Category Archives: Fiber

Cabbage: Nature’s Laxative

There’s something about cabbage…

I found out why cabbage soup can help fight constipation and even cause diarrhea. It’s raffinose.

Raffinose is sometimes called a fiber but more often is characterized as a trisaccharide, oligosaccharide, or complex carbohydrate. It’s all four.

A typical bowl of cabbage soup has three grams of fiber. If you eat two bowls, that’s six grams, still not all that much, but can predictably cause loose stools or diarrhea in  many folks because of a particular type of fiber: raffinose.

The thing about raffinose is that it passes through the small intestine undigested because we lack the enzyme alpha-galactosidase. When raffinose hits the colon, bacteria start digesting it (aka fermentation), potentially leading to gas, bloating, and/or diarrhea. If your “dose” of raffinose is small enough, you won’t have any symptoms. To use cabbage soup as a constipation preventative or remedy, you have to experiment to see what dose works for you.

Raffinose is also found in beans and cruciferous vegetables like brussels sprouts and cauliflower

Steve Parker, M.D.

PS: Ever heard of Beano? The active ingredient is the enzyme alpha-galactosidase. It breaks down raffinose in the small intestine, to simple sugars we can absorb.

PPS: Raffinose is one of the oligosaccharides to avoid if you’re on a low FODMAPs diet.

Comments Off on Cabbage: Nature’s Laxative

Filed under Fiber

Periodic Tests, Treatments, and Goals for PWDs (Persons With Diabetes)

If you don't like your physician, find a new one

If you don’t like your physician, find a new one

So, you’ve got diabetes. You’re trying to deal with it or you wouldn’t be here. You’ve got a heck of a lot of medical information to master.

Unless you have a good diabetes specialist physician on your team, you may not be getting optimal care. Below are some guidelines you may find helpful. The goal is to prevent diabetes complications. Many primary care physicians will not be up-to-date on the guidelines. Don’t hesitate to discuss them with your doctor. Nobody cares as much about your health as you do.

Annual Tests

The American Diabetes Association (ADA) recommends the following items be done yearly (except as noted) in non-pregnant adults with diabetes. (Incidentally, I don’t necessarily agree with all ADA guidelines.) The complete ADA guidelines are available on the Internet.

  • Lipid profile (every two years if results are fine and stable)
  • Comprehensive foot exam
  • Screening test for distal symmetric polyneuropathy: pinprick, vibration, monofilament pressure sense
  • Serum creatinine and estimate of glomerular filtration rate (MDRD equation)
  • Test for albumin in the urine, such as measurement of albumin-to-creatinine ratio in a random spot urine specimen
  • Comprehensive eye exam by an ophthalmologist or optometrist (if exam is normal, every two or three years is acceptable)
  • Hemoglobin A1c at least twice a year, but every three months if therapy has changed or glucose control is not at goal
  • Flu shots

Other Vaccinations, Weight Loss, Diabetic Diet, Prediabetes, Alcohol, Exercise, Etc.

Additionally, the 2013 ADA guidelines recommend:

