Eat your vegetables!

I taught in a public high school for three years before entering agricultural and nutritional graduate studies. In our school cafeteria, a wide array of cooked and raw fresh vegetables was made available to kids. Vegetables were always stationed at the beginning of the buffet line, which coiled around a salad bar. Over and over again, students omitted vibrant green and red colors in order to arrange various shades of white and brown foods on their plates. French fries were a daily staple, often (but sometimes not) accompanied with a side of some sort of breaded or bunned meat.

I found this NYT article to be interesting, entitled “Told to Eat Its Vegetables, America Orders Fries.” Despite millions of dollars and hoards of effort to the contrary, Americans are still undereating vegetables and overeating starches and simple sugars. (2-3 daily servings of meat is actually the only American Dietetics Association recommendation that is properly adhered to by the average American, per a conversation with Stacey Bates, former R.D. for the Texas Beef Council). The proceeding article in Food, Think! will focus more in depth on the American diet and decision-making, but today's article will be about why the order to “Eat your vegetables!” is truly sound advice. 

Vegetables have 4 main benefits (main sources from ADA's website, www.eatright.org): 

1. Antioxidants (Vitamins A, C, E & Flavinoids such as color pigments like red lycopene): These compounds are meant in plants to be absorptive of intense energy, such as sunlight. In the human body, they control the reactivity of dangerous compounds such as free radicals that may alter DNA to induce cancerous growth. Several studies have suggested a strong relationship between phytonutrient intake and cancer prevention: Jeffery, E.H., et al. (2006). Diet and cancer prevention: current knowledge and future direction; Lemonick, M.D. (July 19, 1999). "Diet and cancer: can food fend off tumors?"; Go V.L. et al., (December 2004). "Diet and cancer prevention: evidence-based medicine to genomic medicine". Journal of Nutrition; "Diet And Cancer Prevention: New Evidence For The Protective Effects Of Fruits And Veggies". ScienceDaily. December 7, 2007.
2. B-Vitamins & Folate: essential for growth and creation of new cells and fighting disease. 
3. Minerals: Calcium strengthens bones and necessary for muscle contraction. It also signals for many cell processes; Iron is necessary for oxygen transport within the body; Magnesium is an essential component of most bodily enzymes which mechanize all sorts of bodily functions; Potassium regulates blood pressure, helps maintain fluid and nutrient equilibrium in almost all cells, among other benefits. 
4. Fiber: Vegetables offer two types of fiber, soluble and insoluble. Soluble fiber, or pectin, dissolves in the digestive tract into a gelatinous matrix...probiota feast on it within the digestive tract. Insoluble fiber, like soluble fiber, cannot be digested by human digestive enzymes, and stays intact until it reaches the colon where it is also a food source for probiota. 

Soluble Fiber: Our bodies use internal cholesterol to create bile, which is a kind of detergent that is released into the intestine to break down fat, making them possible for absorption. The matrix that soluble fiber forms in the intestine actually traps bile and the fats they transport, preventing the body's reabsorption and recycling of cholesterol, and also the absorption of the fats they carry. This is why oatmeal, having 2 of the 3 recommended daily grams of soluble fiber, is so famous for lowering cholesterol!

Insoluble Fiber: Because of its abrasive, pipe-cleaning effects, insoluble fiber reduces hemorrhoids, provides a vehicle for bodily wastes, and cleanses any harmful substances that adhere to the inside of the colon. Many studies (below) suggest that the benefits of insoluble fiber work to reduce the incidence of colon and rectal cancers by eliminating damaged cells, cleansing the tract from harmful substances, and promoting the growth of new cells. When probiota break down and ferment insoluble fiber in the colon, a metabolic byproduct (a Volatile Fatty Acid, particularly) is released called Butyrate. Butyrate stimulates growth of new, healthy epithelial (colon-lining) cells. Here area few studies that provide a possible link between insoluble fiber and cancer prevention: Trock et al., (April 1990). "Dietary fiber, vegetables, and colon cancer: critical review and meta-analyses of the epidemiologic evidence". Journal of the National Cancer Institute. Lanza et al., (1992). "Dietary fiber". Micozzi and Moon (1992). Macronutrients: Investigating their role in cancer.

