Winners and losers in the dietary wars
Wednesday, August 10, 2011
Challenges to long-established dietary notions may be good news for dairy and red meat producers, not so good for grain, fruit and potato growers
by DON STONEMAN
On a Friday afternoon in late May, after days of rain, the sun is finally shining on Joe Lach's potato farm, just north of the town of Simcoe. His planter is parked in the yard while workers scramble to replace a broken U-joint on a drive shaft.
Weather and machinery problems don't get to Lach. They are a familiar part of farming. Mention the Atkins diet, though, and Lach bristles.
The Atkins "craze" in 2003 and 2004 hit Ontario's potato farmers hard. Their markets suffered collateral damage from the controversial low carbohydrate, high protein diet as promoted by Dr. Robert Atkins, a Manhattan cardiologist, through his book, Dr. Atkins' New Diet Revolution. Statistics show the potato industry hasn't recovered yet.
The fickle winds of nutritional change are still swirling and a new, more scientifically-based regimen may be on the horizon. Dairy and red meat producers could benefit, but it might spell bad news for grain producers, especially corn farmers, and some fruit growers as well. For potato growers it could be déjà vu.
Potato board vice-chair Chris Kowalski of Everett remembers two years when returns were $3-$4 a hundredweight for potatoes that cost $8 to grow. A New Brunswick potato marketing board newsletter from that time described it as "a perfect storm" with consumers stopping buying spuds at the same time as production in North America was very high.
Atkins died in 2003 of head injuries after a fall. He had suffered for three years from cardiomyopathy. Enthusiasm for the diet waned, and neither Lach nor Kowalski want to see it revived. "He's long gone and the potato business survived it," Lach says. "We felt the pinch. I think the days of the Atkins diets have gone by the wayside."
But, adds Kowalski, "To be quite honest, (potato consumption) never really came back." (See Chart 1, page 17.)
Atkins' eat-all-you-want and don't-count-the-calories diet flew in the face of 30 years of doctrine about what is, and isn't good nutrition, espoused by the professional dietitian community and public health officialdom, and it boosted red meat consumption. But, despite its founder's passing, other Atkins-like diets are still finding favour, with possibly profound effects for agriculture. A body of scientific evidence is growing that low fat, high carbohydrate diets may have gone overboard the other way.
Compiling this data is an American science writer and author named Gary Taubes. In 2002, The New York Times Magazine published an article Taubes wrote on human nutrition policy entitled "What If It's All a Big Fat Lie?" Taubes says his assignment was to delve into what was newly being called an obesity crisis. The article critically examined the "institutionalized" belief that animal-based diets are bad and should be replaced by high carbohydrate foods. That cardiovascular disease and obesity are the result of eating a diet high in animal products has been the policy and the message spread by American health institutions since the mid-1980s.
Some critics say Taubes' article fuelled the popularity of the Atkins Diet, which eschewed carbohydrates and promoted meat consumption, and sideswiped potato growers like Lach and Kowalski.
Certainly, the article launched Taubes, now 54, on a five-year research project which resulted in two books. The first book, Good Carbs, Bad Carbs, is heavily annotated and there are 60 pages of references to back his assertions. The author interviewed an astounding 600 doctors for this book, aimed at health professionals.
His second book, Why We Get Fat and What We Can do About It, is an easier read. In both books, Taubes cites existing data that do not fit the established paradigms that people get fat because they eat too much and do not get enough exercise.
Instead, Taubes argues that obesity is caused by fat accumulation which is regulated by insulin and carbohydrate consumption. His view is that carbohydrate consumption drives the obesity epidemic and reducing intake of saturated fat will not cut the risk of cardiovascular disease or obesity.
He argues that, for half a century, U.S. government and public health agencies have relied upon misinterpreted science in their condemnation of fat. Scientists at several prestigious institutions, such as Duke University's Eric Westman, agree with Taubes and he has been a featured speaker at various professional functions of doctors and scientists.
In a 2002 article published in Food Technology magazine, entitled "Rethinking Dietary Saturated Fat," (http://www.ift.org/foodtechnology/0209feat_rethinking1.pdf), Westman wrote: "It is important to remember that protein and fat are needed in the human diet, but it is debatable whether humans need carbohydrate in their diet at all."
Other notable scientists questioning the current condemnation of fat include Harvard epidemiologists Dariush Mozaffarian and David S. Ludwig. In a commentary published in the Aug. 31, 2010, issue of The Journal of the American Medical Association, entitled "Dietary Guidelines in the 21st Century – A Time For Food," (http://jama.ama-assn.org/content/304/6/681.full ), the epidemiologists write: "The proportion of total energy from fat appears largely unrelated to risk of cardiovascular disease, cancer, diabetes or obesity. Saturated fat – targeted by nearly all nutrition-related professional organizations and government agencies – has little relation to heart disease within most prevailing dietary patterns."
