Cancer and Diabetes: Any Connection?

ResearchBlogging.orgType 2 diabetes is associated with higher incidence of several cancers: liver, pancreas, uterus, colo-rectal, breast, and bladder.  On a brighter note, diabetics have lower risk of prostate cancer.

That’s about all we know for sure, according to a report from an expert panel convened by the American Diabetes Association and the American Cancer Society and published recently in CA: A Cancer Journal for Clinicians.

The report is focused on type 2 diabetes simply because 95% of all worldwide cases of diabetes are type 2; we have much more data.  [Type 1 diabetes, you may recall, has onset much earlier  in life and is fatal if not treated with insulin injections.  The type 1 pancreas produces no insulin.]

This report is a good summary of all we know about the cancer/diabetes connection in 2010.  What we don’t know far outweighs what we do know.

Does optimal treatment of diabetes reduce cancer risk?  Do particular diabetic medications raise or lower the risk of cancer?  If an overweight diabetic loses excess weight, does the risk of cancer diminish?  Sorry, we don’t know.

In men, 25% of all invasive cancers in the U.S. will be prostate cancer.  In women, breast cancer is the leader, comprising 26% of all cancers.  [Common skin cancers are rarely invasive or fatal and are not included in these statistics.  Melanoma, on the other hand, is invasive.]

The lifetime probability of an individual developing invasive cancer in the U.S. is about 4 in 10 (40%).  A little higher in men (45%), a little lower in women (38%).  The American Cancer Society projected 565,650 deaths from cancer in 2008.  If we look at deaths of people under 85, cancer kills more people than heart disease.

The traditional Mediterranean diet is associated with lower risk of prostate, breast, colon, and uterus cancer.  Three of these, you’ll note, are seen at higher rates in diabetics.

Lack of regular exercise is associated with higher cancer rates. 

If I were a type 2 diabetic wanting to reduce my risk of cancer, I’d be sure to exercise regularly, keep my body mass index under 30 (if not lower), refrain from smoking, consider a Mediterranean-style diet, and ask my doctor to monitor for onset of cancer.

Steve Parker, M.D.

Reference: Giovannucci, E., Harlan, D., Archer, M., Bergenstal, R., Gapstur, S., Habel, L., Pollak, M., Regensteiner, J., & Yee, D. (2010). Diabetes and Cancer: A Consensus Report CA: A Cancer Journal for Clinicians DOI: 10.3322/caac.20078

2 Comments

Filed under cancer, Mediterranean Diet

“Health on the Net Foundation” Survey

The Health on the Net Foundation is asking people to tell them how they use the Internet for health/disease information. If you’re willing to participate in their 10-15 minute survey, click on the the following logo:

Survey 2010

You know there’s much misleading information on the Internet regarding health, and most everything else. I appreciate the Health on the Net Foundation for attempting to certify reliable health information resources, such as this website.

Steve Parker, M.D.

Comments Off on “Health on the Net Foundation” Survey

Filed under Uncategorized

MSDP Protects Against MetSyn (NCEP ATP-III Criteria) in FHSOC

ResearchBlogging.orgTranslation:  A Mediterranean-style dietary pattern protected against onset of metabolic syndrome (as defined by National Cholesterol Education Program Adult Treatment Panel III) in the Framingham Heart Study Offspring Cohort.

Made you look! 

Don’t you just love acronyms?  Lately it seems you gotta have a clever acronym for your scientific study or it won’t get published or remembered. 

Metabolic syndrome is a constellation of clinical traits that are associated with increased risk for developing cardiovascular disease (two-fold increased risk) and type 2 diabetes (six-fold increased risk).  It’squite common—about 47 million in the U.S. have it.  Metabolic syndrome features include insulin resistance, large waist circumference, low HDL cholesterol, elevated fasting blood sugar, high triglycerides, and elevated blood pressure. 

For optimal health, you want to avoid metabolic syndrome.

Boston-based researchers reported in American Journal of Clinical Nutrition last December that followers of the the Mediterranean diet had less risk of developing metabolic syndrome; not by much, but it was statistically significant.  The study population was the Framingham (Massachusetts) Heart Study Offspring Cohort.

