Friday, February 23, 2018

Can Viruses Produce Insulin?

Scientists at the Joslin Diabetes Center have found four viruses they say produce insulin-like proteins (viral insulin-like peptides, or VILPs)

The VILPs bound to human insulin receptors and stimulated all the signaling pathways that are stimulated by insulin.

The VILPs also bound to receptors for insulin-like growth factor 1, an insulin-like hormone that affects growth.

Mice injected with the peptides (peptides, like proteins, are chains of amino acids, but they're shorter) had lower blood glucose (BG) levels, indicating that the VILPs can have some of the actions of insulin.

So would these viruses affect BG levels under ordinary circumstances? It's known that they can infect fish and amphibians. And analyses showed that humans are exposed to these viruses in the intestine, possibly as a result of eating fish.

But do the viruses get into human cells? No one knows yet. The mice with lower BG levels were injected with the VILPs rather than getting the viruses from eating infected food.

Because this is such a new finding there's not yet much information about viral hormones that could affect humans, but because scientists think there are more than 300,000 viruses that can infect or be carried in mammals, there are certainly a lot of possibilities.

This finding has no practical application yet, but it opens up a whole new way of looking at hormones, and new approaches often lead to major breakthroughs.

Stay tuned.




Sunday, February 4, 2018

Do Our Bones Control Our Weight?

It is well known that sitting for a long time is unhealthy and contributes to, among other things, the risk of obesity. But no one has explained how this happens.

An obvious explanation is that if you're sitting, you're not exercising, but studies have shown that this is not the answer. Sitting and the amount of exercise are independently associated with risk.

Now a group of researchers has come up with a new idea. They propose that our bones, specifically the osteocytes in the long bones, can sense our weight, and when the weight goes up they signal to the brain that we should eat less. They call this a gravitostat.

The researchers show that this weight control is independent of leptin, the hormone produced by fat cells that tells us to eat less when we get fat enough. People who are overweight often have what is called leptin resistance, meaning the leptin system isn't working well.

The researchers used mice and rats to demonstrate their theory, loading the animals with weights and following their effect on body weight. They found that as they added weights in capsules, the animals' body weight (obviously less the weight of the capsules) decreased steadily. And this weight loss was not due to increased energy expenditure, but to decreased food intake.

In addition to the weight loss, insulin resistance decreased.

Not long ago, scientists thought that fat was an inert substance used only for storing energy. Now they know that fat cells are actually endocrine organs that secrete hormones, for example, leptin, that affect other organs.

Then they thought bones were inert structures that mainly functioned to support our weight. Now they're finding that the bones too seem to be endocrine organs.

What's next? Fingernails?

Whatever, the concept of a gravitostat has a possible practical application, unlike so much of today's diabetes and obesity research, which is one reason I don't report on much of it. Most patients can't use information about some new transcription factor or biochemical pathway to affect their diabetes control.

But if weighting mice with capsules made them lose weight, would weighting humans with increased loads help them lose weight? Would it make your diet work better if instead of just walking, you walked while carrying a 10-or 25-pound load in a knapsack? The rodents were loaded with 15% of their initial body weight.

For a long time I've felt that when people lose a lot of weight, one reason they stall is that they're no longer moving such a big load as before. They start with muscles capable of carrying a large load, but as they lose the weight, those muscles aren't working as hard. So I thought it would make sense to add weights to the body as the weight was lost to avoid losing muscle along with the fat.

In fact, I had grandiose plans to develop weight-carrying vests to which you could add weights as you lost. If you lost significant weight, you would be amazed to find how heavy the vests had become. I planned to get rich on my scheme. Unfortunately,  a little research discovered that such vests already exist, so I had to cancel my plans for a villa on the Riviera.

So using existing vests and weights, would they help humans, like the rodents, lose weight? Remember that rodent research doesn't always translate into human results.

But what's to lose other than a few bucks? Unlike experimental drugs, weights shouldn't have side effects, unless you dropped them on your toes.







Sunday, January 28, 2018

Another Misleading Headline, Sigh

Here we go again. A study is reported with a headline that implies something other than what the study shows.

The headline is "New research finds drinking 100 percent fruit juice does not affect blood sugar levels." Hogwash! Everyone with diabetes knows that drinking fruit juice of any kind makes blood glucose (G) levels go up, usually a lot.

It turns out what they meant was that drinking fruit juice doesn't make the next day's fasting levels increase a lot. My what a surprise! I have a glass of orange juice for breakfast and my BG levels skyrocket, but by the next morning they're down to where they usually are.

