Carbs And Colds

      55 Comments on Carbs And Colds

When I switched to a low-carb diet some years ago, weight loss was only one of the benefits. My arthritis went away, as did restless legs at night, frequent belly aches, psoriasis on the back of my head, and occasional bouts of mild asthma (“mild” because I would wheeze when breathing, but never needed an inhaler).

I also seemed to gain a stronger resistance to colds, flu and sinus infections. When it seems everyone around me at the office is coming down with a nasty cold, I usually don’t have any symptoms at all. Or perhaps I’ll feel tired for a day or two with a bit of a drippy nose, and then it’s over.

One explanation that I read some years ago (sorry, don’t remember where) is that glucose and vitamin C compete for the same cell receptors – and glucose wins. So when blood glucose is elevated, vitamin C doesn’t get into the cells to do its job.

Okay, that makes sense. But I recently read another explanation that also makes sense and is backed up by at least one small but interesting study.

I came across the study while reading an article a reader sent on why the notion that we need five servings of fruits and vegetables per day to be healthy is nonsense. I don’t agree with the conclusion that we only need meat and fish to healthy, by the way. Perhaps that’s true if you’re eating wild-caught fish and caribou who feasted on nutrient-dense wild plants, but unless you live off the land in Alaska, that’s not your meat-and-fish diet. I do agree with the article’s conclusion that the five-per-day rule is arbitrary and encourages some people to consume too much sugar in the form of fruit.

Anyway, the article mentions a study in which researchers measured how efficiently the subjects’ white blood cells were at destroying bacteria and other microorganisms. They measured after fasting (which, interestingly enough, increased the kill-the-bugs efficiency), then measured again at several intervals after having the subjects consume 100 grams of various types of carbohydrates.

All the carbohydrate loads reduced the ability to destroy microorganisms. And in all cases, it took more than five hours for the blood to regain its normal bug-killing efficiency. But what’s interesting is how much the reduction varied. Here’s how much what the researchers call the phagocytic index (think of it as bug-killing ability) declined for the different types of carbohydrate:

Fructose – 45.1%
Sucrose – 44%
Orange Juice – 42.1%
Glucose – 40.5%
Honey – 39%
Starch – 13.4%

Starch clearly doesn’t reduce bug-killing ability to the same degree as simple carbohydrates. In fact, the researches stated that “Starch ingestion did not have this effect” … but there was an effect, so perhaps they meant that given the small number of subjects, it wasn’t statistically significant.

But wait … isn’t starch just glucose molecules bound together? Why yes, it is. But when you eat whole-food starches, it takes time for your body to break them down. You don’t get the same spike in glucose that you’d get from pure glucose or refined carbohydrates that turn to glucose almost instantly.

Most people also don’t pig out on whole-food starches like they do processed carbohydrates. My (ahem) “healthy” breakfast used to be a cup of Grape Nuts and a glass of orange juice. (The official serving size for Grape Nuts is half a cup. Good luck feeling full on that.) Assuming the orange juice was 6 ounces, that’s just over 100 grams of sugar and processed carbs – in other words, the carb load that would reduce my bug-killing ability by 40% or more, according to the study.

By contrast, a small potato (which I sometimes include as part of my sausage-and-egg breakfast) contains about 25 grams of unprocessed starch. Assuming the relationship between carb load and the phagocytic index is linear, that might reduce my bug-killing ability by 3.35%. Since I believe there are benefits from eating small servings of whole-food starches (feeding the gut bacteria, to name one), I’m fine with that.

When you think about the standard American diet, it’s no wonder people are so susceptible to colds and other infections. If the study is correct, we can pretty much guess what happens when people consume 100 or more grams of simple carbohydrates at, say, 8:00 AM, 1:00 PM, 6:00 PM and again at 10:00 PM for that late-night snack. They’d only be at full bug-killing capacity for five hours out of every 24.

