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. 

Monday, January 11, 2021

Subtypes of Type 2 and Prediabetes

 A recent study has suggested that there are six subtypes of prediabetes, with each subtype having different risks of progressing to type 2 diabetes and different risks of various side effects. The study, which was begun 25 years ago, grouped people into clusters depending on factors like blood glucose levels, liver fat, body fat distribution, blood lipid levels, and genetic risks.

They found that people in different clusters differed in insulin secretion and insulin action in addition to the factors listed above.

People in three of the clusters have a low risk of diabetes. People in another cluster produce too little insulin. Those in another cluster have kidney damage even before overt diabetes is diagnosed.

It would be nice to know what cluster a newly diagnosed patent was in, but many patients today have difficulty getting even basic tests, and its unlikely they could get all the tests required to classify them. Even the authors concede that "our clustering aproach is not designed to provide definitive subphenotypes for individual patients in a clinical seting." However it would be useful for researchers.

I suspect that in the future they'll find even more subtypes, but for now this is a start.

Patients can differ a lot in both physical characteristics and economic and emotional ones. One patient might be willing to go on a strict low-carb diet, and another couldn't tolerate that, or couldn't afford it. Treatment may depend on a particular patient's situation, and good doctors take that into account agaialready, rather than relying on a cookie cutter approach.

The full text of this study, in preprint form, can be found here

This is not the first time researchers have tried grouping patients into clusters. Other researchers have grouped people with type 2 diabetes into five subgroups, using GAD autoantibodies, age at diabetes onset, HbA1c, BMI, and measures of insulin resistance and insulin secretion.

They found that the group with severe insulin-deficient diabetes had increased risk of retinopathy and neuropathy, whereas the severe insulin-resistant diabetes group had the highest risk for diabetic kidney disease and fatty liver

Again, most physicians will probably not have the resources to measure all these parameters for every patient, but again, it's a start.

Thursday, December 17, 2020

Does Control Get Easier as We Age?

 Someone recently mentioned to me that their control had gotten easier as they got older. I'm not talking about going from 20 to 30 years old. By older I mean senior citizen status.

This is the second person who has told me that. The first one was a type 1 on basal/bolus insulin. She was on a low-carb diet and didn't need much insulin to cover meals, but she needed some. When she reached her mid-80s, however, she found she sometimes didn't need mealtime insulin at all. And she could again eat peaches, which she adored.

She said her doctor, a GP, said that sometimes happens.

"I'm cured," she often said.

One thing that can make blood glucose (BG) go up is gluconeogenesis in the liver, where glucose is formed from other things. Insulin is supposed to turn the gluconeogenesis off, but when you have insulin resistance, that doesn't happen, and the gluconeogenesis is one reason for high fasting BG levels.

Both these reports are, of course, annecdotal, but when I heard this a second time, I decided to look into it.

Here is a study in rats that says, "It is concluded that the gluconeogenic capacity of liver declines with age regardless of the gluconeogenic regulator." So the concept may have some merit.

Long ago I read somewhere that I unfortunately can no longer find that an Indian doctor said some of the Indian herbs that seemed to work to keep BG levels down did so by damaging the liver, which would reduce gluconeogenesis.

So liver function might be key.

 I was wondering if any others had noticed improved BG control with aging, meaning 70 years old or older.

Of course, there are other reasons control might improve. With time we get accustomed to whatever diet works for us. We usually get less exercise than when we were younger and playing several sets of tennis before lunch. Well, OK, I never did that, but some people did. And we often eat less because with less exercise we're not as hungry.

But if you're doing pretty much the same thing you've been doing for some time and you find your control improving with age, I'd be interested in hearing about it.