Seminal study
Current public policy across North America, Europe and even Australia, stems from the Seven Countries Study, the work of University of Minnesota epidemiologist Ancel Keys in the 1940s and '50s. Taubes says the Seven Countries study was the basis for "The Dietary Goals of the United States," a seminal 1977 report written by the Select Committee on Nutrition and Human Needs, chaired by Democratic Senator George McGovern, that has guided public health policy on nutrition ever since.
The Dietary Goals stated that "too much fat, too much sugar or salt can be and are linked directly to heart disease, cancer, obesity and stroke, among other killer diseases. In all, six of the 10 leading causes of death in the United States have been linked to our diet."
The dietary goals further stated that "last year (1976), every man, woman and child in the United States consumed 125 pounds of fat and 100 pounds of sugar. . . .That is a formidable quantity of fat and sugar." The report generally blamed obesity and bad health on overeating and a sedentary society that needed to exercise more.
Taubes says that was followed by the recommendation of the National Institutes of Health in 1984 that all Americans over the age of two eat less fat.
Yet Taubes describes the scientific evidence supporting Keys' 1950s research as "stubbornly ambiguous" and says that politics won. He points out that, 35 years after Key's recommendations were adopted; obesity in North America has become far worse, not better. His book notes that, by 2000, sugar consumption had risen to 150 pounds per person. While the current epidemic of obesity has been associated with an affluent society, Taube's books cite numerous instances where obesity occurs at the same time as, and is linked to, extreme poverty and malnutrition. He asserts there is something going on besides simply overeating and Keys' link to fat consumption doesn't account for it.
International attention
Taubes argues that refined carbohydrates are responsible for problems like heart disease, diabetes and obesity. He's been fingering fructose and, especially, high fructose corn syrup for years.
Taube's views got attention from the agricultural community overseas. Last fall, the Australian Dairy Board paid Taubes' way to speak there. Glenys Zucco, nutrition media manager for Dairy Australia, says 20 per cent of consumers say they consistently avoid or limit dairy consumption because of health concerns.
"The aim of bringing Gary Taubes to Australia was to challenge the view that intake of saturated fat (and therefore regular-fat dairy foods) should be reduced," Zucco wrote in an email. "Gary's view is that carbohydrate is driving the obesity epidemic and that reducing intake of saturated fat will not reduce risk of cardiovascular disease."
She describes Taubes' message as "very challenging" since "current official dietary recommendations in Australia advise people to reduce fat intake, particularly saturated fat intake, and to increase carbohydrate intake instead."
Zucco says Taubes spoke at two symposia organized by the Nutrition Society of Australia, a general practitioners' conference in Melbourne and at the World Dairy Summit in Auckland, New Zealand. "Considering Gary's views are contrary to current dietary guidelines, it was a considerable achievement that 40 per cent of delegates (at both conferences) said they were supportive of Gary's conclusion, 29 per cent were undecided and 31 per cent disagreed."
"One of the most controversial things he said was that people who are morbidly obese should restrict all sources of carbohydrate, including vegetables containing carbohydrate," Zucco says.
Canadians appear to be even more concerned than Australians about fat in their diet, says Nathalie Savoie, a registered dietitian working for Dairy Farmers of Canada. "In our 2010 tracking survey, 69 per cent say they are concerned about avoiding it; when prompted, it was 77 per cent. When asked what things in milk products were bad for them, 61 per cent spontaneously named fat."
Savoie adds that fat reduction messages may have led to unintended consequences, such as the proliferation of low-fat but highly refined carbohydrate food products on the market, contributing even more to obesity and "metabolic syndrome," a combination of disorders that increase the risk of developing cardiovascular disease and diabetes.
On the positive side, for milk producers at least, there is some promising new research that shows dairy consumption of either high or low fat is "inversely associated" with a decreased risk of diabetes and cardiovascular disease, says Savoie. Harvard epidemiologist Dariush Mozaffarian, for example, suggests there might be a protective effect from eating a specific fat content of dairy food. It is still just a hypothesis "but very promising," Savoie says.
"A lot of us have known for a long time it can't be the fat" that is hurting people, says Creemore Ontario dairy producer John Miller. He allows, however, that it is in the interests of processors to sell consumers skimmed milk fluid products because they can do something else with the fat.
A return to higher fat dairy products in Canada offers no benefit to dairy producers, says Thérèse Beaulieu, assistant director of strategic communications for Dairy Farmers of Canada (DFC).
