Benefits of fasting
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A stronger immune system with water fasting

To boost your immune system specifically against coronavirus Covid-19, please see this separate article HERE.

If you suffer from a weak immune system, water fasting is one of the best things you can do to strengthen it.

Similarly, water fasting is one of the oldest and most effective methods to regain health if your immune system is facing an infection such the flu.  Personally, it’s what I do the moment I feel a virus beginning to stir inside me. And nine times out of ten the fast does its magic – and, miraculously, I stay healthy.

In fact, in the days before vaccines, fasting was even successfully applied in treating life-threatening diseases such as smallpox and typhoid. And during the era of the bubonic plague, doctors acquainted with fasting did just that in order to raise the chances of not becoming infected by their patients.

Why water fasting strengthens your immune system, and how can you apply it to illness

When your digestive system shuts down through fasting, much of the energy normally devoted to digestion is redirected to the immune system.  This is because your immune system is responsible for autolysis: the process of ‘house-cleaning’ which takes place during a fast, in which unhealthy, damaged and old cells are broken down into their constituent biochemical elements and either recycled or burned up for energy.  For during a fast, your body depends on more than just the energy derived through the fat-burning of ketosis.  It searches out all possible sources of energy.  This includes bacteria and viruses, as well as certain types of tumors and cysts.  It’s also the reason that old physical injuries can clear up during a fast, as your body consumes scar tissue as well.  Similarly, newer injuries tend to heal more quickly.  In his book on fasting, Dr. Joel Fuhrman poignantly describes how he successfully undertook a 46-day water fast in order to heal a serious leg injury.

Numerous studies on both mice and men have shown a higher resistance to pathogens both during and after water fasting.  In other words, the changes taking place extend well beyond the length of the fast itself.  Eventually this builds up into a permanent strengthening of the immune system. I’ve noticed such a shift gradually take place within my own body. When I first began water fasting, I was always the first in my family to come down with niggling colds and coughs, but over the years it’s reached the point where I simply never get ill. (Okay, I lie. This is an overstatement. I usually get a minor cold about once every three years or so.)

In addition to this long-term boosting of the immune system, fasting also brings the immune system into balance.  This is the reason that fasting can prove so effective in cases of auto-immune disease, in which the immune system turns against your own body. I’ve had clients who have suffered from auto-immune issues as wide-ranging as ulcerative colitis, Hashimotos, multiple sclerosis (MS) and chronic fatigue syndrome (ME), and there isn’t a single case which hasn’t at least improved through water fasting. Sometimes you have to be patient, perhaps undertaking a series of fasts over many months – and especially so when a lot of healing must take place – but good things come to those who wait. (For fasting to heal from illness, please see the article ‘Self-healing through water fasting.’)

Despite all this good news, if you’re interested in trying out a water fast to cure a cold or the flu, beware!

Although certain aficionados of water fasting might have you believe that every fast can provide a magical cure, this simply isn’t always true.  There are a few things you need to know before you dive in the deep end!

First, I would advise anyone new to fasting not to tackle a common cold or flu this way, because over the first few water fasts a lot of your energy is devoted to clearing out a lifetime’s worth of accumulated toxins.  Your kidneys are working overtime.  Your liver is working overtime.  Fasting with a virus or bacteria in your system only drains your energy further.  You’ll feel truly lousy!  Instead, begin by building up a little water fasting experience while you’re healthy.  As I found out myself, fasting out a minor illness does eventually become easier, both physically and emotionally – although you’ll never feel as good compared to fasting while healthy.

Second, it’s important to begin such a fast as soon as you feel the pathogen in your body.  As with so many other things, an ounce of prevention is worth a pound of cure, and starting your fast early on in the illness will accelerate the healing process, reducing the necessary length of the fast.

Third, it’s important to continue the fast at least until all symptoms have stopped.  If, for whatever reason, you discontinue the fast beforehand, the pathogen may well regain momentum against you.  To be on the safe side, it’s worth continuing the fast for at least an additional 24 hours after symptoms have disappeared.

Anyone considering applying a water fast to a cold or the flu is bound to ask: ‘how long is such a fast likely to last?’  There’s no fixed answer here.  The more experienced in fasting you are, the quicker your body will shut down the digestive system and begin to fight the illness.  Also, the more virulent the pathogen, the longer you’ll need to fast.  If you begin the fast early enough, one or two days may suffice for minor colds.  I find that around three days is more likely for the flu.  For something as serious as typhoid, the famous Dr. Herbert Shelton says that a fast of 7-10 days is enough, with patients stabilizing around the third or fourth day (The Science and Fine Arts of Fasting, p. 429).  In any case, it will take experience in applying water fasting to minor illnesses before you’re able to get a better feel for how you react and how long you’ll need.  Every illness is different.  Every fast is different.  Practice makes perfect!