Several thousand men and women were studied via food frequency questionnaires, lab work, and physical exams.  Adherence to the Mediterranean diet was measured via a calculated score ranging from zero to 100.  No diabetics were enrolled.  Average age was 54.  Follow-up time averaged seven years.

They found that those adhering closely to the Mediterranean diet had fewer metabolic syndrome traits at baseline: less insulin resistance, lower waist size,  lower fasting blood sugar, lower triglycerides, and higher HDL cholesterol levels.

Not only that, the Mediterranean dieters developed less metabolic syndrome over time.  Over seven years, 38% of the folks with least compliance to the Mediterranean diet developed metabolic syndrome.  Of those with highest adherence, only 30% developed it.

This is the first study to show a prospective association between the Mediterranean diet and improved insulin resistance.  Avoiding insulin resistance is a good thing, and may help explain the Spanish study that found lower incidence of type 2 diabetes in Mediterranean diet followers.

Why didn’t the investigators report on the incidence of diabetes that developed over the course of the study?  Surely some of these folks developed diabetes.  Are they saving that for another report?  “Publish or perish,” you know.

You can start to see why the Mediterranean diet has a reputation as one of the healthiest around. 

It would be interesting to score these study participants with a very low-carb diet score (VLCDS—yeah, baby!).  Such diets are associated with lower blood pressure, lower blood sugars, lower triglycerides, and higher HDL cholesterol.  Like Mediterranean diet followers, I bet low-carbers would demonstrate lower prevalence of metabolic syndrome at baseline and lower incidence over time. 

Reference: Rumawas, M., Meigs, J., Dwyer, J., McKeown, N., & Jacques, P. (2009). Mediterranean-style dietary pattern, reduced risk of metabolic syndrome traits, and incidence in the Framingham Offspring Cohort American Journal of Clinical Nutrition, 90 (6), 1608-1614 DOI: 10.3945/ajcn.2009.27908

Comments Off on MSDP Protects Against MetSyn (NCEP ATP-III Criteria) in FHSOC

Filed under Causes of Diabetes, coronary heart disease, Health Benefits, Mediterranean Diet

Seminal Paper: Carbohydrate Restriction for Type 2 Diabetes and Metabolic Syndrome

Carbohydrate-restricted eating is slowly gaining mainstream acceptance as treatment for type 2 diabetes and metabolic syndrome.  I thought it would be useful to present one of the watershed reports that summarize the potential benefits.  The article is from 2008.  Among the co-authors are some of the brightest names in this field: Richard K. Bernstein, Annika Dahlqvist, Richard Feinman, Eugene J. Fine, Robert Lustig, Uffe Ravnskov, Jeff Volek, Eric Westman, and Mary C. Vernon.

ResearchBlogging.orgThese are not wild-eyed, bomb-throwing radicals.  They are on faculty at some of the best institutes of higher learning.  They note that while many of the national diabetes organizations downplay the benefits of carb restriction, we have enough evidence now to warrant careful reconsideration.

Here are some of their major points, all backed up by references (68) from the scientific literature:

  1. Glucose (blood sugar) is a “major control element,” whether directly or indirectly through insulin, in glycogen metabolism, production of new glucose molecules, and in formation and breakdown of fat.
  2. The potential adverse effects of dietary fat are typically seen with diets high in carbohydrate.
  3.  Carb restriction improves control of blood sugars, a major target of diet therapy.  Many of the supportive studies were done with overweight or obese people (85% of type 2 diabetics are overweight).  Very low-carb diets are often so effective that diabetic medications have to be reduced at the outset of the diet. 
  4. For weight loss, carb-restricted diets work at least as well as low-fat diets.  They are usually superior. 
  5. Carb-restricted diets usually replace carbs with fat, resulting in improve markers for cardiovascular disease (lower serum triglycerides and higher HDL cholesterol levels). Replacing dietary fat with carbohydrate—the goal of many expert nutrition panels over the last 40 years—tends to increase the amount of artery-damaging “small, dense LDL cholesterol” in most of the population. 
  6. Carbohydrate restriction improves all five components of the metabolic syndrome: obesity, low HDL cholesterol, high triglycerides, high blood pressure, elevated blood sugar.
  7. Beneficial effects of carbohydrate restriction seem to occur even without weight loss
  8. Still worried about excessive fat consumption?  Many low-carb dieters demonstrate a significant increase in the percentage of total calories from fat, but without an increase in the absolute amount of fat eaten.  That’s because they simply reduced their total calories by reducing carb consumption. 

