Title: Omega3 Fatty Acids: An Untapped Resource for Improving Health
1Omega-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,
2Omega-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)
3Omega-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
4Diet 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
5Epidemiologists?What Do Epidemiologists Do?
- We count bodies!
- 400 dead bodies in one group
- 200 dead bodies in another group
-
-
6What 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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9The 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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12Coronary 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)
-
-
13Lowering 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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17Coronary 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
-
-
18Seven 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
3
Fish
9
5
60
79
3
3
Edible Fat
A
l
c
o
h
o
l
1
5
43
3
6
A
dap
t
ed
f
r
om
A
. K
ey
s
(19
7
0) a
n
d
D
.
Kr
omh
o
ut (1
9
89)
19Fatty Acids from Cholesterol Esters
20The 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.
21The 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.
22The 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.
23The Lyon Diet Heart Study CVD Recurrence During
27-mth Follow Up
24The Lyon Diet Heart StudyIntake of Foodstuffs
(g/day)
25The Lyon Diet Heart StudyPlasma Fatty Acids at 8
Weeks
26The 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
27ALA 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 ?)
28Dietary 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
29Odds Ratio of CHD by Linolenic Acid Intake (Men)
30Odds Ratio of CHD by Linolenic Acid Intake
(Women)
31Odds Ratio of CHD by Fish Intake
32Clinical 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
-
33Advantages 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
34Time to Change to a Mediterranean-type Diet with
Canola Oil?
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41 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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43Is 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
44Testing 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.
45Summary
- 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