Diet Composition, Weight Control, and Breast Carcinogenesis

Summary

In the United States, overweight (BMI \> 25 but \< 30 Kg/m2) and obesity (BMI \> 30Kg/m2) are increasing at epidemic rates. A significant association exists between being overweight or obese and breast cancer recurrence and survival. However, evidence continues to accumulate indicating that achieving or maintaining a healthy weight for height (Body Mass Index, BMI, 18.5-25Kg/m2) is associated with a reduced risk for breast cancer and with a decrease in breast cancer associated mortality. Despite this, there is a lack of randomized controlled trials exploring this association and how the process of fat loss or being successful in actually reaching a healthy weight for height differentially affects biomarkers for cancer recurrence.

Many dietary approaches for weight loss are currently available to the public, and each purports to offer advantages. However, there is little scientific evidence to indicate how these dietary approaches, some of which vary markedly in the foods that they limit or exclude, affect biomarkers for breast cancer risk. In particular, it is not know whether the critical factor in relation to weight and breast cancer is simply weight loss (negative energy balance), irrespective of the manner in which it is achieved, or if certain dietary approaches affect breast cancer risk biomarkers more favorably than others. Published data from our laboratory suggest that dietary pattern does matter, and therefore the goal of this study is to investigate the effects of two popular weight loss dietary approaches that differ in the extent to which they limit carbohydrate or fat consumption (with effects on dietary glycemic load) compared to a usual care group on prognostic markers for cancer recurrence in postmenopausal breast cancer survivors. The investigators hypothesize that in addition to the anticipated effects of fat loss on circulating levels of bioavailable sex steroid hormones, that the effects of excess fat on breast cancer prognosis can be attributed to three interrelated metabolic processes that affect cancer progression: altered glucose metabolism, chronic inflammation and excessive cellular oxidation.

Conditions

• Breast Cancer

Interventions

OTHER

Weight Loss Dietary Pattern

Diet-physical activity program creating a weekly negative energy balance equivalent to 3500 kcal. Intervention groups receive PA protocol promoting the Physical Activity Guidelines and translated in step recommendations, but one of two diets with divergent dietary patterns (opposing fat and CHO content) that do not overlap \>+5% in CHO and fat content. Macronutrient values reflect a 'pattern' or ratio within (LC 3:2 ratio for F:CHO; HC 1:4 ratio for F:CHO ) and between diets (LC:HC 3:1 for fat; LC:HC 1:2 for CHO). Six-week meal plans for five calorie levels available and incorporate educational material, supporting program components (e.g. self monitoring tools) and core competencies reinforcing weight loss behaviors in order to promote high levels of dietary adherence.

Sponsors & Collaborators

• Colorado State University

  lead OTHER

Principal Investigators

• Henry J Thompson, PhD · Colorado State University

• Scot M Sedlacek, MD · Rocky Mountain Cancer Center

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

21 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2008-09-30

Primary Completion

2012-01-31

Completion

2012-06-30

Countries

• United States

Study Locations