Monday, April 12, 2021

CGMs in Nondiabetics

 As continuous glucose monitors (CGMs) become a little less expensive, they're starting to be used by nondiabetics as a way to understand their responses to different foods. You need a prescription, but they're not difficult to get.

On one hand, it annoys me that well-heeled nondiabetics are able to use CGMs when many people with diabetes cannot. On the other hand, the more we understand how foods affect our blood glucose (BG), and the more the general public understands this, the more pressure there will be on the food industry to produce healthy foods that don't raise BG.

Some physicians are even using CGMs themselves so they have better understanding of how foods affect their diabetic patients. This is good.

 If you're interested in this, search on "CGM nondiabetic" and you'll get a lot of hits. Following are a few samples.

Here is a formal study from 2007. Glucose was measured by means of a catheter inserted at the study site. Note that they found BG levels went highest after breakfast, but many people continue to eat carby breakfasts.

 This one is a blog by a "nutritional therapy practitioner" with PCOS (polycystic ovary syndrome). PCOS does increas the risk of developing type 2 diabetes, but it hadn't yet developed in the blogger, Emily Blasik. It was interesting in part because of some of the confusion about carbs. For instance, she mentions eating a "zucchini crust pizza," after which her BG spiked. But if you read the text, you see that the pizza crust included tapioca starch, which has a very high GI. In fact, if you look at the incredients of "cauliflour pie crust" in your supermarket, you'll find that they add flour, most likely to get the crust to stick together.

Here's a blog by a nondiabetic CDE, LilyNichols. It's long, with references and 149 comments currently, but if you have the time you might enjoy it, as she's very thorough, so there's something for everyone.

This blog is by a dietition, Kara Collier. The high-stress day is especially interesting.

And for athletes, especially men, this one in Men's Health, focuses on the effect exercise has on BG. Interestingly, some of the nondiabetic participants found what people with diabetes have found for years: you can eat exactly the same thing at the same time of day and get different results.

Finally (in this blog; there are zillions more blogs about CGMs in nondiabetics), here is a CGM site by a physician.

 What most of the bloggers learned was something people with diabetes have known for a long time: it's carbohydrate that makes BG go up, and "healthy" foods like oatmeal with milk are among the worst offenders, whereas "unhealthy" foods like bacon and eggs keep BG more level. Several also found that strenuous exercise made BG go up (I've always found that). It makes sense, because if your body senses that you're needing more energy, it's going to try to produce extra energy as glucose even if you're fat adapted.

Perhaps when people realize that old-fashioned foods like meat and cheese are kinder to BG levels than pasta and rice, we'll see new food trends. One problem is that in some parts of the world, people can't afford a lot of meat, and they may not be able to eat dairy because as adults they don't have the enzymes that break down lactose. Perhaps one reason they were able to tolerate high-grain diets in the past was because they didn't have enough food to overeat. Or perhaps the high-grain diets did make their BG levels go up but they got a lot of exercise and didn't live long enough to see the long-term effects of the grains.

 Whatever, the study of BG levels in nondiabetics may give us new ways of thinking about BG levels in people with diabetes.

Saturday, March 27, 2021

Fructose and Triglycerides

 When I was diagnosed with type 2 diabetes in 1996, it was thought that although fructose, which is half of sucrose (table sugar; the other half is glucose), didn't raise blood glucose (BG) as much as glucose, it could have an effect on triglycerides (fats).

One source said that although fructose didn't affect blood triglycerides in people with unimpaired glucose tolerance, it could raise them in people with defects in carbohydrate metabolism (e.g., people with diabetes) even at relatively low levels of fructose intake.

Yet despite this, products sweetened with fructose were sold as diabetes friendly. We have to remember that factors other than BG levels are important for health, so higher triglycerides are not benign.

A recent study shows that consumption of fructose or sucrose, but not glucose, doubles the synthesis of triglycerides in the liver. The full text can be found here. Note that this study was done on "healthy lean men." Results might be even more pronounced in those with diabetes.

Increased fat production in the liver is a significant first step in the development of common diseases such as fatty liver and type-2 diabetes, so this is important.

Some people say that diabetes isn't caused by eating sugar. Are they wrong?

Wednesday, March 3, 2021

Asian Glycemic Index

Many people no longer use the glycemic index or the related glycemic load, which rate carbohydrate foods by how quickly they raise blood glucose levels, because they focus on reducing the consumption of carbohydrate foods regardless of their glycemic index. But some people still do use this index.

And now there's a list of Asian foods with glycemic indexes. There's still no African index. But the Asian index should be useful for people who eat a lot of such foods and wonder about their effect on blood glucose levels without testing for themselves.

Long ago, when I gave up regular noodles and didn't yet know about shirataki noodles, I discovered I could eat small amounts of cellophane noodles, also known as glass noodles or bean thread or mung bean noodles (the ones not containing other starches), without a big effect on my blood glucose levels. They're included in this Asian list and have a glycemic index of 28, which is relatively low.

