Does fasting improves immunity?

I have heard that fasting causes regeneration of memory cells(B- and T-lymphocytes) thereby improving immunity.Is this true? If yes, how?

Interestingly this effect seems to be true - there is one paper which claims that fasting for three days leads to the depletion of unused (and especially damaged) immune cells to save energy. When food is back at normal rates, the body starts to renew these cells which have been depleted before. This process also seems to enhance the self-renewal process of stem cells which start to replicate and further differentiate.

This works like in the figure below (from the paper below):

Although this renews a part of the immune cells, I wouldn't say that this improves the immune system. I think that here mostly naive cells (which haven't) come in contact with an antigen are shut off. If you deplete memory cells (which had this contact) this would be counterproductive, since these cells are important for a fast immune response.

There is as well an article in Science Daily, which summarizes the original paper. It can be found here.

Prolonged fasting 're-boots' immune system

Results of a new study on mice and a phase 1 trial of humans suggest that prolonged cycles of fasting – for 2-4 days at a time – not only protect against toxic effects of chemotherapy, but also trigger stem cell regeneration of new immune cells and clearing out of old, damaged cells.

The study, by researchers from the University of Southern California (USC) in Los Angeles, and published in the journal Cell Stem Cell, is the first to show that a natural intervention can trigger regeneration of an organ or system through stem cells.

The team believes the findings could benefit people with immune system damage, for example if they have received chemotherapy treatment for cancer. It could also benefit the elderly whose immune systems are weakened through aging, making them more susceptible to disease.

The scientists say prolonged fasting appears to shift stem cells of the immune system from a dormant state to an active state of self-renewal.

Results from experiments with mice and a phase 1 human clinical trial showed that long periods of fasting significantly lowered levels of white blood cells. In the mice, it flipped a switch that changed the signaling pathways of hematopoietic stem cells – a group of stem cells that generate blood and immune systems.

“We could not predict that prolonged fasting would have such a remarkable effect in promoting stem cell-based regeneration of the hematopoietic system,” says Valter Longo, a professor of Gerontology and the Biological Sciences at the USC Davis School of Gerontology, and director of the USC Longevity Institute.

He says that when you stop eating, the body uses up stored glucose, fat and ketones, and also recycles worn out and damaged immune cells.

“What we started noticing in both our human work and animal work is that the white blood cell count goes down with prolonged fasting,” he explains. “Then when you re-feed, the blood cells come back. So we started thinking, well, where does it come from?”


Recently, the infection transmitted by the latest coronavirus (COVID-19), was associated with significant increase in morbidity and mortality, reflecting major public health issue. However, Ramadan fasting throughout an outbreak may be a new phenomenon for many of Muslims worldwide. The aim of this review was to determine the impact of Ramadan fasting on immune system function during COVID-19 pandemic. This review gathered the contemporary information throughout PubMed, Scopus, and Science Direct databases from relevant articles, to provide understanding of the potential impact of Ramadan fasting on the immune system during pandemic viral infection. The results of this review show many justifiable concerns arise to the consequences of refraining the body from essential nutrients and fluids for prolonged periods of time through a day. Especially this practice might intricate the health status of selected groups including the elderly and people having chronic diseases. On the other hand, many studies suggest that intermittent fasting boost the immune response of the body towards infections. Furthermore, there is no conclusive evidence regarding the relationship between fasting and increasing or decreasing the risk of catching a virus or improving oxidative stress status as well. Therefore, Muslims who practice fasting during pandemic face a circumstance in which no concrete scientific evidence proves the safety or danger of this religious practice. We conclude that there are proven benefits of fasting in augmenting the immune response however, this summoned by many factors including general health status of the person who fasts, lifestyle, and epidemiological circumstances.

Manipulating mitochondrial networks inside cells — either by dietary restriction or by genetic manipulation that mimics it — may increase lifespan and promote health, according to new research from Harvard T.H. Chan School of Public Health.

