Published in Breast Cancer Research and Treatment, the cross-sectional study of 192 Chinese American (CA) and 173 non-Hispanic white (NHW) female breast cancer survivors, soy intake was associated with a 57% reduction in treatment-related fatigue symptoms, compared with no intake.
Soy consumption was also correlated with lower menopausal symptoms but this relationship was only statistically significant in NHW women, found the research team led by Georgetown Lombardi Comprehensive Cancer Center.
”In models stratified by race/ethnicity, associations [of soy intake] with menopausal symptoms and fatigue only were statistically significant in NHW survivors,” elaborated first author Dr. Sarah Oppeneer Nomura.
Women who consumed higher amounts of cruciferous vegetables (over 71 grams/day (g/d)) were 50% less likely to experience menopausal symptoms than those consuming lower quantities (below 33 g/d).
“Cruciferous vegetable intake was inversely associated with menopausal symptoms in the overall population,” added Nomura. “When stratified by race/ethnicity, cruciferous vegetable intake remained inversely, but not statistically significantly, associated with menopausal symptoms.”
The researchers examined possible links between symptoms including hair thinning/ loss, joint problems and memory. Although an inverse relationship with soy intake was found, it was not statistically significant.
Although suggesting the need for further research in larger studies, the scientists argued that this investigation fills an important knowledge gap on links between dietary factors and side effects of breast cancer treatment.
"These symptoms can adversely impact survivors' quality of life and can lead them to stopping ongoing treatments, commented Nomura. "Understanding the role of life style factors is important because diet can serve as a modifiable target for possibly reducing symptoms among breast cancer survivors."
Isoflavones in soy and glucosinolates in cruciferous vegetables may be responsible for the observed beneficial effects, suggest the researchers. Isoflavones can exert mild oestrogenic effects, while glucosinolates may modulate concentrations of enzymes that influence inflammation or oestrogen levels; thus reducing fatigue or menopausal symptoms.
Source: Breast Cancer Research and Treatment
Published online, doi: 10.1007/s10549-017-4578-9
“Dietary intake of soy and cruciferous vegetables and treatment‑related symptoms in Chinese‑American and non‑Hispanic White breast cancer survivors”
Authors: Sarah J.O. Nomura, Judy Huei-yu Wang et al