So my self-testing was correct.

Thursday, February 18, 2021

Metformin and Supplements

 A recent study suggested that the supplement goldenseal interferes with the ability of metformin to control blood glucose levels.

I doubt that a lot of people are using goldenseal, but this study illustrates a general problem: Everything can interact with something else. That means not just drugs and supplements or drugs and other drugs, but drugs and foods or drugs and exercise and probably even drugs and your mental state.

For this reason, whenever you try something new, you should add only one new thing at a time, so if there is an effect, you know it's due to that new thing. If there's no apparent change in anything you can then try something else.

Vermont participates in the HomeMeds program for older adults, and although I hate to admit I'm an older adult, I took part. A nurse came to my house (this was before covid-19) and took a list of all my drugs and supplements. She then took the list to a pharmacist, who made sure there were no bad interactions. The pharmacist didn't see any.

I'm sure you can do the same yourself by making a list and taking it to a pharmacist, or running it through an online site like this. Of course if you're taking a bunch of obscure herbs, the online site might not include them. A pharmacist might be able to research them if willing to take the time.

The important thing is to be alert for any changes in your health when you try something new, even a new vegetable you just found at the grocery store.

Everything can interact with everything else. Sometimes the result is good and sometimes it's not so good. Most interactions are trivial. We just need to notice the major ones.

Monday, February 8, 2021

CGMs for Nondiabetics

 The New York Times today had an article describing the experience of a nondiabetic who tried a continuous glucose monitor. (CGM).

 It's interesting, but it bothers me that affluent nondiabetics can get CGMs when many people who have diabetes cannot because their insurance won't cover them and they can't afford to pay out of pocket. Many people with diabetes probably don't even realize that CGMs exist, not to mention their benefit.

I once met a woman on an elevator in a medical building, and she said she had type 1 diabetes. I asked if she used a CGM and she didn't know what that was.

Today, many people with type 1 get insulin pumps along with CGMs. Type 2s less so. But I've always felt that people with type 2 should use a CGM shortly after diagnosis so they can learn what foods make their blood glucose go up. Different people have different reactions to carbohydrates. Some can eat rice with no problem but potatoes make their blood glucose levels soar. Others the exact opposite.

I'm sure that in the future CGMs will become common for type 2s, and insurers will learn that controlling blood glucose levels means fewer expensive complications, so they'll be willing to pay for CGMs, maybe not all the time but periodically to check and recheck.

I hope that future isn't too far off.

Thursday, February 4, 2021

Scientists to study YMMV

As diabetes patients, most of us understand the concept of YMMV, or "your mileage may vary." A diet that works great for someone else may not work well for you.

 An Israeli study a few years ago showed this to be true. A food that raised blood glucose in one person might have no effect on another.

Now NIH researchers have planned a study to test this concept in 10,000 Americans. The study will start recruiting participants by January 2023, so don't expect results in the near future.

In the meantime, keep testing before and after meals as much as you can to find out which foods are best for you. If you can afford it, a continuous glucose monitor is a good way to document this. Most insurance won't pay for the CGMs for type 2 patients, but I think the information you can get is worth the cost. I occasionally wear one, and it costs me $63 for two weeks (Freestyle Libre).

 After you learn what diet works best for you, you can cut back on the testing somewhat, although it's good to do spot checks to make sure your blood glucose isn't trending up.

Saturday, January 23, 2021

New Theory about Saturated Fat

We all know that dietary saturated fat is bad because it raises blood cholesterol levels, right?

Well, maybe. 

When we get lipid tests like LDL, HDL, and so forth, they draw blood and then measure these things in the blood. They don't measure them inside the cells, or in the cell membranes. And a new study suggests that high blood cholesterol might simply reflect the membrane's need for cholesterol.

Unsaturated fats make membranes more fluid; saturated fats and cholesterol stiffen membranes. What we need is a balance between the two states, and the body is usually pretty good at knowing what we need.

The new theory suggests that when we eat saturated fats instead of unsaturated fats, the membranes don't need a lot of cholesterol to prevent the membranes from being too fluid, so they don't take the cholesterol out of the blood, and hence blood cholesterol levels are higher.

In other words, blood cholesterol levels can fluctuate according to how much cholesterol is needed in membranes. "The effect of dietary fats on blood cholesterol is not a pathogenic response, but rather a completely normal and even healthy adaptation to changes in diet" says the lead author of the study.

The authors call this the homeoviscous adaptation to dietary lipids model. They note that as of now, this is only a theory that needs to be verified. And they distingish between elevated cholesterol levels from dietary changes and elevated cholesterol levels from metabolic disturbances such as inflammation and insulin resistance.

You can read the abstract of the article here. Unfortunately, the full text is behind a paywall.