I’m going to make sure my plate is colored with plenty of vegetables this Thanksgiving. What do you Think?

Meat and Cancer: Not Guilty.

The Union of Concerned Scientists from Johns Hopkins University was the likely little bird that suggested…er, claimed... a relationship between red meat and cancer. Let’s give their statement a little context first about how scientific promulgations are transmitted to mainstream society.

Say this news headline appeared in the paper: Norway at peace for the 66^th consecutive year. Would you frantically rush to grab yourself a copy?

Imagine a world conference on nutrition and health has been called by scientists studying several different foods as risk factors for cancer. The agenda might look something like this:

• ·         No relative risk shown from consumption of conventional vs. organic orange juice
• ·         No effect of turkey vs. chicken consumption on cancer cell development
• ·         Does consuming expeller-pressed rather than extracted canola oil increase risk for cancer? (No)

…you stop reading the agenda here because you begin to suffer a severe case of boredom.

We all know that good news is no news. Publication bias, when something is less likely to be published if it is inconclusive or simply affirms the status quo, exists in the science world just as it does in journalism. Have you seen this message in fine print, usually following an asterisk on a milk carton: "FDA states: No significant difference in milk from cows treated with artificial growth hormones.”  However, it’s a lot more exciting as a consumer to buy milk that’s labeled “rBST Free!” “Milk from cattle not receiving artificial hormones!”…and we assume from these messages that rBST is guilty of making our milk less healthy, while ignoring the FDA’s dry statement (which deserves its own exclamation point!).

As we return to today’s topic of red meat and cancer, keep in mind that scientists hardly know what causes cancer, or even how it is caused. Several carcinogens are known to be found at the crime scene, but the direct culprits are often mysterious. I have seven meta-analytical studies (which compile data from dozens to hundreds of studies to make more powerful, broader claims since the sample populations are bigger) and, to spoil their ending for you, they all are either inconclusive or conclude with no association between red meat and cancer.

That’s good news for me, since my mother had breast cancer and I still get to enjoy all the beef and lamb I like. If you’re still curious and want to read the summaries of these studies, by all means, continue!
 

Alexander et al., 2010 “A review and meta-analysis of red and processed meat consumption and breast cancer”

A meta-analysis that examined over 25,000 cases of breast cancer compared cohorts of high red or processed meat consumption with cohorts of low red or processed meat.  It was found that “no association was observed in the fixed-effects meta-analysis of processed meat intake and breast cancer” and “No significant association between the highest category of red meat intake compared with the lowest category of intake and breast cancer was observed”. Many hypotheses such as cooked and overcooked meat by-products (heterocyclic amines, polycyclic aromatic hydrocarbons), haem Fe from blood consumption, or hormones from eating meat (mammary glands have very sensitive hormone receptors) course through the halls of academia, but significant evidence to prove them has not been garnered in experimentation—if it has, the opposite has been demonstrated within an equal amount of other studies. For more information on heterocyclic amines, see the Addendum at bottom. 

Alexander et al., 2010 “A review and meta-analysis of prospective studies of red and processed meat intake and prostate cancer”

Fifteen studies of red meat and eleven studies of processed meat were analyzed to result in a lack of supportive evidence for a correlation between dietary increments of red meat or processed meat and prostate cancer. The idea that the more meat eaten, the more at risk the person was for cancer, was not supported by the results. Circulating hypotheses for an increased incidence of prostate cancer include higher fat intake in the diet, but this also remains unproven in several studies that have taken place. In fact, high lycopene (from red pigment in fruits and vegetables such as tomatoes) and selenium (from meat) intake may reduce the risk of prostate cancer…so pour that ketchup on your burgers, people!

Alexander and Cushing, 2010 “Red meat and colorectal cancer: a critical summary of prospective epidemiologic studies”

This paper reviewed studies of European cohorts and Asian cohorts, and found no evidence that independently connected red meat to colon or rectal cancer. Red meat can’t be isolated as a cause especially because many competing factors that obscure the causes of cancer exist in the general Western lifestyle: the diet, to name one potential factor besides activity level and others, is typically high in refined sugars, starches, and alcohol, and low in fruits, vegetables, soluble and insoluble fiber.  It was found that men are 10 – 30% more likely to contract colorectal cancer than women are, but it was found to have nothing to do with men consuming more red meat than women do. In fact, a few recent studies demonstrate that red meat fats like conjugated linoleic acid (CLA) and stearic acid (an 18 carbon saturated fatty acid) are anti-carcinogenic, but further studies need to be conducted in order to continue isolating these factors for their cancer-preventative benefits (Bhattacharya et al., 2006; Evans et al., 2009; Evans et al., 2009).

