Category Archives: Glycemic Index and Load

Control Blood Sugar With Extra-Virgin Olive Oil

Steve Parker MD, Advanced Mediterranean DIet

Naturally low-glycemic index Caprese salad: mozzarella cheese, tomatoes, basil, extra virgin olive oil

Italian researchers found that extra-virgin olive oil taken with meals helps to reduce blood sugar elevations after meals in type 1 diabetics. This may help explain the lower observed incidence of diabetes seen in those eating a traditional Mediterranean diet, which is rich in olive oil.

Before going further into the weeds, remember that glycemic index refers to how high and quickly a particular food elevates blood sugar. High-glycemic index foods raise blood sugar quicker and higher compared to low-glycemic index foods.

The study at hand is a small one: 18 patients. They were given both high- and low-glycemic meals with varying amounts and types of fat. Meals were either low-fat, high in saturated fat (from butter), or high in monounsaturated fat from olive oil. Meals that were high-glycemic index resulted in lower after-meal glucose levels if the meal had high olive oil content, compared to low-fat and butter-rich meals.

If meals were low in glycemic index, blood sugar levels were about the same whether the diet was low-fat, high in saturated fat, or rich in olive oil.

Action Plan

If you have type 1 diabetes and plan on eating high on the glycemic index scale, reduce your blood sugar excursions by incorporating extra-virgin olive oil into your meals.

Steve Parker, M.D.

Reference: Bozzetto, Luigarda, et al. Extra-virgin olive oil reduces glycemic response to a high-glycemic index meal in patients with type 1 diabetes: a randomized controlled trial. Diabetes Care, online before print, February 9, 2016. doi: 10.2337/dc15-2189

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Very Low-Carb Diet Beats ADA Diet in Type 2 Diabetes According to New Study

Compared to a mildly carbohydrate-restricted American Diabetes Association diet, a very-low-carbohydrate ketogenic diet was more effective at controlling type 2 diabetes and prediabetes, according to University of California San Francisco researchers.

Some non-starchy low-carb vegetables

Some non-starchy low-carb vegetables

Details, please!

Thirty-four overweight and obese type 2 diabetics (30) and pre diabetics (4) were randomly assigned to one of the two diets:

  1. MCCR: American Diabetes Association-compliant medium-carbohydrate, low-fat, calorie-resticted carb-counting diet. The goals were about 165 grams of net carbs daily, counting carbohydrates, an effort to lose weight by eating 500 calories/day less than needed for maintenance, and 45–50% of total calories from carbohydrate. Protein gram intake was to remain same as baseline. (Note that most Americans eat 250–300 grams of carb daily.)
  2. LCK: A very-low-carbohydrate, high-fat, non-calorie-restricted diet aiming for nutritional ketosis. It was Atkins-style, under 50 grams of net carbs daily (suggested range of 20–50 g). Carbs were mostly from non-starchy low-glycemic-index vegetables. Protein gram intake was to remain same as baseline.

Baseline participant characteristics:

  • average weight 100 kg (220 lb)
  • 25 of 34 were women
  • average age 60
  • none were on insulin; a quarter were on no diabetes drugs at all
  • most were obese and had high blood pressure
  • average hemoglobin A1c was about 6.8%
  • seven out of 10 were white

Participants followed their diets for three months and attended 13 two-hour weekly classes. Very few dropped out of the study.

Results

Average hemoglobin dropped 0.6% in the LCK group compared to no change in the MCCR cohort.

A hemoglobin A1c drop of 0.5% or greater is considered clinically significant. Nine in the LCK group achieved this, compared to four in the MCCR.

The LCK group lost an average of 5.5 kg (12 lb) compared to 2.6 kg (6 lb) in the MCCR. The difference was not statistically significant, but close (p = 0.09)

44% in the LCK group were able to stop one or more diabetes drugs, compared to only 11 % in the other group

31% in the LCK cohort were able to drop their sulfonylurea, compared to only 5% in the MCCR group.

By food recall surveys, both groups reported lower total daily caloric intake compared to baseline. The low-carbers ended up with 58% of total calories being from fat, a number achieved by reducing carbohydrates and total calories and keeping protein the same. They didn’t seem to increase their total fat gram intake;

The low-carbers apparently reduced daily carbs to an average of 58 grams (the goal was 20-50 grams).

There were no differences between both groups in terms of C-reactive protein (CRP), lipids, insulin levels, or insulin resistance (HOMA2-IR). Both groups reduced their CRP, a measure of inflammation.

LCK dieters apparently didn’t suffer at all from the “induction flu” seen with many ketogenic diets. They reported less heartburn, less aches and pains, but more constipation.

