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?

Follow me @FoodThinkForum

I'm now Tweeting new posts @FoodThinkForum...so stay updated more easily!

GMO? OMG!

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.   

Health

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.

Politics

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?

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?

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 beef.org: 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?

Going hormonal over beef

The mention of hormone use in beef often stirs visceral reactions. Uncomfortable with a seemingly “unnatural” production method, consumers may seek relief in USDA Organic brands or Reserve programs where such a practice is shunned. Although synthetic hormone use carries a heavy stigma (yeah, thanks, baseball players), its actual use in livestock production is far more simple, safe, and even beneficial than you’d think.

Beef producers choose to use hormones to increase efficiency by 20% (Wileman et al., 2009): cattle gain more lean muscle on less feed. Remember the carpool effect discussed in the blog post Food Routing: Local or HOV? The more lean muscle material (lean meat) that can be piled onto fewer body frames means less maintenance energy wastage, less fecal/urinary excretion, smaller carbon footprint, less environmental impact per pound of beef. Some are concerned that animal bodies are weighing down too heavily onto their skeletal frames, causing lameness and breakage, but this is impossible given that estrogen improves bone density and strength, and in some cases causes bones to continue growing (Felson et al., 1994). Consumers derive most of their fear from the inaccurate suspicion that they ingest the hormones that the animals are given; they fear that the substances given to live animals linger in meat.

We’ll get one thing straight: hormones are never injected. The dose from a dissolvable pellet per animal immediately begins to signal for muscle building and breaks down after it “delivers its message”. There is no hormone blood-pooling, no accidental over-dosing; it’s just not possible, nor profitable (cattleman common sense: implanting with more than one is a waste of money, does not amount to increased growth, and could get you jailed). Growth promotants are implanted as a slowly-dissolving pellet in the ear, or they are fed in trace amounts. Animals are not allowed to be slaughtered until the compounds have had more than enough time to decompose and reduce down where they reach an equilibrium at a natural blood concentration. This is why, over and over, the FDA and USDA report that beef from implanted cattle are insignificantly different than non-implanted cattle. Despite the following reasons why, on a most basic biochemical level, there is nothing to fear, the FDA and USDA stringently regulate growth promotant use and routinely test for residues in meat. Secondly, the beef industry excels at self-regulation and mutual accountability through the Beef Quality Assurance program.

Beef producers use two kinds of growth promotants:

1.      Hormones (low-dose ear implants, usually a form of estrogen) signal for continued lean tissue development after the animal reaches sexual maturity (Trenkle, 1997).

2.      Beta agonists (mixed in feed) block amino acid breakdown so that the same weight isn’t maintained as the body "idles" and generates heat, but increases as the animal eats dietary protein (Borohov et al., 1987; Dawson et al., 1988).

Both chemicals are naturally occurring in us and in cattle. Being chemically unstable and having limited half-lives, they degrade all the way down until they reach a normal equilibrium concentration in the animal’s body.

A meta-analysis of ten studies by Taylor et al. (2009) summarized that no significant relationship between conventional beef consumption and breast cancer (mammary tissue being most sensitive to estrogen intake) could be alleged.

Let’s put things into perspective (Preston et al., 1997):

1.      Milk estrogen concentration: 0.12 parts per billion (nanograms/gram)

2.      Unimplanted beef: 0.16 ppb

3.      Implanted beef: 0.22 ppb

4.      Eggs: 35 ppb

5.      Soy flour: 1,510,000 ppb !!

6.      Female daily production: 5,000,000 ng

7.      Male daily production: 100,000 ng

Consequently, vegetarians have repeatedly tested positive for higher circulating androgens because of high consumption of soy products (Armstrong et al., 1981; Thomas et al., 1999).

You’ve heard the rumor about precocious development in females (recent generations of girls hitting puberty earlier)? Blaming this on milk and meat consumption doesn’t make sense, but blaming it on diets higher in starch and sugars does. These simple carbohydrates cause insulin levels to rise, which sets off this chemical chain reaction in the body: Insulin --> GnRH (gonadotropin releasing hormone) --> LH (luteinizing hormone) & FSH (follicle stimulating hormone) --> increased estrogen production (Poretsky et al., 1999; Ultrianen et al., 2009; Rosenfield et al., 2009). In starch and sugar, I believe, you have the culprits for early puberty and possibly even ovarian cysts. Similarly, there are  several beef cattle studies that use  high energy diets to increase blood sugar (--> blood insulin) to ultimately decrease the age of puberty in heifers (Corah et al., 1977; Moseley et al., 1977; 1982; Randel & Rhodes, 1980…).

