For Colorectal Cancer It's the Blood Sugar NOT The Insulin Level That Counts

A recently published study based on data from the Womans Health Initiative (WHI) sheds light on a question many of us have wondered about: Is the higher incidence of cancer among people with Type 2 caused by higher insulin levels (or, perhaps injected insulin) or something else?

The study was conducted by a team at The Albert Einstein College of Medicine, which some of you may remember is where Dr. Bernstein earned his M.D.. It has through the years done several low carb studies, too.

The study is summarized here:

Science Daily: High Blood Sugar Levels in Older Women Linked to Colorectal Cancer

The actual abstract is found here:


A longitudinal study of serum insulin and glucose levels in relation to colorectal cancer risk among postmenopausal women. G C Kabat et al. British Journal of Cancer , (29 November 2011) | doi:10.1038/bjc.2011.512

From the abstract we learn that in a group of 4902 middle aged women who were tracked for 12 years, about 1.6 percent developed colorectal cancer. They had had their fasting blood sugar and fasting insulin measured at the beginning of the study and occasionally through the study. This study found that women whose fasting blood sugar was over 99.5 mg/dl (5.53 mmol/L) at the beginning of the study had a greater risk of developing colorectal cancer than those with blood sugars under 89.5 mg/dl (4.98 mmol/L). The relationship held true for subsequent blood tests too.

However--and this is what is interesting about this study--there was no relationship between these women's fasting insulin levels or the calculated HOMA values (which are believed to measure insulin resistance) and their risk of getting this cancer.

So this data would suggest that it is the high blood sugars, not the high insulin which promotes the cancer.

Before you panic because your fasting blood sugar is over 99.5 mg/dl (as is the case with many of us thanks to dawn phenomenon) remind yourself of this: from what we can see in other contexts, it isn't actually mildly elevated fasting blood sugars that damage our bodies. We see the correlation between fasting sugars and complications in studies because in people eating high carbohydrate diets, mildly elevated fasting blood sugars almost always go hand in hand with significantly elevated post meal sugars. Especially in women, who may be diabetic by glucose tolerance test for up to a decade before they would be diagnosed using a fasting glucose test. (You can see the data backing this up HERE.)

So a woman with a fasting sugar of 105 mg/dl, for example, when she eats her morning bagel with jelly, along with a sweetened latte, may easily reach a blood sugar that approaches 200 mg/dl even if it resolves fairly quickly due to a near-healthy second phase insulin release. But if diabetic you should wake up with a blood sugar of 105 mg/dl and eat an egg and bacon for your breakfast with no carbs, you may easily end up with a blood sugar of 95 an hour later, which suggests you would have a similar health outcome to a completely non-diabetic woman with a fasting blood sugar of 89 mg/dl who ends up at 95 mg/dl an hour after eating her breakfast.

It's also worth noting that the statistical measure the study calculated was "risk" not incidence--and that risk is a statistical artifact that magnifies numbers to provide a more dramatic impact. The actual increase in incididence due to elevated blood sugar was likely around 5 cases per thousand or .5%.

But on the positive side, the fact that even after using magifying statistical techniques like "risk" the researchers couldn't find the expected connection between fasting insulin levels, HOMA, and cancer gives us one more, intriguing, piece of data to answer the quesion, "Do people with diabetes get cancer because of high insulin levels (injected or natural) or because of high blood sugars?" Here at least, it looks like the answer is, as is the case with all the other diabetic complications, "It's the blood sugars, stupid!"

This is very good news because our insulin levels are very hard to control and insulin resistance may be genetic and not something we can lower. Even many devout low carbers with Type 2 continue to be insulin resistant no matter what they weigh (based on how much insulin they have to inject to lower their blood sugars.) But insulin resistant or not, we can control our blood sugars--often most effectively with insulin--and if the conclusion of this study is reinforced by findings in other studies, we may be able to relax about the potential impact on cancer of our injecting insulin to control those blood sugars.

One last note: If you have had years of exposure to higher than normal blood sugars, you might be interested in knowing that Metformin has been shown to suppress the growth of existing early colorectal growths in people without diabetes. Read about that HERE.

Though researchers often state that metformin inhibits cancer due to its effect on lowering insulin, this is just a guess. The belief that it is high insulin levels that cause a greater incidence of cancer among people with diabetes is far from proven and that theory is exactly the belief this study debunks.

In fact, there is evidence emerging that metformin's anti-cancer properties are independent of its effect on insulin and have to do with its ability to suppress TORC1, a cell growth factor. (For example, see THIS STUDY.)

NOTE: Since posting this I have reviewed the full text of the study and see nothing to change the conclusions discussed here. It looks very well conducted, involved people from various well-respected public health departments in universities and medical schools, and gives no hint of corporate meddling.