This post was chosen as an Editor's Selection for ResearchBlogging.orgThe authors in 2008 called for a widespread reappraisal of carbohydrate restriction for type 2 diabetes and metabolic syndrome.  It’s been happening, and many patients are reaping the benefits.

Steve Parker, M.D.

Reference: Accurso A, Bernstein RK, Dahlqvist A, Draznin B, Feinman RD, Fine EJ, Gleed A, Jacobs DB, Larson G, Lustig RH, Manninen AH, McFarlane SI, Morrison K, Nielsen JV, Ravnskov U, Roth KS, Silvestre R, Sowers JR, Sundberg R, Volek JS, Westman EC, Wood RJ, Wortman J, & Vernon MC (2008). Dietary carbohydrate restriction in type 2 diabetes mellitus and metabolic syndrome: time for a critical appraisal. Nutrition & metabolism, 5 PMID: 18397522

13 Comments

Filed under Carbohydrate, Fat in Diet

Not Much Available To Prevent Age-Related Mental Decline?

You might find interesting my recent review of an article commissioned by the National Institutes of Health in the U.S.  It’s at one of my other blogs, Advanced Mediterranean Diet.  The NIH panel concluded there’s not much we can do.  But are they right? 

Steve Parker, M.D.

Comments Off on Not Much Available To Prevent Age-Related Mental Decline?

Filed under Health Benefits, Mediterranean Diet

Difficulty Controlling Blood Sugar? Consider Diabetic Gastroparesis

One disorder I see fairly frequently in the hospital is diabetic gastroparesis.  It’s a condition in which the stomach doesn’t empty its contents as quickly into the small intestine (duodenum) as it should.  The nerves that tell the stomach muscles to contract aren’t working properly.  It’s a type of neuropathy.

With gastroparesis, food absorption—including carbohydrates—is slower than usual.  Not only that, if you take pills to lower your sugar, their absorption into the blood stream will also be delayed.

As a result, blood sugars in affected type 1 and type 2 diabetics are difficult to control.  The expected rise in blood sugar after a carb-containing meal is difficult to predict—a major problem if you just injected a rapid-acting insulin!  Oral medication effects are also erratic. 

The frequency of diabetic gastroparesis is unclear.  No doubt it’s more common in people who’ve had diabetes for years, and in type 1 diabetics.

How Is Gastroparesis Diagnosed?

Other than erratic, unexplained poor blood sugar control, are there any other clues to diagnosis?  Symptoms suggestive of gastroparesis include early satiety, abdominal bloating, after-meal fullness, nausea, and vomiting.

The most common diagnostic test for gastroparesis is done at a radiology facility.  The patient eats a meal containing a radioactive chemical called (99m)technetium.  A special camera takes a picture of the stomach after two and four hours to see if the meal has moved on into the small intestine in a timely fashion.

What’s the Treatment for Gastroparesis?

Best to work with your personal physician on that.  It’s not real straightforward, but there is treatment involving meal composition and timing, timing of medications, and drugs to speed up stomach emptying.

Steve Parker, M.D.

Comments Off on Difficulty Controlling Blood Sugar? Consider Diabetic Gastroparesis

Filed under Diabetes Complications

Nutritional Analysis of William Banting’s 1865 Diet

I recently blogged about London’s low-carb diet fad of 1865, originated by William Banting.  He’s often credited with popularizing the first “modern” low-carb diet.  Gary Taubes wrote about it in his Good Calories, Bad Calories book.  A participant at Active Low-Carber Forums took the time to analyze Banting’s diet.

At 100 g of carbs, Banting’s diet had about a third as much as today’s usual U.S. diet.

From elisaannh at Active Low-Carber Forums:

I entered Banting’s diet into my nutritional software and it came up to 1925 calories, 101gr carbs, 8gr fiber and 128gr protein, 34gr fat. I used 5.5 oz when he said 5-6 oz, and did add 3 oz brandy for his “tumbler” of grog which he said “if required”. The total oz for his wine and brandy is quite high, at 20! YUM!

