November 20, 2009 · 2:00 AM

For Heart’s Sake, Should You Avoid Red Meat in a Low-Carb Diet?

Low carbohydrate diets tend to contain disproportionate amounts of fat from animal sources.  Red meat has long been vilified as a major source of saturated fat that some experts believe cause hardening-of-the-arteries (atherosclerosis) via elevations in LDL cholesterol.  Others disagree.  Poultry, fish ,and shellfish generally have lower amounts of saturated fat than red meat.  Would a low-carb diet with a predominance of poultry, fish, and shellfish lead to a more advantageous cholesterol profile?

A 2007 report from U.S. researchers found no lipid advantage to the poultry/fish/shellfish model.    In fact, despite high cholesterol and fat intakes, neither diet caused a significant change in total, HDL, or LDL cholesterol levels.  Triglycerides fell in both groups, but to a statistically significant degree only on the poultry/fish/shellfish group.

Fun Fact:  Did you know that four of every 10 women in the U.S. are trying to lose weight?  The figure for men is one in three.  

Methodology

Researchers in Minnesota and Iowa enrolled 18 subjects (6 males, 12 females) between the ages of 30 and 50 who wanted to lose weight.  Average body mass index was 31.7, which is mildly obese.  The were encouraged to eat an Atkins-style ketogenic diet with a maximum of 20 g carbs/day, providing 1,487 total daily calories, with 7% of calories from carbohydrate, 43% from protein, and 50% from fat.  This included two or three cups of salad greens and low-carb vegetables.  Three ounces of cheese daily was allowed.  Subjects were randomly assigned to eat either red meat or poultry/fish/shellfish.  Dietary intervention lasted 28 days.

[This is very similar to Atkins Induction Phase, although Atkins does not limit total calories.  The researchers did not say why they wanted to limit total calories.] 

Data were not used from six subjects for good reasons (see article).  So final data analysis included only 12 subjects.

Results

Both groups lost the same amount of weight: about 5.5 kg (12 pounds) over 28 days.

Average carbohydrate intake was about the same for both groups: 55 g/day.

Average total daily caloric intake was about the same for both groups: 1,380.

The poultry/fish/shellfish group ate 630 mg cholesterol daily, twice as much as the other group.  [Eggs and shrimp were popular.]

The difference in intake of saturated fat approached, but did not reach, statistical significance (32 g/day in the red meat group vs 25 g).

Neither diet caused a significant change in total, HDL, or LDL cholesterol levels.  Triglycerides fell in both groups, but to a statistically significant degree only on the poultry/fish/shellfish group.

Urine ketones at or above 5 mg/dl were detected on 75% of all dipstick tests.

My Comments

I’m skeptical about the accuracy of the calorie counts.  Most people eating Atkins-style take in about 1,800 cals/day.  The preponderance of females, however, may explain the unusually low average caloric intake.  They didn’t follow their carb restriction very closely, did they?  These were free-living subjects not locked in a metabolic ward.

The researchers note that the allowance of cheese in both groups may have sabotaged their efforts for a clear delineation of higher versus lower saturated fat groups. 

HDL cholesterol usually rises significantly on low-carb diets.  Lack of that here may just be a statistical aberration.

This is such a small study that it’s impossible to draw firm conclusions.  Nevertheless, if someone is losing weight on a low-carb diet, it may not matter much from a lipid viewpoint whether they eat a predominance of meat or a predominance of poultry, fish, and shellfish.  The study at hand cannot address the long-term consequences of such a choice.

Steve Parker, M.D.

Reference:  Cassady, Bridget, et al.  Effects of low carbohydrate diets high in red meats or poultry, fish and shellfish on plasma lipids and weight loss.  Nutrition & Metabolism, 4:23   doi: 10.1186/1743-7075-4-23   Published October 31, 2007

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November 19, 2009 · 12:29 AM

Book Review: 21 Life Lessons From Livin’ La Vida Low-Carb

Here’s my review of Jimmy Moore’s new book, 21 Life Lessons From Livin’ La Vida Low-Carb: How the Healthy Low-Carb Lifestyle Changed Everything I Thought I Knew.  I rate it five stars, Amazon.com’s highest rating.

♦   ♦   ♦

Thinking about quitting your low-carb lifestyle?  Read this book first.

Jimmy Moore is a leading advocate for low-carb eating.  His purpose with this book is to educate, encourage, and inspire overweight people to begin or maintain their own low-carb journey.  And he succeeds in spades.