Alexander et al., 2010 “Processed meat and colorectal cancer: a quantitative review of prospective epidemiologic studies”

Salt, sugar, nitrates, nitrites, phosphate, and spices are all used to cure meat and preserve them against contamination by pathogens. Smoke from wood or liquid smoke flavorings may introduce polycyclic aromatic hydrocarbons as mentioned above in the other Alexander et al., 2010 article, but nitrates and nitrites remain the largest concern, since they have shown to produce cancer in some laboratory animal studies. As mentioned in the July post “Doubtful Dining”, vegetables contain the highest concentrations of all nitrate food sources, next to some cheeses, beers, and whiskeys. The results of this study were similar to the above study regarding red meat, where the isolated variable of red meat could not be associated with colorectal cancer. Again, men were found to be about 30% more likely than women to develop the cancer, regardless of processed meat inclusion in the diet.

Alexander and Cushing, 2009 “Quantitative assessment of red meat or processed meat consumption and kidney cancer”

Again, processed meat and red meat were not shown to be risk factors for kidney cancer; however, obesity and smoking were significant risk factors.

Alexander et al., 2009 “Meta-analysis of animal fat or animal protein intake and colorectal cancer”

Over 1,000 cases of colorectal cancer were analyzed in this study. When comparing high animal fat (more than 50g) daily intake and low animal fat (less than 25g) intake on cancer risk, neither group significantly differed in their relative risk. The same inconclusive result was found for increased increments of fat (~10g increments) and for incremental percentages of energy coming from animal fats. It should be pointed out that the study did not specify the source of the animal fat or what percentages were saturated and unsaturated. If saturated fat from animals were tested, the results would be confounded between whether the fact that It was saturated OR from an animal was the problem. The study included fats from mammals, birds, and fishes. Interestingly, a systematic review from 2005 could not produce consistent evidence for Omega 3’s to reduce colorectal cancer (Maclean et al., 2006).

Alexander et al., 2010 “Summary and meta-analysis of prospective studies of animal fat intake and breast cancer”

It was found that women are more likely to develop breast cancer than men (….still paying attention? Just checking). This study compiled results from 8 other studies on 200 – 7,000 breast cancer cases. It reported that once differences in demographic, ethnic, lifestyle, and diet factors were held even, animal fats did not impact the risk for developing cancer. Perhaps saturated fats or unsaturated fats could still be involved in cancer development, but it is clear that an animal source is no different than a vegetarian source.

I have an Addendum about carcinogenic compounds in overcooked meats...

When pan-fried, smoked, or flame-cooked, meats can form heterocyclic amines which are a known to be carcinogenic. Read more about it on cancer.gov ‘s webpage. Two sentences of note to me were “the doses of HCAs and PAHs used in these studies [observing cancerous growth in lab rats] were very high—equivalent to thousands of times the doses that a person would consume in a normal diet.” and “Population studies have not established a definitive link between HCA and PAH exposure from cooked meats and cancer in humans” (only a correlation has been established).

What do you Think?

Agriculture: Home of Improvements

GMOs
Dr. Nina V. Fedoroff makes these cases and substantiates them in her New York Times article, "Genetically Engineered Food For All" in favor of Genetically Modified Organisms as food:

• "New molecular methods that add or modify genes can protect plants from diseases and pests and improve crops in ways that are both more environmentally benign and beyond the capability of older methods."
• "Myths about the dire effects of genetically modified foods on health and the environment abound, but they have not held up to scientific scrutiny."
• "The European Union has spent more than $425 million studying the safety of genetically modified crops over the past 25 years. Its recent, lengthy report on the matter can be summarized in one sentence: Crop modification by molecular methods is no more dangerous than crop modification by other methods."
• "The process for approving these crops has become so costly and burdensome that it is choking off innovation."

