Thursday, June 23, 2011

Null Hypotheses

Today I wondered, do too many of these posts preach to the choir? Do they all seem to have a predetermined conclusion? As I write, I do not mean to stray from confidence into contentedness. Objectivity cannot exist in smugness (n., a precursor to bias).

I pondered how many of the studies I mention fail to reject the following null hypotheses (the default claims of “innocent until proven guilty”)

1)      Foods grown with synthetic fertilizers and pesticides…
2)      Grain-finished beef…
3)      Conventionally-grown and transported foods…
4)      Hormone and antibiotic use…
5)      Genetically modified organisms…

…Are just as safe, healthy, and environmentally friendly as unmodified, grass-finished, locally grown, and organic foods. There are no real differences.

Take note, the null hypothesis is never accepted in scientific studies, it is only not rejected. It is statistically impossible to prove a negative…like it is impossible to scientifically prove there is no God, etc. A healthy skeptic is skeptical of his or her own skepticism.

I leave you with this thought: Research must continue to reject null hypotheses as long as we seek to feed our world with dwindling resources and novel methodologies. Research that is extensive is also expensive, so I encourage everyone’s support of land-grant universities that make discoveries to support our future.

Never stop researching. Never stop questioning. Never be content with what you know.
Never let anyone think for you. That was my mistake a few years ago.  

So, what do you Think?
What agriculture-related problems shall we continue to seek out and solve?

Tuesday, June 14, 2011

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Food allergies are rampant in the United States, but can the phenomenon be tied to Genetically Modified Organisms?

U.S. intellectual property regulation dictates investigations for patent infringements. The genetic material in GMO seeds is patented and protected. Does this threaten the freedom of non-GMO farmers to retain their own seeds for next year’s crop?

Crops are genetically modified for the realization of this one basic goal: feed 6.7 billion people every day. Water shortages, soil nutrition limitations, pests, and politics, to name a few obstacles, make this goal impossible. GMOs are designed to overcome the first three impediments. They enable environmental stewardship through resource conservation, especially through no-till practices (see benefits from  post “…Determined to Succeed!”). We’ll discuss the health and political implications of GMOs.   

It seems everybody knows somebody with a life-threatening allergy to foods like nuts, milk, soybeans, wheat, and corn. Consumers and even scientists assume that Bt, a gene spliced into seeds that promotes the plants’ resistance to insects, provokes allergic reactions in humans. Because plants are producing their own pesticides (Bt toxins), many suppose that humans are developing allergies to foods containing the compound. While biotech companies claim the Bt protein is destroyed by our stomach acids, other reports claim that allergic reactions have closely coincided with the use of Bt pesticides. Bakshi (2003) described public allegations of allergic reactions to GMOs. Some GMOs that have caused allergic reactions in people did so because a gene from a Brazil nut (a normal allergen-containing plant) was spliced into a soybean. People that were then allergic to the soybeans were so because they had an allergy related to the Brazil nut, but unrelated to the fact that it was a GMO. The author concedes that allergens, such as those from nuts, milk, and gluten, are easily tracked and identified, so that GMOs found to contain these proteins are not released to the human food supply. Given that proteins are not ever absorbed into the body in their original form but rather digested down into peptides of short amino acid chains, it is also unlikely that animals that consume non-food grade GMOs can pass along the allergens to human consumers.  

 In summarizing the safety of GMOs and the rigor with which safety and allergen testing is conducted, I will not proceed to “re-invent the wheel” after Monsanto has composed explanatory websites that are both candid and clear. After being quite frankly impressed, I encourage you to visit Monsanto’s Issues and Answers page.

Small farmers who do not purchase GM seeds fear “bullying” by Monsanto for free-blowing pollen that contaminates their crops. A group of organic farmers filed a pre-emptive suit in March, 2011 against Monsanto in order for a precedent to be set against prosecution for the trespassing of pollen into non-GMO crops. Monsanto has stated that they have “not ever sued and has publically committed to not sue farmers over the inadvertent presence of biotechnology traits in their fields”.