Lower Your Salt Intake? No Way!

For years, I have been lecturing and writing about the nonsensical argument the conventional powers-that-be claim that lowering salt in the diet will reduce your risk of cardiovascular disease. The data has never been shown that lowering salt intake to ridiculously low levels of 1,500mg/day will reduce your risk of heart disease. In fact, many studies show that lowering your salt intake to these levels will cause more heart attacks and mortality. Furthermore, low salt diets will lead to elevated insulin levels. Finally, low salt diets do not significantly lower blood pressure. More information about this can be found in my book, Salt Your Way To Health.

A recent study in JAMA (November 23/30, 2011-Vol. 306, No. 20) looked at the association between sodium excretion and cardiovascular events in patients with established cardiovascular events or diabetes. The authors studied nearly 29,000 adults and found cardiovascular death was increased among those with the lowest and the highest sodium excretion.

Sodium excretion is tied to how much sodium (or salt) is ingested. The more salt that is ingested the more sodium that is excreted in the urine. The reverse is true also; the less sodium ingested, the less sodium excreted. A crude estimate can be made that the amount of sodium ingested is equal to the amount of sodium excreted (as long as someone is not sodium deficient).

We have been told we are ingesting too much salt. The Institute of Medicine (IOM) states, “Americans consume unhealthy amounts of sodium in their food, far exceeding public health recommendations. Consuming too much sodium is a concern for all individuals, as it increases the risk for high blood pressure, a serious health condition that is avoidable and can lead to a variety of diseases. Analysts estimate that population-wide reductions in sodium could prevent more than 100,000 deaths annually.”

The IOM claims that Americans ingest more than 3,400mg of sodium per day which is about 1.5 tsp of salt per day. They claim that we should ingest no more than 1 tsp/day or 2,300mg/day. For those with hypertension, experts recommend less—about 1,500mg/day of sodium.

The recent JAMA (November 23/30, 2011) study found the lowest rate of cardiovascular disease, cardiovascular death, heart attack, stroke, congestive heart failure and non- cardiovascular death occurred when the sodium intake was 4-6,000mg/day. Lower and higher intakes were found to increase a compositd of all the outcomes studied (in a near linear fashion). You read that right; lower and higher salt intakes were all associated with worse outcomes.

In my book, I wrote about the dangers of a low-salt diet. Salt is a vitally important nutrient for the human body. We cannot live without adequate amounts of salt. Don’t believe the low-salt nonsense. However, you should educate yourself about which type of salt is a healthy salt.
The healthiest salt is unrefined salt with its full complement of minerals. Celtic Brand Sea Salt, Redmond’s Real Salt and Himalayan salt are all good brands of unrefined salt.

There are medical conditions where the body does not tolerate large amounts of salt. This can occur with those suffering from kidney failure or congestive heart failure. If you have these illnesses, please discuss your salt intake with your doctor.

Avoid Sucralose

Sucralose is an artificial sweetener found in many low-calorie, sugar-free products. Unfortunately, it has become a staple in our food supply. It is 600x as sweet as table sugar and over three times sweeter than aspartame (i.e., NutraSweet). I would venture a guess that a product that is 600x sweeter than table sugar is not be a healthy item for the human body.

Sucralose contains three chlorine atoms in its structure. Heating sucralose can create a chemical reaction with the chlorine atoms where they are transformed into a toxic product.

A recent study (Env. Sci. Techn. 2011; Aug 31.PMID:21879743) reported that water treatment plants were unable to fully remove sucralose from the finished drinking water. The researchers studied 19 U.S. water treatment plants serving more than 28 million people. The scientists reported that sucralose was found in the finished drinking water in 13 of 19 sites. What this means is that the water treatment plants were unable to remove sucralose from the end product coming out of your tap.

Sucralose is not a healthy product. We eat more artificial sweeteners than any other people on the face of the planet. We also have more obesity than any other people on the face of the planet. I have found it nearly impossible for my obese patients to lose weight if they ingest artificial sweeteners. Besides the weight issues there is a whole host of adverse effects associated with artificial sweeteners including neurological and hormonal problems.

The research behind sucralose has been largely funded by the industry that manufactures sucralose. Industry-funded research has been shown to be biased. I do not believe sucralose is a healthy product. It is best to avoid any food item containing sucralose.

Another Book?

Now that I've discharged my obligations under my contract with the publisher of my novels, I'm considering what to do next. And that is leading me to ask what I could do that would be of use to the people who visit http://Bloodsugar101.com and this blog.

Publishing the book version of the site has taught me that most people still find books a better way to study a complex topic, even when the information in the book is also available on a web site.

