Thursday, November 17, 2005

Food and Health

Yesterday's post was more or less about the economics of food production so I figured today might be good to look at the health impact of industrialized food production. This topic is much harder for me to approach just because there are (a) so many different aspects to health and (b) so many misconceptions. I'll try my best. If it doesn't make sense tell me. If you disagree with me, that's fine, I'd like to hear your opinion. My one request is that you be respectful. I have noticed that people tend to become belligerent when their health and convictions are questioned on this matter. I'm not attacking you, I'm just stating what I think.

The first thing that a person needs to know about being healthy is that it requires monitoring and thought about what you eat. You can't just go to the store and walk down a row grab everything you see and say, "What's wrong with food producers these days? They're giving me so many unhealthy choices!" Realize that eating fruits, veggies and whole grains are going to be the best for you. Period. There is no debate on that issue. It is always better to eat things that as you eat them, they look just like they did when they were growing. Eating a banana is much better than eating banana creme pie. Eating a potato is much better than eating potato chips.

Given the above fact, it is not the food producer's job to only give you healthy choices to eat. That would mean they would lose out on a whole lot of revenue for people who value taste, and quality more than health. It is common to hear about the "Supersize Me" documentary where a man ate nothing but supersized meals from McDonald's and then had all sorts of horrible health reprocussions. What you don't hear that often is in a reaction to that documentary another study was done where a man ate at McDonald's for a month and actually lost weight and got healthier. He just chose the healthy choices at McDonald's over the supersized meals. It is YOUR choice to eat healthy. Nobody is pushing you to eat what you do, but you. (With the exception of small children of course.)

Another concern that is emerging and growing in popularity is the "organic" food. First of all I think this term is a complete misnomer because as it was originally used in science, organic meant of, relating to, or derived from living organisms, or in chemistry it just means that the compound is based on a carbon structure. Guess what? We live in an orgain world. EVERYTHING we eat is based on a carbon structure. Just about everything we eat is from an animal or plant origin.

The newer definition and the one accepted by the consumer of organic foods is a substance, especially a fertilizer or pesticide, of animal or vegetable origin. This means that an organic food is one in which all the pesticides and fertilizers are not synthesized, but derrived from animals or vegetables. As I understand it this means that consumers of organic foods reject any food that has been in contact with antibiotics, or pesticides. Take chicken for example. They can be given antibiotics while they are growing to prevent Salmonella contamination of the lining of their colon. This gives rise to the question of antibiotics in the foods we eat. WHICH IS A VERY GOOD QUESTION. The answer can be found when you do a little research about the regulations of chicken antibiotics in the United States. They must have a period of withdrawl before slaughter to ensure the antibiotics are out of their system and we don't eat them. Yes, statistically speaking you could get a chicken that has antibiotics in it, but the probability of that is minute. There is lots of testing of chicken carcasses before they go to market for quality and safety to the consumer.

Here's another example. How about organic vegetables. The consumer of the organic vegetable says it is healthier for them because they will not be consuming any pesticides. Well, the days of DDT are over. I admit that there are rather unhealthy pesticides that have been invented, but in order for a pesticide to be used on a crop there must be a "reasonable certainty of no harm" to the consumer in any and all of the various exposure routes to the cosumer (ingestion, inhalation, skin contact.) Many pesticides have come out in the past decade that are much better for the human and the environment. Many degrade naturally into innocuous metabolites. Yes, there is a risk of exposure to pesticides, but the body's response of an unhealthy person depends on other things:
  1. What is the hazard?
  2. What is the exposure to that hazard?
  3. How much of that exposure actually makes it into the body as a dose?
  4. The higher the dose the higher the response.

There may be a hazard there, but there have been regulations and guidelines that the US government have set out on how much and what types of uses pesticides can have to reduce the exposure to that hazard low enough that the actual dose into your body is miniscule. In fact your exposure to that hazard has to be low enough to have a 100 fold margin of saftey to the lowest response level. Bottom line, yes the risk is there, but it is really very small.

I think that's enough for today.

3 comments:

Heather said...

Maggie I love your geniosity...

Maggie said...

Heather-I love your geniosity too

Sarah-You raise excellent points. Hopefully I can address a few. First the "reasonable certainty of no harm" was not my language. That's what is stated in the Food Quality Protection Act.

