve cells to repair DNA.”
He also goes into the evolutionary aspect of this theory – how our ancestors adapted and were built for going long periods of time without food.
A study published in the June 5 issue of Cell Stem Cell by researchers from the University of Southern California showed that cycles of prolonged fasting protect against immune system damage and, moreover, induce immune system regeneration. They concluded that fasting shifts stem cells from a dormant state to a state of self-renewal. It triggers stem cell based regeneration of an organ or system. (source)
Human clinical trials were conducted using patients who were receiving chemotherapy. For long periods of time, patients did not eat, which significantly lowered their white blood cell counts. In mice, fasting cycles “flipped a regenerative switch, changing the signalling pathways for hematopoietic stem cells, which are responsible for the generation of blood and immune systems.”
This means that fasting kills off old and damaged immune cells, and when the body rebounds it uses stem cells to create brand new, completely healthy cells.
“We could not predict that prolonged fasting would have such a remarkable effect in promoting stem cell-based regeneration of the heatopoietic system. . . . When you starve, the system tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged. What we started noticing in both our human work and animal work is that the white blood cell count goes down with prolonged fasting. Then when you re-feed, the blood cells come back. ” – Valter Longo, corresponding author (source)
A scientific review of multiple scientific studies regarding fasting was published in The American Journal of Clinical Nutrition in 2007. It examined a multitude of both human and animal studies and determined that fasting is an effective way to reduce the risk of cardiovascular disease and cancer. It also showed significant potential in treating diabetes. (source)