Omega3 Fatty Acids: An Untapped Resource for Improving Health

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Omega-3 Fatty Acids An Untapped Resource for
Improving Health

• R. Curtis Ellison, MD
• Professor of Medicine Public Health
• Director, Institute on Lifestyle Health
• Boston University School of Medicine
• Boston, MA,

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Omega-3 Fatty Acids

• Certain plants contain alpha-linolenic acid
  (ALA)
  
• (plankton, flaxseed, canola oil, soy bean
  oil)
  
• When fish eat plankton, ALA is changed into
• fish oils (EPA and DHA)
• Humans get omega-3 from fish or fish oils
  (EPA,
  
• DHA), or from plants, especially canola oil
  (ALA)

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Omega-3 Fatty Acids CHD

• Many studies have shown that fish consumption
  decreases coronary heart disease (CHD)
  
• Many studies have shown that taking fish oils
  decreases CHD, especially sudden death
  
• Limited studies on ALA, but ALA has potential
  advantages over fish oils

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Diet Coronary Heart Disease (CHD)

• Before WWII, CHD uncommon
• In 1950s-60s, CHD became an epidemic, killing
  2 million/yr in US
  
• Stimulated research on CHD by
  epidemiologists

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Epidemiologists?What Do Epidemiologists Do?

• We count bodies!
• 400 dead bodies in one group
• 200 dead bodies in another group

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What Else Do Epidemiologists Do?

• We try to determine what
• is causing the difference?
• (Are differences in diet explaining the
  differences
  
• in deaths between the two groups?)

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The Seven Countries Study

• Cohorts of healthy men recruited in 7
• countries (Greece, Italy, Yugoslavia, Holland,
  
  
  Finland, USA, Japan)
• Diet and other lifestyle factors assessed,
• laboratory tests done in early 1960s
• Subjects followed over 25 years

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Coronary Heart Disease Seven Dietary
Factors(Ulbricht and Southgate, Lancet, 1992)

• Dietary Promoting Factors?
• Saturated fatty acids
• Hypercholesterolemic Fatty Acids
• (120, 140, 160)
• Thrombogenic Fatty Acids
• (140, 160, 180)

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Lowering Saturated Fat CVD Results from 27
Randomized Trials

• Total mortality RR 0.98 (0.86-1.12)
• CV mortality RR 0.91 (0.77-1.07)
• CV events RR 0.84 (0.72-0.99)
  
  
• BMJ
  2001322757-63
  

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Coronary Heart Disease Seven Dietary
Factors(Ulbricht and Southgate, Lancet, 1991)

• Protective Factors
• Polyunsaturated Fatty Acids, n-6 Series
• 182 linolenic acid
• Polyunsaturated Fatty Acids, n-3 Series
• 183 alpha-linolenic acid
• 205 eicosapentanoic acid (EPA) 226
  docosahexanoic acid (DHA)
  
• Monounsaturated Fatty Acids
• 181 oleic acid
• Dietary Fiber
• Antioxidants

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Seven Countries StudyReview by Professor Serge
Renaud
RAILROAD
Mortality
Bread
Legume




1
F
o
o
d
s
tuff
F
r
u
it
4
6
4

1
30


82

23
3
Meat

3
5

1
40

1
38
(
g
/
d
a
y
)

27
3


1
8


34


12





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Fish

9
5


60


79



3
3
Edible Fat
A
l
c
o
h
o
l

1
5


43


3





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A
dap
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ed

f
r
om

A
. K
ey
s
(19
7
0) a
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D
.
Kr
omh
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ut (1
9
89)
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Fatty Acids from Cholesterol Esters
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The Lyon Diet Heart StudyProfessor Serge Renaud

• A clinical trial of post-MI patients comparing
• a Cretan-based Mediterranean diet with the
• usual diet advised, a low-fat cholesterol
  diet.
  
• Used a Canola-oil based margarine to replace
• butter urged use of olive or canola oil instead
  of
  
• vegetable oils high in linoleic acid.

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The Lyon Diet Heart StudyThe Six Dietary
Commandments

• - More bread
• - More vegetables and legumes
• - More fish
• - Less meat (beef, lamb, pork), replaced by
  poultry
  
• - No day without fruit
• - No more butter and cream, replaced by supplied
  margarine made from canola oil.