I think the diet is a definite improvement over the diet in England at that time period. However, cooked fruit and bread are not necessary, and he doesn’t mention added fat, which I feel his diet is too low in. Perhaps the meat was well marbled, but I did use fish in the calc for his supper at 2 pm (beef and chicken were the other two meats I used to balance it out in the other meals). Prunes were used for the “cooked fruit from a pudding” and apples for his tea time fruit. Green beans were used for his vegetable.

[Reprinted with elisaannh’s permission.]

For screen shots of the calculations: http://picasaweb.google.com/elisaan…feat=directlink

Elisaannh also has a diet blog at http://thelittlebowl.blogspot.com.  Many thanks to Elisaannh, who is a long-haul trucker.

Steve Parker, M.D.

Comments Off on Nutritional Analysis of William Banting’s 1865 Diet

Filed under Weight Loss

The Holy Grail: Prevention of Weight Regain

Losing excess weight is easier than keeping it off.

Neither is exactly a walk in the park.

Prevention of weight regain is the most problematic area in the field of weight management.  You may have heard that “diets don’t work,” but they do.  Many different weight loss programs work short-term, if “work” is defined as loss of five, 10, or more pounds while you adhere to the program for several weeks or months.  The problem is that the lost pounds usually return.

Why?  You get bored with the diet, or your willpower flags, or the diet simply stops working, or the transition from weight loss to maintenance is unclear, or you just feel too bad to go on, or you lose your commitment, or you take a job as a taste tester for Baskin-Robbins Ice Cream, or whatever. 

Most diets ultimately fail in the long run because people go back to their old habits. 

Read on for the secret to prevention of weight regain.  They apply to a majority of weight-loss methods, although many programs ignore this problem because the cure is a hard pill to swallow. 

Moving Ahead

For purposes of further discussion, I will assume that you have already lost excess weight down to your goal and now we must focus on staying thereabouts from here on out.  Finally down to your goal!  A grand accomplishment!  You’ve got a new wardrobe, or the old clothes fit again.  You have more energy and feel younger.  Maybe you cured or improved some health problems.  Perhaps you’re getting more attention from the opposite sex (ooh la la!). 

Our species’ scientific name is Homo sapiens.  It is from the Latin sapere, which means “to be wise.”  Wisdom is the ability to make correct judgments and decisions.  Undoubtedly, your success at weight loss required correct judgments and decisions.  You are not done yet.  You will need sustained wisdom to avoid weight regain.

Be wise about this especially: you can never again eat all you want, whenever you want, over sustained periods of time.  

Now that you have reached your goal weight, you must restrain yourself on a daily basis.  Think about it.  You became overweight because you didn’t watch what you ate and didn’t exercise enough.  You can’t go back to your old ways.  Reject this advice, and you have a 100 percent chance of regaining your lost weight. 

Have you heard of the Energy Balance Equation?

Calorie Intake minus Calories Burned

         =  Change in Body Fat

You have been able to lose fat weight because you ate less energy (calories) than your body required for metabolism and physical activity.  Your body remedied the energy deficit by converting fat into energy.  A pound of fat contains 3,500 calories of energy.  If you lost a pound per week, your body on average converted 500 calories of fat daily into energy (7 days x 500 calories = 3,500 calories = 1 pound of fat). 

Now that you are at your goal weight and want to stay there, you need to add 500 calories per day back into the equation.  Add the calories by eating more food, exercising less, or a combination of the two. But if you add back more than 500, you will regain weight.

The true measure of a successful weight management program is not simply how much weight is lost, but whether the lost weight stays lost over the long run.  What distinguishes weight losers who keep the weight off from those who gain it back?  Two factors, mostly:

          1.  Restrained eating
          2.  Regular physical activity
.

“Successful losers” apply self-restraint on an almost daily basis, avoiding food that they know will lead to weight regain.  They limit how much they eat.  They consciously choose not to return to their old eating habits, despite urges to the contrary.  The other glaring difference is that, compared to regainers, the successful losers remain physically active.  They exercised while losing weight, and continue to exercise in the maintenance phase of their program.  This is true in at least eight out of 10 cases.  It’s clear that regular exercise is not always needed, but it dramatically increases your chances of long-term success. 

In a nutshell, my maintenance phase prescription for you is: Keep exercising, and eat a little more.  Keep exercising, and eat a little more.