Hypoglycemia was not a problem.

If I recall correctly, the MCCR group’s baseline carb grams were around 225 g.

Bottom Line

Very-low-carb diets help control type 2 diabetes, help with weight loss, and reduce the need for diabetes drugs. An absolute drop of 0.6% in hemoglobin A1c doesn’t sound like much, translating to blood sugars lower by only 15–20 mg/dl (0.8–1 mmol/l). But remember the comparator diet in this study was already mildy to moderately carbohydrate-restricted. At least half of the type 2 diabetics I meet still tell my they don’t watch their carb intake, which usually means they’re eating around 250–300 grams a day. If they cut down to 58 grams, they most likely will see more than a 0.6% drop in hemoglobin A1c after switching to a very-low-carb diet.

This is a small study, so it may not be reproducible in larger clinical trials and other patient populations. Results are consistent with several other similar studies I’ve seen, however.

Steve Parker, M.D.

Reference: Saslow, Laura, et al (including Stephen Phinney). A Randomized Pilot Trial of a Moderate Carbohydrate Diet Compared to a Very Low Carbohydrate Diet in Overweight or Obese Individuals with Type 2 Diabetes Mellitus or PrediabetesPLoS One. 2014; 9(4): e91027. Published online Apr 9, 2014. doi: 10.1371/journal.pone.0091027     PMCID: PMC3981696

PS: When I use “average” above, “mean” is often a more accurate word, but I don’t want to have to explain the differences at this time.

PPS: Carbsane Evelyn analyzed this study in greater detail that I did and came to different conclusions. Worth a read if you have an extra 15 minutes.

 

 

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Mediterranean Diet Once Again Linked to Lower Risk of Type 2 Diabetes

Conquer Diabetes and Prediabetes, Steve Parker MD

Olive oil and vinegar

And eating low glycemic load helps, too, according to an article at MedPageToday. The 22,000 Greek study participants were followed for 11 years. From the article:

The findings suggest that eliminating or strictly limiting high glycemic load foods such as those high in refined sugars and grains and following the largely plant-based Mediterranean diet, which emphasizes vegetables, fruits, nuts and legumes, can have a significant impact on diabetes risk, La Vecchia said.

“The impact of the diets was synergistic,” he told MedPage Today. “The message is that eating a largely Mediterranean diet that is also low in glycemic load is particularly favorable for preventing diabetes.”

Spanish researchers found the same thing a few years ago.

The Mediterranean diet is also healthy for those who already have type 2 diabetes.

The Low-Carb Mediterranean Diet may be the ideal way of eating for diabetics.

Steve Parker, M.D.

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Filed under Glycemic Index and Load, Health Benefits, Mediterranean Diet, Prevention of T2 Diabetes

European Guidelines Not In Favor of Low Carbohydrate Diets for Diabetes

Conquer Diabetes and Prediabetes

“Really?”

A recent diabetes treatment guide from European doctors states “there is no justification for the recommendation of very low carbohydrate diets in diabetes mellitus.”

I disagree.

The 2013 guidelines are from the European Society of Cardiology and the European Association for the Study of Diabetes. I compiled the following articles in favor of carbohydrate restriction a couple years ago. You won’t find anything newer listed. Admittedly, all or nearly all of the patients involved had type 2 diabetes, not type 1.

Enjoy!

♦  ♦  ♦

Accurso, A., et al. Dietary carbohydrate restriction in type 2 diabetes mellitus and metabolic syndrome: time for a critical appraisal. Nutrition & Metabolism, 9 (2008). PMID: 18397522. One of the watershed reports that summarize the major features and benefits, based on 68 scientific references.

Boden, G., et al. Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes. Annals of Internal Medicine, 142 (2005): 403-411. In these 10 obese diabetics, a low-carb diet spontaneously reduced calorie consumption from 3100 daily to 2200, accounting for the weight loss—1.65 kg (3.63 pounds) in 14 days. Blood sugar levels improved dramatically and insulin sensitivity improved by 75%.

Daly, M.E., et al. Short-term effects of severe dietary carbohydrate-restriction advice in Type 2 diabetes—a randomized controlled trial. Diabetes Medicine, 23 (2006): 15-20. Compared with a low-fat/reduced-calorie diet, weight loss was much better in the low-carb group over three months, and HDL ratio improved.

Davis, Nichola, et al. Comparative study of the effects of a 1-year dietary intervention of a low-carbohydrate diet versus a low-fat diet on weight and glycemic control in type 2 diabetes. Diabetes Care, 32 (2009): 1,147-1,152. The Atkins diet was superior—for weight loss and glycemic control—when measured at three months, when compliance by both groups was still probably fairly good. After one year, the only major difference they found was lower HDL cholesterol in the low-carb eaters. 