  • Pneumococcal vaccination. “A one time re-vaccination is recommended for individuals >64 years of age previously immunized when they were <65 years of age if the vaccine was administered >5 years ago.” Also repeat the vaccination after five years for patients with nephrotic syndrome, chronic kidney disease, other immunocompromised states (poor ability to fight infection), or transplantation.
  • Hepatitis B vaccination to unvaccinated adults who are 19 through 59 years of age.
  • Weight loss for all overweight diabetics. “For weight loss, either low-carbohydrate, low-fat calorie-restricted, or Mediterranean diets may be effective in the short-term (up to two years).” For those on low-carb diets, monitor lipids, kidney function, and protein consumption, and adjust diabetic drugs as needed. The optimal macronutrient composition of weight loss diets has not been established. (Macronutrients are carbohydrates, proteins, and fats.)
  • “The mix of carbohydrate, protein, and fat may be adjusted to meet the metabolic goals and individual preferences of the person with diabetes.” “It must be clearly recognized that regardless of the macronutrient mix, total caloric intake must be appropriate to weight management goal.”
  • “A variety of dietary meal patterns are likely effective in managing diabetes including Mediterranean-style, plant-based (vegan or vegetarian), low-fat and lower-carbohydrate eating patterns.”
  • “Monitoring carbohydrate, whether by carbohydrate counting, choices, or experience-based estimation, remains a key strategy in achieving glycemic control.”
  • Limit alcohol to one (women) or two (men) drinks a day.
  • Limit saturated fat to less than seven percent of calories.
  • During the initial diabetic exam, screen for peripheral arterial disease (poor circulation). Strongly consider calculation of the ankle-brachial index for those over 50 years of age; consider it for younger patients if they have risk factors for poor circulation.
  • Those at risk for diabetes, including prediabetics, should aim for moderate weight loss (about seven percent of body weight) if overweight. Either low-carbohydrate, low-fat calorie-restricted, or Mediterranean diets may be effective in the short-term (up to 2 years). Also important is exercise: at least 150 minutes per week of moderate-intensity aerobic activity. “Individuals at risk for type 2 diabetes should be encouraged to achieve the U.S. Department of Agriculture (USDA) recommendation for dietary fiber (14 g fiber/1,000 kcal) and foods containing whole grains (one-half of grain intake).” Limit intake of sugar-sweetened beverages.
  • “Adults with diabetes should be advised to perform at least 150 min/week of moderate-intensity aerobic physical activity (50–70% of maximum heart rate), spread over at least 3 days/week with no more than two consecutive days without exercise. In the absence of contraindications, adults with type 2 diabetes should be encouraged to perform resistance training at least twice per week.”
  • Screening for coronary artery disease before an exercise program is depends on the physician judgment on a case-by-case basis. Routine screening is not recommended.
Steve Parker MD, low-carb diet, diabetic diet

Olive, olive oil, and vinegar: classic Mediterranean foods

Obviously, some of my dietary recommendations conflict with ADA guidelines. The experts assembled by the ADA to compose guidelines were well-intentioned, intelligent, and hard-working. The guidelines are supported by 528 scientific journal references. I greatly appreciate the expert panel’s work. We’ve simply reached some different conclusions. By the same token, I’m sure the expert panel didn’t have unanimous agreement on all the final recommendations. I invite you to review the dietary guidelines yourself, discuss with your personal physician, then decide where you stand.

General Blood Glucose Treatment Goals

The ADA in 2013 suggests these therapeutic goals for non-pregnant adults:

  • Fasting blood glucoses: 70 to 130 mg/dl (3.9 to 7.2 mmol/l)
  • Peak glucoses one to two hours after start of meals: under 180 mg/dl (10 mmol/l)
  • Hemoglobin A1C: under 7%
  • Blood pressure: under 140/80 mmHg
  • LDL cholesterol: under 100 mg/dl (2.6 mmol/l). (In established cardiovascular disease: <70 mg/dl or 1.8 mmol/l may be a better goal.)
  • HDL cholesterol: over 40 mg/dl (1.0 mmol/l) for men and over 50 mg/dl (1.3 mmol/l) for women
  • Triglycerides: under 150 mg/dl (1.7 mmol/l)

The American Association of Clinical Endocrinologists (AACE) in 2011 proposed somewhat “tighter” blood sugar goals for non-pregnant adults:

  • Fasting blood glucoses: under 110 mg/dl (6.11 mmol/l)
  • Peak glucoses 2 hours after start of meals: under 140 mg/dl (7.78 mmol/l)
  • Hemoglobin A1C: 6.5% or less

The ADA reminds clinicians, and I’m sure the AACE guys agree, that diabetes control goals should be individualized, based on age and life expectancy of the patient, duration of diabetes, other diseases that are present, individual patient preferences, and whether the patient is able to easily recognize and deal with hypoglycemia. I agree completely.

Steve Parker, M.D.

2 Comments

Filed under Diabetes Complications, Exercise, Fat in Diet, Fiber, Mediterranean Diet, Overweight and Obesity, Prediabetes, Prevention of T2 Diabetes

Eat the Right Carbs to Alleviate Diabetes and Heart Disease

Harvard’s Dr. Frank Hu in 2007 called for a paradigm shift in dietary prevention of heart disease, de-emphasizing the original diet-heart hypothesis and noting instead that “. . . reducing dietary GL [glycemic load] should be made a top public health priority.”  Jim Mann at the University of Otago (Dunedin, New Zealand) authored a 2007 review of carbohydrates and effects on heart disease and diabetes.  Here are highlights from the article summary in the European Journal of Clinical Nutrition:

The nature of carbohydrate is of considerable importance when recommending diets intended to reduce the risk of type II diabetes and cardiovascular disease and in the treatment of patients who already have established diseases. Intact fruits, vegetables, legumes and whole grains are the most appropriate sources of carbohydrate. Most are rich in [fiber] and other potentially cardioprotective components.  Many of these foods, especially those that are high in dietary fibre, will reduce total and low-density lipoprotein cholesterol and help to improve glycaemic control in those with diabetes.

