FOOD, FACTS and FADS

Exploring the sense and nonsense of food and health


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Plant-Based Diets?

Asian

Epidemiology studies support the plant-based diet.  Those cultures that have the lowest risk of heart disease and cancer eat more plant-based diets and less meat and cheese.  For example, Asian and Mediterranean countries traditionally followed this diet and as they increased their intake of Western foods (i.e., more meat), their disease rates increased.

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Ancel Keys – Big Fat Confusion?

An early picture of Ancel Keys, This image is ...

An early picture of Ancel Keys, (Photo credit: Wikipedia)

Time Magazine 1961. Ancel Keys appears on the cover to claim that saturated fat in the diet clogged arteries and caused heart disease.

Time Magazine, 2014. Eat Butter. Scientists were wrong about saturated fat. They don’t cause heart disease.

How did the low saturated fat message begin?  How, when and why did this confusion begin?

Ancel Benjamin Keys was born in 1904 in Colorado Springs, Colorado to teenage parents. In his younger years he had various jobs including a clerk in a Woolworth store. He finished college in 3 years with Honors at Berkeley and earned a MS in Biology followed by a PhD from the Scripps Institute of Oceanography. In 1930 he traveled to Copenhagen to work with Nobel laureate, August Krogh where he studied the ability of eels to survive in both fresh and salt-water environments. He then went to Cambridge and obtained a second PhD in animal physiology from King’s College.

He married a biochemist, Margaret, in 1939 and established the Laboratory of Physiologic Hygiene at the University of Minnesota.   It was this year that “he came to the attention of the United States War Department and was asked to develop and test food rations for parachute troops.” The result was the K ration, which became standard fare for feeding troops in World War II. Journal of Clinical Lipidology, (2011) 5, 434-437.

What made Keys famous was his Seven Countries Study, a study that remains controversial to this day. He initially observed that heart disease rates dropped in countries forced to alter their high fat diets because of the war rationing and reversed to higher rates when these diets returned.

He suspected dietary factors, particularly saturated fat, that might play a key role in atherosclerosis. After conducting some well-designed studies to support his theory, “he formulated an equation that simply showed a 2.7% mg/dl rise in cholesterol for every 1% of calories derived from saturated fat. The equation also suggested that polyunsaturated fat lowered serum cholesterol and dietary cholesterol raised serum cholesterol but to a lesser extent than saturated fat. “ Journal of Clinical Lipidology, page 435

Keys had based his theory on when he had previously visited Italy and Spain. He observed in Naples, Italy that only heart disease patients in hospitals were wealthy men. In Madrid, Spain he took blood samples from some men in one of the poorer districts where heart disease was rare and compared them to samples of more well-off patients with heart disease. What he found were differences in their serum cholesterol values with the higher levels in the wealthy and lower values in the poorer population. The diets of the two groups also differed with the poorer diets lower in fat than those of the wealthy. These observations were central to his theory that saturated fat or animal fat and dietary cholesterol contributed to heart disease.  Levenstein, Harvey, Junk Science Week: Lipophobia and the Bad Science Diet, Financial Post, June 11,2012.

The theory gained some steam when in 1955, President Dwight David Eisenhower had a heart attack at age 64, “ Over the next six weeks, twice-daily press conferences were held on his condition. After his attack, he dieted religiously with a low-fat diet and had his cholesterol measured ten times a year (it had been 165 mg initially)”. Taubes, Gary. Good Calories, Bad Calories, page 1-4.   The low-fat diet had little effect and his cholesterol continued to rise as well as his weight.

Between 1955 and 1958, Keys began to study the male population aged 40 to 59 in rural areas in certain countries. He used electrocardiograph data to detect heart abnormalities and cardiovascular disease. The countries included Yugoslavia, Italy, Greece, Finland, the Netherlands, the U.S. and Japan. The countries he had chosen represented varied intakes of saturated or animal fat; lower levels were found in some populations in Yugoslavia, Italy, Greece, and Japan. Finland, the Netherlands, and the U.S. represented higher levels of animal fat in their diets. Five and ten years later, the researchers returned to identify those who had experienced heart attacks. The lowest rates were found in Crete and Japan with the lowest levels of animal fat; the highest was found in East Finland and the U. S. with the highest levels of animal fat. All in all, Keys studied nearly 13,000 men.  From this study, he concluded that “saturated fats as a percentage of calories was the most powerful lifestyle predictor of heart disease. “Blood cholesterol was the important physiological variable. “ Journal of Clinical Lipidology, page 437.

