points out that some neutral spirits
contain as much as 1.5 grams/liter of methanol, what
is not mentioned is the fact if these spirits are at
least 60 proof (30% ethanol) this still represents the
presence of over 200 molecules of ethanol for every
molecule of methanol that is digested. An exhaustive
search of the present literature indicates that no testing
of natural substances has ever shown methanol appearing
alone; in every case ethanol is also present, usually,
in much higher concentrations. Fresh orange juices can
have very little methanol (0.8 mg/liter), and have a
concomitant ethyl alcohol content of 380 mg/liter. Long
term storage in cans has a tendency to cause an increase
in these levels, but even after three years of storage,
testing has revealed only 62 mg/liter of methanol, with
an ethanol content of 484 mg/liter. This is a ratio
of almost eight times ethanol/methanol. Testing done
recently in Spain showed orange juice with 33 mg/liter
methanol and 651 mg/liter ethanol (20/1 ratio). The
range for grapefruit juices are similar, ranging form
0.2 mg methanol/liter to 43 mg methanol/liter. The lowest
ratio or any food item was found in canned grapefruit
sections with 50- 70 mg/liter methanol and 200-400 mg/liter
ethanol, thus averaging six molecules ethanol for every
molecule of methanol.
This high ethanol to methanol ratio, even a these
low ethanol concentrations, may have some protective
effect. As stated previously, ethanol slows the rate
of methanol's conversion to formaldehyde and formate
allowing the body time to excrete methanol in the
breath and urine. Inhibition is seen in vitro even
when the concentration of ethyl alcohol was only 1/16th
that of methanol. The inhibitory effect is a linear
function of the log of the ethyl alcohol concentration,
with a 72% inhibition rate at only a 0.01 molar concentration
of ethanol. Therefore if a liter of a high methanol
content orange juice is consumed, with 33 mg/liter
of methanol and a 20/1 ratio of ethanol/methanol,
only one molecule of methanol in 180 will be metabolized
into dangerous metabolites until the majority of the
ethanol has been cleared from the bloodstream. If
a similar amount of methanol equivalent from aspartame
were consumed, there would be no competition.
Another factor reducing the potential danger associated
with methanol from natural juices is that they have
an average caloric density of 500 Kcal/liter and high
osmolarity which places very definite limits to their
consumption level and rate.TABLE 1
AVAILABLE METHANOL IN VARIOUS BEVERAGES
METHANOL mg/liter METHANOL (MG.) CALORIC DENSITY
Calories/Liter RATIO Consumed per 1,000 Calories *Methanol
(mg.) Ethanol (wt.) Methanol (wt.) Consumption per
day Juices *Orange, fresh28 1 470 2 475 1 *Orange,
fresh45 33470 70206 mg *Orange, fresh31 34470 72166
mg *Orange, canned2831470 66156 mg *Grapefruit, fresh27
1 400 1 2000 1 mg *Grapefruit31 43400 108 5 7 mg Grapefruit,
Canned31 27400 689 5 mg Grape15 12660 18---- Alcoholic
Beverages Beer (4.5%) 0 400 ------ Grain Alcohol55
1 2950 1 500000 -- Bourbon, 100 proof55 552950 199090
-- Rum, 80 proof15 732300 325000 -- Wines