Secondly I think you pose a good point in the metabolism of certain toxic substances. For example, DDT. It gets converted to DDE which is more toxic and more persistant in the environment. From what you say it seems to me that you think that you are taking away any exposure to conventional pesticides in your food. I hate to say it, but you're not. The thing is that before risk assessment for the original synthetic pesticides (ex. DDT) caught up with the technology they had been heavily used in the environment. The half life of DDT is about 15 years and DDE has a longer half life than that. Even produce that is organically grown will have trace amounts of it because DDT/DDE can become airborne and make its way all over the place.

With that said, I think I need to try to widen the window for what a pesticide is. I'm not just talking about the use of conventional synthetic pesticides, which is currently under review with the EPA and will probably be phased out in the future. Conventional pesticides, which is what I think you object to, have no selectivity for toxicity. They are toxic for the pests as well as the humans. That's why they're currently under review by the EPA. There are a slew of risks and benefits for convetional toxins. Looking at the whole picture of dose, half life, and elimination is complicated. Overall, I think that the jury is still out on their use.

I am also talking about biopesticides. I don't know how much you know about this subject so forgive me if I state things you already know. A pesticide is defined as: a chemical intended to kill, injure, or repel a pest. A biopesticide is a subcategory of pesticide and is defined as: pesticides derived from natural materials. Biopesticides can be broken down further into three categories. Microbial pesticides, plant incorporated protectants, and biochemical biopesticides. From my understanding organic foods can use microbial pesticides, and biochemical biopesticides and still be considered organic. Plant incorporated protectants however, are not considered organically grown. I'm all for using biopesticides in all their forms.

Here is an example to show why I think that all forms of biopesticides should be used. Bacillus thuringiensis is a microbe that produces protein crystals, the microbial pesticide, that is an endotoxin specific for insects. It binds to receptors in an insect gut that makes the insect stop feeding. The reason it is so good is that humans don't have the receptors for the protein in their body at all. Plus, the acidic conditions in our gut break it down. I hope you're ok with using B. thuringiensis because it is used on organically grown foods. In fact it has been used since 1961 as a pesticide. I think it is a much better option than conventional pesticides because it doesn't do anything to the human species. Nothing at all.

Scientists found the plasmid coding for the protein crystals and introduced them into plant DNA for protective purposes. Mostly these proteins are expressed in the leaves and stalk which is perfect because we don't eat them, but the european boreworm does and it dies. Keep in mind if the B. thuringiensis is used in the organically approved way you are eating more of the cry proteins. The first cry protein was approved for use as a plant incorporated protectant in 1995. The great thing about these proteins in the plants is that there is a reduced need for conventional pesticides. There was a big fiasco though when cry9c protein was submitted to the EPA for use. It was given the ok for use in animal feeds only. Somehow the DNA coding for the cry9c protein (not the actual protein) leaked into human food and was found in corn products. When this news was given to the media people panicked and called their local health officials complaining of allergic reactions to the "frankenfoods". Allergic reactions to DNA. Because of the huge media coverage, the CDC did a study on these individuals who had complained (28 in total) and found that they had no immunoglobulin E for that protein. This means that they weren't actually allergic to it. People just freaked because they didn't know what it was in their foods. There was a percieved risk to an unknown substance. That's why cry9c corn is not even on the market. The funny thing is that people had been consuming cry protein corn for years before they even knew about it and hadn't even thought anything of it. I wonder how much of the concern for organic food is actual risk or percieved risk. As in this case.

Maggie said...

Thank goodness we didn't get into a fight! Yeah, I was getting onto my blog today with some scary feeling in my stomach that I may have offended you and I would have to back peddle. I'm so glad that didn't happen.

As far as risk goes, there's risk in everything. 50,000 people die in car accidents each year and yet I still drive to the grocery store, to the bank and even to class if I can get my husband to go with me. Americans find that an accpetable amount of risk. If the risk for the pesticides in the food is too great for you then you made the appropriate choice to switch over to organic.

You said, "An interesting experiment would be, in short, to expose conventional pesticides to liver enzymes and look at the chemical and structural changes that occur, and then test the carcinogenic properties of the resulting molecule." For some conventional pesticides part of this has taken place. For example organophosphates have had them and their metabolites tested. I haven't heard of any Ames testing on them, unfortunatley. Most of the toxic substances that have had extensive research are the bacterial, marine, and other natural toxins that food producers are trying to get out of food rather than add as a pesticide.

There are many large gaps and areas for further study for pesticides in general. The problem that regulatory agencies are faced with is that the technology is progressing faster than the ability to do risk assessment on that technology.