For the past two years I have been warning practitioners about the potentially harmful effects of fructose and sugars containing fructose. There is ample evidence that fructose plays a major role in the development of hypertension, obesity, metabolic syndrome and eventually kidney disease.
Annual sugar consumption in England in 1700 was 1.8kg per person. By 1950 this had risen to 45 kg per head, a staggering increase that has continued to get worse. Remember that sugar (sucrose) contains 50% fructose and is every bit as bad as fructose.
High fructose corn syrup now floods the market and is also similar in composition to sucrose. The extensive use of sucrose in foods and drinks by 1995 was more than 68kg per capita per year or >500 k cal/day and has been climbing steadily ever since.
Once inside the liver, fructose provides glycerol, the backbone for triglycerides. Hepatic metabolism of fructose favours lipogenesis.
Both fructose and sucrose can induce weight gain and features of the metabolic syndrome, increasing triglycerides and systolic BP while impairing glucose tolerance and inducing insulin resistance.
Starch does not do this, because starch is a polymer of glucose.
Fructose is a sugar that raises uric acid levels. Uric acid is an independent predictor of hypertension in 15 of 16 studies. Also a predictor of obesity, hyperinsulinemia and renal dysfunction.
Uric acid reduces endothelial nitric oxide causing vasoconstriction and systemic hypertension. Uric acid increases insulin, insulin resistance and triglycerides secretion in liver. It is quite likely that the fructose induced rise in uric acid is causing many of the common cases of gout and possibly kidney damage.
The high incidence in African Americans of obesity, hypertension, diabetes, kidney and heart disease may be due to their higher sugar intake and subsequent higher uric acid levels.
Though fructose increases the risk of heart disease and atherosclerosis, these can be lowered by reducing fructose consumption.
Overweight children eating large amounts of fructose have been shown to have higher triglycerides, lower HDL and smaller LDL particle size. The small LDL particles are the risk factors for heart disease. Total fructose intake was the only factor related to the small LDL particle size.
So basically, why would you prescribe nutritional or food supplements where fructose has been added as a sweetener when there is such a huge possibility of increasing blood pressure, triglycerides, uric acid, obesity, hyperinsulinemia, the dangerous smaller LDLs and metabolic syndrome.
Practitioners have been telling patients for many years to cut out sugar. New research indicates that we can extend this advise to cover fructose as well.