Benefits of Fasting
July 12, 2017
Numerous studies identify fasting as highly beneficial for humans. We must only note that the appropriate timing varies for each individual.
The potential benefits of fasting are numerous and can be harnessed preventatively or therapeutically, in conjunction with other treatments.
During fasting, levels of this hormone can increase up to fivefold, which aids in fat burning, the development of lean muscle mass, and muscle gain.33-36 However, intense or strength training should not be performed during fasting hours.
Fasting prompts the body to initiate autophagy (degradation and removal of cellular components no longer useful), leading to important cellular repair processes for maintaining cellular health and improving stress adaptability, which, consequently, enhances immune protection against diseases.37-39
Changes occur in genes and molecules, with effects on metabolism related to the prevention or treatment of cancer and cerebral longevity. A human study showed that fasting reduced many of the side effects of chemotherapy.38,40-45
Fasting increases parasympathetic activity (mediated by the neurotransmitter acetylcholine) in autonomic neurons innervating the intestines, heart, and arteries, resulting in improved intestinal motility, reduced heart rate, and lower blood pressure.38
Fasting stimulates the sympathetic nervous system on adipose cells, leading to localized norepinephrine release with lipolytic effects—which promotes greater fat mobilization, sparing muscle glycogen—previously inhibited by insulin.62
Reduction of various parameters for cardiovascular disease risk, including elevated blood sugar levels (highly damaging to vascular walls), blood pressure (due to the diuretic effect in the absence of insulin), very-low-density lipoproteins (VLDL), triglyceride concentrations, adipose tissue, and weight loss, in addition to an increase in HDL (healthy cholesterol).30,31,46-50
Both fasting and a caloric-restrictive diet affect energy metabolism, reduce inflammation, oxidative stress, and insulin resistance, protecting neurons against genetic and environmental factors. With prolonged and frequent fasting, increased neuroplasticity is observed, which is the brain's ability to regenerate and respond to diseases and damage. This is because fasting stimulates the production of BDNF (brain-derived neurotrophic factor), a protein that fosters neurogenesis, the creation of new neurons and synapses.37,38,51-56
Fasting reduces markers of oxidative stress and increases uric acid levels, which also functions as an antioxidant. Indicators of inflammation, including tumor necrosis factor-α, homocysteine, and C-reactive protein levels, also show reductions.38,42,46,57,58
Fasting promotes increased metabolism, resting energy expenditure, and fat mass loss, while preserving lean mass.23,24,30,31,47,48,62. According to studies, depending on the condition, in addition to fasting, adopting a healthy diet with caloric restriction, low in animal protein, and rich in vegetables is necessary.
Prevention and improvement of type 2 diabetes, prevention of type 1 diabetes progression, by altering the expression of sirtuins and the p53 gene.30-32
Although positive evidence for longevity extension is based on animal studies, the main factors involved in aging that are decelerated by caloric restriction in humans include: 1) reduction of oxidative damage to proteins, DNA, and lipids; 2) reduction of chronic inflammation; 3) elimination of dysfunctional proteins and organelles; and 4) decrease in glucose, insulin, and IGF-I.38,59-61
This content is part of Clínica Revitalize's commitment to translating science into accessible clinical practice — without losing rigor or depth.