I'm looking forward to possibly an elimination of pesticide residues thanks to GMO use (Pesticides are already present at no more than trace amounts which the EPA, FDA, and USDA deem safe -- see post, "Organic Or Not).

A Letter to the Editor challenging the above asks "If these foods are safe, why the huge lobbying effort to deny the buying public information about which foods are modified? How about a simple label informing the consumers?" I can appreciate his point. I can also appreciate the lobbying efforts, given that the labeling of milk and meat products with "No Artificial Hormones" has caused this whole national scare against hormones. The scientific community, even decade after decade of research, still cannot get through to people that there is NO difference in hormone levels of milk or meat between animals given or not given implants. Labeling can create unnecessary scares, because people, by nature, are biased in thinking that unmodified food is better than scientific innovation. We're uncomfortable with novelty, and face it, we won't go look up the facts.

Hormone Regulation

A common question regarding hormone implants in beef cattle is: Why does it make sense to castrate the animals and then go back and give them androgynous hormones again? Here are some facts supporting castration and hormone implantation:

Estrogen in bull meat is equal to that of estrogen in cow meat at 1st trimester of pregnancy. Testosterone in bull meat is over 30x that in both non-implanted steer meat and implanted steer meat, given that beef from implanted and non-implanted steers contain insignificantly different levels of testosterone.

Testosterone levels in meat:
0.34–0.73 mg/kg for bulls
0.069 mg/kg in muscle tissue from heifers
0.01–0.14 mg/kg detected in muscle from steers, both implanted and non-implanted.
Thanks to modern practices such as castration and implantation (i.e., no bull meat), we have more beef produced per animal, we have a more tender product, and finally, we have less hormone exposure to estrogen and testosterone in beef.

Sources:
Human Safety of Hormone Implants Used to Promote Growth in Cattle
Fritsche and Steinhart, 1998
Hendricks et al., 1983

So...what do you Think?

Feedlot, Rediscovered.

Will Feed, Inc. (Cozad, NE)

August 24, 2012

We were the only ones up at 6. The sun still tucked itself below the horizon while cattle crouched low on folded legs. Anne and I cruised up and down the alleys of the 3,000 -head feed yard in her truck to “read bunks”. This was her routine for determining from yesterday’s leftovers how much cattle should be fed today. After a meeting with the foreman about the feeding instructions, we returned to the alleyway and were greeted by weanling calves at their gate. These calves were beginning their first full day at the yard. It was time for their morning exercise and training. Anne flushed them away from the gate with a Shhhh and waving arms to send them back into their pen and have them exit in a wide circle back through the gate. She zigzagged behind them, reminding questioning ears and curious eyes where they were to go. The calves obediently, though sleepily, walked forward and away. They occasionally looked over their shoulders and wondered if they were heading the right direction. Anne encouraged them on to the back of a holding pen with her presence only, and held her arms straight out from her sides to have them “park” there. 

When they succeeded in following her directions, she moved to one side of the narrow pen and folded her arms behind her back. She began to slowly walk forward against the direction the cattle faced, and the cattle trotted past her. To slow them down, she slowed her pace. To stop them, she stopped or walked alongside them in the same direction they faced. A bovine’s “tipping point” is right at their shoulder. If you want them to walk forward, you stay behind their shoulder; stop, you stay at their shoulder; change directions, you come in front of their shoulder. After their exercise and training was complete and their behavior became more organized and collected, the calves were sent through the tub, the snake, the chute, and the squeeze to receive their new identification ear tags and vaccinations. 

After toughing out ear piercings and shots, these calves were ready to go home to their pen! Just as I’m sure they’d hoped, there was fresh prairie hay sprinkled with a little feed waiting for them in their bunks. They formed a neat line without a sound. I wish young people could do what young cattle can!

Notice that each animal gets about 300 square feet in every pen. You always see cattle crowded up together in feedlot pens leaving plenty of open space because it’s their natural herd behavior to stay close, especially if food is involved! Also, according to Beef Quality Assurance standards, feed yard pens must be kept free of mud. If water doesn’t drain properly, a skid steer must come and remove the mud. The “hills” in each pen allow a dry space for cattle to congregate in case of heavy rains, so that excess moisture can drain away from them. The entire yard has to slope down toward a water collection ditch that empties into a holding lagoon. Liquids, rich in nitrogen and phosphorus, are pumped onto adjoining crop fields.

