Low-calorie diet and fasting can rejuvenate the heart by 15 years
A new study has confirmed previous experiments in mice on the heart benefits of a low-calorie diet and fasting. The study involved 25 members of the Calorie Restriction Society (Calorie Restriction Society), aged 41 – 64 years, who consumed 1400 – 2000 full calories per day, or were on a zero calorie diet. And for comparison 25 adherents of a typical Western diet of the same age, consuming an average of 2000 – 3000 calories daily. It was found that the subjects’ cardiac muscle function indices were approximately characteristic of an age group 15 years younger than the control group.
“This is the first study to demonstrate that long-term caloric restriction and fasting has a positive effect on heart function in humans,” says Luigi Fontana, of Washington University, St. Louis and one of the authors of this study. Professor Fontana emphasizes that simply restricting calories will not have this effect. Members of the society follow a traditional Mediterranean diet including vegetables, olive oil, beans, fish and seafood and try to avoid sources of “empty calories” – soft drinks, desserts, white bread, etc. For the general public, the researchers recommend moderate calorie reduction in diet and daily exercise. In previous experiments, it was found that mice on a low-calorie diet live an average of 30 percent longer than their “eating” brothers.
Starvation and the heart
American researchers decided to clarify the cardioprotective effects of regular fasting (RF), when food is consumed every other day.
For this purpose, they observed laboratory rats fed every other day (WG group) or daily (control group) for 3 months. Then myocardial infarction (MI) was modeled in animals by ligation of coronary arteries. Twenty-four hours after IM, the size of the infarct zone was half the size in the WG group compared to the control group. In addition, the number of myocytes undergoing apoptosis in this zone was 4 times less in the WG group. According to echocardiography performed 10 weeks after IM, against the background of ongoing RG, remodeling and dilatation of the left ventricle (LV), observed in the control group, were practically absent in the RG group. In particular, among rats with the same infarct zone size 1 week after IM, remodeling was less pronounced, LV dilatation was absent, and LV function was better in the WG group compared with the control group. According to Dr. Ismayil Ahmet and colleagues (National Institutes of Health, Baltimore, Maryland), WG may lead to cellular and molecular changes in the heart similar to those in ischemic preconditioning. This results in increased myocardial tolerance to marked ischemic stress. Futurestudieswill show whether RG has a similar effect in humans
Scientists have discovered exactly why starvation lengthens life expectancy
As far back as the middle of the last century, it was discovered that starvation significantly increases the lifespan of various living beings, from single-celled yeast to primates, but the cause of this phenomenon at the cellular level remained unknown. A study by American biologists shows that the key lies in changes in the work of mitochondria, provoked by starvation. Scientists from Harvard, Cornell and the American National Institute of Health under the leadership of Harvard Associate Professor David Sinclair managed to identify two enzymes that mobilize mitochondria, often referred to as “energy factories”, in times of hardship for cells. This is what makes it possible to prolong cell life and delay cell death. The mitochondrion is a cell organoid that provides cellular respiration, as a result of which energy is released or stored in the easily usable form of adenosine triphosphoric acid (ATP). Absent only in bacteria, blue-green algae and other prokaryotes, where their function is performed by the cell membrane. Usually concentrated in functionally active areas of the cell. SIRT3 and SIRT4 enzymes are related to SIRT1 and SIRT2 enzymes, the importance of which for cell longevity was established earlier. In an article published in the latest issue of the journal Cell, scientists have shown that starvation leads to the activation of a protein encoded by the NAMPT gene, which promotes saturation of mitochondria with molecules of the coenzyme nicotinamidadenine dinucleotide (NAD), one of the main energy transporters in the cell.
According to the researchers, it is the abundance of NAD that allows the “youth enzymes” of mitochondria encoded by SIRT3 and SIRT4 to be fully utilized – instead of the natural decline in the organelles’ activity, which inevitably leads to the death of the entire cell, mitochondria not only restore their efficiency, but start working better than ever before. Increased efficiency, with which mitochondria begin to produce energy, allows you to significantly slow down the aging process of cells, almost turning off the natural mechanism of suicide of old cells. Moreover, as Sinclair and his colleagues managed to establish, the activation of mitochondria can temporarily compensate for the loss of all other sources of life in the cell. Even if its nucleus turns out to be completely inoperable, making it pointless to further preserve the vital unit, the mechanism of cell suicide refuses to start. How exactly mitochondria block cell death, scientists do not know yet.
Starvation helps with jet lag
Starvation helps to better adapt to the change of time zones, scientists from Harvard Medical School (USA) are sure. They found out that the refusal of food for 16 hours allows to “reset” the biological clock and start it anew. Scientists were prompted to an interesting conclusion by the results of a series of experiments conducted on rodents. It turned out that prolonged starvation changes the course of the biological clock to drive away sleep and give rodents the opportunity to still find food. According to scientists, the hunger “translation” of the clock is enough to calmly transfer the flight from the United States to Japan, the time difference between these countries is 11 hours.
