Tuesday, November 6, 2018

Protein and Kidneys

When I was diagnosed with type 2 diabetes in 1996, a nurse handed me the American Diabetes Association 1500-calorie diet, which said I should eat 179 grams of carbohydrate a day. That made no sense to me. So when I saw my doctor, I asked, "If diabetes is a disease in which you can't deal with carbohydrates, why did the nurse tell me to eat all this starch?"

The doctor looked surprised at the question and then thought and answered, "Well, protein damages kidneys, and as a diabetic, you're at increased risk of kidney damage. Fat causes heart disease, and as a diabetic, you're at increased risk of heart disease. The only thing left is carbohydrate."

Many of us have questioned the assumption that protein damages healthy kidneys, so it's nice to see some research supporting that idea. True, this study is a meta-analysis, in which researchers do statistical analyses of previously published research, and meta-analyses can have problems. For instance, the populations studied by each group may not be very similar. The end points may vary. Nevertheless, such studies give suggestions about the issue at hand.

This study says nothing about protein consumption by people who already have damaged kidneys. In such cases, some people think plant proteins are better than animal proteins.

My doctor's statement about fat causing heart disease has also mostly been disproven, but I won't get into that here.

Monday, November 5, 2018

Weight and Nuts

Sometimes people do research and then write it up in a way that reveals that they had preconceived notions about the results. An example of this is a recent report suggesting that eating nuts may help you to lose weight. The report was presented at the American Heart Association's November meeting.

OK, that makes sense. Most nuts contain a lot of fat, and fat slows down gastric emptying, so you feel full longer.

The study involved a food-frequency questionnaire, which can be fairly inaccurate. Who remembers everything they ate last week, or even yesterday? But that's not the problem I'm concerned with.

The researchers said the nuts were eaten "in place of foods generally considered low in nutritional value." So it's not just eating nuts but eating nuts in place of junky foods. One assumes they mean empty calories in sugary drinks or starchy highly processed foods.

But wait! They said "Substituting one serving a day of any type of nuts in place of one serving of red meat, processed meat, French fries, desserts or potato chips was associated with less weight gain over the four-year intervals."

Red meat is low in nutritional value? Since when?

According to P. G. Williams at the University of Wollongong, Australia,

"Lean red meats are:

"• An excellent source of high biological value protein, vitamin B12, niacin, vitamin B6, iron, zinc and phosphorus 
"• A source of long-chain omega-3 polyunsaturated fats, riboflavin, pantothenic acid, selenium and possibly also vitamin D
"• Mostly low in fat and sodium [this analysis refers to meat with fat trimmed]
"• Sources of a range of endogenous antioxidants and other bioactive substances including taurine, carnitine, carnosine, ubiquinone, glutathione and creatine."


This study was done in the lab of Walter Willett, who has long opposed eating red meat, and I suspect that because the researchers consider red meat to be unhealthy, they just lumped it in with foods considered low in nutritional value. This is not good science.

Even perfectly done nutritional studies can be confusing because so many factors are involved. Eating more of X usually means eating less of Y, so if the results are different, which was the crucial factor? Most people, including professional dieticians, make errors when reporting what they ate. And of course there are interactions between foods. Maybe food A has one effect when eaten with Food B but not when eaten with food C. And so forth.

So to see a misleading statement like the above in a report from Harvard is discouraging.

Will we ever know what the healthiest diet is? Probably not, because what works for one person may not work for another. What makes blood glucose go up for one person may not for another. And a diet that person A can stick to for years might be different from a diet person B could tolerate long term.

Our best approach is to try different diets and see how they affect our daily blood glucose levels and less frequent lab results and then choose one that works for us.

And it's probably also a good idea to try to ignore popular press articles about diet, which are often slanted to favor some marketing group. The nut study was funded in part by the California Walnut Commission.