Throughout the morning, the foreman was busy making the day’s rations. Weanlings eat mostly hay for a week, and then the cattle start out on a mix of less than 15% corn, 50% distillers' grains, and 30% hay with some vitamin and mineral supplements. They progress all the way, very gradually over the course of 6 months or more, to a mix of 30% corn, 60% distillers' grains, and about 8% hay, straw, and corn stocks plus some supplement. Shocked to hear that there’s not a lot of corn in the diet? Read this article by BEEF magazine about transitioning away from corn.

They are fed twice a day, precisely the right amount so just a few scraps remain in the bunks by morning: not wastefully so they leave too much behind, and not too meagerly, either. The first night I arrived at Will Feed, I saw Anne and her workers ship cattle out. Three cattle semi-trailers headed for National Beef in Dodge City, KS picked up over a hundred finished cattle, well-rounded and readied for harvest. Look at how big they are compared to the new calves!

I discovered that the relationship people have with cattle at a feedlot can be a lot more intimate than at a cow-calf ranch. Cattle are far more dependent on people in that setting. If Anne or any of her three workers gets sick, sleeps in, or takes the day off, it directly affects the cattle. They can’t find their own food. They can only wait for it. If any steer or heifer walks with just the slightest limp, has eyes that squint just a little too much, or holds their head a little low, the cowboy who rides in pens every day or Anne who exercises the animals every day will notice it and attend to it. Out on the range, some cattlemen go days without seeing the same cow or calf.

The attention to cattle in a feedlot is much more acute. Stressed, sick, depressed, lazy, etc. cattle do not grow good beef. Cattle that have been given hormones or antibiotics improperly will also not grow good beef. Anne believes “We need to set calves up for success.” For the ongoing story of Anne and the animals she cares for, see her blog, Feed Yard Foodie. Anne won Beef Quality Assurance Producer of the Year in 2009, and this year her feedlot is being nationally recognized by Certified Angus Beef. To support her and the Beef Quality Assurance program that guides animal care for the industry, look into what BQA stands for, ask your local producers to get certified, and put some beef on your plate this week!

Hopefully more personal accounts like mine and like Anne's on her blog will serve to reclaim the Power Steer from Michael Pollan and the rest of us who lost confidence in the beef industry. What do you Think?

In Nebraska with Feed Yard Foodie!

I am currently spending the week at Will Feed feedlot in Willow Island, Nebraska! For more information about Will Feed and the amazing story of its primary operator, Anne Burkholder, please visit her blog, Feed Yard Foodie. I'll tell you all about it next week, but until then...we've got cows to feed! Back to work!

Flour or Corn Tortillas?

Two articles by Justin Gillis from The New York Times promote agronomy research for strains of food crops that can better cope with the heating and drying that much of the planet is facing this generation:

Revisiting Climate and the Food Supply
Aug. 18, 2011
and
A Warming Planet Struggles to Feed Itself
June 4, 2011

Wheat is a C3 ("cool season") plant. When temperatures rise above 70 degrees Fahrenheit or so, C3 plants photosynthesize so quickly that oxygen builds up within the plant faster than the plant can obtain carbon dioxide for construction of sugars, starches, and fibers. Wheat then enters photorespiration, where the plant actually consumes oxygen and releases carbon dioxide in a much less efficient process of making carbohydrates. Photorespiration is when the plant "stalls" and has a difficult time growing.

Corn, sugar cane, and sorghum (milo) are C4 ("warm season") plants, as well as many other grasses. A C4 plant has a pathway that helps concentrate carbon dioxide within itself to continue the photosynthesis system to "feed forward", and therefore, continue CO2 sequestration and sugar production. These plants can keep growing and producing carbohydrates while exhaling oxygen in much higher temperatures than C3 plants can.

C4 plants are efficient in "warm seasons", while C3 plants are efficient in "cool seasons". If our world climate continues to warm, will there eventually be more production of corn, sugar cane, and sorghum (milo), while there will be less wheat planted and consumed? What do you Think?

Meat Eaters, Misguided

Vegans are reaching out to the public with a softer message: “Just skip meat and dairy once a week. You can do it!”

