Part 3: What Happens To Your Body When You Fast? – Inflammation and Blood

Get It?  Blood Sugar!
Get it? Blood sugar!

In our previous two posts, we took a high-level look at the hormonal effects of fasting, along with some of the benefits of these hormonal changes. Today, we’ll take a quick look at the effects on inflammation and blood.

Inflammation
inflammation 225x300 Part 3: What Happens To Your Body When You Fast?   Inflammation and BloodInflammation comes in many forms. It might be something you feel after you sprain an ankle or pull your hamstring. Or it might be of a more insidious, persistent, low-level form that wreaks havoc throughout your body over months and years. Cardiovascular disease is one particular form of inflammation that takes a long time to fully develop. And that’s the very problem – if you don’t feel it overtly like a swollen ankle, how can you know to stop what you’re doing?

Well, it looks like fasting can bring down inflammation. Check out this study of Muslims during Ramadan: Interleukin-6, C-Reactive Protein and Biochemical Parameters during Prolonged Intermittent Fasting. Here are the pertinent findings:

No significant changes were observed in serum total cholesterol, triglycerides and LDL levels. TC/HDL ratio (HDL risk factor) was decreased during and after Ramadan in both genders in the fasting group while there were no changes in the nonfasting group. IL-6 (p < 0.001), CRP (p < 0.001) and homocysteine (p < 0.01) levels were significantly low during Ramadan in the fasting subjects of both genders when compared to basal values (1 week before Ramadan).

Dr. Eades reported on this study, so I’ll let him explain what these particular markers mean:

IL-6 is a proinflammatory substance released by macrophages and other inflammatory cells that reaches the circulation and ultimately the liver. …When IL-6 levels are high enough they stimulate the acute phase response in the liver. During the acute phase response the liver releases a number of proteins -including CRP- into the circulation. …CRP is an acute phase protein that binds to certain sites on microbes, probably assists in the helping other parts of the immune system attack foreign and damaged cells, and enhances the consumption of these cells by the macrophages. CRP is an important player in the innate immune response, which is the blind, hardwired early responding part of our immune system.

Both IL-6 and CRP are elevated during inflammation, and both, but particularly CRP, are used as markers for inflammation. There is now a large amount of data showing that elevated CRP levels are a potent risk factor for cardiovascular disease.

Homocysteine can react spontaneously with many biologically important molecules, especially proteins. It can react with and cause damage to the folding of important proteins, i.e., enzymes, immune proteins, receptors, growth factors, and structural proteins, leaving them with a configuration that is less than optimally functional. High homocysteine levels cause oxidative damage and are thought to cause inflammation, especially in the endothelium. As a consequence, elevated homocysteine levels are, like CRP, a fairly potent risk factor for cardiovascular disease.

Dr. Eades even mentions the reduced sleep time of Ramadan, which is known to be an inflammatory agent. When you couple an extra inflammatory agent in reduced sleep with fasting and still see these reductions, it’s quite impressive.

Blood Sugar and Insulin
sugar 199x300 Part 3: What Happens To Your Body When You Fast?   Inflammation and BloodNow, when I think of fasting, I think of decreased blood sugar and insulin levels. Without a constant infusion of glucose, blood sugar stays at a baseline level, as does insulin. And what does keeping insulin levels low do? It improves insulin sensitivity. As we know, insulin resistance is a stepping stone to full-blown Type II diabetes, so improving our sensitivity to this hormone is a good thing.

Here’s a study, albeit extremely small (only 3 subjects), in which they report on their fasting experience and the benefits derived from fasting:

Since May 2003 we have experimented with alternate day calorie restriction [Note: It wasn't even true alternate day fasting.], one day consuming 20′50% of estimated daily caloric requirement and the next day ad lib eating, and have observed health benefits starting in as little as two weeks, in insulin resistance, asthma, seasonal allergies, infectious diseases of viral, bacterial and fungal origin (viral URI, recurrent bacterial tonsillitis, chronic sinusitis, periodontal disease), autoimmune disorder (rheumatoid arthritis), osteoarthritis, symptoms due to CNS inflammatory lesions (Tourette’s, Meniere’s) cardiac arrhythmias (PVCs, atrial fibrillation), menopause related hot flashes.

