Tag: johnson

The Sugar Fix: Chapter 2: The birth of dietary sugar comes about 10,000 years ago in New Guinea. Johnson states that this moment is one that alters history as few other discoveries have.

Sugar is a carbohydrate, one of three macronutrients in our diet (carbohydrate, protein and fat).
Table sugar or sucrose is disaccharide made of the joining of glucose with fructose. Lactose another disaccharide is made from the joining of glucose with galactose.

Fructose is he sweetest monocachide, about twice as sweet as glucose. Most high fructose corn syrup is about 50-60% fructose about he same amount of fructose as found in table sugar. Honey is 70% fructose. Almost all of the fructose we get in our diet comes from sweeteners added to foods.

The drive to eat sweet foods is inherent in our humanness. We don’t need to be taught that fruit tastes better than vegetables. Johnson lays out a teleological argument that follows:

• sweet foods offer a survival benefit by promoting weight gain due to their caloric density.
• weight gain is enhanced by the fact that they don’t promote satiety, so you can over eat, an advantage when food is in short supply and spoilage prevents storing leftovers
• the tendency of fructose to raise blood pressure may have offered a survival advantage to ancestors living on salt poor diets who suffered from chronic hypotension

He suspects that ancient humans ate only 15-20 grams of fructose a day (equivalent to two pieces of fruit) this compares to contemporary humans eating 70-80 g a day.

India was the first country to boil the juice from the New Guinea sugar cane to produce crystalized sugar.

Persian invaders brought home sugar and then the Arab invaders of the 7th century spread sugar from Persia to the rest of the Middle East.

The crusades brought sugar back to England in 1099.

Sugar was thought to have medicinal values and sold at pharmaceutical like prices. In 1319, sugar cost the equivalent of $50 per pound.

Sugar was one of the crops which supported the slave trade between Africa, North America and Europe.

England became a dominant producer of sugar and by 1700, the English were ingesting 4 lbs of sugar a year.

The democratization of sucrose accelerated following the discovery of the by which sugar could be extracted from beets.

In 1866 scientists in Buffalo invented a way to convert corn starch into sweet tasting corn syrup. Corn syrup is made of glucose chains of varying lengths. There is no fructose in corn syrup, so it is not as sweet as sucrose.

In the 1960s, glucose isomerase was discovered. THIS enzyme could convert some of the glucose in corn syrup to fructose ushering in high fructose corn syrup (HFCS).

HFCS is cheaper than sugar mainly because of the phenomenal overproduction of corn in this country. See the Omnivore’s Dilemma. By the end of the 70’s Americans were eating 10 pounds of HFCS every year.

In 1982 the US Government began to limit the amount of sugar which could be imported every year and by 1984 both Coke and Pepsi converted from sucrose to HFCS as the primary sweetener in their respective colas. The sweetwener in most colas is HFCS-55 which has 55% fructose only slightly more than sucrose, 50%.

Johnson states that another common variety of HFCS found in non-carbonated fruit juices is HFCS-42 (42% fructose).

He then claims that much of the harm from HFCS is not because it is anymore toxic than equal amounts of sucrose but rather that, its low-cost has resulted in more consumption.
This explains the expansion in the sizes an portions over the last 20 years. He points out the change in the size of a single serving of Coke. In the fifties it was 6.5 oz and now I am seeing 1 liter bottles (33 ozs) for sale.
The conclusion of the chapter has this wonderful sentence:

More to the point, the composition of basic nutrients that most people eat today is vastly different from what early humans consumed, or even what the typical American ate a century ago.

Johnson starts The Sugar Fix with the assertion that a century ago heart disease, diabetes and obesity were rare conditions.

In 1890 a survey of 5,000 US citizens revealed that only 3.4% of Americans were obese and they were typically isolated to the upper class. This compares to a contemporary rate of 32%. Two thirds of Americans are either overweight or obese. This includes one third of school children. This obesity rate has doubled since 1976 (CDC Source). The rapid increase in girth cannot be explained by genetics. Johnson feels that the rapid change in the frequency of obesity exonerates genetics as the cause, he states that the human genome has been relatively stable going back a few thousand years.

This leaves an environmental change. He then considers and discards changes in physical activity as the etiology. This is supported by the most recent analysis revealed at the 2009 European Congress on Obesity.

Johnson goes on to implicate fructuse. He states that fructose intake has increased 30% since the 1970’s. Fructose is the main source of sugar in fruit. It is half of the molecule sucrose, table sugar. In 1970 the average American consumed half a pound of High Fructose Corn Syrup. By 2000 that had increased to 42 pounds a year. Though HFCS consumption has risen by two orders of magnitude, fructose exposure has only gone up by 30%. This likely means that HFCS has largely replaced the prior source of fructose in the diet, table sugar. The authors don’t address that inconsistancy in this chapter.

Fructose causes obesity through multiple mechanisms:

• fructose causes more and faster weight gain than seen with other sugars
• fructose does not satisfy your appetite resulting in more calorie intake
• increased fructose dulls the brains responce to the normal satiety signals so that following chronic fructose exposure subjects eat more as they don’t sence “fullness”
• fructose upregulates enzymes which promote obesity

Johnson believes that other conditions have increased in prevalence in lockstep with the increased exposure to fructose including:

• hypertension: 73 million Americans
• diabetes: 20 million Americans (CDC Source)
• kidney disease: 20 million Americans
• liver disease: emergence of NASH, now effect 2-5% of Americans (NIDDK Source)
• metabolic syndrome 55 million Americans

The mechanism linking fructose and these problems comes from multiple metabolic consequences of fructose:

• fructose is the only sugar which increases the production of uric acid which leads to hypertension
• fructose increases the production of triglyceridesand lowers HDL
• fructose causes insulin resistance
• fructose causes kidney disease

This last section is not supported by any references or data but Johnson promises to reveal the details later in the book.