The following article has the simple function of to illustrate i concepts cornerstone of the fasting mimicking diet, already exposed by official website sources.
We recommend to kind users of elaborate on reading at the relative place internet or, alternatively, by consulting the bibliographic source more appropriate.
In the following paragraphs they will also be mentioned Comments of our author, which represent a personal evaluation - albeit based on specific competences - e DON'T they should therefore be interpreted as absolutisms.
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The following article focuses on Professor's project Valter longo, director of the department of gerontology at the University of California.
This researcher has developed a nutritional system, to be respected for a few days a year, which - according to preliminary studies - could guarantee some benefit in terms of increasing life expectancy and improving general health. Due to its characteristics, this dietary scheme has been renamed Fasting Mimicking Diet.
The wide media emphasis given to the alleged benefits of this diet does not find sufficient scientific confirmation - see the chapter "negative and critical aspects".
Diet and Longevity
For nearly two centuries, modern medical science has been looking for it correlation existing between diet, improvement area of health e increase dell 'expectation di "vita". In addition to the well-known research on the Mediterranean Diet by Ancel Keys (continued by various scholars), there are many testimonies on the beneficial effect of foods.
Demographers reveal that the first "Blue Zone" in the world - updated September 2021 - is precisely the region Sardinia, located in the center of the Mediterranean basin. In particular, the province of Nuoro stands out (with its epicenter in Seulo, the capital of the Sardinian sub-region of the same name) where men over a hundred years old are really numerous. In these areas the lifestyle has remained "rural" (with high physical movement), as well as the eating habits remain of a Mediterranean tendency (cereals, legumes, vegetables, milk; only local and seasonal fruits; limited to availability: eggs, fish, cheese, meat).
The oldest person in the world - as of September 2021 - is however Japanese, from the Fukuoka area; his name is Kane Tanaka (born January 2, 1903) and he is 118 years old. The lady claims that she mainly consumes rice, fish and soups, which are typical of southern Japan. Again this is not a coincidence, as the second Blu Zone in the world is Okinawa, an island in the far south of Japan, which has a similar food culture.
What do these populations have in common? A higher level of physical activity at home and at work (we are not talking about sport, but about movement linked to everyday life), a diet mainly consisting of fresh local foods - therefore linked to their seasonality and availability - and with high importance of vegetable ones, a low global energy density and the almost absence of junk-food. In short, they have an energy balance that allows them to stay in normal weight.
On the other hand, several researchers have obtained - even before Professor Longo - important results, in terms of increasing the longevity of laboratory guinea pigs, by adopting the principle of calorie restriction; the late Professor Veronesi and the European Institute of Oncology in Milan suggest partial fasting and calorie restriction as pillars of the "anti-aging diet".
It is known to the whole scientific community that the super long-lived populations - such as those of Sardinia, Calabria, Okinawa, Loma Linda (USA - Los Angeles), Costa Rica, Greece - tend to have a mainly vegetarian diet, integrated with little fish, even less meat and generally characterized by basic levels of protein than the modern western one.
The study began with the observation of subjects suffering from Laron Syndrome, ie people genetically lacking in receptors for the somatotropic hormone (GH or somatotropin). This Ecuadorian population, while growing very little, has a risk of cancer and type 2 diabetes mellitus very low.
What caught Longo's interest is the type of diet and lifestyle of these people, who eat mainly fried food and regularly practice smoking and alcoholism. Paradoxically, the opposite of those who, on the other hand, try to prevent cancer, diabetes and other metabolic diseases or its consequences.
After a few decades of monitoring only one of them died of cancer and the others did not develop any chronic diseases. All the deaths that occurred were of natural causes at the age of 80 (very high in the context of the geographical area).
This prompted the researcher to perform a verification experiment in the laboratory.
Compared to healthy and normal guinea pigs with Laron syndrome demonstrate:
- A morbidity for cancer and chronic diseases lower of 50%;
- A superior longevity of 40%;
- A major storage of the cognitive functions.