According to the CDC, cold and flu season peaks in the months December through February. I don’t know if the viruses and bacteria are actually more prevalent during those months, or if it simply means more people succumb. Either way, I believe the holidays, with all that sugar and white four being snarfed up in the form of holiday treats, are at least a contributing factor. We lower our immune system’s capacity to fight infections while simultaneously attending gatherings full of people carrying the viruses and bacteria.

I usually cheat on Thanksgiving and enjoy some pumpkin pie, stuffing with the turkey, etc. Not this year. I’ve learned from past experience that if I’ve got any kind of inflammation going, wheat makes it far worse.

I have good days and bad days with the shoulder. On good days, it’s a mild ache. On bad days, it throbs and I reach for the painkiller.  I’ve only had one bad day in the last four, and I’d like to keep it that way.  Stuffing and pumpkin pie aren’t worth the pain, so I’ll skip them. I sure as heck don’t want a cold or flu to add to the discomfort.

Whether you cheat or not, I hope you enjoy your Thanksgiving. And to our non-American readers, I hope you have a good Thursday.


55 thoughts on “Carbs And Colds

  1. John Case

    >According to the CDC, cold and flu season peaks in the months December through February. I don’t know if the viruses and bacteria are actually more prevalent during those months, or if it simply means more people succumb.

    The peak correlates with the amount if sun exposure = vitamin D. The magnitude is also latitude dependent, and of course it’s inverted in the Southern hemisphere.

    1. Tom Naughton Post author

      I think we’re more likely to succumb for a number of reasons, lack of vitamin D being one of them. I just haven’t seen reliable info on whether there are actually more viruses during peak season.

  2. Willa Jean Dooley

    I’ve known for a while that Keto is just the way I stay healthy. I like the explanations, though.

    Keto pumpkin is easy and delicious. If you’d like a pie, make a recipe of Fat Head Pizza Dough. (My sincere apologies, but that’s just what it’s called now. It’s taken on a life of it’s own.) Roll it thin, make a pie crust and pre-bake it as you would for any other custard pie. Fill. Top with gobs of sugar free whipped cream. You’ll love it. If you serve it to guests, they’ll never know it’s keto friendly.

    Or just have custard and whipped cream.

    Can’t help you with the stuffing though.

    1. Tom Naughton Post author

      Good idea, but of course I’m not much of a cook at the moment. I can’t even button my own shirt without Chareva’s help.

      1. Firebird7478

        You could do what I have done in the past and just eat the filling and toss the dough. Still has sugar but the damage is greatly reduced. I won’t be eating any this year because I am trying to flesh out whether or not I have a Vitamin A toxicity. I spent an hour the other day at Labcorps with a packed waiting room of cranky fasting people only to learn that, no matter how many codes they used to get the Serum A levels tested, Medicare would not approve the test.

        Oh, and I didn’t realize I did not need to fast, and the TV in the waiting room was airing a cooking show.

          1. Firebird7478

            …and I didn’t take my own advice. I figured since I was assigned dessert detail, I should get some of what I paid $35 for. LOL

        1. chris c

          I record all my TV and skip through the ads, which saves a LOT of time. Recently I watched something live and was gobsmacked, pretty much every advert was for some manufactured foodlike substance which no-one sane would eat.

            1. chris c

              We don’t get that in the UK – YET. They do advertise OTC stuff though. Things for colds containing more acetaminophen than is good for you which could wipe out your liver if you took more than one of them, quite legal.

            2. Tom Naughton Post author

              Chareva’s parents had a neighbor who died from liver failure because he took too much Tylenol. It’s one of the reasons I try to keep the stuff to a minimum.

  3. Beatrix Willius

    Having a cold 2-3 times a year is seen as normal. For babies/small children 10 colds are year are normal. The poor things are practically ill the whole year. At least this is what I can see for my neighbour’s children. And doctors tell families that this is normal. So strange!

    1. Tom Naughton Post author

      Unfortunately, we define “normal” as what we see among a population of people who are mostly living on crap diets.

