Chapter Four THE GREATER GOOD Flashcards
What is the reaction of most people towards a theory they once accepted?
The majority shut their ears and eyes to contrary facts to remain faithful to their theories.
What did the NIH establish in 1986?
The National Cholesterol Education Program (NCEP).
What was the threshold for total blood cholesterol set by the NCEP?
Below 200 mg/dl.
What did Surgeon General C. Everett Koop’s report in 1988 state about dietary fat?
It exhorted Americans to cut out the fat.
How many deaths in the U.S. in 1988 were attributed to the disproportionate consumption of high-fat foods?
Two-thirds of the 2.1 million deaths.
What was the main priority of the National Academy of Sciences report on diet and health?
Reducing fat intake.
Who oversaw the surgeon general’s report linking dietary fat to heart disease?
J. Michael McGinnis.
What was the public debate shifted to regarding dietary fat?
Whether Americans should eat low-fat or very low-fat diets.
How many times had low-fat diets been tested prior to national recommendations?
Only twice.
What was the expectation for lowering total fat content in the diet?
To help control weight.
What did Robert Levy and Nancy Ernst state about low-fat diets?
There was no conclusive proof that cholesterol lowering was independent of other dietary changes.
What was the benefit of lowering cholesterol according to the Framingham Heart Study?
No relationship between cholesterol and sudden cardiac death was detected.
What percentage of men with high cholesterol could expect to die of heart disease over six years?
Eight in a thousand.
What did the MRFIT study reveal about total mortality related to cholesterol levels?
No significant difference in death rates for cholesterol levels below 250 mg/dl.
How much extra life might high-risk men gain by avoiding saturated fat, according to the Harvard study?
One extra year.
What was the expected increase in life expectancy for healthy nonsmokers avoiding saturated fat?
Three days to three months.
What did the UCSF study conclude about cutting fat consumption?
It would delay forty-two thousand deaths each year, with an average life expectancy increase of three to four months.
What was the main concern raised by the analysis of dietary fat recommendations?
The actual benefit to individuals might be small or negligible.
Who is credited with the strategy of addressing public health through population-level interventions?
Geoffrey Rose.
What does the mass preventive medicine approach imply about individual benefits?
It offers little to each participating individual.
How many immunizations were needed to save one life during mass diphtheria immunization in Britain?
600 children.
What was the conclusion about dietary fat and heart disease according to Rose’s calculation?
The mass approach benefits the community but not necessarily individuals.
What is the ratio of immunizations to lives saved in mass diphtheria immunization in Britain?
600 children immunized for one life saved
This highlights the challenge in mass preventive medicine where many benefit very few.
According to Rose, how many men in every fifty might avoid a heart attack by avoiding saturated fat?
One man in every fifty
This indicates that dietary changes may not yield significant individual benefits.
What strategy does Rose suggest to motivate people to adopt healthy behaviors?
Create social pressure to change
An example is the societal preference for thinness among young women.
What does Rose argue about the assumption regarding population fat consumption and cholesterol levels?
The entire population chronically overconsumes fat
This affects the ability to identify individual risks related to dietary fat and cholesterol.
What is the ‘sick population’ logic according to Rose?
It explains why individual interventions may have little effect but can benefit the population as a whole
It reflects the need for understanding population-level health rather than just individual health.
What are the four critically important caveats of Rose’s logic?
- It does not differentiate between hypotheses
- Public-health interventions come with potential risks
- It makes challenging underlying science difficult
- It discourages skepticism of the science
These caveats suggest limitations in public health recommendations based on population data.
What is ‘biological normality’ according to Rose?
The conditions to which we are genetically adapted
This concept is used to argue for low-fat or low-saturated-fat diets.
What is the implication of defining the healthiest diet based on Paleolithic nutrition?
The diet we evolved to eat is presumed to be healthiest
This raises questions about modern dietary recommendations.
What did Eaton and Konner’s 1985 analysis conclude about hunter-gatherer diets?
Genetically adapted to eat diets of 20–25 percent fat
This was later revised to indicate higher fat consumption.
What did Eaton, Speth, and Cordain find in their 2000 analysis of hunter-gatherer diets?
Paleolithic diets were extremely high in protein and comparable or higher in fat
This contradicted earlier low-fat dietary recommendations.
What does Rose’s logic imply about the pursuit of further research in public health?
It may discourage further inquiry if a consensus is claimed to exist
This can hinder the scientific process and understanding of public health.
What was the original proposition linking dietary fat to breast cancer?