After identifying this relationship, the researcher tried to recreate the same metabolic-hormonal situation in healthy people on a specific diet. low content di protein of animal origin.
The release of growth hormone is partially influenced by the amount of dietary protein. By increasing them, somatotropic hormone levels can increase, and vice versa.
By applying the fasting mimicking diet, one would occur in normal guinea pigs reduction levels of GH and a greater "purification" of the cell population (understood as the production of new cells and the elimination of damaged ones).
Periodically adopting the fasting mimicking diet would help "reset the body" canceling the negative effects dell 'hormone area of growth present in excess.
It seems that fasting for short periodsinstead of suffering, the body becomes stronger by eliminating the main sources of disease.
The dietary method in question would, however, allow for eat keeping the same effects of fasting on water only.
Let's see them in detail.
- Cell protection and rejuvenation;
- Cell rejuvenation;
- Elimination and replacement of damaged cells.
The effects would affect all tissues and systems: immune, muscular, hepatic, nervous etc.
The fasting mimicking diet mainly affects cancerous cells; however, beneficial effects have also been observed on multiple sclerosis (autoimmune etiology).
In fact, in a study by Longo carried out on mice, each cycle of fasting mimicking diet was able to destroy a harmful autoimmune component, replacing it with a physiological one.
A sharp decrease in multiple sclerosis symptoms was observed in 50% of mice and a complete regression of these symptoms in 20%.
In a clinical study (19 humans), the fasting mimicking diet resulted in a significant decrease in risk factors:
- For type 2 diabetes mellitus.
- For aging.
- For cancer.
In mice, the fasting mimicking diet was responsible for:
- Increase of life in health conditions equal to 11%;
- Almost 50% decrease in tumors;
- Halving of inflammation factors;
- Improvement of cognitive functions.
It seems that the fasting mimicking diet has a beneficial effect even during chemotherapy (on guinea pigs).
Dr Longo found that by applying fasting mimicking in mice it is possible to reduce the progression of the tumor until it stops.
These effects, obtained by fasting or fasting mimicking diet, have been observed in breast cancer, melanoma and neuroblastoma.
In addition, a reduction in the side effects of chemotherapy was observed; this would be due to the "strengthening" of normal cells at the same time as the attack of drugs against the diseased ones.
The interesting aspect is that fasting would push to strengthen only the healthy cells, not the diseased ones that instead "disobey" by not protecting themselves and easily entering apoptosis (self-induced death).
These hypotheses have not yet found confirmation in humans. The only published study limits itself to ascertaining the safety of a "water only" fast before (24h) and after (48h) infusional chemotherapy based on cisplatin, with timid evidence of a possible reduction in side effects; in the study in question, however, there is no comparison with a group of patients on a "normal diet", which severely limits the effective scope of this alleged benefit.
Dr. Longo's studies are not limited tometabolic impact of the diet mimics fasting, but also delve into the effects on weight.
Still on the guinea pigs, by administering the same energy for 30 days to two groups of mice, he differentiated two groups as follows:
- Group 1: identical calories for 30 days.
- Group 2: identical but higher calories than the previous group for 25 days, after which they followed a 5-day fasting mimicking diet.
The effects of the experimental group were:
- Reduction of visceral fat.
- Preservation of muscle mass.
- Reduction of errors in cognitive tests.
I potential benefits of the fasting mimicking diet (observed on mice and still being tested on humans) are:
- Reduction 50% for the risk of cancer.
- Postponement age potentially at risk of disease and increased period of health.
- Increased percentage of tumors benign than malicious ones.
Additionally, people who have already tried the fasting mimicking diet have found:
- Reduction weight up to 2,0 kg, most of which is attributable to the content of visceral adipose tissue *.
- Increased of ketone bodies: index of metabolic use of fats *.