    1. Emily

      Chocolate is my Achilles’ heel. I’ve found, though, that eating a lot more fat decreases my desire for even chocolate. Doesn’t eliminate it though. I think it’s also good to have some treats. For me, a cup of half heavy cream and half whole milk, with cocoa powder, vanilla, and a very small amount of honey, works wonders.

      I’m trying to work my way up to no-sugar chocolate, but I dunno if I’ll get there. Very dark chocolate’s great too, though. Also, more expensive fair trade chocolate is more satisfying, both physically and emotionally. One small square of Domori or Amedi satisfies my chocolate cravings better than a big Hershey’s bar.

  4. Linda

    Just wishing you, Chareva and the girls a Happy Thanksgiving, Tom! I feel like I’m wishing members of my family Happy Thanksgiving after following this blog all these years. I certainly hope the healing is continuing to go well!

    I also hope your weather is better than ours here in north central Florida. We woke to pure slop after a gorgeous sunny day yesterday. Now it is pouring down rain in buckets and about fifteen degrees cooler than yesterday! Oh well, thanks to you, Jimmy and others along the years, I’m still thankful to be healthier than I ever would have been! And that’s a lot to be thankful for!

    And, sorry Tom, but that pizza will forever be the Fathead Pizza to me, too! Willa Jean, I never thought to use that crust for a regular pie crust. Wish I had read this before I made low carb pumpkin custard for myself to eat today while the carboholics eat pie! That’s why this blog is so great! I continually learn more and more.

    So have a great day everyone!

  5. Firebird7478

    “My arthritis went away, as did restless legs at night, frequent belly aches, psoriasis on the back of my head, and occasional bouts of mild asthma (“mild” because I would wheeze when breathing, but never needed an inhaler).”

    Low carb has not helped me with joint pain at all. Sometimes an injury is just an injury. I’ve had trouble breathing, too. Sometimes I believe that is my body our of alignment.

      1. Firebird7478

        Yes. The osteopath does wonders for me, but I have spondylolisthesis in my lower back (since I was 12). It was acting up on me earlier this year and the orthopedic doctor who examined me did something during the exam and made things worse.

        The chiropractor has been little help. In fact, his young associate, 27 and fresh out of school told me the following yesterday as he was adjusting me, “If I had the answer, I would tell you.”

        Head. Bang on. Desk.

  6. Ulfric Douglas

    It smells fishy to me ;
    “… then measured again at several intervals after having the subjects consume 100 grams of various types of carbohydrates.”
    Did they measure again after consuming non-carb foodtuffs too?
    If not, maybe JUST EATING temporarily does the same,
    which makes eating deadly dangerous if it weren’t for that keeping-us-alive side-effect.

    (also, 100 grams?)

    1. Tom Naughton Post author

      Since the results vary by the type of carbohydrate, I don’t think it was just a matter of eating. 100 g does sound like a lot; on the other hand, the typical American intake is more than 300 g a day, so many people are consuming 100 g grams or more per meal.

      1. Walter

        And mayhap a lot more in snacks. Remember the nutritionist’s “Eat every three hours”, it usually some sugar heavy, starch heavy and flour heavy snack, and the fats they do eat are usually omega six heavy.

        Gotta make sure insulin stays high so fat cannot be burned.

        So that the people that say eaten fat goes to body fat are actually right with the rest of their diet.

        1. Tom Naughton Post author

          Yup, we’ve posted those examples of what nutritionists or dietitians eat in a day. Sugar, sugar and more sugar. Low-fat, though!

  7. Uri London

    Resistance to colds and flu was also one of the very noticable changes I felt after going low carb. I always attributed this to the absence of vegetable oils. My reasoning was that now that my immune system is not tilting at windmills, it can effectively handle real threats.
    Now I finally got educated, thank you Tom.

    1. Tom Naughton Post author

      There are no doubt a number of factors involved. Since crappy vegetable oils provoke inflammation, I suspect we feel the effects of an infection less when we give them up, because we’re not as inflamed.

