The metabolic syndrome may be caused by a high fructose, and relatively low fat, low cholesterol diet

This paper was published in the Archives of Medical Science 2011 Feb;7(1):8-20

Study title and authors:
Is the metabolic syndrome caused by a high fructose, and relatively low fat, low cholesterol diet?

Seneff S, Wainwright G, Mascitelli L.
Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, USA.

This paper can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/22291727

The metabolic syndrome is a term that has been used to describe a number of risk factors such as elevated triglyceride levels, small sized dense low density lipoprotein (LDL) cholesterol particles, low levels of high-density lipoprotein (HDL) cholesterol, obesity, insulin resistance, glucose intolerance and elevated blood pressure, and it is associated with an increased risk of type II diabetes and coronary heart disease.

The authors have developed a new hypothesis regarding metabolic syndrome; namely it is a consequence of a high intake in carbohydrates and food with a high glycemic index, particularly fructose, and relatively low intake of cholesterol and saturated fat.

The authors show how the risk factors for metabolic syndrome may be exacerbated by the above way of eating:
(a) Elevated triglyceride levels: Studies show that higher levels of dietary fructose lead to increased triglyceride levels and that zero-cholesterol diets have been shown to increase triglyceride levels.
(b) Small sized low density lipoprotein (LDL) cholesterol particles: The liver normally clears the dangerous small sized dense low density lipoprotein (LDL) cholesterol. However in conditions of excess dietary fructose (fructose is converted to fat by the liver) the liver is overwhelmed and cannot keep up in clearing all the dangerous small sized dense low density lipoprotein (LDL) cholesterol.
(c) Low levels of high-density lipoprotein (HDL) cholesterol: The scientific literature shows that low levels of high-density lipoprotein (HDL) cholesterol is the best predictor of heart disease and is associated with an increased risk of type II diabetes. This may be because that low concentrations of bile salts correspond to a reduction of HDL levels and that low-fat, high fructose diets lead to reduced bile salts because of the reduced need for the bile salts to digest fats.
(d) Obesity: Studies reveal that the obese are often deficient in vitamin D. The best sources of vitamin D are foods rich in saturated fat such as lard, butter and egg yolk.
(e) Insulin resistance: Scientific papers reveal that the overconsumption of fructose leads to liver insulin resistance.
(f) Glucose intolerance: In high carbohydrate, low fat diets, glucose and fructose enter the bloodstream very rapidly due to the abundance of carbohydrates and the lack of buffering in the gut by dietary fats. This causes a sharp rise in blood glucose levels and the excessive glucose and fructose may damage proteins.
(g) Blood pressure: Depleted amounts of cholesterol in the outer shells of fat cells weaken the structure of the cell walls and leads to sodium leakage, which results in excess sodium in the bloostream. This causes the blood vessels to constrict with the resulting increase in blood pressure.

The findings of this paper suggest the metabolic syndrome may be caused by a high fructose, and relatively low fat, low cholesterol diet.

Seneff concludes: "We would urge medical practitioners to encourage individuals exhibiting metabolic syndrome to strongly limit the consumption of dietary fructose and other high-glycemic-index carbohydrates, and to stop discouraging them from consuming foods rich in cholesterol."

Links to other studies:
High dietary intake of fructose leads to diabetes
LDL cholesterol size: does it matter?
Beneficial effects of a high fat, low carbohydrate diet on fat reduction in type 2 diabetic patients with obesity

Excessive intake of fructose may cause Type II diabetes

This paper was published in Endocrine Reviews 2009 Feb;30(1):96-116

Study title and authors:

Hypothesis: could excessive fructose intake and uric acid cause type 2 diabetes?

Johnson RJ, Perez-Pozo SE, Sautin YY, Manitius J, Sanchez-Lozada LG, Feig DI, Shafiu M, Segal M, Glassock RJ, Shimada M, Roncal C, Nakagawa T.
Division of Nephrology, Hypertension and Transplantation, University of Florida, P.O. Box 100224, Gainesville, Florida 32620-0224, USA. johnsrj@medicine.ufl.edu

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/19151107

Johnson puts forward the hypothesis that excessive fructose intake of more than 50 grams per day may be one of the underlying causes of metabolic syndrome (a precursor to type II diabetes) and type II diabetes. Johnson chose the amount of 50 grams per day of fructose as excessive because studies show that obesity rates rise as fructose consumption rises above this amount.

Major sources of fructose are sugar (sucrose) and high fructose corn syrup which were all but absent from the diet in previous eras, but which are now in many, many food products.

Johnsons research unearths the following:
(a) A 30% increase in fructose consumption over the last 30 years has coincided with large rises in the rates of obesity and diabetes.
(b) The ingestion of excessive fructose induces features of metabolic syndrome such as high fasting blood sugar levels, high triglyceride levels, high blood pressure, abdominal weight gain and low levels of the beneficial high density lipoprotein (HDL) cholesterol.
(c) Fructose raises uric acid levels which are implicated in the development of the metabolic syndrome.

This paper shows that type II diabetes may result from the excessive intake of fructose.