Elhayany, A., et al. A low carbohydrate Mediterranean diet improves cardiovascular risk factors and diabetes control among overweight patients with type 2 diabetes mellitus: a 1-year prospective randomized intervention study. Diabetes, Obesity and Metabolism, 12 (2010): 204-209. In overweight type 2 diabetics, a low-carbohydrate Mediterranean diet improved HDL cholesterol levels and glucose control better than either the standard Mediterranean diet or American Diabetes Association diet, according to Israeli researchers.

Haimoto, Hajime, et al. Effects of a low-carbohydrate diet on glycemic control in outpatients with severe type 2 diabetes. Nutrition & Metabolism, 6:21 (2009). DOI: 10.1186/1743-7075-6-21. A low-carbohydrate diet is just as effective as insulin shots for people with severe type 2 diabetes, according to Japanese investigators. Five of the seven patients on sulfonylurea were able to stop the drug. 

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 (2008). DOI: 10.1186/1743-7075-5-14. Obese people with type 2 diabetes following a 20% carbohydrate diet demonstrated sustained improvement in weight and blood glucose control, according to Swedish physicians. Proportions of carbohydrates, fat, and protein were 20%, 50%, and 30% respectively. Total daily carbs were 80-90 g. Hemoglobin A1c, a measure of diabetes control, fell from 8% to 6.8%. These doctors had previously demonstrated that a 20% carbohydrate diet was superior to a low-fat/55-60% carb diet in obese diabetes patients over six months.

Vernon, M., et al. Clinical experience of a carbohydrate-restricted diet: Effect on diabetes mellitus. Metabolic Syndrome and Related Disorders, 1 (2003): 233-238. This groundbreaking study demonstrated that diabetics could use an Atkins-style diet safely and effectively in a primary care setting.

Westman, Eric, et al. The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutrition & Metabolism, 5 (2008). DOI: 10.1186/1743-7075-5-36. Duke University (U.S.) researchers demonstrated better improvement and reversal of type 2 diabetes with an Atkins-style diet, compared to a low-glycemic index reduced-calorie diet.

Yancy, William, et al. A low-carbohydrate, ketogenic diet to treat type 2 diabetes [in men]. Nutrition & Metabolism, 2:34 (2005). DOI: 10.1186/1743-7075-2-34. A low-carb ketogenic diet in patients with type 2 diabetes was so effective that diabetes medications were reduced or discontinued in most patients. The authors recommend that similar dieters be under close medical supervision or capable of adjusting their own medication, because the diet lowers blood sugar  dramatically.

Yancy, W., et al. A pilot trial of a low-carbohydrate ketogenic diet in patients with type 2 diabetes.  Metabolic Syndrome and Related Disorders, 1 (2003): 239-244. This pioneering study used an Atkins Induction-style diet with less than 20 grams of carbohydrate daily.

So there!

Steve Parker, M.D.

h/t to Reijo Laatikainen for tweeting the European article.

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Deteriorating Brain Function Linked to High Insulin Levels and Insulin Resistance: Here’s How You Fight Back

dementia, memory loss, Mediterranean diet, low-carb diet, glycemic index, dementia memory loss

Don’t wait to take action until it’s too late

Insulin resistance and high blood insulin levels promote age-related degeneration of the brain, leading to memory loss and dementia according to Robert Krikorian, Ph.D.  He’s a professor in the Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati Academic Health Center.  He has an article in a recent issue of Current Psychiatry – Online.

Proper insulin signaling in the brain is important for healthy functioning of our brains’ memory centers.  This signaling breaks down in the setting of insulin resistance and the associated high insulin levels.  Dr. K makes much of the fact that high insulin levels and insulin resistance are closely tied to obesity.  He writes that:

“Waist circumference of ≥100 cm (39 inches) is a sensitive, specific, and independent predictor of hyperinsulinemia for men and women and a stronger predictor than body mass index, waist-to-hip ratio, and other measures of body fat.”

Take-Home Points

Dr. Krikorian thinks that dietary approaches to the prevention of dementia are effective yet underutilized.  He mentions reduction of insulin levels by restricting calories or a ketogenic diet: they’ve been linked with improved memory in middle-aged and older adults.

Dr. Krikorian suggests the following measures to prevent dementia and memory loss:

  • eliminate high-glycemic foods like processed carbohydrates and sweets
  • replace high-glycemic foods with fruits and vegetables (the higher polyphenol intake may help by itself)
  • certain polyphenols, such as those found in berries, may be particularly helpful in improving brain metabolic function
  • keep your waist size under 39 inches, or aim for that if you’re overweight

I must mention that many, perhaps most, dementia experts are not as confident  as Dr. Krikorian that these dietary changes are effective.  I think they probably are, to a degree.