Make a mental note of all of the other benefits they saw as well: increased resistance to disease, arthritis, asthma, allergies, and numerous others. Another study also showed an increase in insulin sensitivity in normal weight, healthy young men. Let’s not forget Ramadan improvements in insulin sensitivity. While studies in humans are just beginning to emerge, these findings, along with previous studies in rats and monkeys, coupled with a bit of logic, shows that IF holds promise for improving the body’s response to insulin.

Another effect of high blood sugar, the unfortunate norm in our society, is called Advanced Glycation End-products (AGEs). AGEs are considered to be important elements of the aging process; fewer AGEs, less aging. Since fasting decreases the level of blood sugar during the day, it seems that AGEs will also be decreased.

Wrapping Up
So that’s it for today. I think we’re looking at some pretty powerful medicine in Intermittent Fasting. It seems to positively affect nearly every system of the body. With the next post, we’ll delve into the effects of IF on healing, disease, aging, and longevity. Until then…
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About the Author:
Scott Kustes is a competitor in Master's Track and Field, running the 100m, 200m, and 400m, as well as Long Jump (or Medium Jumping in his case). He holds a Level 1 coaching certification from USA Track and Field. You can follow his updates through his Facebook profile and Twitter feed.

The information and opinions expressed in this article are for information purposes only, have not been evaluated by the Food and Drug Administration and are not intended to diagnose, treat, cure or prevent any disease. Please see site terms and conditions for full details.

6 Reader Comments


  1. Jeff on

    Hey Scott,

    Fantastic post, as usual. My experience is consistent with this. I have been doing IF for about 3 months now. I started with skipping breakfast 3 days per week then extended 2 of those to dinner for almost full day fasts. As a result I have noticed a flip flop in the usual immune issues as compared with my wife who, while eating essentially Paleo like me, isn’t doing IF(she tried, got hungry and ate). She has been having allergy issues like we always both had, but I have not. She also recently caught a cold, and I have not had a sniffle. Usually I am the one to get the colds. I am getting more and more convinced that this is a key aspect to diet and fitness overall.

    jeff

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  2. Mark L. on

    Anyone else experience a curious lack of soreness while recovering from exercise while fasting? Just curious about empirical evidence… I have also seen the same “lack of allergies” during fasting. (this from a once a day claritin user).

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  3. Metroknow on

    I don’t have a lot to add, but I just wanted to let you know how much I’m enjoying this series (and your site in general). Your material really is a cut above. I have been skeptical of the value of fasting, but this set of articles really is opening my mind to the idea. The insulin sensitivity is particularly fascinating to me, as logically I felt like it could have gone either way. Great stuff.

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  4. Evan on

    I’m glad to read research like this. It’s something else I can show all the people who think I’m crazy or stupid for doing IF.

    Speaking of crazy, I began fasting about 8 months ago with a simple one day fast. I found it was easy, and at the time I was also reading about prolonged water fasts, so I decided to try to do a 10 day water fast. I decided to stop on day 8 because I found I was getting irritable and more sensitive to stress. After that, I gradually eased back into eating over the course of 4 or so days. Although I didn’t appear to suffer any ill effects from it, I’m wondering if I did or could have damaged myself seriously.

    Now I usually eat (paleo-style) within a four-hour window every day, with maybe 2 days a week of eating nothing. I feel great, have tons of energy, and as Mark L. was wondering, experience no soreness during recovery after exercise, no matter how intense. Yesterday I walked 18 km in a fasted state and today I feel like I could do it again.

    Thanks again for this.

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  5. Tiffani on

    yea i think that this really help me alot on the things that i nees help on and the things that i never new that much stuff about.

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  6. gweipo on

    I’m on day 4 today of a water fast, as recommended by Dr. Fuhrman. I started the fast as I’ve struggled with hip bursitis for the last 2 months which has stopped me from running.
    I was interested to see that your article didn’t mention the benefits of fasting for all sorts of inflammatory diseases and autoimmune disease. In chapter 8 of his book “Fasting and eating for health” Fuhrman states
    “fasting is an effective way to treat inflammation because it allows the body to remove the noxious stimuli that caused the problem in the first place…”

    I’m hoping to be able to keep it up for the recommended 10 days, but taking one day at a time…

    [Reply]

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