Thursday, October 25, 2018

Glucose in Tears

About 20 years ago, shortly after I was diagnosed with type 2 diabetes, I read an article that described measuring blood glucose (BG) levels in tears. I thought that was wonderful, as it would avoid what popular press articles like to call "painful finger pricks" but which are actually not-very-painful but annoying tests one has to do multiple times a day if one wants good control.

So I mentioned the article to an endocrinologist who was in charge of a clinical study I was in. She laughed and said so many novel ways of measuring BG had been proposed, but none of them had ever made it to the market. "I'll be interested when it becomes commercially available," she said.

Well now, 20 years later, a company based in The Netherlands has proposed measuring BG levels in tears. This version involves putting a tiny sensor under the lower eyelid. The sensor measures BG levels continuously and broadcasts them to a smartphone.

The company has published the results of studies in six patients and says the device is accurate, with no adverse events reported. They are planning a study in 24 people with type 1 diabetes.

Well, it does sound nice, but I'll be interested when it becomes commercially available.

Friday, October 19, 2018

Beta Cell Rest

For many years, some people have been saying that if you can rest your beta cells by decreasing their workload, they can recover some function.

Richard Bernstein, the author of Dr Bernstein's Diabetes Solution, who promotes low-carbohydrate diets for people with diabetes, is one of them. He cites experiments with the Biostator, developed in the 1970s, a machine that kept blood glucose (BG) levels close to normal levels. After only 2 weeks on the machine, he said some people had normal BG levels for up to 2 years, despite eating a standard American diet. [I can't locate a reference for this study.]

The Biostator is large and bulky, and the patients had to be admitted to a research lab for the study, so it's not yet a practical solution, although so-called closed-loop insulin pumps are being developed. But it illustrates the concept. Keeping BG levels normal is good for your beta cells.

A similar effect is often seen in type 1 patients who have a "honeymoon period" shortly after they are started on insulin. However, that effect doesn't last.

There hasn't been much experimental evidence on this topic, although there is some, see here and here. So it was nice to see a recent study that supports the concept. Although, like so many studies, it was done in mice, the results are interesting.

The authors say that improving glucose levels with various diabetes drugs not only increased the insulin content of the beta cells, but restored normal biphasic insulin secretion.

Normally, beta cell secretion of insulin occurs in two phases. After eating carbohydrate, the first phase is very rapid, and it doesn't last long. But it keeps BG from going very high, in part by stopping the liver from releasing glucose. The second phase occurs later and persists until no more carbohydrate is coming into the intestine, and it is able to keep the BG down for a long time.

People with type 2 diabetes almost always lose the first-phase insulin response. This means the BG goes very high after a carbohydrate load, and because it's so high, if they're still able to secrete insulin, the beta cells secrete a lot of it. This is often so much that the person later goes low. In fact, going low about 4 hours after a carbohydrate-rich meal is one of the warning signs of future diabetes. I had this about 5 or 10 years before I was diagnosed with type 2.

So the fact that the first-phase insulin response was restored is promising. I also learned that my first-phase insulin response was restored to about 70% of normal when I was in a study of high-dose aspirin at Joslin. I assume I lost it again when the study was over, although I had no way of testing that.

These authors conclude, "Thus, this study provides evidence that alleviation of metabolic demand on the beta cell, rather than targeting the beta cell itself, could be effective to delay the progression of T2D."

And how can people alleviate the metabolic demand on the beta cell? By eating less carbohydrate, of course. In fact, the "normal" BG levels reported for the Biostator  are not as good as those reported by type 1 patients on the Type1Grit Facebook page. (If you're not on Facebook, you can see results here.) The Biostator was set for BG levels of 90, but they actually fluctuated a lot.

 Low-carb diets have been anathema among some diabetes organizations like the American Diabetes Association, but they are slowly gaining acceptance even by these groups.

