Low-Carb, Plant-Rich Diets Tied to Breast Cancer Survival?

Megan Brooks

June 15, 2023


A new analysis shows a significant association between plant-rich, low-carbohydrate diets and overall survival, but not breast cancer-specific survival, among women with stage I-III breast cancer.


  • The diets of 9621 women with stage I-III breast cancer from two ongoing cohort studies — the Nurses' Health Study and Nurses' Health Study II — were evaluated.

  • Overall low-carb, animal-rich, and plant-rich low-carb diet scores were calculated using food frequency questionnaires after breast cancer diagnosis.

  • Cox proportional hazards regression models adjusted for multiple potential confounding factors

  • Follow-up lasted for a median of 12.4 years after breast cancer diagnosis.


  • Overall, 1269 deaths due to breast cancer and 3850 all-cause deaths occurred during the follow-up period.

  • Researchers found that greater adherence to low-carb (hazard ratio [HR], 0.82 for quintile 5 vs 1) and plant-rich diet (HR, 0.73 Q5 vs 1) was associated with a significantly lower risk for overall mortality but not breast cancer-specific mortality.

  • Overall, adhering to animal-rich, low-carb diets did not significantly influence all-cause or breast cancer-specific survival rates.

  • But replacing 3% of energy intake from available carbohydrates with fish protein was associated with 17% lower risk for breast cancer-specific mortality and 15% lower risk for all-cause mortality.


"The findings suggest that breast cancer survivors could benefit from limiting intake of carbohydrates, especially from fruit juice, sugar-sweetened beverages, and added sugar, and increasing the amount of protein and fat, in particular from plant sources," the authors write.


The study was led by Maryam Farvid, PhD, with the Data Statistics Group, Mission Viejo, California. It was published online June 10 in the journal Cancer and supported by National Institutes of Health and the University of Toronto.


Most women were non-Hispanic White and health professionals, so the results might not generalize to other sociodemographic groups. The authors also noted potential residual confounding, despite controlling for several breast cancer risk factors.


Farvid is a founder of the Institute for Cancer Prevention and Healing and the Data Statistics Group.

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