Advanced Healing MethodsGCU Holistic Health
Fall 2009
Note- The powerpoints on nutrition are mostly drawn from Good Calories, Bad Calories, by Gary Taubes
19th CenturyBanting- 1863- Letter on Corpulence
lost 35 lbs. in 9 mos., 50 in the next few months by avoiding sugar and minimizing starch
Medical community skepticalLancet- “old news,” then “dangerous”: “We advise
Mr. Banting, and everyone of his kind, not to meddle with the medical literature again, but be content to mind his own business.” Then a “fair trial.”
“The great progress in dietary control of obesity was the recognition that meat… was not fat producing; but that it was the innocent foodstuffs, such as bread and sweets, which lead to obesity.” -Hilde Bruch, 1957
For over a century, this was the common wisdom
20th centurySea change by 1970’s- now carbs “help you lose weight.”AMA- low carb diets are dangerous- “bizarre concepts of
nutrition and dieting [that] should not be promoted to the public as if they were established scientific principles.” -1973
Even as major conferences were demonstrating their effect at losing weight without hunger
Now low-fat diets are good to prevent heart disease and to reduce weightDiet-heart hypothesis- dietary fat raises cholesterol and
leads to atherosclerosisObesity from too many caloriesUSDA food pyramid- fats and oils “sparingly,” 6-11 servings
of grains
20th centuryIn the US, average fat intake has dropped from 45%
of total calories to 35%, and cholesterol has fallen40% decline in HTN btw 1976 and 1996, 28% decline
in chronic high cholesterolBut without improvements in health
Incidence of heart dz little changeDeath rates from heart dz down, but due to better tx
Obesity 12-14% of population from 1960’s thru 1980, but in 2004, 1 in 3 Americans obese- diabetes up too
The surge in obesity and diabetes came along with the message that fat is bad and carbs are good
The Diet-Heart HypothesisAKA the “Fat and Cholesterol Hypothesis”2 pillars
The “great epidemic” of heart diseaseThe “changing American diet”
The nation turned away from grains and cereals and toward fat and red meat and paid the price
The Heart Disease EpidemicCVD uncommon until 1920’s, then became #1
killerBut diagnosis bias- at one hospital, CVD dx up
400% btw 1920 and 193o, but incidence unchanged1949- ICD- new category for “arteriosclerotic HD”
And suppression of infectious disease and nutritional deficiency increased lifespan
American Heart Association- public-health advertising, raising research funds
Evidence against the “epidemic” ignored
The Changing American DietShift in American diet during 20th century,
leading to heart disease “epidemic”But data before WWII are unreliableUSDA has estimated 178 pounds of meat per
person in 1830’s, 40-60 more than a century laterPopulation nearly doubled 1880-1910, and meat
production couldn’t keep upAlso Upton Sinclair The JungleThe grainy diet of the early 20th century is itself a
deviation from normal
The Changing American DietFrom WWII, during the supposed “epidemic,”
through the 1960’s, the American diet increased in total fatBut mainly vegetable fats, considered “heart-
healthy”And increase in vegetables and citrus fruitsDecrease in animal fats
CholesterolFound in all body tissuesEssential component of cell membranesInvolved in many physiologic processes
Metabolism of human sex hormonesAlso abundant in atherosclerotic plaquesSo… it must cause the plaques, right?