Frequent consumption of low glycaemic index foods has been reported to confer similar benefits, but it is not clear whether such benefits are independent of the dietary fibre content of these foods or the fact that low glycaemic index foods tend to have intact plant cell walls.

A wide range of carbohydrate intake is acceptable, provided the nature of carbohydrate is appropriate. Failure to emphasize the need for carbohydrate to be derived principally from whole grain cereals, fruits, vegetables and legumes may result in increased lipoprotein-mediated risk of cardiovascular disease, especially in overweight and obese individuals who are insulin resistant.

Why does this matter to me and readers of this blog?  Dietary carbohydrates are a major determinant of blood sugar levels, tending to elevate them.  Chronically high blood sugar levels are associated with increased complication rates from diabetes.  People with diabetes are prone to develop heart disease, namely coronary artery disease, which causes heart attacks, weakness of the heart muscle, and premature death. 

Steve Parker, M.D.

References: 

Mann, J.  Dietary carbohydrate: relationship to cardiovascular disease and disorders of carbohydrate metabolismEuropean Journal of Clinical Nutrition, 61 (2007): Supplement 1: S100-11.

Hu, Frank.  Diet and cardiovascular disease prevention: The need for a paradigm shift.  Journal of the American College of Cardiology, 50 (2007): 22-24.

4 Comments

Filed under Carbohydrate, coronary heart disease, Fiber, Fruits, Glycemic Index and Load, Grains, legumes, Vegetables

Legumes and Whole Grains: Any Role in Diabetes?

Expert nutrition panels consistently recommend whole grains and legumes for people with diabetes.  Why?  And do these foods affect development of diabetes?  I found a pertinent scientific review article on the subject from 2004 in the European Journal of Clinical Nutrition.  Here are some pertinent quotes from the summary:

Epidemiological studies strongly support the suggestion that high intakes of whole grain foods protect against the development of type II diabetes mellitus (T2DM). People who consume approximately 3 servings per day of whole grain foods are less likely to develop T2DM than low consumers (<3 servings per week) with a risk reduction in the order of 20-30%.

The role of legumes in the prevention of diabetes is less clear, possibly because of the relatively low intake of leguminous foods in the populations studied. However, legumes share several qualities with whole grains of potential benefit to glycaemic control including slow release carbohydrate and a high fibre content. A substantial increase in dietary intake of legumes as replacement food for more rapidly digested carbohydrate might therefore be expected to improve glycaemic control and thus reduce incident diabetes. This is consistent with the results of dietary intervention studies that have found improvements in glycaemic control after increasing the dietary intake of whole grain foods, legumes, vegetables and fruit.

. . . it is cereal fibre that is largely insoluble [rather than soluble fiber] that is associated with a reduced risk of developing T2DM.

Thus, there is strong evidence to suggest that eating a variety of whole grain foods and legumes is beneficial in the prevention and management of diabetes. This is compatible with advice from around the world that recommends consumption of a wide range of carbohydrate foods from cereals, vegetables, legumes and fruits both for the general population and for people with diabetes.

Gluten Intolerance

A major protein in wheat is gluten.  The last few years have seen the popular emergence of gluten-free this and gluten-free that.  The idea is that gluten causes a variety of gastrointestinal, immunologic, and other problems, so wheat products should be avoided.  Certainly they should be avoided in people with celiac disease, a well-established medical condition.  I follow a few paleo blogs and know that grains and legumes are not part of that way of eating: the paleos say we are not evolved optimally to process them.    

If legumes or wheat or other grains cause problems for you, don’t eat them.  They have no essential nutrients that you can’t get elsewhere. 

Glycemic Index

In my quest to develop a healthy Diabetic Mediterranean Diet, I’m finding that grains—compared to nearly all other carbohydrate-containing food groups—tend to have a higher glycemic index (GI).   A low GI is 55 or less.  High GI is 70 or greater.  Grains in general raise blood sugar levels higher than many other sources of carbohydrates.  But this is highly variable and depends partially on preparation of the grain.  Whole grain products have a lower GI than highly processed counterparts.  For instance, white bread has a GI of 70; whole wheat bread 67.  Regular spaghetti is 38.  Table sugar’s GI must be sky high, right?  No, its just 61.  A baked potato is a whopping 85.   