In 1961 Keys appeared on the cover of Time magaine with the Seven Countries Study’s alleged link between fat, cholesterol and heart disease that fueled the fear of dietary fat in America. Two weeks later the American Heart Association (AHA) endorsed the theory.  With this announcement, the vegetable oil producers could not get their advertisements out fast enough. Wesson Oil said: “polyunsaturated Wesson is unsurpassed by any leading oil in its ability to reduce blood cholesterol.” Nutrition scientists jumped on the bandwagon. For example, Harvard nutritionist, Frederick Stare advised swallowing three tablespoons of polyunsaturated oil each day. Lipophobia had begun in earnest. Levenstein, Harvey, Lipophobia and the bad science.

Consumption of margarine doubled from 1950 to 1972 and that of vegetable oil rose by over 50% in the 10 years from 1966 to 1976. Ironically, based on the thesis of Keys that saturated fat was the culprit, the AHA and other agencies had urged food processors to use trans fats to replace the alleged deadly saturated fat. Ironically, the most common source of trans fats turned out to be the very margarine they had promoted as heart healthy. From 1956 to 1976, per-capita butter consumption fell by over half.

Key’s hypothesis strengthened in 1977 with Senator George McGovern’s publication of the First Dietary Goals for the U.S., which was the first time that any government group had told Americans to eat less fat and cholesterol to improve health. The document became gospel and had a tremendous impact on consumers and the food industry. In 1980, Hegsted and McGinnis produced the USDA Dietary Guidelines for Americans that concurred with “avoiding too much fat and cholesterol and eating more foods with adequate starch and fiber.”

However, three major studies failed in their support for Key’s hypothesis and without going into the details, each one raised doubts about the  hypothesis. The studies were the Women’s Health Initiative (WHI) in 1991, the Multiple Risk Factor Intervention Trial (MRFIT) in 1982, and the more recent LOOK AHEAD Study. Ironically in 1989, Frederick Stare from Harvard University, who had originally supported the Keys thesis, reversed his opinion and joined the opposite camp of doubters by co-authoring a book entitled Balanced Nutrition: Beyond the Cholesterol Scare.

The Key’s Seven Countries Study, so pivotal in lipophobia has been debunked by many, particularly those who favor the idea of eating meat.. On the other hand, vegans favor the thesis. Here is what the critics of the study say: First, Keys did not randomly choose countries but is accused of picking those countries most likely to support his theory. He excluded France whose diet has been notoriously rich in saturated fat along with a low heart disease rate (The French Paradox). He also excluded Switzerland, Sweden, and West Germany with the similar higher saturated fat intakes but with lower rates of heart disease. He originally gathered data from 22 countries.   However, some point out that even when all 22 countries are analyzed, the trend that fat intake is associated with heart disease still weakly exists.

From his work with the GreeK islands, Crete and Corfu, Dr. Keys and his wife wrote two best-selling books, Eat Well and Stay Well and How to Eat Well and Stay Well the Mediterranean Way. These and a third book they wrote, “The Benevolent Bean,” had the kind of recipes on foods of the Mediterranean regions that Keys had studied. To their credit, their books were among the first extolling the virtues of the popular Mediterranean diet today. After living in Italy for many years and following his own advice, Ancel Keys died in November of 2004 at the age of 100 years old.

Key’s thesis is still hotly debated to this day because of its limitations and lack of  conclusive support from the research community. There are still adherents of the efficacy of the low fat diet, particularly in its effects on atherosclerosis regression or prevention.  The debate has now switched to which diet is heart healthy – a low-fat or a low-carbohydrate diet. However, that is another story.

I truly don’t know if Keys was right or wrong. The purpose of this post is to point out that his legacy remains as one of the leading food crusaders that changed the American plate.  Is the low fat craze finally coming to an end?  Has this national experiment failed?  Will the low carbohydrate diet help curb the obesity epidemic or prevent heart disease?  Sounds like a “soap opera, doesn’t it?  One thing is certain – atherosclerosis is a complicated disorder and until its origin and pathology is conclusively determined, no one will know who was right.

As Keys himself summarizes: “The direct evidence on the effect of diet on human atherosclerosis is very little…. but such evidence as there is, plus valid inferences from indirect evidence, suggests that a substantial measure of control of the development of atherosclerosis in man may be achieved by control of the intake of calories and all kinds of fats, with no special attention to the cholesterol intake”.   Human Atherosclerosis and the Diet, Ancel Keys, Circulation 1952; 5: 115-118.

According to David Katz. MD, Director, Yale University Prevention Research Center,   “For whatever it is now worth, to my read, Keys’ messages were mostly right, a bit wrong and horribly vulnerable to the distortions of mercenary marketing and mass gullibility”. David Katz, MD, MPH The Keys to Good Health, August 14, 2014.


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The School Lunch Mess

 

The school lunch program has been controversial for the last couple of years for a number of reasons.  There are so many problems but a couple stand out.  First, the politics of it all are discussed in the following article.

CLICK HERE.

