Another South African study bears fruit

In this country, we spend billions and billions of dollars on medical research. And millions and millions more on public health education campaigns, which misinform the public. So, it’s quite shocking to think about how little real science exists on some of the most basic questions about the human diet.

For example, very few studies examine the health effects of eating fruit.

So when I came across a new study about fruit–published in the Journal of the American Medical Association–I was really excited. And, even though it’s small in scope, I just had to share it with you.

For the study, South African researchers recruited 17 Bantu and white adults aged 20 to 64 years. Prior to the outset of the study, both groups consumed a conventional western diet.

Then, researchers instructed the participants to begin a fruit-based diet. On this diet, participants ate about 20 servings of fruit per day. They also ate nuts to meet basic micronutrient requirements.

Most fruits contain about 10 g of fructose per “serving.” So if my calculations are correct, it means that participants consumed about 200 grams of fructose per day. That’s almost half a pound of fructose!

This is an extraordinarily high amount. Certainly much, much more than any nutritionist would ever recommend.

And how do you think the participants fared eating this much sugar? Did they gain weight? Did their blood sugar shoot through the roof?

Of course not.

Remember, fructose is natural sugar. Your body recognizes it. And easily metabolizes it, as I said yesterday.

In fact, the South African researchers found no ill effects whatsoever from this very high-fructose diet. Participants did not increase their body weight, blood pressure, insulin, cholesterol, or lipid levels after 12 to 24 weeks.

That’s right.

The participants followed this tremendously high sugar diet for three to six months.

And during this period, researchers actually observed some slight improvements in markers of health.

By comparison, sucrose is a different beast altogether. As you’ll recall from yesterday’s article, sucrose is a refined sugar that combines fructose with glucose. Your body absorbs sucrose rapidly. And it overwhelms your metabolic pathways, contributing to obesity and chronic disease. Even cancer.

But, amazingly this is relatively new scientific knowledge.

At the National Cancer Institute, diet and cancer research finally got started in the early 1980s. At the time, the conventional wisdom was that all sugar was “safe.” And we should be looking at fat as one of the primary causes of cancer.

Until the 1990s, most health experts considered high sugar consumption “harmless.” And possibly even protective against obesity and related diseases because it “displaced” the supposedly evil dietary fats.

About 10 years ago, the American Heart Association finally linked sugar intake to weight gain. And it recommended substantial decreases in daily consumption.

But still, some “experts” miss the target, and caution against fruit for its high fructose content.

Don’t believe them.

Now you know better. And your doctor should too–thanks to this groundbreaking South African research.

Of course, the reality is that people eat foods, not nutrients. And they consume diets, not nutrition. Bad foods and bad diets have too much sugar and too much fat.

In the end, try to practice moderation in all things.


1. “Examining the Health Effects of Fructose,” Journal of the American Medical Association, (, published online 6/3/2012.