Women’s nerve cells tolerate starvation better
The fact that different-sex organisms behave differently under fasting conditions is no surprise to scientists, but all previous studies have been conducted on nutrient-rich tissues (e.g., fat and muscle). Robert Clark and his colleagues came up with the idea of testing whether male and female nerve cells would react differently to nutritional deficiencies.
For the study, two colonies of neurons taken from male and female lab rats were grown; both populations were then fasted for 72 hours. The first significant differences appeared after 24 hours: the scientists who monitored cellular respiration noted a 70 percent slowdown in male nerve cells and a mere 50 percent slowdown in female neurons; the same trend extended to mortality rates. In addition, male cells showed signs of autophagy (an energy replenishment mechanism whose activation results in the destruction of cell organoids). In contrast, female specimens actively accumulated triglycerides and fatty acids in an attempt to prolong their existence.
Researchers, however, prefer not to rush to conclusions, noting that any experiments with cell cultures can not serve as reliable evidence of what really happens in a living organism.
Multiple sclerosis is protected by hunger.
Starvation alleviates symptoms of multiple sclerosis and other autoimmune diseases (rheumatoid arthritis, diabetes, etc.). Mice with a condition similar to multiple sclerosis, which were deprived of food for 48 hours, suffered much less brain damage and performed better in balance and movement tests during this time, and had noticeably fewer symptoms of weakness and paralysis. The paper’s author, Giuseppe Metarese from the University of Naples, hopes that combining diet with medication will make it possible to stop multiple sclerosis in the future. Right now, multiple sclerosis patients are advised to eat heartily, and no one is going to prescribe starvation for patients. Matarese hopes to isolate the components of the diet that have the strongest impact on autoimmune disease. Multiple sclerosis has no cure yet (modern means can only slow it down). Nevertheless, scientists have some novelties. One of them is the hormone leptin, secreted by fat cells after a meal to curb appetite. Matarese found that just before the onset of the disease, leptin production doubled in mice. But in those individuals who ate nothing for 48 hours (similar to 7-10 days for humans) – leptin levels approached normal. Matarese also found that neurons in damaged brain tissue also produced leptin.
Is starvation healthy?
Starvation stimulates the body’s cells’ ability to autophagy and thus contributes to life extension. In experiments on rats, scientists at the University of Florida, working under the direction of Dr. Christiaan Leeuwenburgh (Christiaan Leeuwenburgh), demonstrated that limiting the flow of nutrients into cells prolongs their life by activating autophagy – splitting and processing damaged mitochondria and other cellular structures and using the resulting material to support life. In the process of cellular activity, free radicals are produced, destroying cellular structures. Mitochondria, tiny organelles that provide the energy needed by the cell, are the most susceptible to these toxic by-products of cellular respiration. If damaged mitochondria are not removed from the cell, they begin to release proteins that trigger the cell’s self-destruction. Young cells have the ability to quickly recycle damaged structures and use them to build new organelles or replenish energy stores. Unfortunately, as cells age, they lose this ability, leading to the accumulation of damaged organelles and aging of the entire organism. The authors analyzed the state of cells in 22 young and old rats, half of which were kept on a low-calorie diet and the other half received unlimited food.
The results showed that a low-calorie diet increased the self-cleansing ability of heart cells in old animals by 120% and had little or no effect on cells in young rats.
To assess the effect of calorie restriction on the ability of cells to get rid of toxic waste, scientists evaluated the change in the content of certain proteins in the body of rats depending on their age and diet. It turned out that the cells of old rats eating a low-calorie diet were characterized by the highest level of proteins needed to trigger the autophagy process. Autophagy activation is especially important for heart cells, which contain a huge number of mitochondria. Prompt recycling of damaged organelles is the key to maintaining the performance of the aging heart muscle. The authors plan to search for ways to activate autophagy that do not require calorie restriction, which is very problematic and not always possible.
Starvation extends life to 180 years
It turned out that a meager diet forms a favorable hormonal background that promotes longevity, RIA “Novosti” reports. In an article published in the American Journal of Physiology, researchers from Albert Einstein College of Medicine in New York note that the effect of increased longevity in mice with a limited diet has long been known, as well as the fact that physical activity does not lead to the same effect. “We know that thin people are better protected against many diseases than fat people. However, studies on rodents have shown that they live longer if they are underweight due to a poor diet. Physical activity, which also causes weight loss, does not provide the same benefit. Our study was undertaken to find out why this is the case,” said lead author of the study Derek Huffman (Derek Huffman). D. Huffman’s words are quoted in the message of the American Physiological Society (American Physiological Society), which is engaged in the publication of the journal, notes RIA Novosti. The scientist emphasizes that these data refer specifically to rodents, which differ from humans in many respects.
However, he adds, recent studies have produced similar results in humans. People on a strict diet were found to be more likely to live longer than those who did not restrict their food but got serious exercise. One hypothesis attributed this effect to the fact that exercise causes stress, which damages tissue and DNA. According to another view, it is the caloric restriction of food that benefits the body.
