Law For Food: The law affects what you eat. What you buy to eat affects the law.

Protect Yourself: Eat Locally
2 May 2007, 1:28 pm
Filed under: Ethics of Eating, local v. industrial, Meat

Still looking for the science on this, but I found this paragraph, which encapsulates a lot of the benefits of buying local food.

Q: How can I make sure the food I buy is safe?

A: Cattle that are fed grass instead of grain have less E. coli O157:H7 in their intestines, but most of the beef in supermarkets is from grain-fed cattle. Some ranchers are raising grass-fed cattle, but the beef is more expensive. You can purchase grass-fed beef online from specialty ranches.

In general, it is better to buy locally grown produce. Crops grown on vast industrialized farms have a greater potential for contamination, especially if they are near large cattle feedlots. Packaged spinach and salads contain products from various farms; during sorting, shipping and packaging, the bacteria from one farm can taint the produce from other farms and regions. Produce sold at local Farmers’ Markets usually comes from small farms not located near cattle feedlots. Pay attention to news bulletins if there is an outbreak of E. coli O157:H7 in your area. Throw out any food they advise may be contaminated.

The science on grain-fed beef and E. Coli O157:H7 (the nasty one, and in this post the one I mean when I write “E. Coli”) appears to come from a study published in Microbes and Infections in January 2000 (Vol. 2, Iss. 1, p. 45 ff). The idea, as far as I can tell, is that while a cow’s rumen is pH neutral, feeding it a grain-heavy diet lowers the stomach pH, changing the mix of gastro-intestinal flora in the cow’s stomach and providing a breeding-ground for acid-resistant E. Coli, which are more likely to survive in the human (rather acidic) stomach.

Feeding the cattle hay for even a brief period produced a “dramatic” decrease in both the number and acid-resistance of E. Coli in the stomachs of those cattle.

A review of related studies (J Dairy Sci. 2000 Apr, Vol. 83 Iss. 4, p. 863) confirmed this, this despite an earlier study (Appl Environ Microbiol. 1999 Jul Vol. 65 Iss. 7 p. 3233) which seems to show that hay-fed cattle shed equally acid-resistant E. Coli for a longer period of time than grain-fed cattle, and concluded that hay-fed cattle may increase the dangers of E. Coli infection in humans.

Now, as a curious non-scientist, reading the abstracts, it seems to me that the duration of shedding of E. Coli may not be as important as the number of E. Coli, given that

  1. public food-related health involves management and not elimination of risks,
  2. food-borne illness-causing bacteria are fairly omnipresent in our environemnt and it is our good fortune that they do not often exist in sufficient concentrations to overpower our natural defenses,
  3. the foods most likely to carry E. Coli seem to be perishable to highly-perishable (e.g., beef and dairy, poultry, and produce) and therefore likely to be refrigerated (which slows the spread of bacteria), cooked, and consumed before the bacteria has had a great deal of time to propagate,

I think I would rather face a low concentration of toxin-producing bacteria many times over rather than a high concentration all at once.

What does this mean? In general, it means following the advice at the beginning of this post. The advantages to eating locally, in this regard, are these:

  1. Shorter average time-to-table means less time for bacteria to reproduce on / in your food
  2. Less, and decentralized, processing means fewer post-harvest entry points for bacteria, as well as reduced exposure to bacteria from other foods
  3. Possibly, private, independent tenant ownership / management of farms provides greater incentives to produce clean food by avoidance of tainted irrigation supplies and other sources of illness-causing bacteria (i.e., aren’t you more likely to farm clean if you live on the farm? Isn’t that one of the basic ideas of the market economy — that what one owns, one tends to manage better than what one doesn’t own.)
  4. Possibly, face-to-face retail-level transactions between producer and consumer promote personal accountability to the consumer.

1 Comment so far
Leave a comment

[…] 10 December 2007 Or maybe it’s bash-on-ethanol day here at Law for Food. According to the Food Law Profs Blog, some CAFOs are feeding cattle corn that is a by-product of ethanol production, and that this practice is leading to increased E.Coli presence in the cattle’s digestive tract. I don’t pretend to be a scientist, but my guess would be that the ethanol is produced by fermentation, and that the fermentation lowers the pH of the corn by-product, and that the corn by-product lowers the pH of the digestive tract so as to create an optimal environment for E.Coli to breed. […]

Pingback by About that corn-based ethanol… « Law For Food

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: