Suppression of Implanted MDA-MB 231 Human Breast Cancer Growth in Nude Mice by Dietary Walnut

Abstract

Walnuts contain components that may slow cancer growth including omega 3 fatty acids, phytosterols, polyphenols, carotenoids, and melatonin. A pilot study was performed to determine whether consumption of walnuts could affect growth of MDA-MB 231 human breast cancers implanted into nude mice. Tumor cells were injected into nude mice that were consuming an AIN-76A diet slightly modified to contain 10% corn oil. After the tumors reached 3 to 5 mm diameter, the diet of one group of mice was changed to include ground walnuts, equivalent to 56 g (2 oz) per day in humans. The tumor growth rate from Day 10, when tumor sizes began to diverge, until the end of the study of the group that consumed walnuts (2.9 +/- 1.1 mm(3)/day; mean +/- standard error of the mean) was significantly less (P > 0.05, t-test of the growth rates) than that of the group that did not consume walnuts (14.6 +/- 1.3 mm(3)/day). The eicosapentaenoic and docosahexaenoic acid fractions of the livers of the group that consumed walnuts were significantly higher than that of the group that did not consume walnuts. Tumor cell proliferation was decreased, but apoptosis was not altered due to walnut consumption. Further work is merited to investigate applications to cancer in humans.

Therapeutic Effects of Phytochemicals and Medicinal Herbs on Chemotherapy-Induced Peripheral Neuropathy

“…Cisplatin increased, but walnut decreased the latency to nociceptive stimuli [35]. Dietary walnut suppressed mammary gland tumorigenesis in the C(3)1 TAg mouse [90] and growth of implanted MDA-MB 231 human breast cancer cells in nude mice [91]. It has also been demonstrated that walnut reduces growth of prostate cancer [92,93] and colorectal cancer [94].…”

Health Benefits of Nut Consumption

“…Two separate studies by the same authors, each on different populations, examined the relationship between frequency of nut intake and gallstone disease risk. After following 80,718 women for 20 years, the Nurses’ Health Study [66] showed that frequent nut consumers (≥5/week) had a 25% reduced risk of cholecystectomy compared to non-consumers. Similar findings were observed among nearly 43,000 men in the Health Professional’s Follow-up study [67].…”

Effects of Walnut Consumption on Colon Carcinogenesis and Microbial Community Structure

“…Whole walnut halves were provided by the California Walnut Commission. The amount of walnuts added to the diets was determined on the basis of previous in vivo studies (15,16). In Study 1, mice (4 week-old) were fed AIN-76A diet (Harlan Laboratories, Inc.) supplemented with 0%, 9.4%, 14.1%, or 18.8% of walnuts by weight, which are equivalent to 0%, 15%, 22.5%, or 30.2% of energy from walnuts, respectively.…”