This has been a pleasant surprise, as has been the steady stream of fan mail that the book generates. There's no question that people who read the book learn far more than people who visit the site, if for no other reason than that most people who visit the site only read a couple pages before leaving.

So that raises the question: Should I write another book? And if I do, what should be its subject?

I have some ideas of my own, but before I plunge in I'd love to hear some feedback from you about what topics you would like to learn more about. I'd also like to know, iIf you read my book, Blood Sugar 101, if you thought there was something important that was left out.

Keep in mind, of course, that there are many topics I'd love to be able to write about that are too poorly researched to justify a book. For example, I have spent quite a lot of time looking into the physiology of weight loss, but the more research I read, the less conviction I have that any of it can be trusted. The quality is just abysmal and unlike the publications about diabetes, my many hours of study did not turn up any overlooked gems.

On the other hand, very little has come up that is new since I wrote Blood Sugar 101. In fact, it is rather depressing just how little that would be of any use to someone trying to preserve their health.

But though I might feel that way, life has taught me that one problem with making yourself into an "expert" in some topic area is that the things that bore me after a decade of daily attention to the topic may be exciting to people who haven't soaked their head in this stuff for years.

So I welcome your feedback. What kind of book--if any--do you think would be most useful to a reader who has already read Blood Sugar 101? Click on the comment link below and share your thoughts with me. The only thing I will ask is that you keep your comments on the topic I've sketched out here.

If you want to ask questions or debate other diabetes-related issues, there's a nice community growing on the Blood Sugar 101 Facebook page, where you are welcome to post your thoughts on topics other than the subject of this post.

Vitamin Study Flawed

A study released a few weeks ago stated, “…dietary vitamin and mineral supplements may be associated with increased total mortality risk.” (Archives in Int. Med. Vol. 171. No. 18. Oct. 10, 2011). This article made the rounds in the media with headlines proclaiming, “Dietary Supplements Linked to Higher Mortality.” (Medicalnews.com).

Are supplements dangerous? If you believe the media, the answer is “yes.” Let me sift through the study for you so that you can make an educated decision.

The authors of the study looked at 38,772 older women in the Iowa Women’s Health Study. Their mean age at baseline, in 1986, was 62 years. The study participants self-reported their use of supplements three times over an 18 year period. The authors split the women into two groups; those that took dietary supplements and those that did not.

Let’s go through the results. However, this is where things get tricky. In Table 2, the scientists reported that women who took dietary supplements such as vitamin B complex, Vitamins C, D, and E and calcium had a slightly decreased death rate as compared to nonusers of supplements. When the researchers adjusted the data for various factors such as educational level, place of residence, body mass index and others, the benefits of the supplements disappeared (except for calcium which still showed a benefit).

In Table 3, comparing supplement users to non-users, the study found the risk of cancer mortality decreased in the vast majority of supplement users who used such items as a multivitamin, vitamins A, C, D, E an calcium. However, copper supplementation showed a higher cancer mortality rate. Most other nutrients studied showed a neutral effect. When the authors ‘adjusted’ the data for place of residence, diabetes, high blood pressure and other items, most of the beneficial effects disappeared.

Table 4 looked at the risk of mortality from the use of supplements across the three time periods where the subjects turned in their questionnaires. The only supplements that showed an increased mortality rate were folic acid and iron.

This was a very difficult study to read. The authors seem to have ‘adjusted’ the data to make supplement use appear to be problematic. However, even with their ‘adjustments’ I did not feel the study indicated that supplement use was detrimental. In fact, this paper found many different supplements (Vitamins C, D, E and calcium) actually decreased mortality rate. When the researchers began ‘adjusting’ the data, the positive numbers all began to look worse. However, the authors emphasized the negative results in the abstract and did not mention the positive results (except for calcium). This negative interpretation is what was picked up by the media.

It is interesting to look at Table 4 where multivitamin users had a decreased mortality rate as compared to nonusers. I wonder why the media did not comment on this finding.

This study can be faulted for many reasons. It looked at three surveys from 38,000 women over an 18-year time period. Think about that; these women were only surveyed three times in 18 years. No laboratory tests were ordered. Which supplements did the women take? Did they take them continually over the 18 years? Were the supplements doctor recommended? Did anyone check blood levels of these nutrients? No one knows. Data from surveys are notoriously problematic.

The negative findings of this study occurred when the authors ‘adjusted’ the data. Even most of the negative findings were not significant. There was only a small increase in mortality—about 1% from those taking a multivitamin. This is a very small effect and could be due to chance.

I say, “Forgetaboutit.” This study is a bunch of nonsense. If the authors had emphasized the positive aspects of nutritional supplementation found in this study it would never have been published in this journal.

There are hundreds of articles on nutritional supplements every month. Some are positive, some are negative. My experience has shown the judicious use of supplements has many positive benefits.