It appears that too much fructose in the diet, can lead to the chronic health problems, so how much fructose is safe?
In the first part of this investigation of fructose, I explained the cascade of reactions that takes place in the body in the presence of high fructose intake. I examined the relationship between fructose, metabolic syndrome, AGEs, low fat and low cholesterol diets and their effects on health.
While much of the research into this question is obscure, a growing body of research suggests that greater than 50 grams of fructose a day is detrimental and may start to cause metabolic syndrome and all the consequent problems.
However, some suggest that 25 grams should be the limit, and for people with known metabolic syndrome or its risk factors, 15 grams of fructose a day.
From the book The Sugar Fix: The High Fructose Fallout that is Making You Fat and Sick by Richard Johnson and Timothy Cower, this chart can help you determine how much fructose you get from some of the fruits you are eating.
As you can see, certain fruits are rather low in fructose, and others are really high. If you are not eating any processed foods or soft drinks, you can easily figure out how much you are eating in a day.
Essentially, eating 3 – 4 pieces of fresh fruit a day will give you well under the 50 gm limit that is suggested. That is assuming you are not drinking any HFCS (high fructose corn syrup) in soft drinks or fruit juices.
If you eat processed foods and drink even one soft drink a day, you are getting way more fructose than you should. HFCS is in many processed foods and sodas and will add quite a high amount of fructose and cause weight gain.
Fruit juices also have a great deal of fructose, almost as much as soda. I have never been a big fan of fruit juice. It is empty sugar calories without any nutrition and highly glycemic, because all the fiber is removed. Having all that fructose makes fruit juice even less appealing.
In general, an 8 ounce glass of fruit juice has about 25 gms of sugar which means it has about 12 gms of fructose. In comparison, a 12 ounce can of soda has about 40 gms of sugar and about 20 gms of fructose.
You can see how easy it is to over indulge in fructose when you are drinking these sweet drinks.
Fructose raises uric acid, and uric acid inhibits nitric oxide bioavailability. Insulin requires nitric oxide to stimulate glucose uptake. Studies show if there is a lack of nitric oxide due to inhibition by increased levels of uric acid, this leads to fructose-induced hyperuricemia which may have a pathogenic role in metabolic syndrome.
Dr. Richard Johnson is the chief of the division of kidney disease and hypertension at the University of Colorado, and author of The Sugar Fix, one of the best books on the dangers of fructose.
According to the latest research in this area, the safest range of uric acid is between 3 and 5.5 milligrams per deciliter. There appears to be a steady relationship between uric acid levels and blood pressure and cardiovascular risk, even down to the range of 3 to 4 mg/dl.
Dr. Johnson suggests that the ideal uric acid level is probably around 4 mg/dl for men and 3.5 mg/dl for women. He feels that serum uric acid may be used as a good indicator of sensitivity to fructose.
At your next physical exam, ask your doctor to include the serum uric acid test with the rest of your blood work.
The impact of fructose on nitric oxide also has effects on blood pressure. Dysregulation of blood pressure is another aspect of metabolic syndrome.
Too much fructose has an extremely negative effect on your health.
How much fructose do you eat in a day? Leave a comment and let me know!