Tag Archives: glycemic index

Olive Oil Helps Control After-Meal Blood Blood Sugars

Steve Parker MD, Advanced Mediterranean DIet

Naturally low-carb Caprese salad: non-paleo 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.

I don’t know if results of this study apply to those with type 2 diabetes. Probably, but uncertain. (google it!)

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.

PS: No olive trees were killed to produce my book.

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

 

Do High Insulin Levels Cause Memory Loss and Dementia?

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. Krikorian 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. His theory is also consistent with the commonly seen association of type 2 diabetes with dementia: overweight and obese type 2’s quite often have high insulin levels, at least in the early years.

Dr. K 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 (99 cm), or aim for that if you’re higher and overweight

Nearly all popular versions of the paleo diet would qualify as being low glycemic index.

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

Do Tomatoes Have Too Many Carbohydrates?

Eat greens for vitamin K

Looks reasonable to me

Dr. Richard Bernstein wrote a great book advocating strict carbohydrate restriction for folks with diabetes.  I’m talking about a max of 30 grams a day, compared to 250–300 g in the standard American diet.

Dr. Bernstein cautions his diabetic patients and readers of Diabetes Solution to keep a tight lid on consumption of tomatoes.  An excerpt from page 149:

If you have them uncooked in salad, limit yourself to one slice or a single cherry tomato per cup of salad.

His concern is that tomatoes will raise your blood sugar too high.

That doesn’t make sense to me.  A 3-inch diameter tomato has 7 grams of carbohydrate, 2 of which are fiber.  So the digestible carb count is only 5 grams.  That’s not much.  So do tomatoes have a high glycemic index?  Unlikely, although it’s hard to be sure.  Good luck finding a reliable GI for tomatoes on the Internet.

I think Dr. Bernstein’s wrong about this one, which is rare.  I suppose it’s possible that tomatoes deliver some other substance to the bloodstream that interferes with carbohydrate metabolism, but Dr. Bernstein doesn’t mention that.

Do tomatoes play havoc with your blood sugars?

Steve Parker, M.D.