For more information on why growth promotant use in beef production is safe, refer to Avery & Avery’s 2007 study.

What do you Think?   

Is The Grass(-finished beef) Always Greener?

Two years ago, I would have never written what you’re about to read. I was so convinced that “you are what you eat and you are what you eat, eats” that I not only assumed, but willed for the absolute superiority of grass-finished over conventional beef. I scoffed at the scientists and lecturers that disagreed with my thoughts in defense of conventional beef production. I inspected hairline fractures in their arguments while I leaped over logic gaps to follow “food revolutionists”.

After completing my studies in beef cattle nutrition, I have found that, frankly, the good news I used to hear about grass-finished beef is not all that great, and the bad news about conventional beef is not all that bad. Although I respect niche-market cattlemen for their creation of an artisanal product—I really am particularly fond of the grass-finished taste—I can finally admit that whatever you and I have heard from a handful of avant-garde critics about ecological and nutritional superiority is…hype.

USDA defines “Grass-Fed” as the product of animals whose diet is solely forage-based, without any inclusion of grain. I’m using the term “Grass-Finished” because all cattle, no matter the system, are reared on their grass-consuming mother’s milk and eat forage until the “finishing” stage that brings them up to harvest weight. They either remain on pasture and keep eating forage or enter a feedlot and consume a mixed diet of corn, grain and oilseed by-products, and preserved forages like alfalfa hay or silage. I’ll refer you to Anne Burkholder’s blog if you’d like to know more about how a feedyard is managed.  

Nutrition Facts

While studying ruminant nutrition, I learned that “you are what you eat” somewhat applies to humans and other monogastrics (pigs, horses, etc.), but not quite as much to ruminants. Sort of in the same way milk cultures in to yogurt, ruminants use microbes to “culture”, or ferment, their diet into metabolic intermediates (volatile fatty acids…like lactic acid in yogurt) and microbial bodies (microbial crude protein…like what most of yogurt consists of). What a cow actually digests is much different than what she originally ingests. That helps explain…

1.      Omega 3 content: 0.052 g (3 oz. Grass-fed); 0.039 (3 oz. conventional); Yes, grass-fed beef will consistently have a statistically significant increase in Omega 3, but this difference is inconsequential compared to a 3 oz. serving of salmon, which has 1.83 g. The daily recommended intake of Omega 3 is 1 g…fish oil, yes please…60 ounces of grass-fed beef, no thank you. Indeed, the ratio of Omega 3 to 6 in grass-finished beef, being lower than conventional beef, is more optimal (about 1:4 vs. 1:10; Schmid et al., 2006; Leheska et al., 2008) in the way of reducing arterial swelling, improving circulation, and reducing triglycerides (Morris et al., 1993; Harris, 1997; I will make a qualifying statement about ratios in the section on Fats). I have seen data showing that some grass-finished beef has as much as 0.10 g Omega 3 (Leheska et al., 2008; French et al., 2000), but this value is not likely to improve because of microbial fatty acid alteration in the rumen (natural biohydrogenation – turning polyunsaturated fats like omega 3's into saturated and trans fats). In fact, beef from feedlot-fed cattle have much greater potential to increase in Omega 3 values because of the higher passage rate which reduces microbial interference with the dietary fats. If feedlot animals are fed Omega 3s with linseed or algal oil, their beef increases in Omega 3 to the same level as grass-finished beef (Razminowicz et al., 2007).

2.      Vitamins A and E from grass-fed beef might be found in quantities 7 times higher than conventional beef, but a serving will only provide up to 2% of the daily value for both vitamins (Daley et al., 2010). Beef in general is not a good source of these vitamins.

