For years, women were warned away from soy-laden foods due to their associated risk with interfering with breast cancer drugs like tamoxifen. Simultaneously, however, they’ve also heard that soy is good for you; its estrogen-like compounds called isoflavones have been lauded for their ability to inhibit the development or recurrence of breast cancer.
So which one is it?! A new study by Fang Fang Zhang, a cancer epidemiologist at Tufts University, may have just solved the riddle. She told NPR, “Our finding would suggest that soy food consumption does not have a harmful effect.”
Asia Has It Right
Look what I managed to make: low waste #tempeh. I bough organic soy beans in bulk, bought a starter and inoculated the cooked beans in my oven. Next steeps: finding organic soy beans from around here, trying to flavour the tempeh, trying to make tempeh from other pulses, getting a stainless steel container to make plasticfree tempeh in, starting an underground food market of the kind Sandor Katz describes in his book "The Revolution will not be Microwaved." 🇩🇪Schaut mal, was in meinem Ofen gewachsen ist: mit wenig Müll selbstgemachter Tempeh. Im unverpackt Laden habe ich Sojabohnen gekauft und mir einen Starter zuschicken lassen. Nächste Schritte: regionale bio Sojabohnen finden, Gewürze und anderes in den Tempeh reinmischen, Tempeh aus anderen Hülsenfrüchten ausprobieren, eine Edelstahlwanne suchen, in der der Tempeh wachsen kann, einen geheimen Lebensmittelmarkt gründen, so wie ihm Sandor Katz in seinem Buch "The Revolution will not be Microwaved" beschreibt. #zerowaste #lowwaste #zerodechet #lesswaste #müllfrei #soy #soja #tempeh #indonesian #selbstgemacht #organic #diy #nachhaltig #sustainable #vegan #vegetarian #saarbrücken #saarland #karlsruhe
Research completed in Asia in 2009, showed that soy can indeed protect against breast cancer. This inspired Zhang to try and replicate the result in North America. According to the 2009 Asian study, which included 5,000 Chinese breast cancer survivors, it was found that those who consumed the most soy did better than those with lower intakes four years following a breast cancer diagnosis and treatment.
Zhang explained to NPR that because her soy study had a predecessor showing positive results from consumption of the plant, she wasn’t at all surprised to see women in North America benefitting from consuming it too. She has published her findings in the journal Cancer.
In Zhang’s study, higher consumption of soy was shown to correlate to a longer life after combatting breast cancer. This was particularly applicable to women with hormone receptor negative breast cancers, which often don’t respond to hormone therapy.
For those who were regularly ingesting this plant-based protein, Zhang told NPR, “We found a 21 percent reduction in all-cause mortality among women with the highest dietary intake [of soy], compared to those with the lowest intake.”
However, this increased chance of survival was limited to participants with hormone receptor-negative cancers. For those who had hormone receptor-positive tumors or respond well to hormone therapy, researchers were unable to establish a clear association between soy and survival.
The findings in Zhang’s study were based upon a sample of 6,235 women with breast cancer in the United States and Canada.
Limitations to the Zhang Study
Furthermore, the amount of soy that is typically consumed by a North American female is less than 2 milligrams a day. According to Marian Neuhouser, a registered dietician and nutritional epidemiologist at Fred Hutchinson Cancer Research Center, “If you compare that to Asian populations that on average consume 40 to 50 milligrams, it’s pretty low.”
Finished my package of soy medallions. It's just amazing how you can make them taste great if you just add a ton of spices. Had them with lettuce, pack Choi and some 200g rice…. And ketchup of course but I guess I don't really have to mention that anymore 😜 At some point I will make a recipe video for these medallions but for now I really want to eat less processed food. Wish you all a good night and see you tomorrow 😘🦄
This small amount of consumption leaves it unclear if the results would remain the same if U.S. women were to consume significantly larger amounts of soy.
However, it is possible to say that soy seems to be safe for women to consume. Even if women in the U.S. consumed a lot more. Neuhouser even extrapolates on this though telling NPR, “It could be beneficial for some women who have had a diagnosis of breast cancer.”