As a result, “Meatless Mondays” has gained attention as a food trend. Let’s take a look at the Meat Eaters Guide To Climate Change + Health.

Previously, I have spoken out my concerns for the environment, but I am definitely concerned for my health. My mom was diagnosed with cancer when I was twelve. She survived, thankfully! I learned what an antioxidant was before I could even spell it. Every starch our family ate at the table (to my younger brother’s chagrin) was whole grain and unprocessed. Fiber here, fiber there, fiber everywhere! I spoke of my high cholesterol and potential inheritance of Alzheimer’s (3 of 4 grandparents had it) in previous posts. My fascination for nutrition and its mitigation of genetic risk factors took root in middle school. You bet I’m personally invested in this.

ENVIRONMENT

It is correct to say that the energy efficiency of eating vegetables is greater than eating meat.
It is incorrect to conclude that overall, eating a vegetarian diet is better for the environment. We'll see why.

Anything along the food chain that respires and does not photosynthesize costs energy to maintain, and carbon dioxide is emitted into the atmosphere along the way. This phenomenon is called the Feed Conversion Ratio (FCR).

Feed conversion ratios are as follows:

                 Pounds of feed : Pounds of food produced

                                    1.2:1 Fish

                                    1.9:1 Chicken

                                    5.9:1 Pork

                                    8.7:1 Beef

This mostly has to do with how quickly or slowly the animal grows. Slower-growing animals require more maintenance energy (See “Going Hormonal Over Beef” post). A quick glance at these FCRs might make you think, oh man, beef is so inefficient! While these animals are consuming non-food grade diets (industrial co-products like soybean meal or distiller’s grains that would end up trashed), cattle have a special ability to turn cellulosic fibers into energy for meat and milk production. No mammal produces cellulase, the enzyme that releases glucose from cellulose (long chains of glucose) for utilization. Cattle and other ruminants operate symbiotically with microbes in the rumen to ferment straw, wood shavings, grasses, hulls, and other inedible materials into energy for tissue growth. The 8.7:1 ratio is efficient in its own right.

Question: For organic crop production, what are the two most important sources of fertilizer?

Answer: Manure and Compost.

            Manure, being richer in nitrogen than compost, is most important, and where, pray tell, will manure for fertilizer come from if animal agriculture is eliminated? Because manure is far less rich in nitrogen then synthetic fertilizer, even a 15% reduction in manure production (Meatless Mondays) would amount to serious consequences for the organic produce industry. Manure is a highly valuable resource that is not wasted in the animal agriculture industry.

            To create compost, biomass has to rot down. If well-aerated, it emits more carbon dioxide than methane. Those carbons, however, are not ending up in the form of amino acids and fats in animal tissues to be reused as food for humans. Vegetarian biomass waste is a large component of agricultural animal diets.

Question: What is the main culprit for the destruction of 96% of America’s Tallgrass Prairie?

Answer: Cropland

I love that all beef cattle spend part of their lives on wild, open range. The beef industry keeps wildlife habitat profitable. We all know that economic incentives help guarantee environmental protection. Cattlemen know that overgrazing, overwatering, erosion, destruction of wildlife habitat and water resources will put them out of business as cattle raisers and hunting leasers. If there weren’t a strong demand for beef, ranchers would be selling their open lands for development. I'd rather see ranched lands than plowed lands, and so would wildlife.

HEALTH

While the Guide acknowledged that the environmental impact of feedyard beef vs. grassfed beef is debatable, it needs an update on grassfed’s nutritional profile (See “Is The Grass(-finished beef) Always Greener?” post).

Also, save a few known carcinogens, there are no known CAUSES of cancer. It is irresponsible to assert that red meat causes cancer if, at best, studies are only showing correlations. I am still going to eat the recommended serving, about 6-9 oz. of lean meat a day, for highly bioavailable nutrients, protein, and MUFA:SFA ratios that are greater than 1 (See “Is The Grass(-finished beef) Always Greener?” post).  

If anyone has more questions, I encourage you to browse the older posts and post a comment. Many people are searching for a silver bullet to solve health and environmental problems. Accepting the “Meateater’s Guide To Climate Change + Health” is naïve.

The reality is, life is a costly and complicated thing. Trade-offs are everywhere. What do you Think?