Chapter Three CREATION OF CONSENSUS Flashcards
What did Francis Bacon state about sciences based on supposition and opinion?
The object is to command assent, not to master the thing itself.
By what year did the notion that dietary fat causes heart disease begin to transform into nutritional dogma?
1977
What was the primary change that occurred regarding the belief in saturated fat and cholesterol as health risks?
Public attitude shifted, achieving critical mass independent of science.
What movement emerged in the 1960s related to dietary fat and meat consumption?
An anti-fat, anti-meat movement.
Who predicted mass starvation in ‘The Population Bomb’ and when?
Paul Ehrlich in 1968.
What was the fundamental problem identified regarding world hunger?
An ever-increasing world population.
What dietary shift was suggested by Harvard nutritionist Jean Mayer to improve world food availability?
A shift toward a simplified diet with less animal products.
Who wrote ‘Diet for a Small Planet’ and what was its main argument?
Francis Moore Lappé; it argued that meat-eating is a social and moral issue.
What did the American Heart Association recommend regarding dietary fat by 1970?
To cut back on saturated fat and meat.
What did Norman Borlaug achieve that contradicted Paul Ehrlich’s predictions?
Created high-yield varieties of dwarf wheat that ended famines in India and Pakistan.
What was the American Heart Association’s stance on dietary fat revisions?
Revised recommendations every two to three years, increasingly advising less fat.
What was the significant event on January 14, 1977, regarding dietary recommendations?
Senator George McGovern announced the publication of the first Dietary Goals for the United States.
What was the impact of the Dietary Goals document?
It sparked a chain reaction of dietary advice that became widely accepted.
Who was the staff director of McGovern’s committee and what was his perspective on their knowledge of dietary issues?
Marshall Matz; described their knowledge as that of interested laymen.
What was the first goal of the Dietary Goals regarding carbohydrate consumption?
Raise carbohydrates to constitute 55–60 percent of total calorie intake.
Fill in the blank: The Dietary Goals recommended reducing fat consumption from _____ percent to _____ percent.
40 percent to 30 percent.
What did the Dietary Goals acknowledge regarding the evidence for reducing fat content in diets?
No evidence existed to suggest it would lower blood-cholesterol levels.
What was the response from the National Heart, Lung, and Blood Institute regarding lowering cholesterol?
No one knew if it would prevent heart attacks.
What was the American Medical Association’s concern regarding the Dietary Goals?
Potential harmful effects from radical long-term dietary changes.
What change was made in the revised edition of the Dietary Goals regarding meat consumption?
Changed from ‘decrease consumption of meat’ to ‘decrease consumption of animal fat’.
What was the first recommendation in the revised edition of Dietary Goals?
To avoid being overweight
How did the revised Dietary Goals change the recommendation regarding meat consumption?
It changed from ‘decrease consumption of meat’ to ‘decrease consumption of animal fat, and choose meats, poultry, and fish which will reduce saturated fat intake’
What was the committee’s stance on physical harm resulting from dietary modifications?
They found that no physical or mental harm could result from the dietary guidelines recommended for the general public
What was the first important question investigated by the committee?
Does lowering the plasma cholesterol level through dietary modification prevent or delay heart disease in man?
Who was the driving force at the USDA advocating for McGovern’s Dietary Goals?
Carol Foreman
What was Carol Foreman’s belief regarding the relationship between diet and health?
She believed people were getting sick and dying because of excessive eating
What was the Food and Nutrition Board’s role in the evaluation of Dietary Goals?
They determine Recommended Dietary Allowances and advise the government on nutrition issues
What were the USDA’s official dietary guidelines released in February 1980?
Avoid Too Much Fat, Saturated Fat, and Cholesterol
What did the Food and Nutrition Board recommend in their version of dietary guidelines?
To watch their weight, with no specific dietary advice
What was the response of the House Agriculture Subcommittee to the Food and Nutrition Board’s guidelines?
Described as ‘inaccurate and potentially biased’ and ‘quite dangerous’
What dilemma did Philip Handler present regarding dietary recommendations?
The dilemma concerns whether it is prudent to propose dietary changes based on tenuous evidence
What is the conflict-of-interest accusation often used to discredit?
Viewpoints with which one disagrees
What did Mark Hegsted say about the nature of scientific funding?
