Introduction
Some unscrupulous (and some well-meaning--but uninformed) companies
and their vendors attempt to pass off a graviola supplement product
as equivalent to paw paw. In fact, some companies go so far as
to call their product "Paw Paw"--attempting to capitalize
on the good name of paw paw and even justifying their deception by
saying that graviola is sometimes called "Brazilian paw
paw." Graviola is also known by other names, such as
"guanabana" and "soursop".
The reported use of
graviola as an anti-carcinoma treatment has gone back for
decades. While some people have no doubt seen some success
with graviola, it is important to note the differences and
understand why it is not even close to an equivalent substance to
paw paw when used for this purpose.
Tests
were done under the direction of Dr. Jerry McLaughlin on two leading
graviola products on the market. The first one had
a cyto-toxic potency level of about 4% of the potency of paw paw--in
other words, paw paw had about 24 times
the potency of this product. The second leading
graviola product had a potency level of 2% that of paw paw; so paw
paw was about 50 times as potent as that product.
These results should be unacceptable to those serious about using a
product of this nature to fight cancer.
As will be further
explained below, there are two big
differences between graviola products and paw paw.First, and probably most important,
is the chemistry structure. The chemistry
structure of the graviola compounds does not allow it to be as
potent as that of the paw paw acetogenins. Second,
the manufacturing process of graviola products is inferior
in that it is generally consists of grinding powder from leaves,
twigs, or other parts of the plant. With this type of very
unsophisticated manufacturing process, the amount of active
acetogenins will vary widely by batch, and the amount in any
selected bottle is unknown to the consumer.
Dr. McLaughlin, while
known for his work with paw paw, also did testing of graviola
during his long research career. He not only isolated the
acetogenin compounds in paw paw that have been seen to fight cancer,
but he also found the compounds in graviola and is an expert on the
differences. He did two separate research projects on graviola
leaves, twigs, and seeds, and isolated 28 acetogenin compounds from
that plant.
He has written about
these compounds in many papers (over
300 total!) that he
published, most of them published in prestigious publications such
as the Journal of Natural Products, Heterocycles, Journal
of the American Chemistry Society, Phytotherapy Research,
Journal of Organic Chemistry, Journal of Medicinal
Chemistry, and others. Several of these papers note the
chemical differences between the acetogenins found in the two
species, and discuss what makes those in paw paw much more powerful.
The Scientific and
Physical Distinction
The scientific name of the paw paw used by Dr. McLaughlin in his
research is Asimina triloba. It is a North American
species of paw paw. Although botanically, the paw paw and
graviola are related (both are of the Annonaceae family),
they are not the same--any more than an apple and a pear are the
same. The scientific name of the graviola is Annona
muricata. If one looks at the photographs of the two
below, the physical difference is obvious. Paw paw is on the
left, and graviola is on the right.
Brief History
In the 1970's, the National Cancer Institute started funding Dr.
Jerry McLaughlin at Purdue University to find botanical substances
that had anti-cancer potential. He tested and screened over
3500 species of plants, and found that the acetogenin compounds of
the Annonaceae family had the most potential. He--along with
13 of his Ph.D. students and others--worked with the various species
of this family, including the paw paw and graviola. They found
and isolated over 400 acetogenins in this family, and used some very
sophisticated chemical modeling techniques to determine and show the
differences. About 50 acetogenins
were found in the paw paw, and about 30 in the graviola.
Chemistry
Differences
Of more importance than the number of acetogenins found in each
plant are the potency of these compounds. Dr. McLaughlin and
his students did chemical structure analysis on many of these
compounds, and without exception found that those acetogenins with a
"double ring" chemical structure were many, many times
more powerful than those with only single ring structures. In
fact, Dr. McLaughlin went further to isolate "triple" ring
structured compounds--only to find that they also were inferior to
double ring. The pictures below show 2 different acetogenin
chemical structures--both of which are found in paw paw but NOT
in graviola. These acetogenins (bullatalicin and
bullatacin) have double ring structures. Note the proximity of
the two ring structures to each other. All of the
acetogenins in graviola do NOT have a double ring structure--only
single ring--and this chemical structure causes them to have only a
fraction of the potency of paw paw. (For reference, it is Bullatacin
that was tested by Upjohn Company--now Pfizer--to be 300 times the
potency of Taxol, a leading chemotherapy drug.)
Bullatacin
Bullatalicin
Manufacturing
Differences
The graviola products on the market typically advertise themselves
as "freshly ground powder" of twigs, leaves, etc.
This type of manufacturing process has two main advantages for the
manufacturer--but not the customer. First, it is cheap to
produce. Second, it is easy enough that just about anyone can
do it.
However, there is a
problem--and it is a big one. Dr. McLaughlin found in his
research that the level and potency of the acetogenins--even in
paw paw--varies according to time of year. In fact, it
varies drastically. If the twigs are not harvested during
the month of May, they are essentially worthless. Also, the acetogenin
potency varies even from tree to tree in the same grove!
Again...drastically! The problem remains then, how does the
manufacturer guarantee that the customer gets the required
acetogenin level in each and every capsule of product?
The answer is
standardization. A process must be developed or used by
the manufacturer to test every single batch of product produced and
determine whether or not the potency level is present.
Furthermore, the manufacturing process must be able to allow and
compensate for different levels of acetogenins in order to get the
proper level in each and every capsule. If the product is made
(as are the typical graviola products) simply by grinding up the raw
ingredients and putting them into capsules, there is not much way to
make any adjustments--after all, you can only fit so much material
into the capsule, whether or not it has any acetogenins or
not. Thus, graviola manufacturers generally do not
standardize their products. This process is not easy,
since every single batch of material must be tested and adjustments
made.
However, the process for
that that Dr. McLaughlin developed for the paw paw uses an
extraction of the acetogenins from the paw paw twigs. This
process allows the manufacturer to adjust the acetogenin level
somewhat to be able to guarantee a set amount in each capsule.
Thus, the customer is assured of proper potency.
Much can be said about
the differences. If you would like to hear Dr. McLaughlin
speak on this directly, we invite you to view his Power Point
presentation, which can be access from our Visual
Resources page. If you would like to listen only to the
audio of the slide addressing the testing of the two leading
graviola products, click the player below (you
must have Windows Media Player on your computer). If you would
like to see him discuss on a video clip, go to our Visual
Resources page and click on the appropriate link under the
Question and Answers with Dr. McLaughlin.
