Glycemic Index Shockers

Boy, am I ignorant. That’s all I can say for myself. I’ve railed on about the dangers of diabetes, and sugar, and white foods, and those dangers are very real. But I didn’t know many easy, practical ways to lower the glycemic index (“GI”) of my diet. And I didn’t succeed in caring for my pancreas.

The wake-up punch was a sky-high triglycerides reading in my latest blood test. Basically, pre-diabetic numbers.

But, I switched from delicious white breads to uh … tangy … whole wheat, many years ago! The only bagels I eat are whole-wheat and pumpernick bagels! I cook and eat lots of vegetables! Surely I had been virtuous.

No. Lately (okay, since the holidays) my diet has backslid toward the awesome side: chocolate truffles, white bialys, spaghettini with pesto or bolognese, whole-corn chips and tortillas, a respectable cherry pie from my local Shoprite, etc. (It’s the cetera that get ya.)

I found the GI of 100 foods at http://www.health.harvard.edu/diseases-and-conditions/glycemic_index_and_glycemic_load_for_100_foods  .  There are many shockers.

The average whole-wheat bread barely beats out Wonder Bread, 69 to 73! (lower is better.) The fineness of the flour makes a huge difference. So do other factors besides for fiber and sugar. The French “plain white baguette” scored a pancreas-popping 96 GI! A typical bread with 50% cracked wheat kernels scores a middling 58, and pumpernick, 56. Thankfully, the plain corn chips and whole-corn tortillas score a nice low GI.

A”coarse barley bread, 80% kernels” scores a super-low 34. But isn’t that just baking a mound of barley?  Soon we will know; I have an old Hitachi bread baker, and I just found the manuals online.

Foods often have a worse GI after more processing. Average macaroni scores 50, but Kraft mac’n’cheese comes in at 64. Oatmeal scores a low 55, but the instant version? 79. Most unsweetened fruit juices have acceptable GI, even though they can be a source of empty sugar calories. But most juice “drinks” and juice “cocktails”, as labelled in the USA, have loads of added sugars and high GI. Few soft drinks have low GI. Some soft drinks have more sugar in the USA than the same product in some other countries, and the USA version has a higher GI.

The shape of pasta makes a huge difference! So does the cooking time – more boiling causes a worse GI! For instance, the average boiled spaghetti comes in at a low 46, while after twenty minutes of boiling, it scores a 58. Ordinary Fettucini tested at 32 GI while whole-grain spaghetti came in worse, at 46! Apparently the extra cooking time needed for whole-grain outweighs the extra fiber.

Cooking also transforms many root crops, from medium GI when they are boiled, to high GI when they are roasted! The roasting liberates the sugars so they taste sweeter and the sugar is absorbed faster. You cannot win.

In general, more fiber and less sugar improves the GI, but not in every case. Fatty candies like those truffles actually do not have high GI. (Yes, they still are full of “empty calories”.)

In some cases, I see no clear pattern, so the list is extra helpful. All sorts of potatoes (like Idahos and russets) have medium or high GI. So do sweet potatoes (the white or light yellow smallish American yams). But ordinary yams (such as the bright orange ones) score a low GI when boiled. Since there are dozens of types of yams and roots worldwide, from purple yams to cassava to taro, it may be wise to consult the longer list (see link below), which has about 200 entries for root crops. Many are listed by botanical name, so this may provide a relaxing afternoon of figuring out what’s what.

So what to do, if you desire a long and happy relationship with your pancreas? Eat fruits and vegetables and beans and protein foods. (Meats and fatty products do not cause diabetes, but some can increase cancer and heart disease.)  Bake with coarse grains, rolled oats, fruits, and no sugar or honey or syrup. Or, buy products made that way. Avoid most breads and cereals, and use the list to find ones with low GI. Avoid most root crops: find ones with low GI on the lists, and cook by boiling, not roasting. You too can feel the joys of quinoa and parsnips!

Getting technical: these numbers are on a scale where glucose = 100. On that scale, 55 and below are scores for “low-GI foods”, which should be relatively safe for a person who does not have diabetes. These are from the 2008 survey article by Dr. Fiona S. Atkinson, Dr. Kaye Foster-Powell, and Dr. Jennie C. Brand-Miller in the magazine “Diabetes Care”. As that article says, many results are from very few tests on very few people, so some inaccuracies can be expected. Their full results for over 2000 foods are at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2584181/bin/dc08-1239_1.pdf .

 

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