      1. Walter

        They are not vegetable oils. There is no carrot oil, parsnip oil, potato oil etcetera. What is is seed oils.
        There is soy oil, corn oil, peanut oil, canola oil, safflower oil, cotton seed oil.

        They are all industrially transmogrified seed oils extracted with hexane which is mostly removed and other high industrial processes. Can’t be considered food.

  8. Emily

    Happy Thanksgiving! I hope you keep getting better, as slow and annoying as I know the process is.

    My restless legs went away on a high-fat diet. I don’t think I get nearly as few carbs as you do, though I do eat a lot fewer than most Americans. I also rarely get sick any more, and I used to get sick all the time. I missed about 1/5th of the school year due to illness when I was a kid.

    I do think that a lot of the health improvements on a low-carb diet aren’t just because of cutting back on carbs, but also because of increasing animal fats. In many cases, drastically increasing said fats. Increasing fat without intentionally cutting carbs gave me tons of health benefits. I do try to keep my carbs to a lowish level now, but it’s usually easy. My whole life, I used to look forward to Thanksgiving stuffing starting in September. Now I don’t particularly want any.

    I need some plants or my brain dulls. I can still do math on a very low-carb diet, but my imagination and emotions get boring.

    1. Tom Naughton Post author

      My carb intake is usually in the 50–100 g per day range. I also believe there’s more to a low-carb diet than just eating less of the bad stuff. We also tend to start eating more of the good stuff, including the good fats.

  9. Mike

    I also have noticed a reduction in frequency and duration of colds, though I started supplementing vitamin C & D at the same time as going keto. Keto, and the accompanying weight loss nearly completely mitigated my sleep apnea as well.

    1. Tom Naughton Post author

      I suspect there are many factors involved. When we stop eating sugar and white flour, we tend to eat more nutrient dense foods, to name just one example

  10. Anne Robertson

    I’ve noticed the lack of colds, too, despite being on immunosuppression for my transplanted liver and kidney. However, stress can mess everything up. I’m back on an even keel again after a dreadful 2016 during which I had a minor stroke and a minor heart attack. My keto diet however has helped me to recover much faster than would normally be expected.

  11. Mike

    I must agree with how this lifestyle makes us immune to colds. I used to have horribly blocked sinuses with all usual add-ons. If I catch anything now, it usually lasts maximum half day. I can feel something but it is nowhere near cold. Some people in office fight with common cold for a week without any progress. I also usually wear lighter clothes than others. It is funny when I keep hearing : ‘wear this, wear that, you will catch cold’ – no way 🙂

    1. Tom Naughton Post author

      I suspect that when we eat the way we were designed to eat, we handle colds the way we were designed to handle them — a sniffle and a couple of days of feeling less-than-stellar, as opposed to being blocked and inflamed and miserable for several days.

  12. BobM

    I disagree about all meat (aka zero carb) diets. I’ve been slowly moving that way for a while, and I follow people on twitter who have eaten nothing but meat for years. Some over a decade. While I think low carb is great, some people still have issues with plants. I typically now eat all meat for lunch (no condiments, no vegetables, no plant matter other than maybe olive oil), and eat whatever my wife makes for dinner. That could have some vegetables in it. While I still eat some vegetables, I think they can cause more problems than what little nutrients they have.

    Just finished listening to a book about the Comanches. They ate nothing but buffalo unless they had to. And they only had to when they couldn’t kill buffalo, and at the time there were an estimated 30+ million buffalo. If they couldn’t make a kill for some reason, they would then resort to eating roots or honey or the like. And they were perfectly healthy.

    I will commonly eat 1/2+ pound of shrimp, mussels, anchovies, and sardines, with some olive oil and vinegar as a lunch, along with possibly other meat like liverwurst (lower fat, from US wellness meats) or ground beef. Compare the nutrition in that to ANY vegetable. Vegetables pale in comparison.