Dietary fat causes breast cancer
This was based on international comparisons and observations from the 1970s.
What did studies from Framingham and other locations indicate about fat consumption and cancer rates?
Low cholesterol levels were associated with higher cancer rates
This contradicted the hypothesis that high-fat diets cause cancer.
What were the findings of the Nurses Health Study regarding fat consumption and breast cancer?
Less fat consumption correlated with higher breast cancer rates
This challenged the dietary fat-breast cancer hypothesis.
What did Willett’s long-term observations from the Nurses cohort suggest about saturated fat?
Risk of breast cancer decreased as saturated fat increased
This further undermines the hypothesis that fat consumption is harmful.
What was the response of the National Cancer Institute to the emerging evidence against the fat-cancer hypothesis?
They continued to recommend a low-fat diet despite contradictory evidence
This reflects the influence of established public health beliefs.
What percentage decrease in breast cancer risk is associated with every 5 percent of saturated-fat calories that replace carbohydrates?
9 percent
Who refused to let the hypothesis that excessive fat consumption causes breast cancer die?
Peter Greenwald and the administrators at NCI
What article did Greenwald and his NCI colleagues respond with after the Nurses Health Study results?
The Dietary Fat–Breast Cancer Hypothesis Is Alive
What did the NCI administrators argue about studies refuting the fat-cancer hypothesis?
They could be flawed and any positive evidence was sufficient to keep the hypothesis alive.
What did laboratory studies indicate about high-fat, high-calorie diets in rats?
They have a substantially higher incidence of mammary tumors compared to low-fat, calorie-restricted diets.
What was a significant finding regarding the types of fats that induced tumors in lab rats?
Polyunsaturated fats were far more effective than saturated fats.
What was the conclusion of Kritchevsky’s 1984 study on fat and calorie effects on cancer?
Low-fat, high-calorie diets led to more tumors than high-fat, low-calorie diets.
What did Mike Pariza state about calorie restriction and fat’s enhancement of cancer?
Restricting calories wipes out the so-called fat enhancement of cancer.
What was the conclusion of the 1997 World Cancer Research Fund report regarding fat-rich diets and cancer risk?
They found neither convincing nor probable reasons that fat-rich diets increased cancer risk.
What did Arthur Schatzkin describe the accumulated results from trials testing the fat-cancer hypothesis as?
Largely null.
What did the American Cancer Society recommend in 2002 regarding red meats?
Limit consumption of red meats, especially those high in fat.
By 2006, what was the American Cancer Society’s stance on total fat consumption and cancer risk?
There is little evidence that the total amount of fat consumed increases cancer risk.
What was the goal of the Women’s Health Initiative (WHI) launched by NIH in 1991?
To test the hypothesis that a low-fat diet prevents breast cancer and other chronic diseases.
What was the average calorie reduction for participants on the low-fat diet in the WHI?
120 calories a day less than the controls.
What was the outcome of the WHI regarding breast cancer incidence?
No less breast cancer than those who ate their typical American fare.
What bias was present in the WHI trial regarding dietary counseling?
The women on the low-fat diet received intensive nutritional and behavioral-education, while the controls did not.
What is one reason the WHI findings were not seen as a definitive refutation of the fat-cancer hypothesis?
The established recommendations on disease prevention remained unchanged.
What is the challenge in scientific controversies regarding dietary fat and cancer?
The inability to measure accurately the effects of dietary fat.
What did Francis Bacon suggest as a differentiator between good science and wishful science?
Good science grows and develops based on reality, while wishful science remains stagnant.
What are the three independent propositions in the dietary-fat/cholesterol/heart disease hypothesis?
- Lowering cholesterol prevents heart disease * Eating less fat lowers cholesterol and prevents heart disease * Lowering fat prolongs life
What has the evidence regarding the benefits of low-fat diets become since the early 1980s?
Progressively less compelling.
What did Keys acknowledge about the heart-disease epidemic by the early 1970s?
It may indeed have been a mirage.
What was the initial basis for Keys’s dietary-fat hypothesis?
The congruence between changing American diet and heart disease epidemic.
What finding did the Japanese contingent of the Seven Countries Study report in the mid-1990s?
Fat intake in Japan had increased from the 6 percent of calories.
What was the fat intake percentage in Japan according to the Seven Countries Study?
22 percent of calories
Increased from 6 percent over thirty-five years.
What was the mean cholesterol level in the Japanese community reported by Yoshinori Koga?
Nearly 190 mg/dl
Only 6 percent lower than average American values (202 mg/dl as of 2004).