Beans have a GI around 30 or 40.  And they pack a lot more fiber per serving.  For a diabetic struggling to keep blood sugars under control, which is a better choice: grains or legumes?  I’m leaning towards legumes and other components of a low-glycemic-index diet.   

Steve Parker, M.D.

PS:  [Before you correct my GI numbers, please note I’m  aware that various GI lists don’t agree with each other.]

Reference:  Venn, B.J. and Mann, J.I. Cereal grains, legumes and diabetes.  European Journal of Clinical Nutrition, 58 (2004): 1,443-1,461.

10 Comments

Filed under Fiber, Fruits, Grains, legumes, Prevention of T2 Diabetes, Vegetables

Do Beans and Peas Affect Glucose Control in Diabetics?

Beans and peas improve control of blood sugar in diabetics and others, according to a recent report from Canadian researchers.  The effect is modest.

Dietary pulses are dried leguminous seeds, including beans, chickpeas, lentils, and peas.  Pulses fed to healthy volunteers have a very low glycemic index, meaning they don’t cause much of a rise in blood sugar compared to other carbohydrates.  They are loaded with fiber and are more slowly digested than foods such as cereals.   

Investigators examined 41 clinical trials (1,674 participants) on the effects of beans and peas on blood glucose control, whether used alone or as part of low-glycemic-index or high-fiber diets.  Eleven trials looked at the effect of beans and peas alone, with the experimental “dose” averging 1oo g per day (about half a cup).  The article doesn’t specify whether the weight of the pulse was the dry weight or the prepared weight.  I will assume prepared.

Pulse given alone or as part of a high-fiber or low-glycemic index diet improved markers of glucose control, such as fasting blood sugar and hemoglobin A1c.  The absolute improvement in HgbA1c was around 0.5%.  Effects in healthy non-diabetics were less dramatic or non-existent.

My Comments

This study was very difficult  for me to digest.  The researchers lumped together studies on diabetics  and non-diabetics, using various doses and types of pulses.  No wonder they found “significant interstudy heterogeneity.” 

Cardiovascular disease is common in diabetics.  I’m aware of at least one study linking legume consumption with lower rates of cardiovascular disease.  I was hoping this study would answer for me whether I should recommend legumes such as peas and beans for my type 2 diabetics.  Beans and peas do represent a low glycemic load, which is good.  But I think I’ll have to keep looking for better-designed studies.

Steve Parker, M.D. 

Reference:  Sievenpiper, J.L., et al.  Effect of non-oil-seed pulses on glycaemic control: a systematic review and meta-analysis of randomised controlled experimental trials in people with and without diabetesDiabetologia, 52 (2009): 1,479-1,495.  doi: 10.1007/s00125-009-1395-7

Comments Off on Do Beans and Peas Affect Glucose Control in Diabetics?

Filed under Carbohydrate, Fiber, Prevention of T2 Diabetes

Fiber and Systemic Inflammation

Over three grams of fiber

Over three grams of fiber

High dietary fiber intake helps prevent constipation, diverticular disease, hemorrhoids, irritable bowel syndrome, and perhaps colon polyps.  Soluble fiber helps control blood sugar levels in people with diabetes, and it reduces LDL cholesterol levels, thereby reducing risks of coronary heart disease.

An  article in the journal Nutrition suggests how fiber may have beneficial effects in atherosclerosis (the cause of heart attacks and strokes), type 2 diabetes, and some cancers.  These conditions are felt to be related to underlying systemic inflammation.

Systemic inflammation can be judged by blood levels of inflammatory markers such as interleukin-6, tumor necrosis factor-alpha-receptor-2, and high-sensitivity C-reactive protein.

Researchers looked at 1,958 postmenopausal women in the Women’s Health Initiative Observational Study, comparing inflammatory marker levels with dietary fiber intake.  They found that high fiber intake was associated with significantly lower levels of inflammatory markers interleukin-6 and tumor necrosis factor-alpha-receptor-2.  This association was true individually for total fiber, insoluble fiber, and soluble fiber.  The researchers found no association with C reactive protein.

Bottom line?  High intake of dietary fiber seems to reduce chronic inflammation, which may, in part, explain the observed clinical benefits of fiber.

