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.