    I invite anyone to eat more meat and fewer vegetables, and try to get my own family to do the same.

    On the other hand, I did eat some einkorn bread, potatoes, and the like for Thanksgiving. I’m wearing a continuous glucose monitor (CGM) to test it, and I could not believe how much my blood sugar went up. If I eat a pound of ground beef, I cannot tell by my CGM when I ate, that’s how flat the line is. But even eating a seafood salad and hot and sour soup (the day before Thanksgiving, everyone but me gets sushi), my blood sugar went through the roof, and of course on Thanksgiving, with bread and potatoes and stuffing, it went into the 180s.

    By the way, I find Einkorn wheat does not give me effects similar to modern wheat. I am going to eat a pizza today, though. THAT will give me asthma and other bad effects. But I’ll be back on fasting and a near-all-meat diet tomorrow.

    1. Tom Naughton Post author

      I guess it depends on the tribe. The buffalo-hunting Sioux had cousins farther east, and they regularly met to swap buffalo meat for squash and other plant foods.

      And to repeat the point I made in the post, native people who lived on all-meat diets were eating animals who lived on nutrient-dense wild plants. I wouldn’t want to try that while eating nothing but beef, chicken and pork from animals who didn’t live in the wild.

      My blood sugar would also spike if I ate anything starchy after living on a close-to-zero-carb diet for a long time, but that was a case of my body down-regulating its ability to process carbs — which is fine, of course, if you don’t plan on eating any. After books and articles by Paul Jaminet and Dr. William Davis convinced me there are benefits to including some whole-food carbs in the diet, I re-adjusted. If I eat a small potato, bit of squash, bit of lentil pasta, etc., in a meal, the glucose peak is usually around 125.

    2. Emily

      I need full-fat dairy or I get anxiety disorder. It’s extremely weird and I don’t know why. But it’s not just animal fat because fatty meat does not do the same thing for me at all. Admittedly, I have not tried to drink a cup of bacon grease or eat a cup of lard to test it and I don’t plan to. My digestion does beautifully with a whole lot of dairy, but not with a whole lot of meat.

      I think people’s individual ancestry plays a large part in this stuff. We haven’t evolved to have differences in intelligence, temperament, the really important things. But we know we’ve adapted to have differences in digestion, with many populations unable to digest cows’ milk and others virtually living on it. I have many ancestors who pretty much lived on it. They also loved plants in season, honey, and dried fruit. If I don’t get some plants, my thinking and emotional landscape become bland. Then there are all the individual differences even between people within “tribes,” which are most likely more complex in a population with mixed ancestry like the U.S.

      1. gollum

        I should point out that milk/dairy contains rather large amounts of tyrosine, which is even named after cheese, and a precursor to serotonine I believe. Reports of opioids too.

        Of course it could be some other weird thing. Short-chain butyrate fats maybe.

  13. Jerry White

    I use a photomodulation for my joints. I use a device from Bioflex. See Great way to heal without drugs. Dr Kahn started this for his own shoulder 25 years ago. Also good for getting your mitchrocondria going.

  14. Randal L. Schwartz

    “we can pretty much guess what happens when people consume 100 or more grams of simple carbohydrates at, say, 8:00 AM, 1:00 PM, 6:00 PM and again at 10:00 PM for that late-night snack”. I think you’re missing the “every two hours” part of the typical carb crash. So add in, 10:30am, 3:30pm, and 8pm. And it might not be always 100g of carbs, but something closer to 300-400g a day.

      1. chris c

        I always found it ironic that a doctor who gave their patients three glucose tolerance tests per day would almost certainly face disciplinary action. Yet according to our (UK) government the RDA for carbs is 230 – 300g including 70 – 90g “sugar”, and many dieticians recommend even more. Go figure.

        The ADA used to recommend three meals of 45 – 60g carbs and three snacks of 15 – 30g per day for diabetics. These days they aren’t so blatant, but a while back someone subtracted their recommended protein and fat from their recommended calories and found it worked out to exactly the same.