Trade sanctions by the E.U. against U.S. grown GMOs hinder U.S. provision of food to starving peoples in Africa. American donations of foodstuffs are rejected because of restrictions imposed on GMOs. At Texas A&M, the late Dr. Norman Borlaug “genetically modified” wheat in the 1960s through extensive laboratory-based plant breeding, creating the dwarf wheat variety that keeps an estimated one billion people alive today. For more sources on cumbersome world politics and GMOs, read Pray et al., 2007 and Paarlberg, 2010 . Some E.U. officials concur with pro-GMO Americans that the current politics that reject GMO products for starving areas of the world are unsustainable (Davison, 2009) .

It seems the most underlying fear is that non-GMO participants sell products that our future world’s demands might make obsolete. In our world, I understand that the market is “always right”. What do you Think?

Tuesday, June 7, 2011

The Egregious Case of Escherichia coli

I read this article in the New York Times and pondered the following quote by a German girl: “[E. coli is] a big conversation issue among my friends,” she said. “Some are no longer eating salads. Others are ignoring the medical recommendations. As for myself, frankly, people have died. For me, that’s the bottom line. I no longer eat salads. But then again, this E. coli strain could be in milk, meat, whatever. It is very worrying. I have no idea what to eat anymore.” For the Europeans now battling an outbreak of E. coli O104:H4 sickness and even death by this pathogen are very real fears by both vegetable farmers and non-ag consumers. Lost crops and lost revenues also seriously afflict the vegetable farmers. Everyone from consumers to producers shares an equal magnitude of concern for food safety.

In the United States, Escherichia coli O157:H7 instigates 73,000 cases, 2000 hospitalizations and 60 deaths each year (Food Seminars International, 2011). I certainly find it unfortunate that eating raw or undercooked foods poses a risk to my health, but among all the other risks I juggle in my daily life, I worry the least about my food. I make the choice to trust that my food in the U.S., after passing numerous checkpoints of vigilant FDA and USDA workers, is safe (See Industry Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables and Consumers' Guide to Safe Handling of Raw Produce and Fresh-Squeezed Fruit and Vegetable Juices ).

Honestly, though, when you think of E. coli, doesn’t beef come to mind first? This is probably because the pathogen’s fame debuted in a hamburger served at Jack in the Box in 1993. Since then, the Checkoff dollars from beef cattlemen (a program that extracts $1 a head in every cattle sale) have overwhelmed the scientific community with over $30 million for beef safety research. Also, every year the beef industry spends $550 million to validate and conduct their safety control methods (See the Cattlemen’s Stewardship Review). E. coli is now primarily a fresh produce issue.

What I find frustrating is that there have been some claims (namely the ones made in The Omnivore’s Dilemma by Michael Pollan, and the film Food, Inc.) that grass-finished beef is “safer” than grain-finished beef because the grass-based diet does not culture an optimal, acidic, E. coli environment like a grain-based diet does. FALSE.

What a naïvely dangerous claim to make, and on such faulty science! These two media venues have championed the “junk science” of a pilot study conducted at Cornell testing the “Effect of grain-feeding on the numbers of E. coli in the colonic digesta of cattle (a) and their survival of an acid shock (b) (pH 2.0, 1h). Cattle (three animals, three observations per animal) were fed three ratios of timothy hay to grain (10:90, 55:45, 100:0).” (Russell et al., 2001, the review paper that was able to publish unpublishable data). Look back at the description I gave. Three cattle on three diets? Three observations? That’s like someone assigning you, me, and Dirk Nowitzki Rice Krispies, Cocoa Puffs, and Frosted Flakes, respectively, and after three basketball games concluding that Frosted Flakes is the best cereal for enhancing athleticism. Okay, an extreme example, but you get my point in that without having sufficient replication (a large sample population), it’s not scientific.

If warding off E. coli were as simple as feeding cattle hay, wouldn’t the entire beef industry follow suit? Quite to the contrary, it was found by a referee-journal publication in Calloway et al. (2009)  that it is in fact when the rumen pH is highest (least acidic, especially when the rumen is empty or sometimes when it is full of a high-fiber, grain-free diet) that E. coli proliferate. Because of this, cattle feeders have changed their fasting protocols before slaughter.