Mr. Moore assumes the reader already knows how to do low-carb eating.  If you don’t, I’m sure Mr. Moore would recommend Dr. Atkins New Diet Revolution as the single best source.  As with all diets, low-carb eating has a high drop-out rate.  Most people lose some weight then return to their old way of eating, gaining the weight back.

Even as the author of a balanced, calorie-restricted diet book, I’ll admit that many people have had phenomenal success with low-carb diets, without caloric restriction.  Mr. Moore is one of those: 180 pounds (82 kg) weight loss in one year, and sustained over five years.  Could he be lying?  Sure.  But my gut feeling is he’s not. 

This book is not only a survey of the low-carb world covering the last decade, its an autobiography.  He shares his traumatic upbringing and the frustrating premature death of his morbidly obese brother from heart disease.  You’ll learn about Mr. Moore’s movie career alongside George Clooney.  I was also surprised to learn that Mr. Moore lost 170 pounds (77 kg) in 1999, not on a low-carb diet, but a low-fat one!  Then what happened?  I won’t spoil it for you.  Mr. Moore also owns up to his regrettable and embarrassing affiliation with the Kimkins diet in 2007.

The only weak chapter is the one on childhood obesity.  Mr. Moore moves away from his previous science- and evidence-based arguments, using personal opinion and anecdote more often.  This partly reflects the fact that childhood obesity hasn’t been studied nearly as much as the adult version.

I particularly like Mr. Moore’s review of the scientific evidence in favor of low-carb eating.  The science was inspired and driven by the low-carb craze of 1998-2004.  But the study results weren’t published until after the fad peaked.  So most people aren’t familiar with the science.  Mr. Moore presents it in very understandable terms, which is a gift.

As heavily invested as he is in low-carb eating, does Mr. Moore condemn other methods of weight management?  By no means.  He repeatedly writes: “The point is to find the proven nutritional plan that works for you, follow that plan as exactly as prescribed by the author, and then stick to it for the rest of your life.” 

Steve Parker, M.D.

Additional information: Jimmy Moore’s Livin’ La Vida Low-Carb Blog

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November 18, 2009 · 9:58 PM

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 diabetes.  Diabetologia, 52 (2009): 1,479-1,495.  doi: 10.1007/s00125-009-1395-7

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November 17, 2009 · 2:00 AM

Self-Experimentation: Does Vinegar Promote Weight Loss?

MPj03878520000[1]I reported recently that apple cider vinegar in a Japanese study population reduced body weight by 2.2 to 4.4 pounds (1—2 kg) over 12 weeks.  The dose was 15—30 ml daily, or 1—2 tbsp.  The researchers think the active ingredient is simply acetic acid.

On November 14, 2009, I started another self-experiment: I’m drinking 7.5 ml (1.5 tsp) Heinz apple cider vinegar twice daily, mixing it in 8—10 fl oz of water plus 1/2 packet (1.75 g) of  Truvia sweetener, with or without 1 heaping tsp of sugar-free Metamucil.  I’ll do this for 12 weeks.  If I weighed over 200 lb, I would have chosen the 30 ml/day vinegar dose.  But I’m only 155 lb.

Why Truvia?  We had some in the house, I don’t think I absorb its erythritol and rebiana, and it makes the vinegar much more palatable. 

Why Metamucil?  You can figure that one out, Spanky.

A small-scale “experiment of one” like this isn’t worth much.  Too many variables can affect the outcome.  For instance, the holiday season is just around the corner.  Most Americans gain five pounds between Thanksgiving and New Years.  I’ve been no exception to that in the past. 

I’m not totally committed to the experiment.  But I’ve gotta do something with that huge bottle of vinegar my wife bought.   

Steve Parker, M.D.

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November 16, 2009 · 11:02 AM

Olive Oil in Mediterranean Diet Linked to Lower Body Weight

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The source of virgin olive oil

The University of Navarra in Spain reported recently that a diet rich in virgin olive oil reduces body weight, especially in those genetically inclined to gain weight.  Over one thousand research particpants were placed on a  Mediterranean diet and monitored by lead researcher, Ph.D. candidate Cristina Razquin:

This consisted of a high intake of fruit and vegetables and of non-refined cereals and fish, and the use of virgin olive oil as the main source of fatty food. Moreover, a high intake of legumes and nuts is recommended.