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  1. Sabrina Swainson says

    Hi again Tallis,

    Well, it’s been a while since I posted with the toothache and then we had an hour’s conversation when we worked together with a consultation. I jusut t noticed that the posts don’t have dates on them and I didn’t keep track of how long ago I posted and then we talked, but after our conversation, when I told you my tooth was better, well the toothache came roaring back! But it was all in service of health. I realized that even if the pain went away, I needed to keep up with the antibiotics. They are holistic not pharma but they still need time to work so I went ahead and did a full 2 weeks of using collodial silver and garlic. And the pain went away again and has not been back since.
    I credit that to the fact that, I went ahead and did a 3 day fast, starting a few days after my tooth stopped hurting for the 2nd time. After our talk I felt so inspired to break my 48 hour challenge point in a 3 day fast that I went the full 3 days and at the end of that, I was not hungry, not tired or achy or anything so I went another 24 hours. At the beginning of the 5th day, I did feel tired and hungry so I broke the fast after 99 hours.
    I feel that I would not have been able to jump the psychological hurdle from 48 hours to 99 if we hadn’t spoken.
    I now plan to do another 3 day in May to get really comfortable doing so and maybe another in June or July, just so my body gets really comfortable with making the switch from glycogen burning to ketosis.
    I am looking towards eventually being ready to do the 7-10 day with your guidance, to really unlock deeper healing, both physical and psychological. But most of all I hope to have more ease accessing spiritual modes in the way the body gets more at ease in accessing the ketogenic way of metabolizing.

    Thank you for all you do.

    • Tallis Barker Ph.D. says

      Hi Sabrina,
      Thanks for sharing, and congratulations for making it into the 5th day :-). That’s great news! You did the right thing to continue medicating your tooth, because it would probably have taken considerably longer for a fast alone to heal the issue. I’d just like to emphasise – as you’ve done yourself – that it doesn’t always have to be black-and-white fasting alone or medication alone. Fasting and other modalities can often support each other in the journey back to full health.
      All the best,

  2. Sabrina says

    Hello Tallis,
    I hope that you are well in these trying times of the COVID virus.
    Two nights ago, I came across your blog while researching water fasting. I have now read many of your posts and the comments too. As one of the people who responded said it is rare to find someone actually ‘at home’ and replying to comments, especially with so much knowledge, professionalism and compassion.
    At first, I was just gleaning information but I now want to work with you. Here’s why.

    Right now I have an abscessed tooth which has progressed to the throbbing stage and is involving the neighboring lymph nodes. I knew something was up but I was determined to handle it with collodial silver and garlic and I started a 3 day water fast 50 hours ago.
    Now my partner wants me to go to the dentist and the pressure to do so is growing. But I have a (well-justified) phobia about dentists and don’t want to take pharma antibiotics.

    In reading this post about A Stronger Immune System, it seems that, with an active infection, this may not be the optimal time to fast. Another question that has also emerged with the reading is whether a 3 day fast is long enough. Also, from another post, I learned I should have cleaned my system out more thoroughly and eased into it with green drinks.

    I am going to fill out your intake form for the consultation because I need personal coaching and I know the value of that. But I thought I’d post this here to get things going and to offer it to someone else who is reading your posts and the comments as carefully as I did but who perhaps can’t afford coaching right now.
    I will post again once we’ve worked together and share my experience. I really want to get healthy again!
    After a sickly childhood, and an average adulthood of declining health, I worked hard in my 50s to get healthier and I felt vibrant most of the time! But I supported that with a lot of supplements and I can’t do that right now. At 63 I have lost the connection to that feeling of vibrant health and am now shying away from ‘hard things ‘that I used to tackle full on. I know some of it is feeling the unease and sheer pain that most of us are feeling on a global scale right now, because of the virus. And as you know, present pain like a toothache makes everything seem a bit more bleak.

    I need coaching to help me find my way back to be stronger for whatever is coming and I would also like to feel more connected to my spirit and less connected to my body.

    Thanks for taking the time to read all this. May you continue to be well and happy.

    • Tallis Barker Ph.D. says

      Hi Sabrina,

      Thanks for sharing, and I look forward to receiving the contact form so we can get started. I don’t like to comment on specific cases – especially when they concern specific health problems – in this public space, because so often things can be taken out of context and misapplied by other people.

      No, it’s not an ideal time to fast if you’re concerned with general detox and health, but it’s very much the ideal time to fast if the purpose of the fast is specifically to deal with this problem. I’m going to say here and now, though, that if the abscess is deteriorating quickly, a water fast may not be enough to turn the tide. We’ll just have to see. This will also depend on how quickly your body can access deep healing over the coming days. If we work together, it may also be worth involving elements of dry fasting, as this is even more effective than water fasting in reducing inflammation and strengthening the immune system. I’m not going to go into any greater detail about this here, though, because dry fasting is an extreme practice, and I don’t want anyone to get any ideas about (mis)applying this to their own situation. Dry fasting to address a health issue is always best practised with expert advice alongside.

      In the meantime, please continue your water fast, and I look forward to hearing from you soon,

  3. Jay says

    Does prolonged fasting help fight or possibly cure viruses like hpv? Will the body be able to autolyze warts during a 14-30 day water fast?

    • Tallis Shivantar says

      Hi Jay,

      Prolonged fasting strengthens your immune system, and this is the reason why you can fight viruses more effectively, both while fasting as well as in the months afterwards. Unfortunately, it’s impossible to tell ahead of time whether or not a water fast will actually fully heal you from stubborn viruses like hpv, but it will depend largely on the length of the fast and the strength of your own immune system. In terms of autolyzing warts, there’s a good chance that 14-30 days should be enough, especially if the final length of the fast is closer to 30 days.

      When using fasting to tackle illnesses, I often work with clients using periods of dry fasting within a prolonged water fast in order to maximise healing. I can’t go into specific details here in this public space, as every case is different, every person is different in how easily they respond to dry fasting, and I don’t want to encourage everyone to dive too deeply into dry fasting, because without proper guidance this can easily lead to breaking off the fast too early.

      I would definitely encourage you to aim for the longest possible water fast that you can manage both physically and psychologically, as this will reap the greatest benefits.

      All the best,

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