Glucose competes with Vitamin C. Mismanaging this competition is detrimental to your health.
Glucose AKA Blood Sugar
Glucose is a main body fuel that provides cellular energy. It is essential to life. However, it is akin to the Goldilocks story. To little is no good. Too much contributes to vast chronic health conditions. We need to be just right.
Vitamin C is a water soluble (dissolves in liquid) nutrient. One interesting tidbit for us human is we can’t make it internally. Unlike most other animals who can make their own, we must get our Vitamin C from dietary sources.
Its is an antioxidant itself and supports glutathione (the body’s “master antioxidant”) recycling 1. It also provides collagen/connective tissue support and helps with immune function. Not too shabby.
Insulin promotes vitamin C uptake at the cellular level 2. Most know insulin as an escort for glucose into the cells. The problem lies when blood sugar rises. High blood sugar inhibits uptake of Vitamin C3.
It is critical we get take care to keep our Vitamin C uptake ideal.
When Vitamin C Falls Behind
If we continue spiking blood sugar and tanking Vitamin C uptake, what happens?
White Blood Cells (WBC) are a component of the immune system. One role they have is to undergo phagocytosis (engulf/swallow invaders) when pathogens present. This process also uses a high amount of oxidative stress to kill the pathogens. WBCs accumulate high concentrations of Vitamin C to protect themselves (Vitamin C, the antioxidant)4. Not surprisingly, dietary sugar consumption decreases the WBC’s ability to undergo phagocytosis5. Sugar can make you sicker.
Skin & Connective Tissue
Vitamin C takes part in collagen synthesis. If we are suboptimal in Vitamin C are collagenous structures could be at risk. This risk is greater since most American’s don’t get enough dietary collagen. Eating muscle meats and avoiding connective tissues skirts consumption.
Skin is one tissue reliant on collagen. So, logically, Vitamin C is critical in skin health6. High blood sugar decreases Vitamin C, and therefore collagen status, but there is another consequence. Sugar binds to proteins in a process called glycation (the same process as brownie meat). High sugar, more glycation. This is what the diabetic lab value HbA1c (glycosylated hemoglobin) tracks. Glycation degrades skin health, while Vitamin C is protective7.
Tendons have a high collagen composition. Here again, Vitamin C is important is important in their composition8. Might those high sugar sports drinks make it easier for an ACL injury? Potentially.
Our blood vessels also have a collagen component. The absence of sufficient Vitamin C impairs collagen formation in the vasculature, whereas Vitamin C can boost function9.
Linus Pauling, who was a staunch advocate of Vitamin C, made a connection between deficiency and Lp(a). Lp(a) is a lipoprotein, like LDL (AKA “bad cholesterol”). Lp(a) is a concern, partly because of its propensity to promote clotting. Pauling showed low Vitamin C increased Lp(a)10. And this makes sense with the paragraph above. If vessels are breaking down, they become leaky. Lp(a) then promotes clotting so our blood doesn’t escape. I included this discussion in my detailed paper on cholesterol and statins.
We can tie this section right back to too much blood sugar. Doctors treat diabetes like a cardiovascular disease. Glucose degrades Vitamin C status. This lowered status causes leaky vasculature. The body responds by patching it with Lp(a) and clotting. Time to back off on the sweets?
Let’s look at a few ways to rescue Vitamin C from sugar
When To Eat
The most reliable way to avoid high blood sugar is fasting11. I spent over 20 pages detailing the importance of Why When To Eat Matters, please have a look for more details. In the meantime, expanding time between calories consumed will be helpful.
Avoid Sugar Spiking Foods
I also touch on this in the Why When To Eat Matterspaper. Sure, sugar will increase blood sugar. But, refined carbohydrates such as any flour product will raise your blood sugar more than regular sugar itself. That bowl of pasta? Think of it as pure sugar in your blood stream.
Getting nutrients from food is always best. Many fruits and vegetables are high in Vitamin C. However, caution is required on fruits. Fruits in excess can drive up blood sugar – aim for 1-2 servings max per day. Fruit juices are in the never category.
Supplementing during a fast and during a meal that is higher on the sugar end both can be beneficial.
While we don’t worry about scurvy, less than ideal Vitamin C levels are a concerning situation. Understanding we make this so with blood sugar provoking foods provides us an avenue to take corrective action. These foods are Vitamin C blockers. We need to avoid these and restore Vitamin C to recover.
- https://www.ncbi.nlm.nih.gov/pubmed/11687303 ↩
- ncbi.nlm.nih.gov/pubmed/9550452 ↩
- https://www.ncbi.nlm.nih.gov/pubmed/16118484 ↩
- https://lpi.oregonstate.edu/mic/vitamins/vitamin-C ↩
- https://academic.oup.com/ajcn/article-abstract/26/11/1180/4732762 ↩
- https://www.ncbi.nlm.nih.gov/pubmed/18505499 ↩
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3583887/ ↩
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6032621/ ↩
- https://www.ahajournals.org/doi/full/10.1161/01.CIR.0000012513.58079.EA ↩
- https://onlinelibrary.wiley.com/doi/full/10.1002/oby.22449 ↩
- https://www.ncbi.nlm.nih.gov/pubmed/18160753 ↩
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3254006/ ↩
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4915787/ ↩