A new study found men with a common gene variant saw estrogen levels stabilize from eating phytoestrogen-rich soy and flax. This hints at a personalized nutrition approach for keeping hormones in check.

A new randomized controlled trial published in Nutrients investigated the effects of increased soy and flaxseed consumption on hormone levels in prostate cancer patients^[1]. The findings suggest specific phytoestrogen foods may help modulate estrogen levels in certain genetic subgroups. This has implications for incorporating natural approaches into prostate cancer treatment.

Overview of Study Design and Results

The study enrolled 135 Swedish men scheduled for prostate removal surgery. They had localized, low to intermediate-risk prostate cancer. Participants were randomized to either increase phytoestrogen foods or make no diet changes for 6-8 weeks before surgery.

The intervention group consumed roasted soybeans, green soybeans, and flaxseeds daily. This provided approximately 200 mg/day of phytoestrogens - 100 mg from soy isoflavones like genistein and 100 mg from flaxseed lignans. The control group received standard Swedish dietary guidelines with no added foods.

Blood samples were collected at study baseline and endpoint to analyze hormones affected in prostate cancer - testosterone, estradiol, sex hormone binding globulin (SHBG), and insulin-like growth factor 1 (IGF-1). Samples were also analyzed for soy and flaxseed phytoestrogen levels.

The results showed phytoestrogen foods significantly increased blood levels of lignans like enterodiol and isoflavones like genistein in the intervention group compared to controls. However, soy and flax intake did not affect testosterone, SHBG, or IGF-1 overall.

A key finding was a trend toward decreased estradiol level increases in the phytoestrogen group among men with a specific estrogen receptor gene variation (ESR2). This subgroup (43% of participants) showed a 22% lower risk of rising estradiol compared to controls. The other genetic subgroup showed no difference in estradiol changes.

Implications for Natural Prostate Cancer Healing

The findings suggest soy foods and flaxseeds may help regulate estrogen activity in localized prostate cancer, especially among men with certain genetic profiles. This aligns with past research on phytoestrogen mechanisms^[2].

Phytoestrogen compounds like enterolactone and genistein can bind to estrogen receptors in tissues and either stimulate or block downstream estrogenic effects^[3]. Their weak estrogen-mimicking properties may counteract stronger endogenous estrogens like estradiol that can drive prostate cancer progression^[4].

Additionally, lignans and isoflavones exhibit numerous anticancer benefits beyond estrogen binding, including reducing inflammation and angiogenesis^[5]. The rich fiber in flax and soy also feeds gut microbes involved in health-promoting conversions of phytoestrogen precursors^[6].

This research indicates adding soybeans, tofu, miso, flaxseeds, and other phytoestrogen-rich foods to the diet may help modulate estrogen balance and related tumor-fueling factors^[7]. Combining this with antioxidants like green tea and pomegranate and spices like turmeric could enhance anticancer phytonutrient intake^[8,9].

However, optimal intakes likely depend on individual factors like microbiome health, genetics, medications, and stage of prostate cancer^[10]. Blood testing before and during dietary changes can help determine effective amounts for hormone optimization^[11].

Overall, this adds to growing data on plant-based nutrition as a complementary prostate cancer strategy alongside conventional treatments. More research is still needed, but nourishing the body with phytoestrogen-containing natural foods appears a wise supportive approach.

To learn more about the health benefits of soy, flaxseed, and prostate cancer, please see the links below for our databases on each subject:

• Soy
• Flaxseed
• Prostate Cancer

References

1. Ahlin, R., et al. Effects on Serum Hormone Concentrations after a Dietary Phytoestrogen Intervention in Patients with Prostate Cancer: A Randomized Controlled Trial. Nutrients. 2023 Jan; 15(1): 1792.

2. Dixon RA. Phytoestrogens. Annu Rev Plant Biol. 2004;55:225-61.

3. Mueller SO, et al. Phytoestrogens and their human metabolites show distinct agonistic and antagonistic properties on estrogen receptor α and ERβ in human cells. Toxicol Sci. 2004 Jul;80(1):14-25.

4. Dobbs RW, et al. Estrogens and prostate cancer. Prostate Cancer Prostatic Dis. 2019 Jun;22(2):185-194.

5. Mahmoud AM, et al. Plant Polyphenols as Chemopreventive Agents Against Prostate Cancer. Eur J Cancer Prev. 2022 Nov 24.

6. Lampe JW. Is equol the key to the efficacy of soy foods? Am J Clin Nutr. 2009 Jul;89(3):1664S-1667S.

7. Applegate CC, et al. Soy Consumption and the Risk of Prostate Cancer: An Updated Systematic Review and Meta-Analysis. Nutrients. 2018 Jan 10;10(1):40.

8. Chen L, et al. Phytonutrients for Controlling Starch Digestion and Colorectal Cancer: An Integrative Review. Nutrients. 2022 Nov 5;14(21):4597.

9. Russo GL, et al. Rationale for Dietary Antioxidant Treatment of Prostate Cancer. Front Oncol. 2021 Feb 3;11:612349.

10. Grammatikopoulou MG, Goulis DG. Dietary Factors and Supplements Influencing Prostate Specific-Antigen (PSA) Concentrations in Men with Prostate Cancer and Increased Cancer Risk. Nutrients. 2020 Sep 23;12(10):2985.

11. Masko EM, et al. Low-Carbohydrate Diets and Prostate Cancer: How Low Is "Low Enough"? Cancer Prev Res (Phila). 2022 Jun;15(6):571-573.