- Reduction CPR (C reactive protein) blood inflammatory marker.
- Reduction equal to 50% of IGF-1 (GH-stimulated insulin-like growth factor 1) *.
Following the restoration of the usual diet, the values tend to normalize. However, after at least 3 cycles of fasting mimicking diet the parameters are on average lower (even if not comparable to those observed at the end of the cycles).
*WARNING! The effects mentioned in points 1, 2 and 4 are to be contextualized in the fasting mimicking diet and should not be interpreted as unequivocally positive or sought with alternative nutritional systems.
How does it work
Your average country of normal weight that meets (more or less) the criteria of the Mediterranean diet can perform a cycle of fasting every 3-4 months (3-4 times a year).
An obese subject suffering from metabolic pathologies (hyperglycemia, hyperlipemia, hypertension) could apply in the fasting mimicking diet even once a month.
Based on the results, prof. Longo has studied a diet that can offer the same benefits while respecting contemporary Western rhythms.
Le rules of the fasting mimicking diet are:
- To consume mainly proteins of vegetable origin to the detriment of those animals coming from meat and cheeses. These would activate the genes that promote growth, aging and sometimes degeneration (up to cancer). Fish proteins do not seem to be as harmful, statistically the consumption of fish is not frequently associated with the onset of chronic diseases and tumors;
- Verify you are suitable to the fasting mimicking diet: the fasting mimicking diet exerts a series of quite radical effects (reduction and expansion of tissues and organs, for example the liver and muscles). Not everybody are able to tolerate it and, for some individuals, it can be "uncomfortable". Absolutely not recommended to those suffering from certain diseases. Before starting it is essential to evaluate:
- Weight and Body Mass Index
- Blood pressure
- Body temperature
- Hematocrit and sideremia etc.
- Periodically (30 days to 4 months, depending on the subject), follow 5 days di programmed feeding: Dr. Longo has collected in a box all the foods to be consumed in the period of time in question. The kit is commercially available; however, it is possible to reproduce the diet at home by managing the foods available on the market.
While taking advantage of the commercialized meals, it is advisable apply to a professional diet that follows and evaluates the path of the fasting mimicking diet.
E' inadvisable continue the fasting mimicking diet over il period indicated or at too short intervals; the effects could be, in some respects, diametrically opposed (wasting, damage to internal organs, aggravation of anorexia, etc.).
The fasting mimicking diet lasts 5 days, in which energy intake progressively decreases from day 1 (1.000kcal) to day 5.
The foods are exclusively of vegetable origin and mainly provide carbohydrates and few unsaturated fats.
Quoting the official source of the system:
"The caloric scheme foresees that on the first day they consume about 1000 kcal divided between 34% carbohydrates, 56% fat and 10% protein.
In the following 4 days it drops to 750 kcal, divided between 47% carbohydrates, 44% fat and 9% protein.
A super simplified example of the regimen to be maintained over 4 days at 750 kcal could be: 400 g of courgettes, 300 g of red cap, 300 g of carrot, 250 g of onion, 20 g of extra virgin olive oil and 20 g of nuts. "
You should avoid the fasting mimicking diet who is into accretion, pregnancy, nursing he elderly.
Furthermore, subjects are not considered suitable for the fasting mimicking diet affected by:
- severe underweight;
- insulin-dependent diabetics;
- hyperinsulinemia and recurrent hypoglycemia;
- severe anemia;
- eating disorders (especially anorexia);
- osteoporosi o osteopenia;
- serious illnesses and in the absence of medical consent.
Negative and critical aspects
The main criticisms on the Fasting Mimicking Diet concern the small number of scientific studies supporting the claimed benefits.
Many articles and television broadcasts take for granted the health benefits of this eating pattern in humans, when in reality sufficient scientific confirmation is lacking.
