9 facts about the benefits of periodic fasting with links to scientific research

Scientists claim that temporary abstinence from eating is a way to improve the health of the whole body.

Scientific studies confirm that interval fasting has a beneficial effect on the functioning of the cardiovascular, digestive, nervous, and endocrine systems, as well as helps reduce the risk of cancer and increase life expectancy.

However, periodic fasting can bring not only benefits, but also harm. The technique has a significant list of contraindications, which you should first familiarize yourself with. If in doubt, it is better to consult a doctor.

What is periodic fasting?

Interval (periodic) fasting is a special diet in which periods of fasting and eating are systematically alternated. The basis of the diet is not the qualitative composition of the food, but only a temporary characteristic. You can eat anything and as much as you want, but only in a certain period of time.

There are several methods of interval fasting:

1. 16/8. This protocol implies that a person fasts 16 hours a day, and eats only in an 8-hour interval. Observing it is not as difficult as it seems: it is enough to skip breakfast. As a result, you can eat food, for example, only from 13:00 to 21:00 every day. The rest of the time is reserved for fasting. But you can also choose any other 8-hour interval for eating.
2. Eat-Stop-Eat. According to this method, it is necessary to fast 1 or 2 times a week for 24 hours. Only regular water intake is allowed – about 1.5-2.5 liters per day.
3. 5/2. In this case, food is taken as standard 5 days a week, then 2 days – no more than 500-600 calories per day.

The first method (16/8) is the most popular and easiest to use. In addition to the above, there are many other ways of fasting.

9 useful properties

Therapeutic fasting can alter gene expression, suppress inflammation, prevent malignancies, and even prolong life. The proven beneficial properties of periodic fasting are discussed below.

1. Changes in gene activity

During the fasting period, the following gene changes develop in the body:

1. The inclusion of autophagy - the "removal" of debris inside cells, which promotes protection of nervous tissue from various atrophic and destructive pathologies. The initiation of autophagy is associated with methionine deficiency, which develops during starvation, and inhibition of mTOR kinase activity.
2. Cancer prevention. Starvation activates a number of sirtuin proteins (SIRT1, SIRT2, SIRT3) that block the proliferative activity of cells and protect the human body from the formation of malignant diseases. An additional advantage is the increased resistance of cells to oxidative stress.
3. Improvement of trophic nervous tissue. During the absence of nutrients in the body intensifies the activity of a number of neurotrophic factors (GDNF), inhibits the work of substances such as IGF-1 and NF-KB. The combination of these changes reduces the risk of brain stroke, Alzheimer's disease, and cancer several times.

2. Restoration of cells and hormonal background

During fasting, the human body undergoes a temporary restructuring of all systems. The body goes into a mode of increased fat intake, which requires a change in the hormonal background, activation of cell and tissue repair reactions.

The following changes are typical:

1. Falling insulin levels. According to the data American experts, a significant decrease in the concentration of insulin in the blood, observed during fasting, contributes to a more active burning of fat reserves (mainly abdominal fat).
2. Increase in the concentration of growth hormone. Somatotropic hormone (STH) level increases at least 5 times! As a result, there is an active burning of fats, an increase in muscle mass. The human body receives a reserve of strength for "emergency actions".
3. Cell repair. The body on its own launches the process of removing excess particles from cells, restoring destroyed membranes and organelles, improving trophic (due to local changes in vascular tone of the microcirculatory bed) of affected tissues.

3. Weight loss

Intermittent fasting causes you to eat less food for a certain period of time.

It also has an effect on hormonal function that activates lipolysis (fat breakdown).

A separate value is given to the increase in norepinephrine. It increases the rate of destruction of fats in the body by more than 10 times and their subsequent use to meet energy needs.

Scientists from the UK proved that fasting increases the metabolic rate by 3.6-14%, helping the body burn even more calories.

It should be mentioned separately major meta-analysis , completed in 2014. In the course of the work, it was found that interval fasting can reduce body weight in both men and women by 3-8% in 3-24 weeks.

4. Prevention of type II diabetes mellitus

The development of type II diabetes mellitus is based on insulin resistance – a decrease in the sensitivity of peripheral tissue cells (muscle and fat) to insulin, followed by a violation of glucose uptake from the bloodstream.

According to scientists, intermittent fasting can reduce sugar levels (on an empty stomach) by 3-6%, and insulin levels by 20-31%.

There is also a decrease in the incidence of diseases associated with long-term diabetes mellitus. These include diabetic nephropathy and retinopathy.

5. Slowing down cell death and aging processes

Oxidative stress is an important stage in the realization of programmed cell death and natural aging.  Oxidative stress responds for the formation of unstable free radicals that destroy important structures in the body (enzymes, DNA).

