Of late, the words “toxic”, “sugar” and “fructose” have been
widely used together, implying a most dangerous aspect of sugar on human
metabolism. The irony is that in Greek mythology, Cronus, the Titan leader was
fed so much honey that he fell into a deep sleep during which time his son Zeus
killed him. The original words of the Greek legend refer to the “intoxicating
effect” of the large intake of honey on Cronus. Just as we are amused but not
troubled by the language or beliefs of Greek mythology, we should not be so
troubled by the same nonsense reformulated in modern Californian
mythology. Honey was always held as a
truly prized food: hard to harvest, made by bees through some mysterious
process foreign to all other plant and animal foods, golden in colour and above
all, sweet as nothing else ever known to man. The sweetness of honey was down
to a combination of two simple sugars, fructose and glucose present at 55% and
45% respectively. Sugar, as we know it today, is also an ancient food but
newer, relatively speaking, than honey. It is plant-derived and the very first
commercial facility for the extraction of sugar in crystalline form from sugar
cane or sugar beet was located on the Island of Crete. The Arabian merchants who funded this
production facility had another name for Crete, which they called Qandi. Hence
the term “candy”, used today mainly in the US for sugar confectionary products.
The main component of this sugar derived from cane or beet is the sugar “sucrose”
which is a couplet of two sugars joined together, fructose and glucose.
Honey and particularly sugar, dominated the sweetness aspect
of the human diet. That was to change in the 1980’s with the advent of high
fructose corn syrup (HFCS) production, driven by simple economics. In the
period up to the early 1980’s, US and global sugar prices were pretty identical
and highly subject to wild fluctuations in market supply. Thus, in 1974 and
1979-1980, US and global sugar prices soared 5 fold in two separate market
peaks. The advent of a new technology that could replace sugar with an
identical alternative at a stable low price became a simple no-brainer. Sugar
was priced out of the US markets with strict import quotas introduced in the
early 1980s to maintain very high domestic sugar prices, double the global
price. HFCS was to almost completely
replace sugar in the US diet. The manufacture of HFCS is technically simple.
Starch, which is a polymer of glucose units, is extracted from corn and enzymes
are used to first break down the starch to glucose. Half the glucose is
converted to fructose, again using a simple enzyme system. The glucose and fructose can now be blended
together and the most popular blend with consumers was 55% fructose and 45%
glucose, an identical blend to that found in honey. HFCS intakes soared 8-fold in the US from
1975 to the 80s-90s. However, in recent years HFCS intake has fallen in the US
and is now back to values in 1980. During the surge in the use of HFCS, that of
sugar fell pro rata.
In 2004, some leading US obesity researchers published data
to show that the epidemic of obesity in the US coincided with the surge in HFCS
use in the food chain. Whilst most scientific commentators have dismissed this
putative link, the debate rages on with thousands of doom-laden Internet
postings fuelled by a handful of media-friendly scientists. The term “high
fructose corn syrup” was in hindsight a foolish name to introduce since HFCS is
quite simply not high in fructose, equal in fact to the level found in honey
and almost equal to the level found in sugar. Fructose is the element of HFCS
that has been singled out as the bad part and the research in this area leaves
a lot to be desired. To begin with, humans don’t and never have consumed fructose
in isolation. It is always consumed with glucose and thus experiments in humans
or animals using diets with high fructose levels with no accompanying glucose
are basically unrealistic. They may show what is possible but they have no
bearing on what is probable. In a paper presented to the US Experimental
Biology conference in 2012[1],
the levels of fructose used in these diets was compared to the average daily
intake of fructose by US adults. In every one of the 37 human studies and every
one of the 21 animal studies, the level of fructose used exceeded the US
average intake value (9% of calories). Of course the average hides high
consumers so this paper also looked at the fructose intake of the top 5% of
fructose consumption (15% of calories). Only 3 human and 1 animal study were at
or below this very high level of intake. The majority of animal studies used as
much as 55% of calories from fructose, a situation, which is impossible to
envisage in the human diet except maybe in the make-believe land of milk and
honey.
None of these studies needed to be funded since a natural
experiment was being acted out on both sides of the Atlantic. Just as the US
jacked up sugar prices to promote HFCS usage, in the EU sugar beet farmers were
protected under the CAP limiting the use of HFCS to 5% of total supply. Thus
beverages in the US contain HFCS whilst beverages in the EU do not.
Nonetheless, obesity levels have grown dramatically either side of the
ocean. While the debate on HFCS rages on
the Internet, two key organisations have pinned their colours to the mast. Both
the American Medical Association[2]
and the American Dietetic Association[3]
have issued position statements dismissing any claim that HFCS use contributes
to obesity or associated biochemical abnormalities of blood lipids or blood
glucose.
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