Rejuvenated with fasting

Last Updated: 28 October, 2025By

Fasting makes you biologically younger, as it activates cell rejuvenation and repair. Research shows that only when you abstain from food does your body experience a renewal of cells/organs, stem cells and the production of growth hormones – even for nerve cells! As soon as you start eating, these processes are interrupted. Natural fat is ok, but the slightest carbohydrate and protein stops the deepest effects of fasting. Therefore, Water Fasting is The queen of all fasts. For as long as humans have existed, fasting has been the body’s own ‘medicine’ – providing maximum healing and rejuvenation. Research supports all this, and it opens up hugely exciting possibilities!

Who doesn’t want to rejuvenate? It means more alertness and clarity of mind and thoughts, lighter body, no (or rarely) pain or aches, good nutritional intake, smoother and healthier skin without swelling, and better sleep. At the same time, you get a strong and good immune system, and allergies decrease or disappear completely. Personally, I find rejuvenation to be one of the most fascinating aspects of fasting, as getting older is inevitable – and I’ve seen a lot of tangible rejuvenating results on my own body, skin and energy levels. It feels good, as this year I turned 60.

Health and well-being is never set in stone. It is constantly fluctuating, depending on what you feed your system.

Writing the Sannas Fastebok gave me a different perspective on what aging really is, and how reducing internal toxicity, increasing flow, and promoting water fasting can keep your body young – for a very long time. Listen to what the world’s foremost expert on longevity says, backed by 20 years of research on both humans and animals:  

With the right, healthy lifestyle, you can maintain – or regain – the health and physical stamina you had in your 40s. We can live to be 100 with the health and stamina (endurance and strength) of a 40-year-old! Professor Luigi Fontana

Good health is ‘fed’ by a healthy lifestyle, it is something we can do every day. The beauty is that we can change the way we feel at any time by changing our lifestyle, and water fasting is the fastest way to make that change!  

NOTE fasting is not for everyone, see below.

Premature ageing

But first: what is ageing? Many scientists and doctors say that ageing is actually a disease, and this is in line with what Professor Fontana says above about being able to live to be 100 with the health of a 40-year-old! In fact, the biggest threat to health today is premature ageing, which is now both common and widespread due to modern lifestyles and industrialized food. Four signs of premature ageing are:

  • swelling
  • energy shortage
  • chronic pain
  • fatigue that you can’t sleep through.

The result of this process of premature ageing may only become apparent after many years of overload (by toxins) and reduced function. Examples of obvious symptoms include rheumatism, osteoporosis, atherosclerosis, high blood pressure, kidney failure, respiratory problems and cancer. But there is a lot we can do – the body responds quickly when we start a healthy lifestyle. Because what you feed your body determines the outcome.

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Fasting rejuvenates!

We don’t have to age…. we can get older with a reasonably young body!

Research shows that fasting rejuvenates the body, brain and hormonal system like nothing else does, paving the way for optimal health. Rejuvenation equals stronger, healthier and higher functioning. As early as the 1960s, Russian research was published showing that starvation (fasting) occasionally prolongs life. These studies have been repeatedly verified and demonstrated in both animals and humans. The strong rejuvenating effects of fasting are fascinating results  

Fasting renews and rejuvenates, so it is excellent for health and number one for self-healing. Even more potential cleansing comes from water fasting, when you drink only water. This is why it is called therapeutic fasting, as it results in lower blood pressure, reduced insulin requirements and inner peace. Weight loss is a guaranteed effect of water fasting, because the body quickly releases much of the swelling, that is, inflammation and bound fluid.

Fasting provides deep cleansing and detoxification of the body because the following central processes are activated:

  • autophagy (self-purification i.e. internal cleaning)
  • stem cell formation
  • growth hormones
  • reduced oxidative stress
  • improved insulin sensitivity
  • inhibited cell division, resulting in fewer random DNA mutations = lower risk of cancer and fewer old, fragile cells
  • Apoptosis , which clears cells of damaged DNA so that it is not passed on to new cells.