The study, published Oct. 26 online in Cell Metabolism, sheds light on the basic biology involved in cells’ declining ability to process energy over time, which leads to aging and age-related disease, and how interventions such as periods of fasting might promote healthy aging.

Mitochondria — the energy-producing structures in cells — exist in networks that dynamically change shape according to energy demand. Their capacity to do so declines with age, but the impact this has on metabolism and cellular function was previously unclear. In this study, the researchers showed a causal link between dynamic changes in the shapes of mitochondrial networks and longevity.

The scientists used C. elegans (nematode worms), which live just two weeks and thus enable the study of aging in real time in the lab. Mitochondrial networks inside cells typically toggle between fused and fragmented states. The researchers found that restricting the worms’ diet, or mimicking dietary restriction through genetic manipulation of an energy-sensing protein called AMP-activated protein kinase (AMPK), maintained the mitochondrial networks in a fused or “youthful” state. In addition, they found that these youthful networks increased lifespan by communicating with organelles called peroxisomes to modulate fat metabolism.

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“Low-energy conditions such as dietary restriction and intermittent fasting have previously been shown to promote healthy aging. Understanding why this is the case is a crucial step toward being able to harness the benefits therapeutically,” said Heather Weir, lead author of the study, who conducted the research while at Harvard Chan School and is now a research associate at Astex Pharmaceuticals. “Our findings open up new avenues in the search for therapeutic strategies that will reduce our likelihood of developing age-related diseases as we get older.”

“Although previous work has shown how intermittent fasting can slow aging, we are only beginning to understand the underlying biology,” said William Mair, associate professor of genetics and complex diseases at Harvard Chan School and senior author of the study. “Our work shows how crucial the plasticity of mitochondria networks is for the benefits of fasting. If we lock mitochondria in one state, we completely block the effects of fasting or dietary restriction on longevity.”

Next steps for the researchers including testing the role mitochondrial networks have in the effect of fasting in mammals, and whether defects in mitochondrial flexibility might explain the association between obesity and increased risk for age-related diseases.

Other Harvard Chan authors included Pallas Yao, Caroline Escoubas, Renata Goncalves, Kristopher Burkewitz, and Raymond Laboy.

Funding for the study came from the Lawrence Ellison Foundation, the Glenn Foundation for Medical Research, the National Institutes of Health, and the American Diabetes Association/Canadian Diabetes Association.

Immune system and age

As we age, our immune response capability becomes reduced, which in turn contributes to more infections and more cancer. As life expectancy in developed countries has increased, so too has the incidence of age-related conditions.

While some people age healthily, the conclusion of many studies is that, compared with younger people, the elderly are more likely to contract infectious diseases and, even more importantly, more likely to die from them. Respiratory infections, including, influenza, the COVID-19 virus and particularly pneumonia are a leading cause of death in people over 65 worldwide. No one knows for sure why this happens, but some scientists observe that this increased risk correlates with a decrease in T cells, possibly from the thymus atrophying with age and producing fewer T cells to fight off infection. Whether this decrease in thymus function explains the drop in T cells or whether other changes play a role is not fully understood. Others are interested in whether the bone marrow becomes less efficient at producing the stem cells that give rise to the cells of the immune system.

A reduction in immune response to infections has been demonstrated by older people's response to vaccines. For example, studies of influenza vaccines have shown that for people over age 65, the vaccine is less effective compared to healthy children (over age 2). But despite the reduction in efficacy, vaccinations for influenza and S. pneumoniae have significantly lowered the rates of sickness and death in older people when compared with no vaccination.

There appears to be a connection between nutrition and immunity in the elderly. A form of malnutrition that is surprisingly common even in affluent countries is known as "micronutrient malnutrition." Micronutrient malnutrition, in which a person is deficient in some essential vitamins and trace minerals that are obtained from or supplemented by diet, can happen in the elderly. Older people tend to eat less and often have less variety in their diets. One important question is whether dietary supplements may help older people maintain a healthier immune system. Older people should discuss this question with their doctor.