Atherosclerosis in rabbits fed olive oil and cholesterol- 1913- but rabbits are herbivores, and lesions in tendons and CT suggest more a storage disease
Plaques in chickens, too, but could also be induced in pigeons fed corn and corn oil, and in a variety of animals, including baboons, eating predominantly vegetarian diets
CholesterolDoctors could measure the levels as of 1934
So it remained importantScience unable to establish that atherosclerotic
patients had more blood cholesterolAlso unable to establish that people with high
cholesterol had arteries any more cloggedAnd, dietary cholesterol has very little effect on
blood cholesterolWeight gain and stress raise, exercise and weight
loss lower, also fx from sex hormones, diuretics, alcohol
Fat and CholesterolAncel Keys- physiologist at U Minnesota- starting
1940’sNaples (and Madrid)- rich more HD than poor, and
rich ate more fatDietary fat raises cholesterol leads to HD
Data from several countries HD disappeared in Sweden during WWII food rationing
Dietary fat down- less meat, eggs, dairy But also fewer calories consumed, weight loss Increased physical activity, sugar and flour eaten less too
Study of six countries- the more dietary fat, the more HD mortality- but data available for 22 countries, and the effect vanishes when all are included
DebateKeys- CHD strongly influenced by dietary fat
Skeptics- “show us the science”Proponents- obligation to help patients- need to act-
urgency Press fed the fire also- positive feedback loop
Selection (or confirmation) bias- choosing evidence that supports conclusion Everything else “misinterpreted, irrelevant, or bad data”- like
studies of Navajos, Irish immigrants, African nomads, monks, etc, showing no relation btw dietary fat and HD Masai nomadic herders live on milk, blood, and meat, and have
blood cholesterol levels among the lowest ever measured Extensive atherosclerosis, but no HD Cholesterol up when they then ate Western diet First “feedback mechanism to suppress endogenous chol
synthesis” Then “The peculiarities of those primitive nomads have no
relevance to diet-cholesterol-CHD relationships in other populations”
Framingham Heart Study1950- 5100 residents given physicals, the examined
every two years to see who got HDRisk factors- HTN, abnormal EKG, obesity, smoking,
family historyCholesterol- blood levels over 260 assoc with 5x greater
HD risk than chol under 200- compelling evidenceBut- the men who died of HD more likely to have
low chol, and little assn for women at allAnd (despite NIH preventing publication) men with very
high (>300) and very low (<170) chol have same amount and types of dietary fat No correlation btw dietary fat and either blood chol or
HD- true in virtually every study comparing these within a single population
Western Electric Study 19575400 male employees- looking at HD among those who ate
the most and the least fat88 cases of HD- 14 in high-fat group, 16 in low-fatDietary fat not assoc with death from CHD
So- “If viewed in isolation, the conclusions that can be drawn from a single epidemiologic study are limited. Within the context of the total literature, however, the present observations support the conclusion that the [fat] composition of the diet affects the level of serum cholesterol and the long-term risk of death [from CHD] in middle-aged American men.”
This analysis then cited in AHA and NHLBI (Nat’l Heart, Lung, and Blood Institute) report The Cholesterol Facts as one of seven “epidemiologic studies showing the link btw diet and CHD [that] have produced particularly impressive results,” … “showing a correlation btw saturated fatty acids and CHD.”
Seven Countries StudyAncel Keys, 195613,000 middle-aged men, mostly rural populationsProspective study- physicals at the beginning, then
assess health periodically3 Keys lessons
Blood cholesterol levels predict HD riskSaturated fat (not total fat anymore) predicts blood chol
and HDMonounsaturated fat is protective
But- why do eastern Finns have 3x the HD of Western Finns with the same diet?
And- Keys chose countries in advance that he knew would support the hypothesis!French paradox- lots of saturated fat, not much HD
Spain and Italy, too
StudiesProspective (or other epidemiological studies)
tend to be biased, of low quality, or incompleteData also subject to interpretations
Controlled trials are better- create two identical groups, change one variablePlacebo-controlledDouble-blind
Blinding impossible in diet trials, and it’s impossible to make just one change in a dietWhen eliminating saturated fat, do you replace it
with carbs or polyunsaturated fat? Veggies or starches?
Studies of Fat and HDMany studies from 1950’s to 1970’s studying
cholesterol-lowering diet (replacing saturated fat with polyunsaturated)
Only two studied low-fat diet and HD (!), testing middle-aged men who had already had MI’sHungary- lowering dietary fat reduces HDBritain- it does not- cholesterol down, but HD the same
Anti-Coronary Club Trial- late 1950’s- comparing saturated with polyunsaturated- 1100 patientsMembers on the “prudent diet” had 1/3 the HD of
controlsBut 26 members died, 8 from HD, and only 6 controls,
none from HD
More Studies UCLA VA 1969- replacing animal fat with vegetable oil- cholesterol
down 13%, 66 HD deaths, compared with 96 controls But 31 CA deaths in experimental group, 17 controls Risk of death equal in two groups
Helsinki study- 1965-71- 2 mental hospitals- cholesterol-lowering diet HD deaths down by half, men (not women) lived a little longer
Minnesota Coronary Survey- 1968- 9000 mental patients Half got American diet, half cholesterol-lowering
Low in cholesterol and saturated fat, high in polyunsaturated Cholesterol down 15%, men fewer MI’s, women more, overall
increased rate of HD 269 deaths in experimental group, 206 in controls Study unpublished for 16 years: “We were just disappointed in the
way it came out.” AHA- started recommending low-fat diets in 1961 NIH- called for a “definitive test” of the fat-cholesterol hypothesis in
1971 But ended up with two smaller tests
That HD could be prevented with cholesterol-lowering drugs That HD could be prevented with cholesterol-lowering diet, smoking
cessation, and BP meds Neither of these actually tests the hypothesis
1960’s and ‘70’sAnti-fat, anti-meat movement
Moral- resource useAHA- fewer conditions- not just high-risk men
with past MI, high chol, or smoking hxNow everyone recommended low-fat diet- 1970And AHA seen as main source of expert info
1970’s- polyunsaturated fats assoc with CA in animalsSo advice to eat less fat and less saturated fat
Dietary Goals for the US1977- now government says eating less fat helps health
Staff director Marshall Metz: “We really were totally naïve, a bunch of kids who just thought, Hell, we should say something on this subject before we go out of business.”
