Ann's NOTE: It has been shown that our fruits and vegetables contain uneven amounts of nutrients. Studies point out that food grown on the east coast may contain less selenium than from other areas. Studies have shown that organically grown fruits and vegetables contain more nutrients than commerically-grown, pesticide sprayed produce.
Here is information on how food preparation affects nutrients: (excerpts)from Ralph Moss, Ph. D. Weekly Cancer Decisions, Newsletter #114, 1/04
Two studies published late last year suggest that
many people may be eating fruits and vegetables that
are seriously lacking in vitamins and antioxidants.
test done at one of Spain's major research centers
measured the levels of flavonoids (a kind of
antioxidant) that remained in fresh broccoli after it
was cooked by four popular methods--steaming, pressure
cooking, boiling or microwaving.
The authors looked at both the total flavonoid content
as well as several derivatives in the edible portion of
freshly harvested broccoli.
The results, they said,
"showed large differences among the four treatments in
their influence on flavonoid…content in broccoli."
Conventional boiling led to a 66 percent loss of
flavonoids compared to fresh raw broccoli.
cooking was not much better, with 47 percent of one of
the major antioxidants left after cooking (the majority
of it was found in the cooking water, which is usually
tossed down the drain.) There was a major disadvantage
detected when broccoli was microwaved. The loss of
flavonoids with that method was an incredible 97
"On the other hand," the Spanish authors wrote,
"steaming had minimal effects, in terms of loss" of
antioxidants. In fact, there was almost no difference
in antioxidants between raw and steamed. "Therefore we
can conclude that a greater quantity of phenolic
compounds [i.e. compounds with antioxidant activity -
ed.] will be provided by consumption of steamed
broccoli as compared with broccoli prepared by other
Blanching and Storing
Many people, pressed for time, resort to frozen foods
instead of fresh. But what are the effects of blanching
foods, i.e., soaking them in hot water, which is
commonly done before commercial freezing?
In a separate
study, Finnish scientists found that blanching and
long-term freezing of 20 commonly used vegetables also
affected the level of various beneficial compounds in
Blanching, they discovered, destroyed
up to one-third of the vitamin C content of vegetables,
and this was followed by a further slight loss during
storage. Folic acid turned out to be particularly
sensitive to blanching, with more than half of this
important B vitamin being lost, although levels
remained stable during freezer storage.
sterols (also common antioxidant compounds) were not
affected by either blanching or freezer storage.
Dietary fiber was not adversely affected and minerals
in general were stable. But phenolic antioxidants and
vitamins were much more sensitive. There was a 20-30
percent loss of antioxidant activity detected in many
From this pair of studies we can see that if you buy a
package of frozen broccoli in the supermarket and then
microwave it according to instructions you will be
getting almost NONE of the antioxidants and vitamins
you expected from this food.
The same is probably true
of other vegetables. Blanching and freezing will take
away some nutrients, and then harmful (albeit very
common) ways of cooking will take away the rest.
has profound implications for the National Cancer
Institute's five-a-day fruit and vegetable program. It
is clearly not just the QUANTITY of fruits and
vegetables that matters but the QUALITY as well.
The best idea is to
buy fresh organic produce at the health food store or
food coop, and then to steam it until it reaches a
degree of "done-ness" that agrees with your digestion
While some cooking is usually desirable,
less is better. Steaming baby bok choi with Asian
mushrooms, or broccoli rabe, collard greens, and
endive can be good.
Try adding tofu, cooked brown rice, and some
seafood (avoiding those varieties with high mercury
content). Season with saffron, sesame oil or tamari
--Ralph W. Moss, PhD
Vallejo F, Tomás-Barberán FA, García-Viguera C, et al.
Phenolic compound contents in edible parts of broccoli
inflorescences after domestic cooking. Journal of the
Science of Food and Agriculture Volume 83, Issue 14 , Pages
1511 - 1516. Published Online: 15 Oct 2003
Puupponen-Pimiä R, Häkkinen ST, Aarni M, et al. Blanching
and long-term freezing affect various bioactive compounds of
vegetables in different ways. Journal of the Science of Food and
Agriculture. Volume 83, Issue 14 , Pages 1389 - 1402
Published Online: 15 Oct 2003
SOURCE: Ralph W. Moss, Ph.D. Weekly CancerDecisions.com
Newsletter #114 01/04/04
Food Additives & Contaminants, 11/06
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