What and when we eat affects our immune system. Here’s how.

Professor Valter Longo, director of the USC Longevity Institute, is investigating how fasting and diets that mimic fasting’s effects can help immune function, including vaccine efficacy and the body’s response to infection by viruses such as influenza and the novel coronavirus.

Professor Valter Longo

Professor Valter Longo, director of the USC Longevity Institute, is investigating how fasting and diets that mimic fasting’s effects can help immune function, including vaccine efficacy and the body’s response to infection by viruses such as influenza and eventually COVID-19.

Fasting and fasting mimicking diets appear to “get rid of damaged or mis­guided cells and replace them with younger and more effective immune cells,” he says, improving many signs of health in mice.

The Longo laboratory is demonstrating that cycles of fasting or fasting-mimick­ing diets, followed by refeeding a normal diet, promote stem cell-dependent rejuvenation of the immune system in old mice. Early clinical trials show this process of “cleaning up” older white blood cells during short periods of fasting, then spurring the restoration of the normal levels of the infection-fighting cells when fasting stops, may also happen in humans, providing potential health benefits.

Longo says these findings support clinical trials to deter­mine whether they are effective in improv­ing immune system function in elderly humans without causing detrimental side effects and increasing vaccination efficacy in older adults. Upcoming trials will test the fasting-mimicking diet’s effect on flu, and, if funded and when it becomes available, coronavirus vaccination in humans, he adds.

Vaccine efficacy is an especially important issue for older adults due to immunosenescence – the gradual decline of immune system function with age – and the higher risk of serious complications from viral infection. On average, the seasonal flu vaccine has a response rate of slightly above 50 percent, meaning almost half of older vaccine recipients don’t make enough antibodies to successfully fight the virus.

Some early findings also indicate that fasting could provide mice with more resistance to viral infection itself. “We want to see if certain dietary interventions that can make a virus less infectious or cause fewer negative effects,” Longo says.

Earlier trials of the fasting-mimicking diet reduced cardiovascular disease risk factors, including blood pressure and signs of inflammation (measured by C-reactive protein levels), as well as fasting glucose and reduced levels of IGF-1, a hormone that affects metabolism. It also shrank waistlines and resulted in weight loss, both in total body fat and trunk fat, but not in muscle mass. In cancer patients, the fasting-mimicking diet appeared to sensitize cancer cells to chemotherapy and lessen treatment side effects.

Trial participants on the special diet were required to eat food products supplied by the nutrition company L-Nutra during fasting periods of just five days each month. The diet, which was designed to mimic the results of a water-only fast, allowed for participants to consume between 750 and 1,100 calories per day. The meals for the fast-mimicking diet contained precise proportions of proteins, fats and carbohydrates.

While many of the results are promising, Longo cautions that any kind of fasting or fasting-mimicking diet should only be undertaken with a doctor’s guidance in those that have diagnosed diseases or suspect having a disease. Sheltering in place during the COVID-19 pandemic may provide an opportunity for individuals to try a fast or fasting-mimicking diet especially those who are overweight or are gaining weight, but he advises that the most important thing to do in the face of potential illness is to stay well-nourished in general, especially for the essential workers who are at the highest risk for exposure.

Longo encourages a balanced pescatarian or Mediterranean diet versus long-term restrictive, low-calorie dieting. The immune system can get depressed with a poor diet or a diet that is too restrictive, he says. “This is not the time to push yourself to the limit.”

Longo is the founder of and has an ownership interest in L-Nutra the company’s food products are used in the human studies of the fasting-mimicking diet. Longo’s interest in L-Nutra was disclosed and managed per USC’s conflicts-of-interest policies. USC has an ownership interest in L-Nutra and the potential to receive royalty payments from L-Nutra. USC’s financial interest in the company has been disclosed and managed under USC’s institutional conflict of interest policies.