What significant change occurred in heart disease rates in Japan since 1970?
The chance that a Japanese man would die of heart disease had steadily diminished.
What did Keys initially dismiss regarding heart disease death rates in Japan?
The possibility of misdiagnosis contributing to low heart-disease death rates.
What did Keys conclude about cholesterol in 1987?
Cholesterol is not as important as previously thought.
What is the ‘French paradox’?
A nation that eats a high-fat diet and has little heart disease.
What was the purpose of the MONICA study launched by the WHO?
To monitor cardiovascular disease in various populations.
How many populations and people were tracked in the MONICA study?
Thirty-eight populations in twenty-one countries, roughly six million people.
What was the conclusion of the MONICA study regarding heart disease mortality?
Declining worldwide, independent of cholesterol levels, blood pressure, or smoking habits.
What did Tunstall-Pedoe suggest about classical risk factors in populations?
Their contribution can be overshadowed by other dietary, behavioral, environmental, or developmental factors.
What has research indicated about low-fat diets and longevity?
They may cause more harm than good.
What did David Jacobs learn about cholesterol levels in Japan?
Low cholesterol levels were linked to hemorrhagic stroke.
What did the Framingham study find regarding cholesterol and mortality?
No association with life expectancy for individuals over fifty.
What was a significant finding in the Framingham study regarding cholesterol decline?
Those with declining cholesterol were more likely to die prematurely.
What did the 1990 NIH workshop reveal about cholesterol and mortality?
Men with cholesterol below 160 mg/dl tended to die prematurely from various causes.
What assumption did proponents of Keys’s hypothesis make about low cholesterol?
That low cholesterol is due to pre-existing conditions, not the cause of death.
What is meta-analysis?
A technique to pool data from studies to assess the true size of a benefit or harm.
What did the Cochrane Collaboration conclude in its 2001 review regarding dietary fat?
Low-fat or cholesterol-lowering diets had no effect on longevity.
What was suggested by the Cochrane review of multiple-risk-factor interventions?
No effect on mortality from such interventions.
What did Keys attribute the decrease in heart disease during World War II to?
Reduced availability of meat, eggs, and dairy products.
What is the relationship between cholesterol levels and heart disease mortality according to the 1990 NIH conference?
Both high and low cholesterol levels could increase mortality.
Fill in the blank: The MONICA study tracked heart disease and risk factors in ______ populations.
thirty-eight
True or False: The MONICA study confirmed Keys’s hypothesis regarding cholesterol levels and heart disease.
False
What experience in wartime Europe contributed to the understanding of heart disease incidence?
Food shortages coincided with dramatic decreases in the incidence of heart disease.
What did Keys attribute the decrease in heart disease during wartime to?
The reduced availability of meat, eggs, and dairy products.
What other factors besides fat may have influenced health during wartime?
Changes in diet and lifestyle.
What diseases saw a drop in mortality during the war?
- Infectious diseases
- Diabetes
- Tuberculosis
- Cancer
What major conclusion did Keys draw about coronary heart disease (CHD) after World War II?
The incidence of CHD could drop to about one-fourth the preceding rate in a few years.
Who was the fourth author mentioned in the text and what was his area of study?
Henry McGill, a pathologist who studied atherosclerosis.
What was the issue with women in clinical trials regarding dietary fat?
Women were not included in any of the clinical trials.
What does the evidence suggest about high cholesterol in women?
It is not associated with more heart disease, except possibly in women under fifty.
What assumption did Browner’s analysis make regarding dietary fat?
Restricting dietary fat would reduce cancer deaths.
What was William Taylor’s perspective on patients’ motivations regarding dietary changes?
Most patients do not come in wanting to contribute to public health statistics.
What doubts did Melvin Konner express about the Paleolithic diet?
They probably underestimated the amount of meat based on extrapolations for hunter-gatherers.
What paradox is mentioned regarding weight loss?
They did not lose any weight despite dietary changes.
What surprising finding was reported by Swiss public-health authorities in 1979?
Cardiovascular mortality declined while animal fat consumption increased by 20 percent.
What did Steve Hulley and collaborators conclude about blood cholesterol in women?
High blood cholesterol is not associated with all-cause or cardiovascular mortality in women.
What study was excluded from the final analysis due to it not being a randomized trial?
The Helsinki Mental Hospital Study.
What was the significance of the Helsinki Mental Hospital Study?
It provided compelling evidence that cholesterol-lowering diets lowered mortality.
