Thursday, April 12, 2012
Fructose to the rescue
Many claim fructose should be avoided especially for people with the so-called metabolic syndrome. Yudkins started most of the hysteria with his book "Pure, White and Deadly", during the time "the cholesterol hypothesis" was very popular and he argued that it was fructose and not fat that raised the so-called "bad lipids". Uffe Ravnskov member of the editorial board of cholesterol has reviewed the literature and he see's no connection between blood lipids and disease(0).
In 1864 Dr. William Budd in England used large amounts of sucrose to treat diabetes, P.A. Priorry did the same in France in 1867.
Free fatty acids block glucose metabolism.(1) One of the points where free fatty acids block glucose is at the point where it is converted to fructose. When fructose is available it can bypass this barrier to the use of glucose and continue to provide pyruvic acid for oxidative metabolism. If mitochondria are damaged and not producing energy pyruvate can leave the cell as lactate allowing continued glycolitic energy. This can provide enough energy to the brain to sustain life in an emergency.
Liver has the highest capacity for metabolizing fructose but other organs and skeletal muscles can metabolize it via the Glut5 expression.(2, 3)
The ability of mitochondria to oxidize pyruvic acid and glucose is lost to some degree in cancer.(4) This disturbed redox balance of the cell will usually lead to the cell's death but if the cell can survive, the disturbed redox balance favors growth and cell division, rather than the normal differentiated function. Fructose prevents oxidative damage by maintaining and restoring the cell's redox balance(5).
Fructose lowers serum phosphate and fruit is protective against prostate cancer by lowering serum phosphate(6). Age suppressing gene Klotho suppresses the re-absorption of phosphate by the kidneys and inhibits the formation of activated vitamin D opposing the effect of the parathyroid hormone. In the absence of the gene animals serum phosphate is high; these animals age and die prematurely(7). Serum phosphate is increased in osteoporosis(8), treatments that lower serum phosphates improve bone remineralization with retention of calcium phosphate(9). Close association between high serum phosphate in normal range in humans and increased risk of cardiovascular disease has been found(10). Increase in respiratory quotient and co2 production by fructose/glucose is probably a factor for lowering serum phosphates because high altitude and carbonic anhydrase inhibitor increase blood co2 and decrease serum phosphate(11,12,13).
Sucrose is less fattening than glucose because more calories can be consumed without gaining weight. In one study rats ate 50% more calories in the form of coca cola or sucrose compared to a normal diet without gaining additional weight(14)
Fructose protects against Vitamin D deficiency in rats(15).
Sucrose is used to decrease pain in many settings including infants and adults.(16)