There is a surplus of solids non-fat (protein and lactose) in Canada and it gets made into skim milk powder. The fat in low fat yogurt has been replaced with other dairy products, she asserts, such as modified milk ingredients.
If there was an increase in demand for butterfat, more protein would also be produced, and it would make the solids non-fat surplus worse; even more money would be spent getting rid of the surplus and the blend price would go down, says Richard Sanchez, DFC's assistant director of policy and economics. Currently, the protein surplus is disposed of, at a very low price, to the animal feed market.
"That makes my blood boil when I hear them say that," says Miller. The former chair of the Simcoe County milk committee calls it a "defeatist attitude" among the people paid to market his product.
Fructose a problem
Taubes has spoken a number of times in Canada, including at McGill University in Montreal. One of his critics is Joe Schwarz, director of McGill's office for science and society. Schwarz is firmly in the camp that says consumption of saturated fats should be limited and polyunsaturated fats are a healthier choice.
Schwarz says Taubes "has collected a lot of data, out of which, I think, he has made more than is reasonable. There is so much scientific information published today. You can cherry pick and demonstrate anything you want to demonstrate."
Schwarz admits that fructose is a problem and agrees that "we are eating more fructose than ever before. It is metabolized differently in the body than is glucose. There is a contention that (fructose) is more conducive to obesity."
He says the best way to deal with that is to cut back on fructose-laden soft drinks. He describes North American consumption of soft drinks as "just stunning." He also believes that lifestyle and exercise habits "are very important."
Fructose production, as a food ingredient, is an important market for the Ontario corn crop. The sweetener market "is about one-quarter of the overall Ontario corn crop by Grain Farmers of Ontario estimations," says Andria Loucia, its public relations co-ordinator.
Fructose is also found in fruit, of course. John Kelly, vice president, Erie Innovations and Commercialization, Ontario Fruit and Vegetable Growers Association, doesn't see Ontario markets being adversely affected by consumers being afraid of eating fruit.
"We don't consume enough fruit as it is now (according to the food guide and dietician recommendations)," Kelly says. "Ontario markets should be aware of all issues that can impact consumption, but at this point I don't think the general consumer will decrease their fruit intake based upon this information. It is clear that the benefits outweigh a perceived challenge of fructose content and consumers should be encouraged to eat enough fruit to meet requirements." He allows that in some instances obese consumers and diabetics must pay close attention to how much fruit they eat. "I am a supporter of the ‘whole diet' approach when it comes to consumption," Kelly says.
McGill's Schwarz take issues with another of Taubes' key points – that exercise builds appetite. In Why We Get Fat, Taubes refers to a survey of 12,000 marathon runners (subscribers of a particular magazine). Most continued to put on weight even while running. Among many other sources, Taube's quotes from guidelines published in August 2007 by the American Heart Association and the American College of Sports Medicine which say: "It is reasonable to assume that persons with relatively high daily energy expenditures would be less likely to gain weight over time, compared with those who have low energy expenditures . . . . So far, data to support this hypothesis are not particularly compelling."
Taubes concludes that more work needs to be done. "If reducing ‘calories-in' doesn't make us lose weight and if increasing ‘calories-out' doesn't even prevent us from gaining it, maybe we should rethink the whole thing and find out what does."
Schwarz rejects Taubes' argument. "When it comes to nutrition, the laws of thermodynamics will never be repealed. If you take on more calories than you expend, you will put on weight." However, Taubes and Schwarz do agree on something. Junk science is used to reach conclusions that perhaps shouldn't be reached. One example of junk science Taubes points to is "observational trials." He says this type of science needs to be viewed sceptically.
Study challenged
One example is a study cited in a syndicated column published in Ontario newspapers in March by television celebrity Dr. Mehmet Oz and Michael Roizen, another medical doctor. They recommended that all red meats be avoided because "they jack up your risk for many cancers, heart disease, metabolic syndrome and, more than anyone knew, stroke."
The column described a "major new study" that found women who eat as little as 3.6 ounces of red meat daily are 42 per cent more likely to have a stroke than those who eat less than one ounce.
Taubes argues that no such conclusion can be reached from the study because the two groups might be different in many ways besides eating, or not eating, meat.
Generally healthier living habits on the side of vegetarians are one example of this. "You are comparing red wine-drinking, brie-eating vegetarians from Berkeley to redneck truck drivers in West Virginia and saying the only difference between them is how much meat they eat," Taubes argues. There are too many other variables, he says. Income and education may also play a part.
Taubes says he explained why these types of studies were flawed during an interview on the widely-watched Dr. Oz show in February. The show ran several minutes over, and when it was aired, his explanation was cut. Taubes is unhappy that the key point of his argument was edited out.