We’ll have more details when the research is published in a peer-reviewed scientific journal.  Olive oil is a type of fat.  This finding of lower body weight on an olive 0il-rich Mediterranean diet run counter to the generally accepted idea that dietary fat causes body fat.  Lower body weight is linked to lower risk of diabetes.

Steve Parker, M.D.

Reference:  A diet rich in virgin olive oil reduces body weight, according to research by the University of Navarra.  Press release, August 3, 2009.

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November 15, 2009 · 2:00 AM

Low-Carb Diet Helps Obese Swedes With Diabetes

Swedish boyObese people with type 2 diabetes following a 20% carbohydrate diet demonstrated sustained improvement in weight and blood glucose control, according to two Swedish physicians.  These doctors also have research experience with traditional low-fat diets in overweight diabetics, having demonstrated that a 20% carbohydrate diet was superior to a low-fat/55–60% carb diet in obese diabetes patients over six months.

What Was the Intervention?

Proportions of carbohydrates, fat, and protein were 20%, 50%, and 30% respectively.  Total daily carbs were 80–90 g. 

Recommended carbs were vegetables and salads. 

Rather than ordinary bread, crisp/hard bread was recommended (3.5 to 8 g carb per slice).  Starchy breads, pasta, potatoes, rice, and breakfast cereals were excluded. 

They were instructed to walk 30 minutes daily, take a multivitamin with extra calcium daily, and to not eat between meals. 

At the outset, diabetic medications were reduced by 25–30% to avoid low blood sugars.   

Results

The doctors followed 23 patients over the course of  44 months.  Average initial body weight was 101 kg (222 pounds).  After 44 months, average body weight fell to 93 kg (205 pounds).  Hemoglobin A1c, a measure of diabetes control,  fell from 8% to 6.8%. 

My Comments

In these pages over the last few months, we’ve seen the effectiveness of low-carb diets in people with type 2 diabetes in widespread populations: Japanese, U.S. blacks and caucasions, and, now, Swedes. 

The standard Western diet derives 55–60% of its energy from carbohydrates.  If you’ve been following this blog, we’ve looked at diets containing 40%, 30%, 20%, and 10% carbs.  Have you noticed the trend? 

Reducing the percentage of carbohydrates in the diet improves diabetic control and loss of excess weight.  And the more you reduce carbs, the greater the degree of diabetic control and weight loss.   

Steve Parker, M.D.

Reference:  Nielsen, Jörgen and Joensson, Eva.  Low-carbohydrate diet in type 2 diabetes: stable improvement of body weight and glycemic control during 44 months follow-up.  Nutrition & Metabolism, 5:14   doi:10.1186/1743-7075-5-14

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November 14, 2009 · 2:00 AM

Happy World Diabetes Day!

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Flag of the United Nations

This is World Diabetes Day.  See the International Diabetes Federation website for details. 

Steve Parker, M.D.

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November 13, 2009 · 2:00 AM

Moderate Low-Carb Diet Just as Effective as Insulin Shots in Type 2 Diabetes

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Mount Fuji

A low-carbohydrate diet is just as effective as insulin shots for people with severe type 2 diabetes, according to research recently announced by Japanese investigators.

Thirty-three uncontrolled Japanese type 2 diabetics, similar numbers of men and women, were placed on a low-carbohydrate diet for six months.  The diet provided 30% of energy from carbs, 44% fat, and 20% protein.  [By point of reference, the average American derives 55–60% of energy from carbs.]  Average caloric intake was 1,852/day.  [I’m not sure what provided the other 6% of calories – I suspect distilled liquor.]  Average body mass index was 24  and did not change during the six months.  The only adverse effect was mild constipation.  Two people dropped out of the study before completion.  Seven participants were on sulfonylurea drug therapy.

Protein and fat intake were unlimited.  They were given a list of high-carbohydrate foods to avoid (see reference).

Results

Hemoglobin A1c, a standard test of diabetes control, fell from10.9% to 7.8% at three months and 7.4% at six months.  Five of the seven patients on sulfonylurea were able to stop the drug.  No patient required insulin therapy or hospitalization. 

Comments

The low drop-out rate may be a testament to the palatability of this low-carb way of eating.

Japanese diabetes may not be exactly the same disease as American or European diabetes.  For instance, Japanese diabetics are not as overweight.  Only 3% of the Japanese population is obese (body mass index over 30), compared to 30% of the U.S. population. 