According to scientists , prolonged fasting leads to inhibition of the effects of oxidative stress on the central nervous and cardiovascular system.

Turkish scientists installed that temporary fasting is effective in fighting inflammation – an important risk factor for many diseases. The effect is primarily associated with inhibition of the activity of tumor necrosis factor alpha.

6. Improving the health of the cardiovascular system

Diseases of the cardiological profile, according to statistics , ranked first in the world in terms of mortality.

Intermittent fasting allows you to lower blood pressure, affect glucose concentration and cholesterol levels in the blood.

For example, at the Institute of Kinesiology and Nutrition (USA) discovered that intermittent fasting leads to reduction of total cholesterol and its fractions in blood plasma (LDL, TAG), reduces the volume of adipose tissue in the body.

There was also a significant decrease in the level of systolic blood pressure – within 10-15%.

7. Cancer prevention

Cancer is the uncontrolled division of individual groups of cells that gradually destroy all surrounding tissues and the body as a whole.

As already mentioned, a change in the activity of genes prevents malignant degeneration of body cells.

Scientists from the USA have established that temporary starvation significantly increases the survival rate of rats suffering from cancer. The effect is associated with inhibition of the proliferation of pathological cells.

French experts have proved that temporary fasting reduces the incidence of lymphoma, as well as the causes of its growth. It is noted that a limited refusal to eat can increase the effectiveness of chemotherapeutic agents.

8. Improving brain function

Temporary abstinence from food contributes to the normalization of metabolic processes at the brain level. First of all, it is the suppression of chronic inflammation and free radicals, increased glucose absorption.

Detected that short–term hunger increases the secretion of a special hormone - BDNF, the lack of which is directly related to depression and similar mental disorders.

Animal experiments also demonstrate that temporary starvation reduces the likelihood of death when foci of ischemia (stroke) appear.

Specialists of the National Institute on Aging (USA) found out that fasting can delay the onset of Alzheimer's disease and improve its course.

9. Increased life expectancy

Interval fasting has a positive effect on all human organ systems, prevents a wide range of extremely dangerous diseases (coronary heart disease, myocardial infarction, stroke, malignant neoplasms, etc.), which leads to an increase in life expectancy.

American scientists have identified that the average duration of male rats who were on intermittent fasting (1 day of hunger, 1 day of full nutrition) lived about 83% longer.

Contraindications

There is a significant list of contraindications in which periodic fasting can adversely affect the health of the body. These include:

1. Body weight deficiency (weight deviation of more than 15% from the standard values or a BMI of less than 18.5).
2. Tuberculosis of any organ.
3. Type I diabetes mellitus.
4. Any pathology of the thyroid gland, hyperthyroidism and hypothyroidism.
5. Heart rhythm and conduction disorders (atrial fibrillation, AV blockades of II and III degrees).
6. Condition after myocardial infarction (within 30 days from the moment of vascular catastrophe).
7. Chronic heart failure of IIb - III degree.
8. Chronic viral hepatitis.
9. Cirrhosis of the liver.
10. Chronic renal or hepatic insufficiency of any etiology.
11. Thrombophlebitis.
12. Arterial hypotension.
13. Cholelithiasis, stagnation of bile.
14. Peptic ulcer of the stomach and duodenum, gastritis.
15. Pregnancy and breastfeeding. During gestation, the fetal brain may die from a nutrient deficiency. During breastfeeding, the child's body receives significantly less nutrients.
16. Age less than 14 and over 75 years old.

Possible side effects

During fasting, the following adverse conditions may occur:

1. Constipation. Constipation often develops with a monotonous diet with a deficiency fiber or with prolonged hunger. Taking herbal laxatives (Frutolax) is usually enough.
2. Headaches. Are typical for the initial period of fasting. Painful sensations, in most cases, have a diffuse character and significantly aggravate the general condition, forcing to abandon interval fasting. The reason is insufficient blood flow to the central parts of the nervous system . If you have a headache, it is recommended: rub the collar area with a waffle towel, massage your head with your palms (from forehead to crown). If such methods do not help, you should consult a specialist or stop fasting.
3. Dizziness and weakness. Symptoms signal an insufficient amount of nutrients entering the body. It is recommended to make an audit of the diet.

Conclusion

Thus, interval fasting is a scientifically proven way to improve the health of the entire body, which has its pros and cons.

The range of positive properties is multifaceted: reducing the likelihood of developing type II diabetes mellitus, myocardial infarction and stroke, malignant neoplasms, atrophic and degenerative brain diseases, weight loss, as well as general life extension.

The technique has many contraindications that must be taken into account. If there are difficulties or adverse reactions, it is recommended to consult a specialist. Only a doctor is able to correctly assess the state of health and make the right decision.