The water fasting activates:

  • Autophagy: Fasting provides the natural break the body needs to sort out what’s bothering it and to break down older, poorly functioning proteins, cells and junk. It’s called autophagy, and we need to pause eating to allow the body to self-clean. It is absolutely necessary, otherwise this vital function does not happen. Autophagy is one of the most exciting and research-documented new breakthroughs in anti-aging and longevity. It is very important because impaired autophagy increases the scope for disease processes in the body, especially cancer and neurodegenerative diseases (such as Alzheimer’s, Parkinson’s, memory impairment and various forms of mental illness).
  • The production of new stem cells is extremely important as they form new, healthy cells and can also help repair damaged organs in the body. Stem cells are non-specialized cells with the ability to mature into different cell types. Recent research has shown that our body’s tissues and organs can be renewed at any age, as our own innate adult stem cells can be transformed into different cell types: liver, intestinal, lung and skin cells. Fasting is by far the best way to naturally activate the production of stem cells in the body.
  • Growth hormones are produced that build muscle, and increased muscle mass rejuvenates. Fasting increases metabolism because adrenaline and growth hormone are produced, with major cell renewal taking place. More growth hormone activates the body’s production of new cells, more muscle and renews organs. Growth hormone allows you to build muscle even when you are fasting, so exercise is good. When researchers compared calorie restriction with water fasting, the latter was four times more effective in preserving muscle mass.
  • NGF, brain growth factors strengthen the psyche, increase mental sharpness and memory. Fasting stimulates neurogenesis: the growth of new neurons and more neural pathways. So we get smarter both from limited energy intake (fasting) and exercise (building muscle)! Fasting promotes the production of brain growth hormones, nerve growth factor (NGF), which has the potential to, among other things, strengthen the psyche and counteract depression and dementia. But the effect also includes the growth of new neurons and neural pathways throughout the body, so lots of positives.
Our body consists of about 2/3 parts water and water is enormously healing in itself, a magical liquid with unique properties!

Advantage of waterproofing – VASS

Water fasting, drinking only water, is easy, costs nothing and you can achieve multiple health benefits even faster. One of the most important functions of fasting is to clean the gut to allow for deeper healing, so why not make water fasting more effective and maximize it by emptying the gut first? That’s why I’ve developed the VASS protocol, which stands for water fasting Sanna special.

VASS is only 1.5 days but gives the equivalent of 3-4 days of water fasting because it starts with emptying the intestines with a salt water flush. Just drinking water is a bit boring so might as well maximize the result in less time, I thought when I developed the method. VASS also includes a couple of potentiators that improve the result, giving an effect equivalent to half the time. When the contents of the intestines are emptied out, the body cleanses and heals faster at a deeper level with repair of the intestinal mucosa and more.

The saline flush involves drinking 1-1.5 liters of saline solution (water with 2-3 tsp of sea salt dissolved in it, so the same concentration as the extracellular fluid. But the body expels it quickly and flushes the entire small and large intestine, which is uniquely good. If you don’t flush, it’s due to a lack of sea salt’s many minerals, which is quite common today – and then the body absorbs all the salt.  

The body is highly intelligent, with accumulated knowledge from millions of years of evolution!

A woman who usually water fasts wrote that what she usually feels after several days of water fasting, she feels quite soon after the Salt Water Flush. It max kicks off the body for healing. This is why it is so important to prepare well, and I write extensively about it in the book and have chapters on pre-fasting.

  • Feedback from Veronica D. 55 years old who lost 10 kg and got great results. She describes: “I lost 10 kilos, and everyone asks how I did it and how I can look younger now at 55 than at 45. It’s because all the cells are replaced by fasting, the skin is rejuvenated, the liver and kidneys are cleansed. It’s an upgrade for the whole body, and I now have great values! I’m so grateful for this advice, and also inspire my health clients. My new good habits are: mostly eating one meal a day (OMAD: one meal a day) with paleo and keto diets. And a couple of times a month I water fast 24 to 72 hours (1-3 days).

Less swelling = less inflammation = better health! 

Dr. Sanna Ehdin

Read more about fasting:

-> Waterphoto Jeremy Bishop, Unsplash

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Fasting is not a slimming method I would like to emphasize that fasting is a method of cleansing, renewal and rejuvenation. The purpose of fasting is not “dieting”, but BALANCE! As a bonus, you will even lose weight with properly executed fasting, as better health allows the body to find its ideal weight. Among the absolute best is that the waistline comes back!

NOTE: not everyone should fast!

  • people who are malnourished, severely underweight or anemic 
  • Children under the age of 18. 
  • Pregnant and breastfeeding women. 
  • People with eating disorders such as anorexia or bulimia. 
  • Seriously ill people on medication. 
  • Those who are in poor general health or have kidney
    disease, as the kidneys are stressed during this purification process. 
  • Those with type 1 and 2 diabetes, taking prescription medication, gout or high uric acid can fast, but may need medical supervision (according to Dietdoctor Andreas Eenfeldt). Most people should be able to do a food fast, but always check with medical and/or health professionals if you are unsure.

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