Fasting for 72 Hours Can Reset Your Entire Immune System

University of Southern California – According to a study done by USC scientists at the University of California, fasting for three days can have a significant improvement in your body’s health. The six-month study was done on both mice and human’s who are currently going through chemotherapy noticed a significant improvement in their health as the white blood cells and other toxins in the body were flushed out over the course of the fast.

“When you starve, the system tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged,” Longo said. “What we started noticing in both our human work and animal work is that the white blood cell count goes down with prolonged fasting. Then when you re-feed, the blood cells come back. So we started thinking, well, where does it come from?”

Basically, when you fast for a prolonged amount of time, your body uses the stored glucose, fats and produce ketone bodies that are especially good for your brain, to keep you going and you flush out anything that your body doesn’t need, like damaged cells and toxins. When your eating regularly harmful toxins in the body can attach themselves to these fats and live on but when you fast, your body is forced to lighten itself. It’s like the survival of the fittest, only the strong survive. “PKA is the key gene that needs to shut down in order for these stem cells to switch into a regenerative mode. It gives the OK for stem cells to go ahead and begin proliferating and rebuild the entire system,” explained Longo, noting the potential of clinical applications that mimic the effects of prolonged fasting to rejuvenate the immune system. “And the good news is that the body got rid of the parts of the system that might be damaged or old, the inefficient parts, during the fasting. Now, if you start with a system heavily damaged by chemotherapy or aging, fasting cycles can generate, literally, a new immune system.”

Further research is needed to discover how the rest of the organs in the body are affected beyond stem cell regeneration. At least we know for now, for people that go through the extremely taxing experience of chemotherapy, prolonged fasting can help your body get back to normal, and possibly even better than before.

Additionally, here is a Ted Talk on the benefits of intermittent fasting.

Does Masturbating Boost Your Immune System? We Asked a Doctor

Masturbation has tons of health benefits&mdashis a strong immune system one of them?

Now that coronavirus COVID-19 has been officially confirmed as a pandemic by the World Health Organization, even those who were insisting “it’s no worse that the flu” are starting to fill up the vegetable drawer with fresh greens and stockpile hand sanitizer. 

So what else can boost your immune system? Is the rumor that masturbation helps to ward off infection simply too good to be true? 

If you’re hoping that all you need to do to keep the new coronavirus at bay is get handsy under the sheets, you’ll be interested in a study carried out by the Department of Medical Psychology at the University Clinic of Essen, Germany, which was published in the journal Neuroimmunomodulation in 2004. 

Using a group of 11 male participants, the study looked at the effects of orgasm through masturbation on while blood cell count and immune system. Each participant’s white blood cell count was recorded five minutes before and 45 minutes after reaching solo orgasm, and the post-orgasm count was higher. 

Does this small study mean that people should start indulging in solo pleasure to stay healthy? Not so fast.

“There have been a couple of very small studies suggesting that chemicals related to the body’s immune system are impacted by sexual stimulation,” Gail Saltz, MD, an associate professor of psychiatry at the New York-Presbyterian Hospital Weill-Cornell School of Medicine, tells Health. However, she points out that the studies are very small and haven’t been replicated. “To my knowledge, no study says specifically that masturbation boosts the immune system in a way that prevents or helps fight off infection,” says Dr. Saltz. 

But that doesn’t mean masturbation doesn’t come with a whole host of mental and physical health benefits. Although few studies focus specifically on the perks of solo sex, orgasms in general are believed to reduce stress, reduce blood pressure, increase self-esteem, and relieve pain. 

While there aren’t scientifically solid major studies that show a clear link between masturbation and the release of endorphins (stress and pain-relieving chemicals) in the brain, it’s understood that physical activity in general helps to increase those feel-good chemicals. According to the Mayo Clinic, virtually any form of exercise can act as a stress-buster. And masturbation counts as physical activity, right?

