There are two main factors to consider when choosing between
organic and regular produce, namely pesticide
residues and nutrition.
Information
appears below. Freshness and flavor are important, but these
depend on more than how the crop is grown and when it is
harvested. I
recall reading somewhere that vegetables tend to be higher in
trace minerals than fruits. If correct, this means that
organic vegetables tend to be more important for nutritional content
than organic fruits.
It is sometimes argued that organic food is more expensive. This may be
true pound for pound, but that is misleading since it does not count health and
medical bills: The nutritional benefits (see below) can lead to better
health; pesticide residues may cause health problems in the long term.
- ANTIOXIDANT levels in crops
have fallen 50% in the past 25 years due to changes in farming and
processing (Nutr. Rse. 96:16 quoted in Alt. 11/02 p.132). Perhaps
fresh organic foods would have "normal" levels, but I've seen no
information on that.
- VITAMIN
B12 occurs in bacteria and can be obtained from eating
ruminants, unwashed foods, and nodules of some root vegetables.
The nodules are more likely to be found on organic root crops and are
lost when peeling.
- MINERAL CONTENT may be the most important nutritional
difference between organic and regular produce since heavy use of
fertilizer inhibits absorbtion of some minerals, which are likely to be
at lower levels to begin with in soils that have been
abused. This may be caused in part by the lack of beneficial
mycorrhizae fungi on the roots since high levels of fertilizer tend to
kill them. Standard diets tend to be
low in various minerals,
resulting in a variety of problems including osteoporosis and reduced
immune system.
The Baer report (Rutgers Univ.,
1984) "Variations in Mineral Contents of Vegetables" contained
information on organic versus regular crops. The
Macrobiotic Cancer Prevention Cookbook excerpted information on
five vegetables.
Entries are levels in regular crops as a percentage of levels in
organic crops Ash provides a measure of the amount of major
minerals present, but not trace minerals which I've listed
separately. I converted actual amounts to percentages and
rounded. Since I rounded, a zero does not mean total absence in
the regular crop. Excluding boron, only two trace minerals
entries had high percentages. These were due to low levels of the mineral in organic cabbage,
not high levels in regular cabbage, and so are not significant.
Levels of minerals in regular crops as a percentage
of levels in organic crops
(The lower the %, the better organic is for you.)
|
ash |
boron |
manganese |
iron |
copper |
cobalt |
snap beans |
40% |
15% |
2% |
5% |
5% |
0% |
cabbage |
60% |
15% |
15% |
21% |
0% |
0% |
lettuce |
30% |
15% |
1% |
2% |
5% |
0% |
tomatoes |
40% |
10% |
1% |
0% |
0% |
0% |
spinach |
40% |
15% |
1% |
1% |
0% |
0% |
High values in cabbage due to low
absolute levels of Mn and Fe in organic cabbage.