Another way to reduce the load on the beta cell is to inject insulin. The standard treatment of type 2 used to be to tell people to lose weight and exercise and come back in three months. Now some say it's better to start right out on insulin. This will reduce the workload on your beta cells and let them recover somewhat at a time when you still probably have a lot of them. Here is an example of that. Then when they have recovered a bit, you can phase out the insulin.

Waiting for three months, especially if given a high-carb low-fat diet, will just burn out more of these precious cells. And most overweight patients have been trying unsuccessively to lose weight for decades, so telling them to lose weight isn't very helpful.

One problem is that some people don't like needles, and they see using insulin as a sign of failure. It's not. It's taking charge of your health. And if you use it from the get-go so your beta cells recover and you then stick to a sensible diet, you may be able to go off all drugs in the future.

Rest your beta cells, and your beta cells will thank  you.



Saturday, September 1, 2018

Sucralose revisited

Does sucralose (Splenda) have effects that were not reported when it was approved by the FDA in 1998? This research suggests that it does. A summary can be found here.

The developers originally claimed that most of the sucralose was not absorbed from the intestine but was secreted unchanged in the feces. And they said the small amount that was absorbed was secreted unchanged in the urine.

But this research shows that, at least in rats, some of the sucralose is metabolized to produce two new products that haven't been described before. They also show that some of the sucralose accumulates in fatty tissue.

The researcher say that the reason their findings differ from those used to gain FDA approval because they used more sensitive methods.

No one knows what the effect of having sucralose or its metabolites in fatty tissue is, so the researchers suggest that sucralose should be reexamined by the FDA. This is a long process, so in the meantime what should consumers do?

One commenter said that the amount of sucralose given to the rats is the equivalent of a 150-lb person drinking about 90 Diet Cokes in one day, suggesting that this research is irrelevant to real life. However accumulating a tiny amount in the fat tissue every day could build up over time in a person consuming a lot of sucralose.

Sucralose seems to be passed into breast milk, and because growing infants are more susceptible than adults to the effects of any toxins, it would be prudent to find alternative sweeteners during pregnancy and nursing.

Today, as I pointed out recently, we have a choice of many sweeteners. We really don't know the long-term effects of consuming a lot of any of them, even those extracted from the stevia plant. So one approach would be to give up sweet things altogether. Most people wouldn't want to do that.

Another approach would be to eat small amounts of different sweeteners, rather than choosing only one. And downing huge amounts of diet sodas is not a great idea regardless of how they are sweetened.

We should remember that this is only one study, done in rats, and it needs to be replicated before the results are certain. In the meantime, we should be aware of the possible detrimental results from yet-another sweetener.

Friday, August 31, 2018

Are low-carb diets dangerous?

The popular press is having a field day with this studywith headlines like "Is your low-carb diet killing you?"

Well, my exhaustive analysis is as follows:

HOGWASH!

If you want more details, Zoe Harcomb has done a thorough review.
 

Tuesday, August 28, 2018

Sugars


When I was diagnosed with type 2 diabetes in 1996, the number of artificial sweeteners was limited. There was saccharin, of course, which had been discovered in 1878 and offered for sale in the 1880s. But studies in rodents showed that it could cause bladder cancer when used in huge amounts, so some people were wary of it.

Cyclamate, aspartame, and sucralose became popular in the 1960s and 1970s. Then it was discovered that huge amounts of cyclamate produced bladder cancer in rodents, and in 1970 it was banned in the United States. It is still sold in Canada. Both aspartame and sucralose are still on the market in the United States.

Aspartame was controversial, with internet groups claiming all sorts of horrid side effects, although the FDA said it was safe. In 2002 a related sweetener, neotame, was approved.

Another sweetener, acesulfame K, had a slightly bitter taste and was primarily used mixed with other sweeteners.

Today there are a myriad of artificial sweeteners. Stevia, which comes from a South American plant, has been used there for more than 1500 years. One can use the whole leaves, and one summer summer I grew stevia and used some of the leaves, but some people complain of a licorice flavor. The whole or ground leaves have not been certified by the FDA as GRAS (generally recognized as safe) for food products, although they approved it as a supplement..

