In How the Pieces Fell into Place – part 1 I described how I discovered the negative impact on nutrition of sugar/carbohydrates on good health, but where, and how, did it fit in to the elaborate jigsaw puzzle known as life ? In part 2, I will delve a little deeper on the topic of sugar (and carbs) and some of the problems arising from over-consumption.
Sugar, is the common name for sucrose, a disaccharide composed of one molecule of glucose and one of fructose. The chemical formula is C12H22O11.
Sucrose is rapidly absorbed following ingestion and prompts a rapid elevation of blood sugar levels, which in turn initiates a powerful endocrine response that is designed to mitigate the increases in blood glucose. Hormones released from the pancreas and adrenal cortex include insulin, glucagon, epinephrine and cortisol. Insulin lowers blood glucose level and glucagon elevates it – they work antagonistically attempting to maintain it within acceptable bodily limits.
Let’s take a step backwards to help us better understand the present and the future…
For thousands of years, humanity’s exposure to sucrose was typically limited to the content found in fruit. Prior to the late 18th/early 19th century sugar consumption was usually less than 25lbs per year, however mechanization of the production process reduced the cost and created vast new untapped markets ready to be exploited. All of which led to today’s massive consumption of on average, between 130 and 150 lbs of sugar each year in the US. Many people do not realize that sugar is frequently used as a cheap filler in processed foods and can be as addictive as cocaine ! It also possesses no nutritional value beyond pure calories.
There are several modes of action by which sugar can impact normal bodily function, including tooth decay and direct irritation of Gastro-Intestinal tissues. However, it is increased hormonal responses – of which higher insulin levels appear to be the primary instigator of degraded health – that are the most significant.
Many people are familiar with The Glycemic Index or GI, (a measure of the rate of increase of blood sugar following ingestion of a specific food, expressed relative to the standard, glucose, which is defined at a GI of 100). A few years ago there began a push to focus dieters on the GI for the various foods being consumed. Now in the absence of better nutritional information, the index would help, but unfortunately it is not a panacea and leaves a lot to be desired. For example, it takes no account of the size of the serving of the individual food item, rather it is based on testing 50g of the said item. Clearly many foods are eaten in greater or lesser quatities per serving. The GI also considers foods in isolation, rather than in the traditional meal setting consisting of multiple food items eaten together. Finally, different food storage and preparation methods which can influence the GI number are not taken into consideration.
To counter the serving size issue the Glycemic Load was developed which merely takes the GI value and multiplies it by the typical serving size.
Well this is better than the GI alone, but still has some glaring deficiencies, primarily the fact that there are several foods with low GI/GL scores that can instigate unexpectedly high insulin responses. At this point I was getting very frustrated as I could not find a clear answer to my nutritional dilemma. Enter the Insulin Index and a closer examination of the effects of insulin on the body.
Coming next : How the Pieces Fell into Place – part 3…Insulin, the hormone that quite literally shapes your life.