Go out of your way to be physically active for 30 to 45 minutes on at least four days per week, if not all days.  Walking is fine.  The more you exercise, the more you can eat without getting fat again. 

At the end of your weight-loss phase and the beginning of the maintenance phase, it is surprisingly easy to start overeating.  Forewarned is forearmed.  Avoid this landmine any way you can.  It helps to continue monitoring food consumption and exercise on your food diary while eating an additional 200–500 calories per day.  Continue weighing daily.  Keep exercising.  After a month or two of this regimen, you’ll have an intuitive sense of what and how much you should be eating without regaining weight.  Then stop the daily log routine. 

Another option for transition to the maintenance phase: if you have been exercising regularly but loathe it, you could stop exercising and stay on your current calorie level diet.  In other words, don’t start eating more.  See what happens with your weight.  Perhaps you could later eat an extra 100 to 200 daily calories without gaining weight.  Continue recording your daily intake and weight for a couple months.  

Weigh yourself daily during the first two months of your maintenance-of-weight-loss phase. After that, weigh weekly.  Daily weights will remind you how hard you worked to achieve your goal.  When you look now at a brownie, candy bar, or piece of pie, you ask yourself, “Do I really want to walk an extra hour or jog an extra three miles today to burn off those calories?” If so, enjoy. Otherwise, forego the unneeded calories. 

Be aware that you might regain five or 10 pounds of fat now and then.  You probably will.  It’s not the end of the world.  It’s human nature.  You’re not a failure; you’re human.  

But draw the line and get back on your old weight-loss program for one or two months.  Analyze and learn from the episode.  Why did it happen?  Slipping back into your old ways? Slacking off on exercise?  Too many special occasion feasts?  Allowing junk food back into the house?  Learn which food item is your nemesis—the food that consistently torpedoes your resolve to eat right.  For example, I have two—candy, and sweet baked goods such as cookies and muffins.  If I just look at them I add a pound.  Remember an old ad campaign for a potato chip: “Betcha can’t eat just one!”?  Well, I can’t eat just one cookie.  So I don’t get started.  I might eat one if it’s the last one available.  Or I satisfy my sweet craving with fresh fruit or a diet soda.  Just as a recovering alcoholic can’t drink any alcohol, perhaps you should totally abstain from…?  You know your own personal gastronomic Achilles heel.  Or heels.  Experiment with various strategies for vanquishing your nemesis. 

It’s OK to overindulge in food infrequently (10–12 times per year), on special occasions such as birthdays, wedding anniversaries, holidays.  But you must counteract the extra calories by cutting down intake or by exercising more, either before or after the feast.  No big deal.

Click to read additional ideas on prevention of weight regain.

Steve Parker, M.D.

Comments Off on The Holy Grail: Prevention of Weight Regain

Filed under Weight Loss, Weight Regain

Does Lipid Overload Cause Diabetes?

An up-and-coming theory to explain type 2 diabetes suggests that abnormal lipid metabolism, not glucose/sugar metabolism, is the primary metabolic defect.  Roger H. Unger, M.D., wrote about this in the March 12, 2008, issue of the Journal of the American Medical Association.

Early in the writing of this blog entry, I realized it is much too technical for most of my readers.  If you are not interested in physiology, you can quit reading now.  It’s OK  . . . really.  This may be the most boring blog post of mine you have ever read.  I’m writing this to solidify my own understanding of a new theory.

I assure you my prose in The Advanced Mediterranean Diet weight-loss book is not nearly this technical.

Still with me?  [Get out now while you’re still awake!] 

Definitions and Physiology

Diabetes is defined by high blood glucose (sugar) levels. 

ResearchBlogging.orgThe lipid family includes triglycerides (fats and oils), sterols (e.g., cholesterol), and phospholipids (e.g., lecithin, a major cell membrane component).  Fats are almost entirely composed of trigylcerides.  When fats are broken down, fatty acids are produced.  On the other hand, fatty acids can be joined together, along with glycerol, to form triglycerides. 

Glycogen is a storage form of glucose in liver and muscle tissue.  In olden days, some called it “animal starch.” 