The degree of carbohydrate restriction in this study is not nearly as severe as with the Ketogenic Mediterranean Diet.  Yet the improvement in hemoglobin A1c was dramatic after just three months.

Being aware of genetic and other influences on disease, I’m always wary about generalizing research results from one race or ethnic group to others.  When it comes to the efficacy of low-carb eating in people with type 2 diabetes, however, we’ve seen similar results already in white and black Americans. 

Steve Parker, M.D. 

Reference:  Haimoto, Hajime, et al.  Effects of a low-carbohydrate diet on glycemic control in outpatients with severe type 2 diabetes.  Nutrition and Metabolism, 6:21   doi:10.1186/1743-7075-6-21

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November 12, 2009 · 2:18 AM

Which Drug Is Best for Treatment of Type 2 Diabetes?

Physicians now have an amazing array of drug therapies  for control of type 2 diabetes.  Until now, there has been no consensus as to which drugs to use, and when.

The American Association of Clinical Endocrinologists and the American College of Endocrinology have just issued a joint statement with specific drug recommendations.  Their algorithm is quite detailed.  Here are a few highlights you might not know about:

  • Regular human insulin is not recommended
  • NPH insulin is not recommended
  • The following should be used earlier and more frequently:  GLP-1 agonists (exenatide) and DPP-4 inhibitors (sitagliptin and saxagliptin)
  • sulfonylureas are a lower priority
  • metformin is still a key drug

In the U.S., exenatide is sold as Byetta; sitagliptin is Januvia; saxagliptin is Onglyza; metformin is Glucophage (among others). 

If you have type 2 diabetes and are arguing with your physician about optimal drug therapy, this treatment algorithm may be a helpful tie-breaker. 

Steve Parker, M.D.

Reference:  Statement by an American Association of Clinical Endocrinologists/American College of Endocrinology consensus panel on type 2 diabetes mellitus: An algorithm for glycemic control.  Endocrine Practice, 15 (2009): 540-559.

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November 11, 2009 · 2:00 AM

Drink Vinegar and Lose 2-4 Pounds Effortlessly

CB052540Japanese researchers recently documented that daily vinegar reduces body weight, fat mass, and triglycerides in overweight Japanese adults. 

Beverages containing vinegar are commonly consumed in Japan.  The main component—4 to 8%— of vinegar is acetic acid.  Vinegar can lower cholesterol levels, lower blood pressure, and limit increases in blood sugar after meals. 

Japanese researchers studied the effects of vinegar on 175 overweight—body mass index between 25 and 30—subjects aged 25 to 60.  Men totaled 111; women 64.  Average weight 74.4 kg (164 pounds).  They were divided into three groups that received either a placebo drink, 15 ml apple vinegar (750 mg of acetic acid), or 30 ml apple vinegar (1,500 mg acetic acid).  Placebo and vinegar were mixed into 500 ml of a beverage, half of which was drunk twice daily after breakfast and supper for 12 weeks.  Changes in body fat were measured with CT technology.  Subjects were told to eat  and exercise as usual.   

Results

By the end of the 12 weeks, weight had decreased by 1-2 kg (2.2 to 4.4 pounds) in the vinegar drinkers, with 30 ml of vinegar a bit more effective.  CT scanning showed that the lost weight was fat mass rather than muscle or water.  Triglyceride levels in the vinegar groups fell by about 20%.  The placebo drinkers saw no changes. 

Four weeks after the intervention ended, subjects were retested: values had returned to their baseline, pre-study levels. 

The scientists report that the acetic acid in vinegar inhibits production of fat and may stimulate burning of fat as fuel.  Although vinegar contains many other ingredients, they think the acetic acid is responsible for the observed changes.

My Comments

It’s possible that apple vinegar components other than acetic acid led to the weight loss and lowered triglyceride levels.  Further study could clarify this.

These results may or may not be applicable to non-Japanese races.

This study supports the use of vinaigrette as a salad or vegetable dressing in people trying to lose weight with diets such as the Ketogenic Mediterranean Diet.  Vinaigrettes are combinations of olive oil and vinegar, often with various spices added.  If you eat a salad twice a day, it would be easy to add 15 ml (1 tbsp) of vinegar to your diet daily. 

With a little imagination, you could come up with other ways to add 15–30 ml (1–2 tbsp) of vinegar to your diet.

Steve Parker, M.D.

Reference:  Kondo, Toomoo, et al.  Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects.  Bioscience, Biotechnology, and Biochemistry, 73 (2009): 1,837-1,843.

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