Cholesterol and glucose are two biochemicals and components of diet that generate interest among individuals concerned about healthy eating and living. Both are essential to life and health, but both can also have negative effects on the body, if consumed in the wrong proportions, due to the way in which they're metabolized.
Significance of Cholesterol
Though cholesterol is often vilified as a component of diet--mostly because the typical American diet is very high in cholesterol--it's actually an important biomolecule that contributes to cellular health and physical well being. Cholesterol, note Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry," helps maintain the integrity of cell membranes and is the starting material for many other important biomolecules, including the steroid hormones and vitamin D.
Significance of Glucose
Like cholesterol, glucose is often represented in a negative light. Even more than cholesterol, however, glucose is essential to life, and humans can't function normally without it. Ubiquitous in nature and in the diet, glucose is part of both table sugar and starch, and cells use it to provide for their energy needs. Explain Drs. Garrett and Grisham, while most cells can use any one of several different molecules for energy, some cells--brain cells in particular--rely especially on glucose.
Considerations
Because of the way in which human metabolism works, both dietary glucose and dietary cholesterol can end up leading to negative health effects. The cells require cholesterol so much that they can make it themselves--and in fact do so, using saturated fat as a starting material--meaning that excess consumption of cholesterol or of saturated fat leads to cholesterol overload. Similarly, the digestive tract takes up glucose for the cells, but certain sources of glucose lead to sugar overload.
Effects of Excess Cholesterol
Too much cholesterol in the body, either as a result of too much dietary cholesterol or too much dietary saturated fat, causes cholesterol to start building up in the bloodstream in the form of LDL, or low density lipoprotein, which is often called "bad cholesterol." This form of cholesterol, notes Dr. Lauralee Sherwood in her book "Human Physiology," can form plaques inside artery walls, narrowing arteries and increasing the likelihood of heart attack and stroke.
Potential for Glucose Overload
While the cells require glucose, they respond best to a steady supply. As such, rapid increases in blood sugar brought about by dietary intake of large quantities of simple sugars or refined--that is to say, white--starches can overload the body's metabolic ability to process glucose. As a result, explains Dr. Gary Thibodeau in his book "Anatomy and Physiology," the pancreas over-releases the hormone insulin, which leads to excess fat storage and can result in low blood sugar.
References
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
- "Human Physiology"; Lauralee Sherwood, Ph.D.; 2004
- "Anatomy and Physiology"; Gary Thibodeau, Ph.D.; 2007