Insulin is a protein hormone produced by pancreatic beta cellsInsulin has multiple actions, not just blood sugar lowering:  

  1. lowers blood glucose levels by driving glucose into cells
  2. inhibits breakdown of glycogen into glucose
  3. inhibits formation of new glucose molecules by the body
  4. stimulates glycogen formation
  5. promotes storage of triglycerides in fat cells (i.e., lipogenesis, fat accumulation)
  6. promotes formation of fatty acids (triglyceride building blocks) by the liver
  7. inhibits breakdown of stored triglycerides
  8. supports protein synthesis 

Fatty acids in muscle tissue block the uptake of glucose from the bloodstream by muscle cells.  Fatty acids in liver tissue impair the ability of insulin to suppress breakdown of glycogen into glucose, and impairs the ability of insulin to suppress production of new glucose molecules.  In other words, an “excessive fatty acid” environment in liver and muscle tissue promotes elevated glucose levels.

Got that?  [This is very difficult material.]  Now on to . . . 

The Lipocentric Theory of Type 2 Diabetes

Type 2 diabetes may be caused by:

  1. Eating too many calories [especially carbohydrates?], leading to…
  2. High insulin levels, leading to…
  3. Stimulation of fat production, leading to…
  4. Increased body fat, leading to…
  5. Deposition of lipids in cells where they don’t belong (that is, not in fat cells), leading to…
  6. Resistance to insulin’s effects on glucose metabolism, leading to…
  7. Lipid accumulation in pancreatic beta cells, damaging them, leading to…
  8. Elevated blood glucose levels, i.e., diabetes.

Perhaps the key to understanding this is to know that “insulin resistance” refers to insulin having less ability to suppress glucose production by the liver, or less ability of various tissues to soak up circulating glucose.  Insulin resistance thereby leads to elevated glucose levels.  But insulin’s effect of “producing fats” (lipogenesis) continues unabated.  Excessive fats, actually fatty acids, accumulate not only in fat cells, but also in liver cells, muscle cells, pancreatic beta cells, and others.  This lipid overload can damage those cells.

If This Theory Is Correct, So What?

Steps #1 and 2 of the lipocentric theory involve excessive caloric intake and high circulating insulin levels, leading to problems down the road.  So overweight people should restrict calories and try to lose at least a modest amount of weight.  Particularly if already having type 2 diabetes or prone to it.   

And what about people with type 2 diabetes who have insulin resistance and have poorly controlled glucose levels?  Most of these have high insulin levels already, contributing to a fat-producing state.  Adding more insulin, by injection, wouldn’t seem to make much sense if there are other alternatives.  The extra insulin would bring glucose levels down, but might also cause lipid overload with associated cellular damage. 

Effective clinical strategies according to Dr. Unger would include 1) caloric restriction, which helps reduce weight, high insulin levels, and fat production, and 2) if #1 fails, add anti-diabetic drugs that reduce caloric intake [exenatide?], that reduce lipid overload [which drug?], or that do both.  

Dr. Unger suggests consideration of bariatric surgery, for caloric restriction and cure of diabetes.

Compared with dietary fats and proteins, carbohydrates generally cause higher circulating insulin levels.  And type 2 diabetics taking insulin shots need higher doses for higher intakes of carbohydrate.  So it makes sense to me to consider preferential reduction of carbohydrate consumption if someone’s going to reduce caloric intake.

Dr. Unger and I agree that reduction of excessive food intake and excess body fat is critically important for overweight people with type 2 diabetes.

Steve Parker, M.D.

References: Unger, R. (2008). Reinventing Type 2 Diabetes: Pathogenesis, Treatment, and Prevention JAMA: The Journal of the American Medical Association, 299 (10), 1185-1187 DOI: 10.1001/jama.299.10.1185

7 Comments

Filed under Causes of Diabetes, Overweight and Obesity

Let Freedom Ring!

Arizona’s Constitution of 1912 has always held that “the right of the individual citizen to bear arms in defense of himself or the state shall not be impaired.”

Arizona’s governor a few months ago signed into law a bill restoring Arizonans’ freedom to carry firearms discreetly without a permit.  Previously, we had to ask the state for written permission, but could carry a handgun openly.  The “open carry” option sometimes scared hoplophobes.  And some of us didn’t want the bad guys to know we were armed.

Remember: When seconds count, the police are only minutes away.

Steve Parker, M.D.

7 Comments

Filed under Uncategorized