Scientists are often funded based on their alignment with government positions
What was the outcome of the National Diet-Heart Study?
It was not conducted, leading to reliance on smaller studies
What was the conclusion of the studies conducted in Honolulu, Puerto Rico, Chicago, and Framingham?
None of them succeeded in establishing a clear relationship between dietary fat and health
What was suggested as a dietary recommendation based on the studies in Puerto Rico and Honolulu?
To eat more starches, as those free of heart disease consumed more starch
What suspicion arose regarding the government’s advocacy for fat reduction?
It changed how many investigators perceived their obligations and interpreted their data
What dietary change was suggested regarding starch intake?
To eat more starch.
What was the primary reason for recommending less fat in the diet?
To avoid gaining weight.
What shift occurred in the perception of investigators regarding dietary fat?
They began to reconcile their findings with government recommendations.
What association was found between low cholesterol levels and cancer risk?
Low cholesterol levels were associated with a higher risk of cancer.
What notable studies reported the association between low cholesterol and cancer?
Three Chicago studies by Jeremiah Stamler and colleagues.
Which trial first suggested the link between low cholesterol and cancer?
Seymour Dayton’s VA Hospital trial.
What was the finding regarding colon cancer and cholesterol levels in the Framingham Study?
Men with cholesterol below 190 mg/dl were more than three times as likely to get colon cancer.
What action did the NHLBI take in response to the low cholesterol and cancer association?
Hosted three workshops to discuss the issue.
What conclusion did the NHLBI reach regarding the low cholesterol and cancer link?
The evidence was considered inconsistent and only ‘suggestive’ of a link.
What were the two major trials the NHLBI initiated in the early 1970s?
The Multiple Risk Factor Intervention Trial (MRFIT) and the Lipid Research Clinics (LRC) Coronary Primary Prevention Trial.
What was the aim of the MRFIT study?
To address multiple risk factors for heart disease.
What were the results of the MRFIT trial announced in October 1982?
Slightly more deaths occurred in the treatment group than in the control group.
What was the primary finding of the LRC trial regarding cholesterol levels?
Cholesterol levels dropped by 4% in the control group and 13% in the treatment group.
What was the conclusion regarding the effectiveness of cholestyramine in the LRC trial?
It improved the chance of survival by less than .2 percent.
What did Rifkind assert about cholesterol-lowering diets after the LRC trial?
Lowering cholesterol with diet and drugs can cut the risk of heart disease.
What was criticized regarding the extrapolation of drug study results to diet?
It was deemed unwarranted and unscientific.
What was the outcome of the NIH consensus conference regarding cholesterol levels?
Concluded that low-fat diets afford significant protection against coronary heart disease.
What did the consensus conference reveal about the diversity of opinions on cholesterol-lowering?
There was no true unanimity among experts.
What did the consensus panel consist of?
Only those who would predictably support lowering cholesterol.
What did the LRC investigators acknowledge in their JAMA article?
Their attempt to ascertain a benefit from diet alone had failed.
How many calories per gram do fats supply?
9 calories per gram
How many calories per gram do protein and carbohydrates supply?
4 calories per gram
What percentage of calories from fat may result in difficulty losing weight for those not engaged in heavy physical activity?
40 percent
What was the significant finding of the Honolulu Heart Program in 1985 regarding high-fat diets?
High-fat diets were significantly associated with a lower risk of total mortality, cancer mortality, and stroke mortality
What association was found between percentage of calories from fat and dietary cholesterol intake with heart disease?
Both were associated with a higher risk of heart-disease death
What hypothesis does the Honolulu Heart Program data support?
The diet-heart hypothesis
What caveat did the Honolulu Heart Program authors include regarding low fat intakes?
Men with low fat intakes have a higher total mortality rate than men with higher fat intakes
What did the MRFIT investigators report about lung cancer rates in the treatment group?
Men in the treatment group had more lung cancer than the controls
What percentage of men in the treatment group quit smoking compared to the usual-care group?
21 percent in the treatment group vs. 6 percent in the usual-care group
What did the MRFIT investigators suggest might explain the higher lung cancer mortality in the treatment group?
Lower cholesterol levels
What type of association did serum cholesterol show with lung cancer mortality according to MRFIT?
Marginally significant inverse association
True or False: The MRFIT investigators concluded that lower cholesterol levels are a likely explanation for higher lung cancer mortality.
False