Rest assured that the Mediterranean diet is naturally high in fiber.

Steve Parker, M.D.

Reference:  Ma, Yensheng, et al.  Association between dietary fiber and markers of systemic inflammation in the Women’s Health Initiative Observational Study.  Nutrition, 24 (2008): 941-949.

1 Comment

Filed under Fiber

High Glycemic Load and Low Grain Fiber Increase Risk of Type 2 Diabetes in Men

Minimally refined grain

Minimally refined grain

A study published in 1997 helped establish the association between glycemic load, dietary fiber, and type 2 diabetes in men.

Methodology

Over 42,000 mostly middle-aged men in the Health Professionals Follow-up Study, without diabetes at baseline, were followed over six years to see if  diet composition was related to onset of type 2 diabetes.  Food intake was determined by a questionnaire.  95% of participants were white.

Results

523 cases of type 2 diabetes developed.  Men with the highest glycemic index eating pattern were 37% more likely to develop diabetes compared to the lowest glycemic index.

Cereal (grain) fiber was inversely related to risk of diabetes.  That is, the higher the intake of grain fiber, the lower the risk of developing diabetes.

The combination of high glycemic load and low cereal fiber yielded the highest rate of diabetes.

Total dietary fiber was not associated with reduced risk of diabetes.

Fiber from fruits and vegetables was not associated with diabetes one way or the other.

As other studies found, total carbohydrate intake was not related to risk of diabetes.

Take-Home Points

These findings may or may not apply to women and non-white ethnic groups.

Grains in a minimally refined form reduced the incidence of diabetes in this population.

Diets with a high glycemic load increase the risk of diabetes, at least in men.

Elsewhere, I’ve reviewed studies indicating that, in women, both high glycemic load and high glycemic index eating increase the risk of type 2 diabetes.  Click here for details.

We must wonder if  established cases of diabetes would respond positively to diets with low glycemic load and grains in a minimally refined form.  Or is it too late?

Steve Parker, M.D.

Reference:  Salmeron, Jorge, et al.  Dietary fiber, glycemic load, and risk of NIDDM in Men.  Diabetes Care, 20 (1997): 545-550

Comments Off on High Glycemic Load and Low Grain Fiber Increase Risk of Type 2 Diabetes in Men

Filed under Carbohydrate, Causes of Diabetes, Fiber, Glycemic Index and Load

Fiber and Systemic Inflammation

mpj0433185000011High dietary fiber intake helps prevent constipation, diverticular disease, hemorrhoids, irritable bowel syndrome, and perhaps colon polyps.

Soluble fiber helps control blood sugar levels in people with diabetes, and it reduces LDL cholesterol levels, thereby reducing risks of coronary heart disease.

An article in the journal Nutrition suggests how fiber may have beneficial effects in atherosclerosis (the cause of heart attacks and strokes), type 2 diabetes, and some cancers.  These conditions are felt to be related to underlying systemic inflammation.

Systemic inflammation can be judged by blood levels of inflammatory markers such as interleukin-6, tumor necrosis factor-alpha-receptor-2, and high-sensitivity C-reactive protein.

Researchers looked at 1,958 postmenopausal women in the Women’s Health Initiative Observational Study, comparing inflammatory marker levels with dietary fiber intake.  They found that high fiber intake was associated with significantly lower levels of inflammatory markers interleukin-6 and tumor necrosis factor-alpha-receptor-2.  This association was true individually for total fiber, insoluble fiber, and soluble fiber.  The researchers found no association with C reactive protein.

Bottom line?

High intake of dietary fiber seems to reduce chronic inflammation, which may, in part, explain the observed clinical benefits of fiber.

Average adult fiber intake in the U.S. is 12 to 15 grams daily.  Expert nutrition panels and the American Heart Association recommend 25 to 30 grams daily from whole grains, fruits, and vegetables.

Nutritionist Monica Reinagel at NutritionData.com has reviewed soluble vs insoluble fiber and good sources of soluble fiber:  oranges, apples, carrots, oats and oat bran, psyllium husk, nuts, legumes, and flaxseed.  Click the link for good sources of insoluble fiber.

Rest assured that the Mediterranean diet is naturally high in fiber.

Steve Parker, M.D.

Reference:  Ma, Yensheng, et al.  Association between dietary fiber and markers of systemic inflammation in the Women’s Health Initiative Observational StudyNutrition, 24 (2008): 941-949.

5 Comments

Filed under Fiber