        +1 on the colds, and most other infections too – and the few symptoms that didn’t resolve on low carb went away when I gave up wheat. Almost certainly dropping the Omega 6s and replacing them with less inflammatory fats has a place too, and so does stopping sun avoidance and getting your Vitamin D and NO levels up too. Is there anything they tell us to do that doesn’t destroy your health?

        The vitamin C using GLUT receptors and not being blocked by all the glucose is probably a factor, and I suspect running on ketones is also a factor.

        Nothing’s perfect though, while I might feel like I’m going to get a cold, and then that I just had a cold for s few days without the actual cold in the middle, I succeeded after 12 years in getting one last winter, and I’ve just been using chloramphenical drops for blepharitis. In both cases I blame my thyroid for going off on one again.

        Thanks for reminding me of the late Barry Groves, I also dug out this

        I think we all met that dietician.

  15. Geoff

    Since going paleo (after watching Fat Head in 2010) I don’t even remember the last time I got a cold. Use to get one at least once a year sometime during the winter. Now I may get the sniffles and a sore throat for a day or two then its gone, almost like allergies, which I don’t have.

  16. Bob Niland

    Since shifting to my current diet/lifestyle in 2011, I haven’t had so much as a cold. From time to time, I’ll get the ‘ol familiar feeling like “I’m getting a cold, or flu”, and the next day, it’s gone. Haven’t had a flu shot in years. This may be the experience of a properly functioning immune system.

    In a recent program video conference, someone else mentioned this phenomenon, and others reported the same thing. Why don’t we hear more about this? Perhaps because humans are particularly inept at noticing when the unexpected doesn’t happen.

    I have to largely credit grain-free, very-low-net-carb (which overlaps with your discussion), but can’t rule out contributions from the vitamin D, magnesium and thyroid support. Attention to microbiome didn’t really enter the program until 2014, and that is specifically expected to further boost immune function.

    1. Tom Naughton Post author

      I’d love to see an RTC on how diet affects susceptibility to colds and flu, but I doubt it will happen.

      1. Bob Niland

        I’d love to see an RCT on the less intangible benefits of this way of eating, but that’s not going to happen either. Even when people try, like NuSI did, saboteur PIs lurk.

        This is a grass roots revolt.
        Don’t eat the grass seeds.

  17. Wade B

    This post couldn’t have appeared at a better time. I had switched to a hybrid Paleo type diet about 8 years ago and most of the things you mentioned were true for me as well. I was pretty sick actually and the diet helped get my health back. I was pretty happy with it. I hadn’t really had the cold or flu in that entire time and I used to get sick 2 or 3 times a year. So that was pretty amazing to me.

    Then recently I had started reading and watching a lot of stuff about whole food plant based diets and thought well maybe that would work just as well for me. So I switch to a largely starch based diet with tons of veggies. I like the diet. I fee full, the food is good, and I have been happy… Until I started to notice some things. I started to have joint pain. I blew it off as probably too much nightshades and that I needed to make sure I peeled my potatoes. I noticed my energy levels weren’t as stable for me. And finally the big one hit this week. I got my first cold/flu in 8 years. I have had a lot of time in bed sicker than a dog to reflect on this and have decided that it must be the dietary changes.

    I have to admit I am not happy about this because I liked the new diet, but not at the expense of my health. So I am changing my diet back to meat, eggs, nuts, and veggies and will just have to deal with it. But I just wanted to share that this post was right on the money. Whole foods, lower carbs, living fresh foods when possible have been the key over the years and I shouldn’t have assumed that just whole foods alone were the key to my health success. That does not appear to be the case. At least not for me, so I am heading back to where I came from after a 3 month experiment with the whole food plant based diet. Hopefully things will clear back up and I won’t be visited by the cold/flu again. I am still recovering as I type this and can’t wait for it to be over with!


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