Dr. Weil on Organic Foods

[Guest guest]

Are Organic Foods Unsafe?

Provided by DrWeil.com

Q: A relative of mine who is an oncologist recently told me that

organic foods harbor a highly carcinogenic fungus. He said that

exposure to pesticides is less of a risk and that in fact the

pesticides and other chemicals take care of the fungus. I am

confused. Can you help? -- Harriet

A: With all due respect to your relative, this is a bogus argument

against organic foods. True, there are carcinogenic fungi, but they

don't develop on fruits and vegetables. One of the most troublesome

fungal carcinogens found in foods is aflatoxin, produced by certain

strains of the molds Aspergillus flavus and A. parasiticus that grow

on peanuts stored in warm, humid silos. Peanuts aren't the only

problem sources; aflatoxin has been found in pecans, pistachios and

walnuts, as well as milk, grains, soybeans and spices. Aflatoxin is

a potent carcinogen, known to cause liver cancer in laboratory

animals and may contribute to the incidence of liver cancer in

Africa where peanuts are a dietary staple. Aflatoxin occurs in both

organic and conventionally grown foods.

I'm not telling you about aflatoxin to worry you, but to point out

what foods are most likely to harbor carcinogens from fungi. (The

United States government routinely tests crops for aflatoxin and

doesn't permit them to be used here for human or animal food if they

contain levels over 20 parts per billion.)

Over the years, there have been a number of assaults on organic

foods. In 2000, the ABC News program 20/20 carried a report in which

experts stated that consumers should be more concerned about

bacteria on organic produce than about pesticide residues on

conventionally produced fruits and vegetables. However, the report

conceded that bacteria can also be found on conventional produce and

that both types of fruits and vegetables should be thoroughly washed

before eating. Oncologists sometimes worry that the immune-

suppressive effects of chemotherapy leave cancer patients more

vulnerable to infections, including food-borne ones. Food-borne

infections from produce are rare and are just as likely from

conventional produce as organic.

Although we don't yet have many studies demonstrating the

differences between organic and conventionally grown foods, proving

that one is better than the other, there is evidence of pesticide

residues in 71 to 90 percent of conventionally produced foods

compared to 13 to 23 percent of organically grown foods. Pesticides

are definitely not good for you.

To guard against bacteria (and remove pesticides), carefully wash

and rinse berries, green beans, and other fruits and vegetables that

you can't peel and remove the outer leaves of leafy vegetables.

Unfortunately, water alone won't do the trick - use a drop or two of

dish detergent in a small tub of water and rinse thoroughly after

washing. You should also check the lists of the most and least

contaminated crops provided by the Environmental Working Group

(http://www.foodnews.org/walletguide.php).

Weil, MD

Last Reviewed: March 2005