[Prev][Next][Index][Thread]
Micronutrition (fwd)
---------- Forwarded message ----------
Date: Fri, 18 Feb 1994 05:21:20 -0500
From: Bob Cruder <miacoden!bcruder@CSN.ORG>
To: Multiple recipients of list GARDENS <GARDENS@UKCC.uky.edu>
Subject: Micronutrition
One major failure of the "green revolution" is a slow but consistent
alteration in the trace mineral content of foods. Soil constituents break
down at a fixed rate regardless of the amount of vegetable matter that
intensive farming can produce.
While plants require three macro-nutrients (NPK) and another half-dozen
or so micro-nutrients, humans require more. Those extras are not included
in fertilizer because they do not increase yield, apparent quality or
market price. The resultant produce becomes more nutrient poor over time.
The macro-nutrients that are applied in chemical fertilizers are produced
by industrial processes that yield trace amounts of heavy metals which
are not ordinarily present in soil. These potentially toxic materials
have been increasing over time.
The following numbers come from the November 1993 Journal of Applied
Nutrition and compare the mineral content of commercial produce to
organic produce (which is similar to that of vegetables produced before
the "green revolution"). The percentages are averaged for apple, pear,
potato, wheat and corn but would be similar for leafy crops as well.
Element % Comment
Aluminum 167 No nutritional use, implicated in Alzheimer's
Boron 59 Required for calcium metabolism
Cadmium 95 No nutritional use, carcinogenic
Calcium 61 Required to prevent osteoporosis
Chromium 56 Cofactor for insulin/glucose utilization
Cobalt 100 Component in vitamin B12
Copper 68 Deficiency implicated in arthritis and CHD
Iodine 58 Required for thyroid hormone production
Iron 63 Required for hemoglobin/myoglobin production
Lead 141 No nutritional need, neurotoxic
Lithium 46 General need unproven, used to treat BAD
Magnesium 42 Lowers blood pressure, cofactor in calcium use
Manganese 36 Used in antioxidant enzymes, deficiency symptoms
include premature loss of hair pigment.
Mercury 133 Neurotoxic
Nickel 60 No nutritional use
Phosphorus 52 With calcium a component of bone
Potassium 44 Deficiency causes hypertension, neurological
damage and cardiac arrest.
Rubidium 139 No nutritional use
Selenium 20 Used in antioxidant enzymes, deficiency reduces
protection against cancer, infection and age
related damage.
Silicon 54 Cofactor for growth of skin, hair, nails and
bone
Sodium 39 Deficiency not likely
Strontium 43 No nutritional need
Vanadium 93 Cofactor for insulin/glucose utilization. Can
reverse type II diabetes.
Zinc 63 Used in anti-oxidant enzymes. Deficiency
implicated in cataracts, macular degeneration,
loss of taste/smell and immune deficiencies.
Extremes included corn with 6% of natural manganese content and apples
with 1000% of natural mercury content.
I suggest that even if worldwide food production can be made to keep up
with rising population, (an unlikely event in the opinion of the
Worldwatch Institute and most world governments) the quality of that food
may decline to the point that mortality due to deficiency/toxicity
exceeds that from starvation.
Bringing formerly cultivated land back into use is likely to exacerbate
the effects noted above since mineral exhaustion or pollution was what
took it out of use in the first place. While organic farming methods can
restore nutritional value, they cannot currently match the yield that the
world requires from such staples as cereal grains.
That yield cannot be maintained by current methods anyway. An
International Rice Research Institute research farm in Los Banos found
that yield from the best yielding rice varieties declined 40% in a 24
year period starting in 1968 using the best fertilization technique and
in spite of improvements in the rice varieties during that period.
The twofold solution is obvious, organic methods AND major reductions in
world population. Neither will suffice alone.
Bob Cruder - bcruder@miaco.com