permaculture

[warning@norex.com.au (David de Vries)]

Dear All

Looking at the recent archives, I was interested in the natural carcinogen
thread.  I can lay some claims to expertise on this subject in a previous
life, including working at the National Cancer Institute in the US and pubs
like-

Blumberg, P.M., Pettit, G.R., Warren, B.S., Szallasi, A., Schuman, L.D.,
Sharkey, N.A., Nakakuma, H., Dell'Aquila, M.L. and de Vries, D.J.  The
protein kinase C pathway in tumor promotion.  In Skin Carcinogenesis:
Mechanisms and Human Relevance.  New York, Alan R. Liss (1989) 201-212.

de Vries, D.J., Herald, C.L., Pettit, G.R. and Blumberg, P.M. Demonstration
of sub-nanomolar affinity of bryostatin 1 for the phorbol ester receptor in
rat brain.  Biochemical  Pharmacology  37:4069-4073 (1988).

de Vries, D.J., McCauley, R. and Walker, F. Identification of acutely
active compounds within extracts of marine organisms using the EGF binding
site of human A431 cells. Toxicon  32:553-559 (1994).

The phorbols above are the active, irritant component of the Euphorbiaceae
and are v. potent tumor promoters.  I have always been sceptical of their
use in Pc e.g. living fences.

Dan Hemenway stated:
"Maybe a useful outcome of this discussion, if there is to be one, would be to
list known species (ege poke weed) and conditions (e.g. granite bedrock) that
create significant carcinogens.  I think we can readily get lists of known
plant and animal toxins and that this would be an excercise in reguritation
not worth the electrons.  A bibliography on plant toxins would be more
useful."

I am not sure a list or bibl. would be much use. In some agreement with
Ames, I generalise "everything causes cancer in the lab".  Curiously,
another  generalisation also applies "all life forms contain
anti-carcinogens".  A bibliography of the large number of plants and
animals that have been tested (and found positive) for carcinogens would be
a bit overwhelming.  Sorting through to identify the real environmental
threats (synthetic or organic) is the trick. The simplest course of action
is to apply a diversity approach to your lifestyle i.e. don't sit in the
same building breathing the same air and eating the same food grown and
prepared in the same manner.

To expand the discussion further, I recall the strongest epidemiological
evidence points to methods of food preparation being the most significant
causes of cancer esp. some pickling, BBQing and smoking techniques.

To expand further.. In Australia, my observation is that the incidence of
smoking tobacco (+commercial additives) amongst permies is higher than the
general population.  This, plus their penchant for sitting around
camp-fires is a bit suicidal...
The least they could do is vary the plant smoke they inhale!

Apologies for a long, wandering first post!

David