low fat center for energy balance journal club shannon armbruster md gynecologic oncology october...
TRANSCRIPT
The Clash of the Diets
Low Fat
Center for Energy Balance Journal ClubShannon Armbruster MD
Gynecologic OncologyOctober 15, 2015
Overview
• Background– Breast Cancer Facts– Diets and Breast Cancer Risk
• Paper Presentation– Design, Setting, Participants– Intervention– Results– Conclusion/Relevance
The Facts:
• In 2012: 224,147 women in the United States were diagnosed with breast cancer.*†
• In 2012, 41,150 women in the United States died from breast cancer.*†
†Source: U.S. Cancer Statistics Working Group, CDC.
40 50 60 700
5
10
15
20
25
30
35
40
45
14.7
23.8
35.738.5
Risk of Breast Cancer Stratified by Age (SEER)
Age (years)
Dea
ths
per 1
000
Wom
en
ACOG and ACS: Mammograms at “age 40 years and older, offered annually”
Recommendations:
What does the Mediterranean diet (MeDiet)
have to do with it?
Methods: 605 patients (mostly men) with Cardiovascular disease (CVD) randomized to MeDiet or control
Results: Reduction in Risk of cancer 61% in Experimental Group (12 v 2 cancers of all subtypes)
Methods: 121,700 women from Nurses’ Health Study followed from 1984-2002
Results: • Greater adherence to the MeDiet resulted in lower risk of ER –
breast cancer
Methods: 335,062 women followed in a cohort study for 11 years
Results: • Mediterranean diet (MeDiet) reduced breast cancer by 6% overall• 7% reduction in post menopausal women• ER/PR- tumors reduced by 20% in postmenopausal women• Lack of association between MeDiet and breast cancer in premenopausal
women
Methods: 33,731 women followed in a cohort study for 9 years
Results: • No significant association between MeDiet and breast cancer • Premenopausal women: Non-significant trend of increasing
compliance with MeDiet and lower risk of breast cancer• No clear trends in post menopausal women
Methods: 49,258 women aged 30 to 49 years at recruitment, followed from 1991/1992 to 2008
Results: • No significant association between MeDiet and breast cancer in
this cohort
The next step…
Purpose: Evaluate the incidence of breast cancer after implementation of 2 Mediterranean diet interventions (olive oil v. nuts) or a low-fat diet
Participants
• Framed with the PREDIMED (Prevencion con Dieta Mediterranea) trial
• Women 60-80 years of age– Diabetes Mellitus Type 2– At least 3 major CVD risk factors
– Smoking, hypertension, elevated low-density lipoprotein cholesterol level, low high-density lipoprotein cholesterol level, overweight /obesity, or family history of premature coronary heart disease
Randomization and Intervention
4282 Women
MeDiet with EVOO
N=1476
MeDiet with Nuts
N=1285
Control Diet (Low-Fat)N=1391
Interventions
MeDiet Groups:• Sessions:– Baseline and quarterly
assessment – Personalized Advice
• Incentives:– Given Extra Virgin
Olive Oil or Nuts
Control Group• Yearly low-fat diet
leaflets• Sessions*• Incentives:– Non-food items*
* Protocol modification in Oct. 2006
Baseline Characteristics of Female PREDIMED Participants
Risk of Invasive Breast Cancer: Per Intervention Group
Results
• High consumption of EVOO needed to obtain significant protection
• Non-significant reduction with nuts
Strengths
• Randomized design• Little residual confounding• Blinding of medical info while assessing
outcomes
Limitations
• Secondary analysis• Small number of breast cancer cases identified• No proof baseline mammograms were free of disease• No confirmation that all women even received a
mammogram• Lack of diversity• Reproductive factors are unknown for participants• Changes due to diet or olive oil?• For the first 3 years, the control group was less
“intense”
Limitations: Low-Fat Diet
• High fat diets associated with a higher risk of breast cancer– WHI (Women’s Health Initiative): higher risk of
breast cancer with higher total fat consumption• There is a possibility that the low-fat group
would have had better outcomes, if they truly followed a low-fat diet
Proposed Biologic Mechanisms
Anti-carcinogenic properties of EVOO
Oleic Acid: Anti-proliferative properties
Polyphenols: role in breast cancer prevention
Oleocanthal: inhibition of tumor growth, proliferation, migration, and invasion of BC cells
Oleuropein: increased apoptosis of cultured breast cancer cells
Hydroxytyrosol: reduce intracellular reactive oxygen species and prevent oxidative DNA damage
Lignans: seen in association with lower rates of post menopausal breast cancer
The Clash of the Diets
Low Fat
Comments/ Discussion
• Weight as a factor?• Impact of Reproductive Factors– Breast feeding– When a patient had children
• Generalizability?