Beyond health benefits, masturbation might even help your relationship. One study, published in the Journal of Sex Education and Therapy, found that women who masturbated had happier marriages compared to those who didn’t give themselves sexual pleasure. 

Will masturbating stop you from getting sick? In a word, no. To boost your immune system, you need to start with diet and exercise. “The most important way to keep your immune system functioning normally is the old-fashioned way that nobody likes to talk about: diet and exercise,” Timothy Mainardi, MD, an allergist and immunologist based in New York City, previously told Health

Other immunity-boosting tips from Mainardi include getting plenty of sleep, washing your hands with soap and water, and using hand sanitizer when you’re out in public. Masturbating may not be on the list, but we can think of worse things to be doing if you end up self-isolating. 

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it&aposs possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the򠳜, WHO, and their local public health department as resources.

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Fasting for three days can regenerate entire immune system, study finds

Researchers say fasting "flips a regenerative switch" which prompts stem cells to create brand new white blood cells Credit: PEGAZ/Alamy

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F asting for as little as three days can regenerate the entire immune system, even in the elderly, scientists have found in a breakthrough described as "remarkable".

Although fasting diets have been criticised by nutritionists for being unhealthy, new research suggests starving the body kick-starts stem cells into producing new white blood cells, which fight off infection.

Scientists at the University of Southern California say the discovery could be particularly beneficial for people suffering from damaged immune systems, such as cancer patients on chemotherapy.

It could also help the elderly whose immune system becomes less effective as they age, making it harder for them to fight off even common diseases.

The researchers say fasting "flips a regenerative switch" which prompts stem cells to create brand new white blood cells, essentially regenerating the entire immune system.

"It gives the 'OK' for stem cells to go ahead and begin proliferating and rebuild the entire system," said Prof Valter Longo, Professor of Gerontology and the Biological Sciences at the University of California.

"And the good news is that the body got rid of the parts of the system that might be damaged or old, the inefficient parts, during the fasting.

“Now, if you start with a system heavily damaged by chemotherapy or ageing, fasting cycles can generate, literally, a new immune system."

P rolonged fasting forces the body to use stores of glucose and fat but also breaks down a significant portion of white blood cells.

During each cycle of fasting, this depletion of white blood cells induces changes that trigger stem cell-based regeneration of new immune system cells.

In trials humans were asked to regularly fast for between two and four days over a six-month period.

Scientists found that prolonged fasting also reduced the enzyme PKA, which is linked to ageing and a hormone which increases cancer risk and tumour growth.

"We could not predict that prolonged fasting would have such a remarkable effect in promoting stem cell-based regeneration of the hematopoietic system," added Prof Longo.

"When you starve, the system tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged," Dr Longo said.

"What we started noticing in both our human work and animal work is that the white blood cell count goes down with prolonged fasting. Then when you re-feed, the blood cells come back. So we started thinking, well, where does it come from?"

Fasting for 72 hours also protected cancer patients against the toxic impact of chemotherapy.

"While chemotherapy saves lives, it causes significant collateral damage to the immune system. The results of this study suggest that fasting may mitigate some of the harmful effects of chemotherapy," said co-author Tanya Dorff, assistant professor of clinical medicine at the USC Norris Comprehensive Cancer Center and Hospital.

"More clinical studies are needed, and any such dietary intervention should be undertaken only under the guidance of a physician.”

"We are investigating the possibility that these effects are applicable to many different systems and organs, not just the immune system," added Prof Longo.

H owever, some British experts were sceptical of the research.

Dr Graham Rook, emeritus professor of immunology at University College London, said the study sounded "improbable".

Chris Mason, Professor of Regenerative Medicine at UCL, said: “There is some interesting data here. It sees that fasting reduces the number and size of cells and then re-feeding at 72 hours saw a rebound.