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The Lyon Diet Heart StudyResults

• Trial stopped early by Monitoring Board
  because of unacceptably higher CVD rates in
  control group (low-fat diet).
  
• Mediterranean alpha-linolenic acid rich diet in
  the secondary prevention of coronary heart
  disease. De Lorgeril M, Renaud S, Mamelle N, et
  al. Lancet 19943431454-9.
• Cretan Mediterranean diet for prevention of
  coronary heart disease. Renaud S, de Lorgeril M,
  Delaye J, et al. Am J Clin Nutr
  1995611360S-7S.

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The Lyon Diet Heart Study CVD Recurrence During
27-mth Follow Up
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The Lyon Diet Heart StudyIntake of Foodstuffs
(g/day)
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The Lyon Diet Heart StudyPlasma Fatty Acids at 8
Weeks
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The Lyon Diet Heart StudyCardiac Death and
Non-fatal MI(46 months follow up)
Cretan diet 0.28 (95 C.I. 0.15-0.53)
183 (n-3) 0.20 (95 C.I. 0.05-0.84)
183(n-3) plasma levels at 2 months,
adjusted for age, sex, smoking, choles
terol, BP, other risk factors
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ALA and CHDStudies Showing Protective Effects

• Proc Soc Exp Biol Med 1992200177-82.
• Prospective study in 6,250 men (death
  ?)
  
• BMJ 199631384-90. Prospective study in health
  
  
• professionals (non-fatal MI ?)
• Am J Clin Nutr 199969890. Prospective study
• in 70,000 nurses (cardiac death ?)

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Dietary Linolenic Acid and Coronary Heart Disease

• The NHLBI Family Heart Study
• Luc Djoussé, James S. Pankow
• John H. Eckfeldt, Aaron R. Folsom
• Paul N. Hopkins, Michael A. Province
• Yuling Hong, R. Curtis Ellison

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Odds Ratio of CHD by Linolenic Acid Intake (Men)
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Odds Ratio of CHD by Linolenic Acid Intake
(Women)
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Odds Ratio of CHD by Fish Intake
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Clinical Trials Showing that N-3 Fatty Acids
Prevent CHD

• Intervention trials demonstrate the inverse
  association between n-3 fatty acids and CHD
  without changes in serum cholesterol
  
• Risk Ratio
• N N-3
  Cardiac Death Non fatal MI
  
• DART 2,000 Fish 0.70 1.00
• GISSI 11,000 Fish oil 0.80
  0.96
  
• Lyon 600 Canola oil 0.24
  0.27
  
• India 1,000 Mustard oil
  0.33 0.47
  

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Advantages of Canola Oil Over Fish Oils for
Preventing CHD

• Many people do not like to eat fish
• The usual fried fish consumed in US has very
• low levels of fish oil (and who likes
  mackerel?)
  
• Increasing concerns about organic chemical
• contamination of fish and fish oil
• Data are beginning to show better protection
• against CHD from ALA rather than fish oils

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Time to Change to a Mediterranean-type Diet with
Canola Oil?

• Yes!

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Mediterranean-type Diet

• A diet that is preferable to the very low-fat
  diets of the American Heart Association
  
• Preferable to the very low-carbohydrate diets
  (Atkins, South Beach, etc.)
  
• Canola Oil and canola oil-based margarine
  belong on the Med-Diet (avoid trans fats!)

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Is the Mediterranean-type Diet Acceptable in
North America?

• Our Institute developed such a diet
• Used olive oil and canola oil-based margarine
• Tested in people in Boston on a strict low-fat
  diet following heart surgery
  
• Tested among African-Americans with
  heart disease in South Carolina
  

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Testing a Med-Diet in South CarolinaComments
from 27 African-American Subjects

• I was very pleasantly surprised how
• delicious the meal was.
• It contained more fats and oils that my
• current diet, so the meal was a treat!
• This diet is something I can live with.

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Summary

• Diet affects the risk of CHD and death
• The Mediterranean-type diet seems to
• be the healthiest option
• Canola oil canola oil-based margarine
• key components of this Healthy Diet