Longo initially studied the effects of the fasting mimicking diet on yeasts (S. cerevisiae), later obtaining confirmations on laboratory guinea pigs. However, currently (October 2016), there is only one published clinical study (on humans), with only 38 subjects enrolled (of which 19 controlled with a normal diet and 19 subjected to 3 cycles of fasting mimicking diet). Analyzing the study in question, potential gaps in the choice of the sample emerge, which - although well represented by age and sex - seems rather vague as regards the weight of the subjects enrolled and the related cardiovascular risk factors. These are not subtleties, but very important aspects to understand on what type of population the above-mentioned benefits would be valid (e.g. if they only affect overweight subjects or even normal weight subjects).
An even more serious shortcoming is the absence of a control group subjected to an identical diet in terms of caloric intake but "normal" in composition (for example Mediterranean or very rich in animal proteins, since the latter are thus demonized by the fasting mimicking diet). If this comparison had been made, similar results would probably have been obtained in the two groups; in fact, logic and experience suggest that the calorie restriction in itself (and the consequent weight loss) is much more important than the dietary composition. In this regard, there is no lack of scientific studies that indicate that diets with a high protein content, but low in calories, are associated with an improvement in cardiovascular risk and longevity. For example, a study of the Fulani - nomadic ethnicity of West Africa - which follows one diet low in calories but rich in animal protein and saturated fat and an active lifestyle - highlighted a lipid profile indicative of a low risk of cardiovascular disease. Longo himself in a 2014 study highlights how a high-protein diet - although deleterious for subjects aged 50-64, would instead be associated with a reduction in the incidence of cancer and overall mortality for subjects. over the age of 65.
The fact that the diet provides for the use of specific commercial products (kits of "pre-packaged meals") raises further doubts about the impartiality of the media magnification of the alleged - and all to be demonstrated! - benefits of this diet.
Based on these arguments, one wonders whether some form of commercial speculation is actually hiding behind all this promotional emphasis.
The negative aspects of the fasting mimicking diet are certainly related toapplicability.
Hunger, stomach cramps, weakness, fatigue, irritability, dehydration (if you don't pay due attention to drinks) and general malaise can accompany the entire therapeutic period.
Statistically it seems that most practitioners complain of a reduction in side effects on the third day, especially as regards mental performance (effect of ketone bodies suppressing hunger); nevertheless, muscle fitness and fine motor skills ne suffer heavily.
As anticipated, some "beneficial" effects can turn out to be a double-edged sword:
- First of all, weight loss is partially due to dehydration and the depletion of muscle and liver glycogen stores. This means that while it tends to be beneficial, the fasting mimicking diet is also debilitating. It must NOT be applied in case of intense sporting activity;
- Secondly, the increase in ketone bodies is attributable to a condition of hypoglycemia and lipid oxidation. Potentially toxic, these compounds are the result of a compromised / incomplete cellular metabolism (due to glucose deficiency). The brain works only "on sugars" ( DON'T is able to oxidize fats), but can use ketone bodies, albeit in limited quantities. The excess of ketone bodies creates dehydration, kidney and liver fatigue, inhibition of physiological stimuli and poor mental efficiency (further worsened by hypoglycemia);
- GH (consequently IGF-1) participates in the growth and replacement of all tissues in the body. Its effects are completely physiological and should not be considered negative; just think that the GH peak occurs in the period of physical development at a young age, when chronic diseases and tumors are statistically rarer. Furthermore, somatotropin is continuously (albeit "illegally") used as an anti-aging molecule; the positive effects on tissue rejuvenation are evident, although they can create side effects.
The fact remains that the excess of food of animal origin now seems quite clearly correlated to the increase of some metabolic and tumor pathologies; this correlation is particularly valid for preserved meat products, that is salted, dried, fermented, smoked and / or treated with preservatives to improve their flavor or conservation (see further information on red meat).
However, the correlation between these foods, somatotropic hormone and IGF-1, and the diseases mentioned in the article does not yet seem completely clear.