The Mediterranean diet is high in fruits and vegetables and relatively low-glycemic.  It’s usually mentioned by experts as the diet that may prevent dementia and slow its progression.

Read the full article.

I’ve written before about how blood sugars in the upper normal range are linked to brain degeneration.  Dr. Krikorian’s recommendations would tend to keep blood sugar levels in the lower end of the normal range.

Steve Parker, M.D.

PS: Speaking of dementia and ketogenic, have you ever heard of the Ketogenic Mediterranean Diet?  (Free condensed version here.)

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Filed under Carbohydrate, Dementia, Glycemic Index and Load, ketogenic diet

Low Glycemic Index Diets Reduce LDL and Total Cholesterol

…according to a recent report in Nutrition, Metabolism & Cardiovascular Disease. LDL cholesterol is the type we think contributes to coronary artery disease and other forms of atherosclerosis.

Learn about glycemic index at NutritionData.

My Low-Carb Mediterranean and Ketogenic Mediterranean Diets are undoubtedly “low glycemic index.”  The Advanced Mediterranean Diet would also be significantly lower GI than the standard American diet.

Steve Parker, M.D.

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Filed under Glycemic Index and Load, Heart Disease

Random Thoughts On Paleo Eating for People With Diabetes

Not really pertinent, but I like buffalo

I was interviewed a couple months ago by Amy Stockwell Mercer, author of Smart Woman’s Guide to Diabetes. All I knew beforehand was that she was interested in my thoughts on the paleo diet as applied to diabetes.  I think she had run across my PaleoDiabetic blog.

In preparation, I collected some random thoughts and did a little research.

What’s the paleo diet?

Fresh, minimally processed food. Meat (lean or not? supermarket vs yuppiefied?), poultry, eggs, fish, leafy greens and other vegetables, nuts, berries, fruit, and probably tubers.

Non-paleo: highly processed, grains, refined sugars, industrial plant/seed oils, legumes, milk, cheese, yogurt.

The paleo diet is also called Old Stone Age, caveman, ancestral, hunter-gatherer, and Paleolithic diet.

Is the paleo diet deficient in any nutrients?

A quick scan of Loren Cordain’s website found mention of possible calcium and vitamin D deficits. Paleoistas will get vitamin D via sun exposure and fish (especially cold-water fatty fish). Obtain calcium from broccoli, kale, sardines, almonds, collards. (I wonder if the Recommended Dietary Allowance for calcium is set too high.)

What About Carbohydrates and Diabetes and the Paleo Diet?

Diabetes is a disorder of carbohydrate metabolism. In a way, it’s an intolerance of carbohydrates. In type 1 diabetes, there’s a total or near-total lack of insulin production on an autoimmune basis. In type 2 diabetes, the body’s insulin just isn’t working adequately; insulin production can be high, normal or low. In both cases, ingested carboydrates can’t be processed in a normal healthy way, so they stack up in the bloodstream as high blood sugars. If not addressed adequately, high blood glucose levels sooner or later will poison body tissues . Sooner in type 1, later in type 2. (Yes, this is a gross over-simplification.)

Gluten-rich Neolithic food

If you’re intolerant of lactose or gluten, you avoid those. If you’re intolerant of carbohydrates, you could avoid eating them, or take drugs to help you overcome your intolerance. Type 1 diabetics must take insulin. Insulin’s more optional for type 2’s. We have 11 classes of drugs to treat type 2 diabetes; we don’t know the potential adverse effects of most of these drugs. Already, three diabetes drugs have been taken off the U.S. market or severely restricted due to unacceptable toxicity: phenformin, troglitazone, and rosiglitazone.

Humans need two “essential fatty acids” and nine “essential” amino acids derived from proteins. “Essential” means we can’t be healthy and live long without them. Our bodies can’t synthesize them. On the other hand, there are no essential carbohydrates. Our bodies can make all the carbohydrate (mainly glucose) we need.

Since there are no essential carbohydrates, and we know little about the long-term adverse side effects of many of the diabetes drugs, I favor carbohydrate restriction for people with carboydrate intolerance. (To be clear, insulin is safe, indeed life-saving, for those with type 1 diabetes.)

That being said, let’s think about the Standard American Diet (SAD) eaten by an adult. It provides an average of 2673 calories a day. Added sugars provide 459 of those calories, or 17% o the total. Grains provide 625 calories, or 23% of the total. And most of those sugars and grains are in processed, commercial foods. So added sugars and grains provide 40% of the total calories in the SAD. (Figures are from an April 5, 2011, infographic at Civil Eats.)