By studying two groups of mice, one of which was restricted in food and the other was subjected to exercise, the scientists found that both groups had decreased levels of a marker (8-hydroxyguanosine) that indicates DNA damage. At the same time, the animals that received as much food as they wanted and were not subjected to exercise had very high levels of this marker. Thus, the first hypothesis was disproved – the researchers concluded that the extent of DNA and tissue damage increases with age, accelerated by obesity, but slowed by a low-calorie diet and/or exercise. “Instead, the study showed that caloric restriction of food leads to favorable changes in the body’s hormonal background that exercise does not.
The scientists concluded that these changes in metabolism contribute to life extension,” the report says. D. Huffman emphasizes that the benefits of exercise for humans are higher than in mice, because humans are more prone to cardiovascular disease, which can be prevented by regular exercise. “I don’t want to say that the results of this study can be applied to humans right now. But it shows the physiological changes that exercise and caloric restriction of food cause. We can continue this research until we understand how this works in relation to humans,” notes the scientist.
A number of researchers claim that under conditions of artificial restriction of nutrient intake into the body (starvation) leads to an interesting phenomenon.
Malignant cells, which are fed from the surrounding tissues, often die. It is well known that malignant cells, because of their rapid growth, require significant amounts of nutrients, several times greater than normal cells. Obesity and an unhealthy diet appear to increase the risk of cancer. Researchers from Ben Gurion University (Israel) decided to test whether restricting nutrition to a reasonable minimum has a direct effect on tumor growth. Under such conditions, normal cells multiply more slowly. And the fast-growing abnormal cells found in malignant tumors die off because they need disproportionately large sources of energy to grow at this rate. They face a dilemma: either grow no faster than the rest of the body, or die, in an attempt to reproduce faster than their limited energy supply allows. Scientists believe that by reducing dietary intake to a reasonable minimum, you can, if you will, starve your tumor.
Interestingly, in 1993, a university in Louisiana had already observed 23 pancreatic cancer patients on a low-calorie, high-fiber diet.
In total, they lived an average of 1.5 years, while their fellow patients on a regular diet lived an average of only 6 months. Importantly, in 1998, researchers at the National Cancer Institute in Maryland also concluded that being overweight combined with a high-calorie diet increased the risk of pancreatic cancer. Targeted clinical trials are now needed to prove the benefits of a low-calorie diet. Researchers at Ohio State University report that rats on a low-calorie diet had smaller prostate tumors than those rats who ate whatever they wanted. It should be noted that this hypothesis only works for tumors whose cells grow faster than normal cells and whose nutrition comes from surrounding tissues.
In total, they lived an average of 1.5 years, while their fellow patients on a regular diet lived an average of only 6 months. Importantly, in 1998, researchers at the National Cancer Institute in Maryland also concluded that being overweight combined with a high-calorie diet increased the risk of pancreatic cancer. Targeted clinical trials are now needed to prove the benefits of a low-calorie diet. Researchers at Ohio State University report that rats on a low-calorie diet had smaller prostate tumors than those rats who ate whatever they wanted. It should be noted that this hypothesis only works for tumors whose cells grow faster than normal cells and whose nutrition comes from surrounding tissues
Many people know that the most effective way to prevent aging is a calorie-restricted diet, – continues the story gerontologist Nikolai Akhaladze.
This has been proven in numerous experiments. In particular, if pikers or mice are not fed, by limiting their caloric intake by 30-40%, their lifespan is lengthened by a third compared to those that consume caloric food. To what extent do these trends apply to humans? Fifteen years ago, I was asked to examine members of the Kiev ValeoCenter – people who lead a healthy lifestyle. They not only constantly bathe in water bodies and maintain motor activity (exercise, running), but also limit themselves in caloric food, adhere to fasts. As surveys have shown, the biological age of these people is 10-15 years less than their calendar age. And this is despite the fact that most of them began to deal with their health after they had suffered strokes, heart attacks and other serious diseases.
This has been proven in numerous experiments. In particular, if pikers or mice are not fed, by limiting their caloric intake by 30-40%, their lifespan is lengthened by a third compared to those that consume caloric food. To what extent do these trends apply to humans? Fifteen years ago, I was asked to examine members of the Kiev ValeoCenter – people who lead a healthy lifestyle. They not only swim in water bodies and maintain motor activity (exercise, running), but also limit themselves in caloric food, keep fasts. As surveys have shown, the biological age of these people is 10-15 years less than their calendar age. And this is despite the fact that most of them began to deal with their health after they had suffered strokes, heart attacks and other serious diseases.
American experts say that even 1 day of fasting a month can be very beneficial to your health.
Scientists have conducted a study that showed that people who abstain from food every first Monday of the month, a 40% reduction in the risk of cardiovascular disease. And in patients with asthma, the number of attacks decreases. According to experts, mild stress, which is experienced by the body during moderate fasting, positively affects the immune system and reduces the likelihood of cancer. Some experts even say that it is not necessary to fast the whole day: you can skip breakfast or dinner. The obligatory condition is that if you decide to fast, do it regularly and drink water during this process.
