Low-Fat Dietary Pattern Intervention and Health-Related Quality of Life: The Women’s Health Initiative Randomized Controlled Dietary Modification Trial

Abstract

Background Intensive dietary intervention programs may lead to benefits in vitality and other components of health quality. The Women’s Health Initiative (WHI) Dietary Modification (DM) intervention includes a large randomized controlled trial of an intensive intervention. Objective To evaluate whether the intervention is associated with improved health-related quality of life (HRQoL) subscales, overall self-reported health, depressive symptoms, cognitive functioning, and sleep quality. Design Randomized controlled trial was analyzed as intent to treat. Participants Between 1993 and 1998, 48,835 women aged 50 to 79 years were recruited by 40 clinical centers across the United States. Eligibility included having fat intake at baseline ≥32% of total calories, and excluded women with any prior colorectal or breast cancer, recent other cancers, type-1 diabetes, medical conditions with predicted survival less than three years. Intervention Goals were to reduce calories from fat to 20%, increase vegetables and fruit to 5+ servings and increase grain servings to 6+ servings a day. During the first year, 18 group sessions were held, with quarterly sessions thereafter. Main Outcome Measures RAND 36-Item Health Survey was used to assess HRQoL at baseline, year 1, and close-out (about 8 years post randomization), and estimate differential HRQoL subscale change scores. Statistical analysis performed Mean change in HRQoL scores (year 1 minus baseline) were compared by randomization group using linear models. Results At one year, there was a differential change between intervention and comparison group of 1.7 units (1.5, 2.0) in general health associated with the intervention. DM intervention improved physical functioning by 2.0 units (1.7, 2.3), vitality by 1.9 units (1.6, 2.2), and global QOL by 0.09 units (0.07, 0.12). With the exception of global QOL, these effects were significantly modified by BMI at baseline. Conclusions DM intervention was associated with small, but significant improvements in three health related quality of life subscales: general health, physical functioning, and vitality at one year follow-up, with the largest improvements seen in the women with the greatest baseline BMI.

Fruit and vegetable intake and breast cancer prognosis: a meta-analysis of prospective cohort studies

“…The findings of this meta-analysis reported a non-significant association between fruit and vegetable intake and breast cancer prognosis, probably because the consumption of fruits and vegetables may not be a strong dietary determinant of breast cancer mortality but has an indirect effect on breast cancer prognosis (41,42) . Many related articles regarding the association of fruit and vegetable intake with breast cancer prognosis mainly focus on the association between fruit and vegetable intake and weight change among breast cancer patients (43)(44)(45)(46)(47) . Thomson et al (48) indicated minimal short-term changes in body weight in response to a high-vegetable, low-fat diet in breast cancer survivors.…”

Dietary Patterns and Quality of Life in Older Adults: A Systematic Review

“…Studying QoL in healthy older adult populations may be especially important as it might have implications on our understanding of healthy ageing, and inform strategies for maintaining health in older years. The limited number of studies that have attempted to measure dietary patterns in relation to QoL have shown that adherence to healthy patterns may have beneficial effects on QoL in women [ 60 ] and in older adults [ 20 ]. The aim of this review was to evaluate evidence of the association between dietary patterns and QoL in older adults, with the intention of providing a better understanding of the potential for dietary patterns to improve QoL.…”

Nutrition and Health-Related Quality of Life in Older Adults in the US, NHANES 2009-2012

“…Those who self-rated their diet quality as excellent, very good, or good were 3.1 times more likely to have a good or better (vs fair/poor) HRQOL, after adjusting for demographic and nutrition-related variables. Assaf et al (2016), Germain et al (2013), and Rasheed and Woods (2013) also investigated the relationship between diet and HRQOL though in different populations and with different diet quality and outcome measures. Rasheed and Woods (2013) conducted a systematic review and metaanalysis of studies examining nutrition and quality of life in older adults in both intervention and observational studies.…”

“…This one global QOL item was on an 11-point scale, with 0= "As bad or worse than being dead" and 10= "Best quality of life." After one year, the SF-36 component scores for general health, physical functioning, and vitality significantly improved with the DM intervention, after adjusting for age, ethnicity, and weight, suggesting that dietary modification is associated with improved HRQOL (Assaf et al, 2016).…”

“…Since NHANES only has two days of dietary data per individual in each survey cycle, research on more than two days of data was not possible for this thesis, but the significant relationship between HEI and HRQOL warrants the need for more research on diet quality. Furthermore, there is little research on using HEI as an actual diet quality predictor variable with a global HRQOL outcome (Assaf et al, 2016), regardless of the number of days used to measure diet. Dietary data collected in NHANES could also be used to look at components of the HEI in addition to the total HEI scores this thesis research analyzed.…”