Taubes similarly dismisses a recently released documentary, Forks Over Knives. It is based on the work of Professor Colin Campbell of Cornell University and Dr. Caldwell Esselstyn, a former heart surgeon at the Cleveland Clinic.
Taubes says Esselstyn based his conclusions on "about two dozen patients." Taubes says Campbell's work, known as the China Study, shows that "there is no association between animal protein and cancer mortality."
Taubes cites examples of cancer-free populations examined in the last century, including the Native Americans of the Great Plains, the Inuit and the pastoralist Masai tribe in Africa, all of which, he says, consumed nothing but animal products.
Both Campbell and Esselstyn sit on the advisory board of Physicians Committee for Responsible Medicine, a Washington-based, charitable-status organization which aggressively promotes a vegan diet. It is affiliated with the animal rights group, People for the Ethical Treatment of Animals.
Nearly all livestock producers suffered when Senator McGovern's select committee slagged red meat and dairy consumption. Pork, beef and dairy consumption went into free fall (See Table 1). Producers fought back by funding campaigns to promote their products, with varied results.
The potato industry took some steps as well when it was hurt at the height of the Atkins diet craze.
Fabulas and Adoras
A couple of varieties of potatoes grown on Lach's Norfolk County farm have been identified in tests as having a "low glycemic index," which means the starch breaks down into sugar relatively slowly during digestion. Lach says more than 125 varieties were tested and Fabula and Adora were at the top.
Lach says he grows Fabulas and Adoras, not to meet a low-glycemic potato market, but rather because they are a productive variety that is good to grow, easy to store and is liked by consumers. He says grocers have been reluctant to market them as anything special. Lach produces what is called a premium pack potato, the uniformly-sized potatoes that consumers pick over at the store and put into a bag themselves, paying 85-95 cents a pound.
Lach moved to Norfolk from a vegetable farm in the Grand Bend area in 1978 and grew tobacco for a few years before he saw the industry was foundering. He took an early buyout and grew corn and soybeans for a while before going back into vegetables. "The business just grew," he says. "You have a good product and you get a reputation." Lach ships directly to Loblaws and Sobeys.
Lach gets his seed from HZPC North America in Prince Edward Island. The website for seed stock supplier HZPC Americas Corporation says "Adora is naturally selected Low Carbohydrate dense potatoes." Its description of Fabula potatoes does not mention carbohydrates or glycemic rate. HZPC's marketing manager did not return repeated telephone requests for an interview.
In New Brunswick, Agriculture and Agri-Food Canada plant breeder Benoit Bizimungu is screening about 100 candidate varieties for a lower glycemic index potato, high in slowly digestible starches and high in dietary fibre. An Agriculture Canada press release says modern commercial potatoes "possess some of the highest glycemic indices of all food products. . . . producing a blood glucose level spike shortly after eating."
Trends are slow to change in the dietetic world. In October, 2009, Taubes made a presentation to an American Dietetic Association conference in Denver, Colo. His talk was on the history of dietetic advice. The presentations were marked and he saw the individual report cards. He says responses to his presentation ranged between high marks and zeroes and the low marks were accompanied by comments that he shouldn't have been at the podium because he was neither a medical doctor nor a dietitian.
Taubes doubts that public health officials will ever change their views on fats. "The bad fats will remain saturated fats, but bad carbohydrates will enter into it as well," he predicts. The regulatory agencies and the American Medical Association will never admit they were wrong because they would lose all credibility and also possibly be open to lawsuits.
Taubes says he isn't the first to argue against the Seven Countries Study and its attack on dietary fat. "These arguments have been made in the past but were always defeated…. Maybe the Internet will change this on some level."
Ancient diet
Dr. Atkins may be dead but his company and theories live on. The Palaeolithic diet movement "doesn't have the baggage of Atkins. It is catching on," says Taubes. Palaeo dieters mimic the presumed ancient diet of wild plants and animals that humans consumed before agriculture began 10,000 years ago. They eschew bread and potatoes. (They also eschew dairy, so they are no boost to milk producers.)
Taubes asserts that, as long ago as the 1820s, writers observing fat people noted that they favoured foods such as bread, potatoes and pasta. That view held through the 1950s and the 1960s. "My mother knew that pasta made her fat," Taubes says and a protein rich diet is not a fad diet. "The fad is the low fat diet of the last 40 years."