Anyone going from the SAD to pure Paleo eating will be drastically reducing intake of added sugars and grains, our current major sources of carbohydrate. Question is, what will they replace those calories with?

That’s why I gave a thumbnail sketch of the paleo diet above. Take a gander and you’ll see lots of low-carb and no-carb options, along with some carb options. For folks with carbohydrate intolerance, I’d favor lower-carb veggies and judicious amounts of fruits, berries, and higher-carb veggies and

Will these cause bladder cancer? Pancreatitis?

tubers. “Judicious” depends on the individual, considering factors such as degree of residual insulin production, insulin sensitivity, the need to lose excess weight, and desire to avoid diabetes drugs.

Compared to the standard “diabetic diet” (what’s that?) and the Standard American Diet, switching to paleo should lower the glycemic index and glycemic load of the diet. Theoretically, that should help with blood sugar control.

A well-designed low-carb paleo diet would likely have at least twice as much fiber as the typical American diet, which would also tend to limit high blood sugar excursions.

In general, I favor a carbohydrate-restricted paleo diet for those with diabetes who have already decided to “go paleo.” I’m not endorsing any paleo diet for anyone with diabetes at this point—I’m still doing my research. But if you’re going to do it, I’d keep it lower-carb.  E.g., under 100 g of digestible carb daily. It has a lot of potential.

Are There Any Immediate Dangers for a Person With Diabetes Switching to the Paleo Diet?

It depends on three things: 1) current diet, and 2) current drug therapy, and 3) the particular version of paleo diet followed.

Remember, the Standard American Diet provides 40% of total calories as added sugars and grains (nearly all highly refined). Switching from SAD to a low-carb paleo diet will cut carb intake and glycemic load substantially, raising the risk of hypoglycemia if the person is taking certain drugs.

Drugs with potential to cause hypoglycemia include insulin, sulfonylureas, meglitinides, pramlintide, and perhaps thiazolidinediones.

Who knows about carb content of the standard “diabetic diet”? Contrary to poplular belief, there is no monolithic “diabetic diet.” There is no ADA diet (American Diabetes Association). My impression, however, is that the ADA favors relatively high carbohydrate consumption, perhaps 45-60% of total calories. Switching to low-carb paleo could definitely cause hypoglycemia in those taking the aforementioned drugs.

One way to avoid diet-induced hypoglycemia is to reduce the diabetic drug dose.

A type 2 overweight diabetic eating a Standard American Diet—and I know there are many out there—would tend to see lower glucose levels by switching to probably any of the popular paleo diets. Be ready for hypoglycemia if you take those drugs.

Paleo diets are not necessarily low-carb. Konner and Eaton estimate that ancestral hunter-gatherers obtained 35 to 40% of total calories from carbohydrates. I’ve seen other estimates as low as 22%. Reality likely falls between 22 and 65%. When pressed for a brief answer as to how many carbohydrate calories are in the paleo diet, I say “about a third of the total.” By comparison, the typical U.S. diet provides 50% of calories from carbohydrate.

Someone could end up with a high-carb paleo diet easily, by emphasizing tubers (e.g., potatoes), higher-carb vegetables, fruits, berries, and nuts (especially cashews). Compared with the SAD, this could cause higher or lower blood sugars, or no net change.

A diabetic on a Bernstein-style diet or Ketogenic Mediterranean Diet (both very-low-carb) but switching to paleo or low-carb paleo (50-150 g?) would see elevated blood sugars. Perhaps dangerously high glucoses.

Any person with diabetes making a change in diet should do it in consultation with a personal physician or other qualified healthcare professional familiar with their case.

Steve Parker, M.D.

Fun Facts!

  • A typical carbonated soda contain the equivalent of 10 tsp (50 ml) of sugar.
  • The typical U.S. adult eats 30 tsp (150 ml) daily of added sweeteners and sugars.
  • U.S total grain product consumption was at record lows in the 1970s, at 138 pounds per person. By 2000, grain consumption was up by 45%, to 200 pounds per person.
  • Total caloric sweetener consumption (by dry weight) was 110 pounds per person in the 1950s. By 2000, it was up 39% to 150 pounds.
  • Between 1970 and 2003, consumption of added fats and oils rose by 63%, from 53 to 85 pounds. [How tasty would that be without starches and sugars? Not very.]
  • In 2008, “added fat” calories in the U.S. adult diet were 641 (24% of total calories).

Fun Facts provided by the U.S. Department of Agriculture.

 

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