3.      Fats: Although grass-finished beef has consistently less fat overall than does conventional beef (about 10% less fat, Leheska et al., 2008), the types of fat grass-finished beef offers concerns me. If you ever eat a burger made of grass-fed beef, you'll notice something strange. The grease that falls from the burger to your plate will in a few minutes harden into a hard wax-like substance, reminiscent of candle drippings. Conventional beef patties drip grease that remains oily and doesn't harden much as it cools. As someone with hypercholesterolemia, I am very sensitive to monounsaturated fat—saturated fat ratios. When I lived in Spain during college, I didn’t watch this and almost went on statin medication as a skinny 21-year-old! Monounsaturated fat (MUFA; think olive, canola, pecan oils) makes my HDL (good) cholesterol rise, while saturated fat (SFA; think hard fats like butter, grizzle) makes my LDL (bad) cholesterol rise. Your HDL/LDL can reflect your MUFA/SFA dietary intake (Adams et al., 2010; Gilmore et al., 2011). Grass-fed beef has less MUFA than SFA (ratio of 0.71 – 0.95), while conventional beef has a more optimal ratio of 1.1 – 1.31. Keep in mind that I may cancel out beef's positive "ratio" effects by over-consuming Omega 6 or SFA, so that my overall diet ratio may be far from optimal. Grain-finishing deposits more MUFA, especially where the beef is marbled, while grass-finishing deposits more SFA and even trans fats (3 g in Choice grass-finished beef vs. 0.14 g in Choice conventional beef per serving) because of ruminal biohydrogenation (Smith et al., 2009; other data c/o Dr. Smith). For lower amounts of trans-vaccenic fats, I recommend buying conventional beef or grass-fed beef that grades USDA Select or lower.

4.      CLA: The alleged benefits of CLA (conjugated linoleic acid, a fatty acid only available in products from the cattle/sheep family) are that it fights cancer, reduces arterial inflammation, and lowers body fat. These have been confirmed in laboratory rodent studies (Schultz et al., 1992; Parodi, 1994; Belury, 1995; Nicolosi and Laitinen, 1996; Pariza et al., 1996) but not in human studies (Brown et al., 2010). Grass-finished beef can offer up to two or three times as much CLA as conventional beef, but both are still a good source at ranges of 0.1 – 0.15 g per serving (Leheska et al., 2008; French et al., 2000).

While scientific credence for health advantages of grass-finished beef wanes, I still buy both types of beef, because both provide 29 different cuts of lean (< 10% fat) meat that don’t even need seasoning like other meats do. As someone prone to anemia and upper respiratory issues that is also at risk for Alzheimer’s disease, it’s good to know that a serving of beef has three times as much iron, six times as much zinc, and seven times the vitamin B12 of chicken. Plus, it’s nice to get as much iron in one serving of beef as there is in three cups of raw spinach, or as much protein as 230 calories of raw tofu, 374 calories in beans, or 670 calories in peanut butter (25g protein from 180 calories of lean beef!). 

Environmental Facts

Any animal management system that does not advance the growth rate of its animals will be inadvertently spending resources for maintenance more so than production, which is wasteful. Slow growing animals will consume more food and water and excrete more solid and gaseous waste per unit of meat or milk they produce. Grass-finished cattle go to market at almost twice the age and at lighter weights than do grain-finished cattle. In light of this…

1.      Land Use: Some neo-agricultural purists advocate finishing all beef produced in this country on pasture. Putting climatic limitations and weather capriciousness aside, let’s say all the acres of grain crops used to finish cattle at feedlots were converted to pasture. It requires 3 times more land to finish cattle on grass than it does to grow crops for finishing cattle in a feedlot (Avery & Avery, 2007). In order to produce the same amount of beef, an additional 60 million acres of non-forested land that receives > 38” annual rainfall would be required to support this goal (Capper et al., 2009). Did anyone find Atlantis yet?

2.      Methane Production: Cattle consuming grass produce as much as 3 times more methane than cattle on a feedlot diet. This has to do with different fermentative pathways that can operate in response to different diets. Since I’m a nutrition nerd, please post a comment and ask about it you’re curious. However, I typically view cattle methane production as a moot point because cattle contribute to only about 15% of world totals (Wahlen et al., 1993…see post “Bitten hands that feed…”).

3.      Sanitation:  Free-ranging cattle like those on a grass-finished system are free to excrete wastes directly into groundwater. Waste deposited by feedlot cattle is contained and treated. Feedlots must follow stringent regulations for water quality control. They must submit a site-specific Pollution Prevention Plan that is engineered to “prevent and limit discharge of pollutants to surface and ground waters” and must include a plan for a catastrophic 100-year, 24-hour rainfall event. For more details, read Avery & Avery, 2007.

I buy beef in general because it keeps open range and wildlife habitat profitable as ranchland instead of as pavement or row crops. Beef cattle management protects 75% of wildlife habitat in the United States from development. 

What do you think?