I’m going to wash my American-grown vegetables before stacking them on my 160ºF hamburger patty tonight…and I’ll have a salad on the side. What do you Think?

Thursday, June 2, 2011

Vive la résistance? (Antibiotics)

People who shy away from buying meat from animals given antibiotics do so to avoid exposure to antibiotic residues or to antibiotic resistant microbes. Modern germ warfare has significantly improved the quality and longevity of human life…as it has for animals, too…and the prospect of antibiotic resistance threatens that accomplishment.

Before we discuss the antibiotics that may have been used in producing your hamburger, we’ll stage the context: hands and dishes that contact it have just been washed with antibacterial soap, and the kitchen counters have been wiped down with antibacterial wipes. Maybe you nicked your finger cutting the tomato and applied Neosporin to it, and maybe it’s allergy season, so you’re fighting a sinus infection with the help of an antibiotic.

Funny how agriculture gets all the attention for an antibiotic scare…when one third of people try to take antibiotics for the common cold (McNulty et al., 2007), or when somewhere between 10 and 44% of people quit taking their antibiotics before the prescribed duration when they start feeling better (Pechere et al., 2007).

Antibiotics have a specific withdrawal date: they can only be administered before a certain time frame before the animal is harvested. Like synthetic hormones, antibiotic products are excreted from the body or decompose within the body. The “withdrawal date” denotes the time by which this elimination has been carried out to a satisfactorily low, safe level. Meat products are also routinely tested for antibiotic residues. If they test positive, they are thrown out and never enter the food supply. See these resources by Antibiotic Use in Cattle and Antibiotic Approval Process.

In beef cattle production, antibiotics are used therapeutically (in response to serious illness) and subtherapeutically (pre-emptively or for improving efficiency). Subtherapeutic antibiotics like metaphylaxis, tylosin, and monensin are used to reduce sicknesses by 50% upon receiving a cattle shipment, to improve growth efficiency by 17% and reduce respiratory problems, and to improve feed efficiency by 10%, respectively (Wileman et al., 2009; Griffin, 2007)

Metaphylaxis can consist of the following drugs: Ceftiofur (Naxcel & Excenel), Florfenicol (Nuflor), long-acting Oxytetracycline, and Tilmicosin (Micotil) and chlortetracycline and sulfamethazine (Griffin, 2007)
In human medicine, these are either used ubiquitously (like tetracycline) or not at all. On its own initiative, the beef industry is emphasizing low stress shipping and handling of calves in working pens, sale barns, or trailers. Slow, reduced-stress weaning techniques also reduce the prevalence of shipping fever and respiratory diseases that are common to cattle that newly arrive to feedlots. The industry is en route to mandating best practices that would preclude the need for metaphylaxis treatment. The Beef Quality Assurance website has more information on self-regulation in the beef industry. After this treatment, unless a feedlot steer becomes sick (he’ll be quarantined and his file becomes red-flagged), no other antibiotic treatment other than tylosin and monensin or lasalocid will be administered.

Tylosin and monensin (or lasalosid, an ionophore like monensin) pose no threat to human medicinal effectiveness because these antibiotics are not used in human medicine. Also, the killing efficacy of ionophores is due to macro-mechanisms that are extremely unlikely to be overcome by bacterial gene mutations (Russell and Houlihan, 2003).

Monensin and lasalosid eliminate inefficient rumen microbes and promote efficient ones so that cattle can derive more energy from their food and waste less carbon-hydrogen molecules on methane production and eructation. Ionophore use reduces methane emissions in cattle and fosters efficient beef production: more gain on less feed…and we’re back to the “carpool effect.” I went into a grocery store last week and saw a note from the farmers that produced the meat which bragged, “We raised this beef without the use of ionophores!” I was disappointed.

What I finally find to be most interesting is that the same prevalence of resistant bacterial strains has been found on both organic, “antibiotic-free” animal production systems and conventional systems in large-scale studies of poultry, swine, and beef cattle operations (Young et al., 2009; Barlow et al., 2007). That tells me antibiotic resistance is far more likely to be linked to household abundance and prescription abuse than to agricultural practices. What do you Think?