Most fruits and many vegetables contain fructose. It makes up half of table sugar. In table sugar, fructose combines with glucose to make sucrose. Small amounts of fructose cause no problems. However, large amounts contribute to hypertension and fatty liver. A diet of high potassium foods naturally limits fructose, so excessive fructose is no concern.
Fructose In The American Diet
On the modern American diet, the average American eats about 55 gm of fructose. But approximately 100 years ago the average American ate only about 15 gm of fructose. Most of the increase today comes from beverages containing sugar, specifically sodas. And sodas are not one of the high potassium foods.
Additionally, other sources are the high fructose syrups added to many foods to sweeten them. If you eat a high potassium diet, you eat mostly foods as they are found in nature. This means you avoid dishes with added fructose. The fruit and vegetables in the high potassium diet will contribute about 15 gm of fructose. So you will consume about the same amount of fructose as your ancestors consumed in the early twentieth century.
Effects Of Too Much Fructose
Excessive fructose in the diet has two bad direct effects. One is that it causes the liver to process the extra fructose (the only place it is processed) into excessive fatty acids and triglycerides. When their levels get too high they contribute to plaque in the arteries, and accumulation of fat in the liver cells. Consequently, this leads to nonalcoholic fatty liver disease (NAFLD), and a reduction in liver function. And up to a third of American adults have some form of NAFLD.
Another undesirable effect of too much fructose is increased sodium resorption and absorption. In particular, the intestinal cells absorb more sodium in the presence of fructose. And the kidney cells resorb more sodium. Consequently, too much sodium and not enough potassium in the body contribute to hypertension, osteoporosis and kidney stones.
However, if you are on the high potassium diet, you are getting more than 3 times as much potassium as sodium. You are protecting yourself from these possible effects that others on a low potassium diet will get as a result of the increased sodium resorption.
Too Much Fructose?
How much is too much fructose? There is no sharp line between enough and too much. Fifteen grams a day should be fine. Fifty five grams may be too much. 55 gm of fructose is about 22 teaspoons of sugar, since half of sugar (sucrose) is glucose and half is fructose.
If you eat the portions we discussed in this post, you will avoid getting too much fructose. Even if your fruit and vegetable portions are mostly fruit you should be in a very healthy range.
Next post will include a table of the high potassium fruits with the amount of fructose they contain.
The “Links To Food Potassium Tables” tab at the top of the page has a list of tables by food group. Click on the food group with your food of interest to find a table listing its potassium and sodium content.