Meanwhile, the war on fat continues. According to the May 23 Wall Street Journal, the U.S. Department of Agriculture is proposing to eliminate the white potato from federally subsidized school breakfast programs and sharply limit it on lunch menus. While this approach may be aimed at reducing fried foods, it's still not good news for table potato growers like Joe Lach. Canada is the world's largest producer of French fries and those acres will grow some thing if French fry demand falls. Good old American politics kicks in again. BF
Key U.S. dietary goals
- Increase carbohydrate consumption to account for 55-60 per cent of the energy intake.
- Reduce overall fat consumption from approximately 40 to 30 per cent of energy intake.
- Reduce saturated fat consumption to account for about 10 per cent of total energy intake and balance that with poly-unsaturated and mono-unsaturated fats, which should account for about 10 per cent of energy intake each.
- Reduce cholesterol consumption to about 300 milligrams a day.
- Reduce sugar consumption by about 40 per cent to account for about 15 per cent of total energy intake.
- Reduce salt consumption by about 50 to 85 per cent to approximately three grams a day.
- Increase consumption of fruits, vegetables and whole grains.
- Decrease consumption of meat and increase consumption of poultry and fish.
- Decrease consumption of foods high in fat and partially substitute polyunsaturated fats for saturated fat.
- Substitute non-fat milk for whole milk and decrease consumption of butter, eggs and other high cholesterol sources.
- Decrease consumption of sugar and foods high in sugar content and decrease consumption of salt and foods high in salt content. BF
The pendulum swings on red meat consumption
Canadians don't eat too much red meat, according to Karine Gale, a registered dietitian and nutrition manager with the Beef Information Centre.
The average Canadian's diet includes 17 per cent of calories from protein. The recommended range is 10-30 per cent, so the average consumer could eat twice as much meat and stay within the guidelines, Gale says.
Where would those calories come from? That average Canadian gets 28.5 per cent of calories from grains, 20.5 per cent from meat and alternatives, 16 per cent from vegetables and fruit and 12.3 per cent from milk products. Missing from that equation is 22 per cent of calories from non-essential foods such as chocolate bars, chips, soft drinks and spreads. "When you think about it, that's not even a food group," Gale says.
Canada's Food Guide recommendations do change from time to time. (The Guide was last revised in 2007.) Gale describes the Food Guide wording as "led by Health Canada and the greater scientific community." Health professions comment on it, as does industry. "I suppose there might be people who argue it is a political process," Gale says.
"It is based on the status of the scientific evidence at the time. It is supposed to be very removed from politics."
Recommendations have changed over time on fat, but certainly not in the direction of a high fat diet, Gale says. The recommendation to keep fat calories at 20-35 per cent of the diet still holds. There is a movement towards lower saturated fats, the ones that aren't found in meat, as long as they aren't trans fats and hydrogenated oils. Under pressure from consumers and government, food processors mostly removed trans fats in recent years.
There seems to be a change in where calories are coming from, Gale says. Diets have become "heavier in carbohydrates and particularly in refined carbohydrates . . . . We are coming to recognize that this is a recipe for bad health."
The new American food guide was launched in January. Gale says one of its recommendations was that we should be looking at reducing refined grains and added sugars and solid fats, and emphasizing nutrient-dense foods and beverages. "That is kind of new language that hasn't really appeared (before) in new versions of either American or Canadian food guides."
It's no surprise there is an energy excess in our diet, Gale says. "We are starting to realize it is not fat that is the problem. It is excess calories," she says. Fat just happens to carry more calories per gram than carbohydrates or proteins.
Jim Clark, general manager of the Ontario Cattle Feeders Association, says the cattle industry is like a pendulum swinging back and forth between extremes as it tries to find what consumers want.
Breeders replaced their short and fat British breed cattle with European exotics that were leaner, but the product was less attractive for many consumers because it lacked juiciness. Now the pendulum has swing back. The highly popular Certified Angus Beef brand "is positioned perfectly" for the current consumer trend, Clark says, but he wonders when the pendulum will swing the other way again. Clark says all of these changes in genetics are expensive for the industry. "We try to react too much to markets without truly knowing what the consumer is looking for."
What dieticians and the medical associations have to say influences consumers, says Clark, who is battling obesity himself. Baby boomers are concerned about their health. "The Internet lets you basically become an armchair scientist. I think there are things we don't decipher correctly from what we read."
"What drives consumers' decisions is very complicated." adds Brian Sullivan, chief executive officer of the Canadian Centre for Swine Improvement. "We have seen a drop in per capita consumption of red meats over time. What all is behind that, I am not sure."
Sullivan says producers largely responded to big incentives paid by packers for lean pigs. That might be partly because consumers wanted lean pork. But Sullivan thinks it is mostly economics. A leaner hog produces more meat that can be sold rather than a lot of fat that has to be trimmed off. BF