But that's not what the headline said.

Furthermore, saying that 100% fruit juice is innocent  implies that fruit drinks with added sugar are not. No, they didn't say that, but most people would think that.

The study did find that those who drank the fruit juice had higher insulin resistance. Did that go into the headline? Of course not.


Then there's the problem that this was a meta-analysis, in which researchers combine results from many studies in order to get statistically significant results, which depend on the size of studies. Such studies have many problems, including how they select the studies for the meta-analysis.

A similar study was sponsored by Juice Products Association, which suggests even less credibility.

But the worst sin is implying that fruit juice has no effect on BG levels, whether the studies were similar or not. We all know they do.




Friday, January 26, 2018

Misleading Headlines

A recent headline read, "Study links low carbohydrate intake to increased risk of birth defects."

Now, if you read that headline and didn't read the following story carefully, what would you think? You'd probably think that a lack of carbohydrate causes birth defects and hence low-carb diets should be avoided if you're planning to get pregnant.

But why would eating less carbohydrate cause birth defects? One explanation, and I think a good one, is that folic acid supplementation tends to prevent neural-tube birth defects, and for this reason the government mandated adding folic acid to enriched bread and other cereal products. Because people on LC diets don't eat much, if any, cereal products, they wouldn't be getting this protective folic acid.

Folic acid is also in liver and leafy greens like spinach, but some people may not like spinach and leafy greens, which is one reason bread and some cereals are supplemented.They assume everyone eats bread and cereal.

Many people don't read whole articles. They just read the headlines and assume they're accurate summations of the essence of the story. So why didn't the headline in this case say, "People on low-carb diets may need to supplement with folic acid if they could get pregnant." 

Another factor proposed to explain birth defects is any kind of dieting before conception or early in prenancy. One study showed that weight-loss dieting during the first trimester doubled the risk of neural-tube defects. This makes sense, as restricting calories could result in various deficiencies, including folic acid.

There's a lot of this type of spinning research studies. People have preconceived notions and analyze the research and write headlines from their point of view. Not long ago, the popular meme was low fat. That's now out and "more fruits and vegetables" is in. "Plant-based" is another popular meme.

I wonder what it will be 50 years from now?

BTW, a similar report came out in 2007. Why they're revisiting it is not clear.

Wednesday, January 17, 2018

The Most Important Thing

People sometimes ask me, "What's the most important thing to do if you're diagnosed with type 2 diabetes?'

My answer: "TAKE THIS DISEASE SERIOUSLY."

Well, actually, I don't usually shout, but I sometimes want to. If you're reading this, then I think you're taking this disease seriously, trying to learn as much as you can about it so you can control it.

But too many people don't. They want the doctor to give them a pill so they can go on exactly as they have in the past, eating too much, especially foods that make their blood glucose (BG) go up, and getting no exercise.

One problem in type 2 control is that the results of not controlling well aren't immediate. You won't break out in blue spots if you a big piece of chocolate cake with ice cream. Your hair won't turn pink if you eat a huge pile of mashed potatoes and gravy with Texas toast on the side. Some people feel bad when they have high BG levels. Others don't.

I was diagnosed with fasting levels in the 300s, and I went into the 400s after meals. But I felt fine.

No, the effects of high BG levels are insidious. The glucose gloms on to various substances in your body and eventually causes complications. The damage from the glucose can result in cataracts, retinopathy that can lead to blindness, neuropathy that can make your feet hurt all the time, vascular problems that lead to heart attacks, amputations, and impotence, kidney disease, and more.

None of these complications are pleasant. But if you take this disease seriously and control your BG to normal or near-normal levels, the chances that you'll get complications are low.

It's not easy.Watching your friends pig out at an ice cream stand while you drink a cup of black coffee, no sugar, isn't fun. Different people have different ways of dealing with this. Some can eat just a couple of spoonfuls of some treat and leave the rest. Others find it works best to avoid the treats altogether. I'm in the latter group. If I ate a couple of spoonfuls of some treat, I'd crave it all. When I haven't eaten bread, cake, and ice cream for years, I no longer want them, even if all around me are eating them.

This situation of not wanting the treats isn't instantaneous. It takes a while before you can deal with these situations easily. But persistence pays off.

Well, I'd rant on and on, but right now I'm craving a lamb chop with broccoli and butter, so I'd better go.