“That could be potentially useful because that is not such a long time that it would be terribly harmful to someone with cancer.

“But I think the most sensible way forward would be to synthesize this effect with drugs. I am not sure fasting is the best idea. People are better eating on a regular basis.”

D r Longo added: “There is no evidence at all that fasting would be dangerous while there is strong evidence that it is beneficial.

“I have received emails from hundreds of cancer patients who have combined chemo with fasting, many with the assistance of the oncologists.

“Thus far the great majority have reported doing very well and only a few have reported some side effects including fainting and a temporary increase in liver markers. Clearly we need to finish the clinical trials, but it looks very promising.”

Doctor’s Note: Fasting during Ramadan can boost your immunity

Mosques are closed and lockdowns are in place, but this Ramadan may have some unexpected health benefits.

This year, the Muslim fasting month of Ramadan will be like no other it will occur in the middle of a global pandemic.

Ramadan, which began on the evening of April 23, will see a month-long period of fasting, worship and devotion to Allah. It commemorates the Quran being first revealed to the Prophet Muhammad.

Muslims who are fit enough to do so are expected to fast (not eat or drink fluids at all) between the hours of sunrise and sunset for four weeks. As well as being a month of reflection, Ramadan traditionally brings people together in the evening for food and prayer.

Mosques around the world are usually at their busiest during this month, but many now remain closed and social distancing and self-isolation to prevent the spread of coronavirus have become mandatory in many countries. As a result, this year Ramadan will feel very different for a lot of Muslims around the world as families are separated.

But what about the health implications of observing Ramadan under lockdown and during a viral pandemic?

Can fasting affect a person’s chances of contracting the coronavirus?

In fact, fasting is believed to be beneficial to the body in a number of ways, including through the effect it has on boosting our immune systems. It is possible that our ancient ancestors recognised the benefits of fasting: As well as during the month of Ramadan in the Muslim calendar, fasting is also observed in the month of Lent in the lead-up to Easter for Christians, and during Yom Kippur in Judaism.

There is also evidence that the ancient Egyptians fasted for long periods to purge their bodies of ailments and disease.

Perhaps they were all on to something?

More recently, studies have shown that fasting can actually have beneficial effects on the immune system by reducing the amount of general inflammation that can occur in cells around the body.

Fasting is thought to put the body into an “energy conservation mode” due to the lack of nutrients coming in. In an effort to save energy, the body recycles many of its old or damaged immune cells, which later promotes the generation of new, healthier immune cells when the fasting period ends.

These new cells are quicker and more efficient at fighting infections so overall immunity improves.

The key thing that sets a religious Ramadan fast apart from diets that promote weight loss through intermittent fasting regimes is the abstinence from drinking water. This may make all the difference.

While a study has shown that prolonged water fasting beyond 12 to 24 hours can have a slight detrimental effect on the immune system, putting you at a slightly increased risk of catching any kind of infection, it also showed that immunity returned to a better state soon after eating and drinking again.

Granted, these studies were not looking at the specific fasting that takes place in Ramadan but separate studies show that the religious fasting of Ramadan has comparable health benefits to other types of fasting. This comes with the caveat of having a healthy diet in the periods between fasting: We all know there is a tendency to overindulge in fried foods such as samosas and pakoras during the breaking of the fast, and that certainly will not help the immune system.

Fasts will vary in length depending on where a person lives in the world and what time of year the month of Ramadan falls in, but the evidence suggests that abstaining from both food and water for up to 12 hours can have an overall beneficial effect on your immune system.

It is important to stress that the Muslim faith only expects fasting from those who are healthy enough to do so, and fasting must not be used simply as a way to boost your immune system.

As this will be our first Ramadan during a coronavirus pandemic, it is impossible to know whether fasting may offer some level of protection against getting the illness itself and, although it is not beyond the realms of possibility, it is important to stick to the things that we do know work: social distancing, hand-washing, hygiene and self-isolation.