Friday Facts: Isn’t Fruit Full of Sugar?

Once again I’m posting one small section from Dr. Michael Greger’s excellent book “How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease which I HIGHLY recommend buying and reading.

What About All the Sugar in Fruit?

There are a few popular diets out there that urge people to stop eating fruits because their natural sugars (fructose) are thought to contribute to weight gain. The truth is, only fructose from added sugars appears to be associated with declining liver function, high blood pressure, and weight gain. How could the fructose in sugar be bad but the same fructose in fruit be harmless? Think about the difference between a sugar cube and a sugar beet. (Beets are the primary source of sugar in the United States. ) In nature, fructose comes prepackaged with the fiber, antioxidants, and phytonutrients that appear to nullify adverse fructose effects.

Studies show that if you drink a glass of water with three tablespoons of sugar (similar to what would be in a can of soda), you’ll have a big spike in your blood sugar levels within the first hour. That causes your body to release so much insulin to mop up the excess sugar that you actually overshoot and become hypoglycemic by the second hour, meaning that your blood sugar drops even lower than it would if you were fasting. Your body detects this low blood sugar, thinks you might be in some sort of famine situation, and responds by dumping fat into your bloodstream as an energy source to keep you alive. This excess fat in the blood can then go on to cause further problems. (See chapter 6.)

But what if you eat a cup of blended berries in addition to the sugar? The berries, of course, have sugars of their own— an additional tablespoon’s worth— so the blood sugar spike should be even worse, right? Actually, no. Study participants who ate berries with their cup of sugar water showed no additional blood sugar spike and no hypoglycemic dip afterward; their blood sugar levels merely went up and down, and there was no surge of fat into the blood.

Consuming sugar in fruit form is not only harmless but actually helpful. Eating berries can blunt the insulin spike from high-glycemic foods like white bread, for example. This may be because the fiber in fruit has a gelling effect in your stomach and small intestine that slows the release of sugars or because of certain phytonutrients in fruit that appear to block the absorption of sugar through the gut wall and into your bloodstream. So eating fructose the way nature intended carries benefits rather than risks.

Low-dose fructose may actually benefit blood sugar control. Eating a piece of fruit with each meal could be expected to lower, rather than raise, the blood sugar response. What about people with type 2 diabetes? Diabetics randomized into a group restricted to no more than two daily pieces of fruit had no better blood sugar control than those randomized into a group told to eat a minimum of two pieces of fruit per day. The researchers concluded that “the intake of fruit should not be restricted in patients with type 2 diabetes.”

Surely there must be some level of fructose consumption that’s harmful even when served in Mother Nature’s green-light form, right? Apparently not.

Seventeen people were asked to eat twenty servings of fruit per day for months. Despite the extraordinarily high fructose content of this fruit-based diet— the sugar equivalent of about eight cans of soda a day— the investigators reported beneficial outcomes with no overall adverse effects for body weight, blood pressure, insulin, cholesterol, and triglyceride levels. More recently, the research group who invented the glycemic index found that feeding subjects a fruit-, vegetable-, and nut-based diet that included about twenty servings of fruit per day for a couple of weeks had no adverse effects on weight, blood pressure, or triglycerides— all while lowering LDL (“ bad”) cholesterol by an astounding thirty-eight points.

– Excerpt from “Greger MD, Michael; Stone, Gene. How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease.” 

What is interesting to me about this is the recent research that has linked spikes in blood sugar to triggering dementia and Alzheimers. For example:

Alzheimer’s could be caused by excess sugar: new study finds ‘molecular link’

I hope that this research does not cause people to stop eating fruit!

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