by Catherine W. Britell, M.D.
For most of our lives we have been told that “eating more fruits and vegetables” will make us healthier and leaner. Who hasn’t heard the adage, “An apple a day keeps the doctor away?”
Note: This article is intended to help us to pick the best fruits for us, it does not advise fearing all fruits. Nutrient dense fruits are amazing!
Three things about fruits that a lot of people have found helpful:
1. Not all fruits are created equal (aka blueberries are generally preferable to conventional apples)
2. Fruits are not the same as non-starchy veggies (aka 10+ servings of leafy greens per day = good while 10+ servings of bananas per day may not be as helpful for individuals struggling with their body composition)
3. If you are struggling with fat loss and you are eating sufficient non-starchy veggies, nutrient dense protein, and whole food fats, replacing some fruits with some additional non-starchy veggies may be helpful
Yet, now we learn that fructose, the “fruit sugar”, is really not very good for us. As a matter of fact, increased fructose intake in the form of high fructose corn syrup is being blamed in large part for the skyrocketing incidence of obesity and diabetes.
In order to understand why this is the case, it’s useful to think about the availability of energy over the many thousands of years during which our ancestors evolved. They “lived off the land”, and the living wasn’t easy; but in the summertime there was fruit. The fruit of old was, of course, nothing like the sweet cultivars of today. The sugar content was much lower, but the amazing thing about fruit then as now was fructose. What was so useful about fructose for our ancestors and problematic for us was/is that it cannot be metabolized by any cells other than those in the liver.
Fructose doesn’t require insulin in order to be absorbed into the liver cells, and it is converted there to triglycerides, which can then be easily stored as fat in the liver and adipose tissues. Furthermore it doesn’t cause an increase in insulin, doesn’t stimulate leptin(satiety hormone)production, , and actually increases ghrelin (hunger hormone), so you can eat lots of fructose without feeling full, and indeed, ingesting fructose will make you feel even hungrier. This was a great advantage to our ancestors, leading to automatic fat storage without blunting the appetite, causing sleepiness, or decreasing alertness. And of course, those who were best at storing fat during the summertime survived the winter and were thus more successful at reproduction. So, every molecule of fructose was “metabolic and genetic money in the bank” for our ancestors.
But obviously, we’re different. We do not lack enough fat to get through the winter – for most of us, the opposite is true. Furthermore, fructose in the form of very sweet fruits and more significantly when added to processed foods in the form of high-fructose corn syrup, is available in huge quantities year-round. That’s a recipe for increased serum triglycerides, heart disease, obesity, fatty liver, and a number of other “modern” health issues.
So, if fructose can be bad for us, why eat any fruit at all? Why indeed? Well, for one thing, it really tastes good. More importantly, many fruits are highly NUTRITIOUS. For example, here are some wonderfully nutritious fruits:
- slow down effects of aging on cognitive function
- prevent cancer
- add healthy fiber
- very high in antioxidants and vitamins
- lower blood sugar
- decrease inflammation (lower C-Reactive Protein)
- High in soluble fiber
- High in vitamin C, pantothenic acid, niacin, vitamin-B6 (pyridoxine), vitamin E and K,
- High in magnesium, copper, and manganese.
- High Vitamin C
- Prevents kidney stones
- Prevents cancer
- Decreases cholesterol
- High in Fiber
- High in Vitamin C, Vitamin A, tryptophan
- low in sugar; NO FRUCTOSE
- Very high in potassium
- High in thiamin
- Very high in vitamin B6
- Very high in vitamin C
So, how should we consider fruit? Highly edible, for the most part. For those of us who are naturally thin and healthy, we should be able to eat as much of our favorite fruits as we wish. For those whose goal, however, is to decrease our body fat, we may wish to limit our fruit intake to one or fewer servings per day, and concentrate on those fruits that have a lower total sugar and particularly lower fructose content.
Here below is a list that I compiled from a number of online sources showing the various sugar content in selected fresh and dried fruits. By comparison, I’ve include Coke Classic® in the list. It’s important to remember that all values are per 100 mg. (Nobody ever stops at 100 mg – 100 cc – of Coke)
Cathy (craving some blueberries right now)
DrCathy’s Big Fruit List – Sugars in Fresh and Dried Fruits
|Total Sugars||Glucose||Galactose||Fructose||Sucrose||Maltose||Total Metabolic
Comparison with High-Fructose soft drink
***Note: All values are per 100 g. (Nobody ever stops at 100 g – 100 cc – of Coke)