How to Spot “Fake News”
By ryan heeney / April 15th, 2022
I happened to come across this article recently which was featured in The Atlantic titled, "The Startling Link Between Sugar and Alzheimer's":
Being that The Atlantic is a well respected publication, I was intrigued. I was also feeling brave enough to be "startled" that morning, so I clicked the link.
Here is a summary of the study from the article:
So to summarize, in the study they found that high blood sugar led to faster cognitive decline—fair enough.
But here's a few major problems with that headline.
First, the dietary "sugar" you consume is not necessarily the determinate of glucose you will have floating in your bloodstream (blood sugar level). The ability (or inability) of your cells to metabolize glucose will be the largest deciding factor of whether your blood sugar will be high or not.
I know I use this example often but I feel it's worth repeating: if you have a hole in the bottom of your boat that's letting in water, stop trying to figure out ways to get rid of the water over the side of the boat and instead just plug the hole.
In this case, plugging the hole would be lowering your level of free fatty acids in the blood (which blocks the cells ability to use glucose) and increasing the metabolism. This allows the cells to begin using glucose for fuel, therefore lowering your level of blood glucose. In my opinion, consuming adequate carbohydrate in the form of fruit, fruit juice, sucrose, honey and some safe starches; and then avoiding polyunsaturated fat (especially from fried foods, vegetable oils, nuts and seeds) and doing things like getting enough sleep, getting adequate sunlight, getting adequate sodium, etc., are all things that I think you could do to improve the use of glucose by the cell.
Secondly, get this—plain old white sugar is actually lower on the glycemic index than your “healthy whole grain breads”. The glycemic index is a way to measure how much a food will cause a rise in blood sugar after the consumption of that food. Depending on how high blood sugar rises, a value is then assigned. The higher the value, the greater the rise in blood sugar from that food.
Here are a few examples:
Table sugar (sucrose) has a glycemic index value of 65.
Now take a look at the value of some commonly known starchy foods:
But how could this be?
How could shredded wheat, a plain bagel, a french baguette, pretzels—foods that have zero sugar—be higher than pure white sugar on the glycemic index?
Fructose is why.
Table sugar (sucrose) is a disaccharide, meaning it is a sugar composed of two different sugar molecules. The two molecules that table sugar is composed of are the monosaccharides fructose and glucose.
Sucrose = glucose + fructose
Pure glucose has a glycemic index of 100.
Starches are made up of glucose and is why white bread is close to 100 on the glycemic index. Refined starches on their own break down and enter the bloodstream very rapidly. Whole grain starches are only slightly better, but they should be avoided for other reasons.
Pure fructose on the other hand has a glycemic index of just 15!
Not only is fructose low on the glycemic index, there are actually very few foods that are as low!
Now this doesn’t mean to start spooning these carbohydrates until your mouth ad libitum because they are such dense sources of calories, but mainstream nutrition seems to be completely mischaracterizing these sugars.
There's a couple reasons the glycemic index of fructose is so low. First is because fructose is sent right to the liver where it is slowly divvied out into the bloodstream as the liver sees fit. Secondly is because fructose doesn't affect the secretion of insulin like pure glucose does.
So because of the fructose and glucose components of white sugar—the two molecules together “average out” and give sucrose the value of 65 on the glycemic index.
The link below is to Harvard's Medical School website where you can see fructose's value on the glycemic index plus a variety of the other foods I mentioned. Notice how low so many "sugary fruits" on the glycemic index are—this is mainly due to the high fructose content of fruit.
Lastly, my major gripe of that article, albeit a small one, is the picture of a cupcake they used to represent "sugary foods". What most people think of as "sugary foods" are almost always more fat by calories than sugar. I wrote about this subject in my article “Sugary Foods”?.
Now, as to the link between Alzheimer's and high blood sugar? I don't know the mechanism for why that could be—but I could almost certainly tell you it's not because of the consumption of dietary sucrose (table sugar). As much as some folks want it to be sugar, and whatever their motives might be to point the finger at sugar, when you take a look a little bit closer... it's not sugar. It's fake news.
Quick note: Don't always let the glycemic value of a food determine whether you choose it or not, my focus on the glycemix index in this article was to prove a point at the absurdity of the title of the article published. I don't put a great on the glycemic index when individually considering a food on its own. These foods are almost never eaten on their own and instead are eaten in combination with one another. When combined in our stomachs, the glycemic values of all these foods basically average together. Because of the very high glyceimic index of starches though, I do believe it is important to eat them with some fat and protein to lower their particularly high glycemic value. Potatoes, white rice, sourdough bread, etc., can still be enjoyed in moderation if eaten correctly.
Also, while on the topic of sugar, an interesting thing to do is to look up "fruitarians" on YouTube. These are people that subsist completely on fruit. They can eat anywhere from 3,000-6,000 calories a day and it almost all comes from sugar in the form of fruit (although some fruitarians supplement with white sugar too). One thing you will notice is that they are all very thin. Probably too thin (from lack of protein), but very thin nonetheless. If sugar is so fattening, why don't these people become obese? They are getting more than sufficient amounts of calories but don't seem to gain a pound. How could this be? Well if I had to guess, it's because they keep their dietary fat intake low and their cells are able to use the sugar efficiently. A fruitarian diet is by no means optimal, but it proves a point.