55-60% carbs, fats from 40% to 30%, only 1/3 saturatedThey admit there’s no evidence that lowering dietary fat
lowers blood chol, but justify it with weight loss “Fat supplies 9 calories per gram, whereas protein and
carbohydrates … supply only 4 calories per gram. … Consequently, … the consumption of a diet deriving 40 percent of its calories from fat may result in a continual struggle to lose weight.”
So… USDA Dietary Guidelines for Americans “Avoid Too Much Fat, Saturated, Fat, and Cholesterol”
And (in NEJM), “To be a dissenter was to be unfunded because the peer-review system rewards conformity and excludes criticism.”
Yet More Studies4 studies, 1980-84, trying to establish a
relationship btw dietary fat and health- none succeeded
And low cholesterol levels found to be associated with higher risk of CA- many studies (p. 54 GCBC)NHLBI: “Surprise and chagrin”
So… now they’re combing the literature for those few studies showing no link, then arguing the evidence is inconsistent
And (more NHLBI), high chol causes HD, but low chol only a sign of people who might be CA-proneCause and effect?
NHLBIstudies
Multiple Risk Factor Intervention Trial (MRFIT) 12K men with chol >290 Half advised to quit smoking, take BP meds,
eat low-fat, low-chol diet 7 years later, more deaths in experimental
groupLipid Research Clinics (LRC) Coronary
Primary Prevention Trial 3800 men with chol >265 All told to eat chol-lowering diet, half given
chol med 71 deaths in control group, 68 in experimental So… Keys was right, and lowering chol saves
lives (?) “It is now indisputable that lowering cholesterol with
diet and drugs can actually cut the risk of developing heart disease and having a heart attack.”
But- extrapolation from drug study to diet Now- massive health campaign (see p. 59)
The LRC results “strongly indicate that the more you lower cholesterol and fat in your diet, the more you reduce your risk of heart disease.”
AHA president: If everyone ate chol-lowering diet, “we will have [atherosclerosis] conquered” by the year 2000
1984- NIH “consensus conference” to establish unanimity
Getting the Word Out1988- Surgeon General’s Report on Nutrition and
HealthThe “disproportionate consumption of food high
in fats” could be held responsible for 2/3 of the 2.1 M US deaths in 1988
“The depth of the science base… is even more impressive than that for tobacco and health in 1964.”
National Academy of Sciences- Diet and Health“Highest priority is given to reducing fat intake,
because the scientific evidence concerning dietary fats and other lipids and human health is strongest and the likely impact on public health the greatest.”
The media reports it, and now the debate is about low-fat vs. very low-fat
The Fat-Cholesterol HypothesisLowering cholesterol prevents HD
Evidence ambiguous –statins, for example, work to lower chol and reduce MI’s, but the heart effect is probably more by reducing inflammation, like aspirin
Eating less fat or saturated fat lowers cholesterol and prevents HDEvidence ambiguous
And prolongs lifeEvidence ambiguous, diets may cause more harm
than good
Ancel Keys1970’s: The HD epidemic may have been a
mirage“No basis” to make the claim that trends in HD
mortality reflect changes in diet1984: Misdiagnosis in Japan in 7 Countries Study
now possible: The cardiologists “might have been misled by the local physicians who signed the death certificates and provided details.”
1987: “I’ve come to think that cholesterol is not as important as we used to think it was.”