But another problem has been occurring – our kids don’t like the new foods being introduced.   As one parent pointed out:  “my kid just won’t eat cold, tasteless vegetables – would you?” This blog has repeatedly said that education of our kids on the reasons why these foods are healthier for them and techniques for involving them in their food choices are the best way to help alleviate this problem.  Another necessary approach is to teach the food preparers how to make these food items more palatable and appealing.  I’m not a fan of the Academy of Nutrition and Dietetics due to its corporate ties, but sometimes they do present some good advice.  Here is a direct quote from their website, eatright.com.

 

The Academy’s School Nutrition Services dietetic practice group has more than 1,200 members, working in school districts, federal and state agencies, business and industry, and colleges and universities, all dedicated to the integrity and promotion of school meal programs and the advancement of sound nutrition for children.

With the implementation of the Healthy, Hunger-Free Kids Act, SNS members make sure students are exposed to and can learn about nutritious foods served as part of school meal programs. For example:

We have a farm-to-school approach to nutrition education that links the classroom, dining center and school garden. A featured food of the month and locally procured items are highlighted on the menu, and schools can grow and harvest produce for the dining center. Classroom teachers are also integrating nutrition education into Common Core.” – Tarrah DeClemente, MPH, RDN, LDN, Chicago Public Schools, Chicago, Ill.

With the Pick a Better Snack program in Iowa, students are very willing to try new foods when presented in a fun learning environment. When kids learn about the foods they are trying, play games and see their classmates trying the fresh fruit and vegetable snacks, students usually do try the snack, and most often times like them.” – Abbie Scott, RD, LD, Jackson Elementary and Howe Elementary, Des Moines, Iowa.

We collaborate with a local nonprofit to provide taste tests in elementary school cafeterias, as well in the classroom of two elementary schools in our county. The classroom nutrition education is part of the Fresh Fruits and Vegetable Program that provides funding for fresh produce as well as lesson plans.” – Mary Andreae MS, RD, LDN, Buncombe County Schools, Ashville NC. 

Search this blog for “school lunch” for other approaches to this problem if it ever becomes solvable.


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Where to Buy Honey?

Figure 2. Honey bee collecting pollen

Figure 2. Honey bee collecting pollen (Photo credit: Wikipedia)

Some interesting news about how honey is ultra-filtered that removes the pollen or adulterated with corn syrup.  We need to know since a lot of the honey in our stores come from China with a bad track record of food safety issues.

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The Scoop on Stevia

Stevia rebaudiana

Stevia rebaudiana (Photo credit: Wikipedia)

Why Stevia?

The big soda companies are introducing two new low-calorie drinks, both using stevia as a sweetener. Look for a new green label on both products. In mid October, PepsiCo is coming out with Pepsi True and will only be available for now online at Amazon. Coca-Cola’s new product called Coca-Cola Life is already available in Argentina, Chile, Great Britain, and Mexico. In November, it will debut nationwide in the U.S. For now, it is only available in Georgia, Florida, and North and South Carolina.

Pepsi says its new soda will have 30% less sugar than regular Pepsi and has no high fructose corn syrup or artificial sweeteners. Coke’s Life contains 60 calories, which is 35% fewer calories than other sodas.

According to WebMD, stevia is a natural, no-calorie sweetener derived from a South American plant.  Its prized species is Stevia rebaudiana that grows in Paraguay and Brazil where people have used leaves from the stevia bush to sweeten foods for centuries. Now it has entered the sugar substitute market. This market is growing.  According the American Journal of Clinical Nutrition in 2012, just 18% of U.S. adults used low-or no-calorie sweeteners in 2000.  Now, 24% of adults and 12 % of children use sugar substitutes.

Stevia comes in tabletop green packets, liquid drops, dissolvable tablets, spoonable products, and baking blends. Some people report that stevia has a metallic aftertaste which could be a problem for many soda drinkers.  Stevia is 200 times sweeter than sugar.

Is Stevia Safe?

The FDA does approve the use of a chemical, called Rebaudioside A, a glycoside, as Generally Recognized as Safe (GRAS) and is  used in Truvia and Pur Via brands. This compound has generally been found to not affect blood glucose or blood pressure. Whole-leaf stevia or crude stevia extracts are not FDA-approved, since little research has been done on its safety in high doses. The FDA only grants or denies approval to food additives, not supplements. Therefore, health food  and natural food stores can sell whole stevia and crude extracts without needing FDA approval only if it is labeled  as a supplement, not a food. The general consensus says that using this sweetener in small doses does seem safe.  However, as it begins to be used in more and more products, safety becomes more of an issue.

Some health concerns include the possibility of low blood pressure and may be of concern to many people taking antihypertensive medications, particularly calcium channel blockers. Other concerns may be that stevia can interact with anti-fungals, anti-inflammatories, anti-cancer drugs, insulin and oral anti-hyperglycemic medications.. People using large amounts of stevia should talk with their doctors and pharmacists.

 

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