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HARVIE, HOWELL, AND EVANS
TABLE 1. World Cancer Research Fund Prevention Guidelines for Breast Cancer and Cardiovascular Disease
Breast Cancer Risk Reduction
CVD Risk Reduction
1. Be as lean as possible without becoming underweight
2. Be physically active for at least 30 minutes every day
3. Avoid sugary drinks and limit consumption of energy-dense foods (to achieve weight control) (to achieve weight control)
4. Eat more vegetables, fruits No effect
5. Eat more whole grains and legumes such as beans
6. Limit red meats (i.e., beef, pork, and lamb) and avoid processed meats Modest effect with processed meat
7. Limit alcoholic drinks to 2 for men and 1 for women per day Lowest risk of coronary heart
disease 1-2 drinks/day
Stroke 1 drink/day (40)
8. Limit consumption of salty foods and foods processed with salt No effect
9. Do not use nutritional or vitamin supplements to reduce risk of disease
Abbreviation: CVD, cardiovascular disease.
Supported by meta analyses of randomized trials or one or more randomized trials.
Association in three or more observational studies.
Association in one or two observational studies.
gest that alcohol intake before the fırst term of pregnancy is
particularly associated with cumulative risk. 20 Unresolved
questions include the specifıc effects of binge drinking,
whether dietary folate intake can reduce the excess risk of
higher alcohol intake, and interactions with genes involved
in alcohol metabolism/detoxifıcation and folate metabolism.
22 Light drinking (10 g/day) is also linked to breast cancer
risk; however, zero alcohol intake is not recommended
because light drinking is consistently linked to reductions in
overall (17%) 23 and cardiovascular (20%) 24 mortality.
Alcohol increases risk of breast cancer among both preand
postmenopausal women and for both ER-positive and
ER-negative disease. Studies have suggested that alcohol affects
risk equally or to a greater extent among women with a
family history (defıned as an affected fırst-degree relative)
compared to women with no family history. 20
PHYSICAL ACTIVITY
The American College of Sports Medicine recommends a total
of 150 minutes per week of moderate intensity cardiorespiratory
exercise to reduce all-cause mortality and improve
quality of life. 25 The optimal level of physical activity for
breast cancer risk reduction appears to be greater than these
recommendations, with an estimated 3% reduction in risk
for every additional 180 minutes of moderate intensity exercise
per week. 26 Physical activity is associated with reduced
risk among pre- and postmenopausal women and among
women with a family history, albeit with an apparent smaller
effect than for the general population, and reduced risk of
both ER-positive and ER-negative cancers. 27 Potential anticancer
effects of physical activity include reductions in endogenous
sex hormone concentrations, insulin resistance,
and chronic low-grade inflammation. In addition, other
pathways are emerging as potentially important, including
those involving oxidative stress and telomere length,
global DNA hypomethylation, immune function, 28 and
increased gene expression of BRCA and other DNA repair
genes. Although being “fıt but fat” appears to protect
against heart disease, 29 this is not the case for breast cancer,
in which cancer protective effects of exercise are
mainly seen in women who are a healthy weight and not
among the overweight and obese. 26
DIETARY FACTORS AND BREAST CANCER RISK
If a women is a healthy weight, exercises regularly, and moderates
her alcohol intake does the actual composition of her
diet matter?
Fruit, Vegetables, and Fiber
The 5-a-day campaign was launched in the United States in
1991 by the National Cancer Institute and the Produce for
Better Health Foundation with the aim of preventing cancer.
Since these initial campaigns, emerging evidence has consistently
linked fruit and vegetable intake, particularly vegetable
intake, to reduced overall and cardiovascular mortality but
not specifıcally to cancer mortality. 30 The WCRF Continuous
Update Project recently stated there is no convincing evidence
that fruits and vegetables play a role in the etiology of
colorectal, breast, and pancreatic cancers. 31
Recent systematic reviews have linked higher fıber intake
with a lower risk of breast cancer, with a 5% risk reduction for
every additional 10 g of fıber per day. Fiber may reduce risk
by reducing the reabsorption of estrogen and androgens in
the bowel and hence their circulating levels. Soluble fıber appears
to be the most protective, possibly through its benefıcial
effects on insulin sensitivity. 32
Meat, Fish, and Dairy Foods
Vegetarian or vegan diets do not specifıcally reduce risk.
Women with a higher consumption of meat are at slightly
increased risk; each additional 100 g of red meat per day increases
risk by 4% (relative risk [RR] 1.04 [1.00 to 1.07]) and
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