We found in the clinic that people who are on the fat side tend to feel sleepy, and sitting for three to five minutes is noted to make them doze off. If they lost weight and ate less, would that make the mind clearer? Would it not snore? Does Steve Jobs have a point when he says that a motivated person should stay moderately hungry? Today let’s briefly talk about the effects of calorie restriction on the brain. Delaying brain aging The aging of the brain is not only related to declining synaptic function, but also because neurons are constantly damaged by oxidative stress. Caloric restriction not only accelerates synaptotagmin transport and removes more harmful proteins, but also reduces oxidative stress damage to the brain. It has a good effect on slowing down brain aging and protecting brain tissue. In addition, aging of the brain also observed a decrease in the glutamate receptor subunit, which affects memory and learning functions of the brain; however, in the brains of calorie-restricted mice, this subunit remained relatively stable during aging. Finally, caloric restriction can have a reversing (yes reversing~) effect on nerve growth factors that already appear to be aging. Caloric restriction was found to increase the expression of heat shock proteins and enhance the protective response of neuronal cells to external damage. Prevention of stroke Obese people often have high blood lipids (20%), high blood pressure (25%), high blood sugar (15%), and atherosclerosis, which are all risk factors for stroke. We also found that some obese people have significantly elevated homocysteine, which is also a risk factor for stroke. Fortunately, one of the means of caloric restriction, alternate-day fasting, has been found in basic research to reduce the risk of stroke. In addition to its ability to lower body weight, stabilize blood pressure, regulate blood lipids, and improve atherosclerosis, caloric restriction enhances protection against the proteins involved and also reduces inflammatory factors and thus inflammation-related damage. In addition, caloric restriction also prevents the hypertrophy of astrocytes due to aging, a function similar to the preventive effect of caloric restriction on cardiomyocyte hypertrophy. Also, in a rat model of epilepsy induction using pentazocine, it was found that the success rate of induction was lower in rats that underwent caloric restriction; i.e., caloric restriction could have a protective effect on the brain to reduce the onset of epilepsy. People who drink a lot of alcohol and coffee have slower minds and memory loss; however, caloric restriction prevents hippocampal neurons from damage by excitotoxins and reduces neuronal degeneration. Caloric restriction needs to be adhered to Unfortunately, short-term, or low-intensity, caloric restriction is not enough to induce these benign effects. The average intensity of caloric restriction needs to be sustained for more than eight weeks to help the brain “clean out the junk”. In my personal analysis, the key to caloric restriction’s “waste removal” effect is to activate cellular autophagy. In the presence of insufficient calories, cellular autophagy may be activated by engulfing discarded organelles or misfolded proteins in the cell and converting them into calories or amino acids that the body can use directly. For cells to activate this ancient and conservative mechanism, low intensity caloric restriction requires a long time course, whereas the form of caloric restriction we are currently studying – short-term fasting – can achieve this effect quickly. Negative effects Of course, the current study also found that caloric restriction has a corresponding negative response on the brain. For example, the dendritic tree of the hippocampal dentate gyrus is more vulnerable during caloric restriction and may be more susceptible to shocks; nevertheless, it will have a better reorganized morphology and less dysfunction after this vulnerable period is over. This requires us to try to avoid stimulation of the brain by exogenous damage during caloric restriction; so, do you know why we are not allowed to drink alcohol and coffee during the fast? Also, during caloric restriction, brain-derived neurotrophic factors, which are involved in the maintenance of dendritic tree function, were monitored to decrease by about 15% in the central nervous system, but increase by about 20% in the periphery. Perhaps this suggests that caloric restriction may improve peripheral neurological disorders? In conclusion, caloric restriction has many benefits for the good maintenance of brain function, especially in overweight individuals; its specific mechanisms of action include slowing aging, anti-oxidative stress, and preventive protection, but care should also be taken to avoid its adverse effects.