However, companies have also isolated the sweet compounds from the stevia leaf, mostly one called rebA, or rebaudioside A. These purified compounds have been FDA approved for use in food. RebA can have a bitter taste if one uses too much.

All of these sweeteners are vastly sweeter than table sugar, or sucrose. For example, saccharin is 200 times sweeter, and neotame is more than 7000 times sweeter than sucrose. This means one has to use tiny amount, difficult to measure. And for this reason many companies cut the sweetness of the compounds with substances like maltodextrin. Some even use glucose. When one is on a low-carb diet, the addition of these bulking agents is problematic.

Another problem with these compounds is that because you need so little of them, they won't reduce the freezing point of frozen desserts as sucrose does. So if you try to make ice cream with saccharin or stevia, it will become rock hard when you put it in the freezer. Fran McCullough in her excellent book The Low Carb Cookbook, published in 1997, has several pages devoted too making ice cream that won't turn into icebergs. None of the suggestions like using alcohol or gelatin worked for me,

But today we have more options, with granular sweeteners that are measured just like table sugar. A popular combination is erythritol combined with a sweeter compound.

Erythritol is a sugar alcohol, but unlike sorbitol and similar sugar alcohols, it doesn't cause gas. This is because it is absorbed into the bloodstream and excreted in the urine rather than going down the intestinal tract to be fermented in the colon to produce gas. It's not quite as sweet as sucrose, so most products combine it with one of the supersweet substance mentioned above.

One popular granular sweetener is Truvia, which consists of erythritol and stevia. Another one combines erythritol and lo han guo, which comes from a southeast Asian plant. Like RebA, the extract has been clasified GRAS. A third, Swerve, combines erythritol and "oligosaccharides." They all seem to contain "natural flavorings," without saying what they are.

All three of these products are now available at my local supermarket.

Two new granular sugars have also come on the market. These are allulose and tagatose. Both are isomers of fructose. An isomer is a compound with the same chemical formula but with a slightly different arrangement of atoms so the enzymes that process them may not recognize them.

Allulose is now available at my supermarket, but you can also get it and tagatose online. These product are not cheap. A pound of sucrose costs about 50 cents. A pound of allulose is about $12.

Despite the price, I decided to try the allulose and tagatose. First I tested the effect on BG, using tiny amounts (1 teaspoon) so I wouldn't spike too high with the control (sucrose). Just 1 teaspoon of sucrose made me go up 20 points on an empty stomach first thing in the morning, and I was back to 80 in an hour. One teaspoon of tagatose made me go up 6 points, as did allulose. As my BG usually goes up after I get up even if I don't eat, it's not clear if this is meter variation, effect of getting up, or the allulose/tagatose, but it doesn't look as if these sugars have a big effect. I don't want to test larger amounts.

I didn't test Truvia or Swerve.

Then I made some ice cream. Eureka! The ice cream was delicious and didn't get rock hard in the freezer. Then I made some crustless cheesecake. Same thing. At last, despite the price, we can occasionally have a traditional dessert with very little effect on blood glucose levels.

Today liquid sweeteners are also more easily available. I didn't use to buy sucralose at the grocery store because of the carby bulking agents it contained. A liquid version was available online, but not at my grocery store. Now the local grocery store carries both liquid sucralose (Splenda Zero) and a stevia version (also Splenda Zero but in a green bottle). Sweet Leaf has offered liquid stevia for some time. Of course the liquids contain preservatives, so if you're sensitive to those, this wouldn't be an answer.

Who knows what new products will emerge in the future or what horrendous side effects will be attributed to the existing sweeteners. Ideally, it would be good to not eat anything sweet so one would lose the taste for sugars. But this isn't an ideal world, and I do like whole-milk yogurt with some flavoring and some sweetener. At least we now have more choice.