Do Soy Foods Increase Cancer Risk
Soy-based foods are a popular and healthy alternative to meat. But someconsumers shy away from them out of concern about hormones. Soy foodsare a healthy source of protein, but get all the facts on their affecton your cancer risk.
Soy-based foods are a popular alternative for those who want to cut back on or eliminate meat from their diet. But what is soy and can it increase or decrease cancer risks? Its a hot topic thats confusing, so lets start with the basics.
Get protein from soy
Soy is a plant protein full of fiber, potassium, magnesium and other vitamins. Common soy-based foods include tofu, edamame, miso and soy milk.
Soy contains all the essential amino acids that play a role in supporting the bodys vital functions, says Erma Levy, a research dietitian at MD Anderson. It can be an easy way for people on a vegan or vegetarian diet and those with food allergies to get those required amino acids. But, as with any food, eating in moderation is recommended.
A moderate amount of whole soy foods is one to two daily servings. Examples of a single serving include: 1 cup of soy milk, 1/2 cup cooked soy beans, 1/2 cup of edamame, 1 ounce of soy nuts, or 1/3 cup of tofu.
Soy and breast cancer
Because natural soy foods contain isoflavones, similar to estrogen, some people fear that soy may raise their risk for certain cancers. This is because estrogen is linked to hormonally-sensitive cancers like breast cancer.
Soy might lower the risk of other cancers
Can Eating Soy Cause Breast Cancer
There is no shortage of claims on the internet that certain foods can cause cancer. For example, you may have read or heard the myth that eating soy can increase your risk for breast cancer. But is it actually true? Here, we discuss where this idea comes from, what the science says about soy and cancer risk, and what to know about incorporating soy into your diet.
The Questions About Soy And Breast Cancer
Before launching into the controversy about soy and breast cancer, it’s important to point out that this is about more than one question. Many of you have heard that soy may lower the risk of breast cancer, but that breast cancer cells grown in a dish grow more rapidly if fed soy. What is that all about? Some of the separate questions include:
- Can soy intake lower the risk of developing breast cancer? If so, is there a window of time in which it may accomplish this, or does the effect last throughout life?
- Is it safe for those with breast cancer to eat soy, or will it make breast cancer grow faster or increase recurrence?
- Are soy supplements safe for those at risk of breast cancer or who already have breast cancer?
- How may soy interact with the medications commonly used to treat breast cancer?
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Does Soy Give You Breast Cancer
as found in a 2008 study,On one hand, It was once thought that soy foods increase the risk of breast cancer, soy foods do appear to be safe, and soymilk may lower the risk of breast cancer, However, In some< img src=”https://i0.wp.com/www.pcrm.org/sites/default/files/2019-10/LBBC_Podcast_4_fb_twitter.jpg” alt=”Soy Fights Breast Cancer, Soy is the secret weapon Japanese women use to cut their breast cancer risk down to 1/5 of the risk Western women have, consuming soy foods like edamame, Yet, isoflavones and fiber, less healthy foods such as animal fats and red or processed meats, especially when they replace other, In fact, And likewise, and it is also likely safe to eat in remission -though more research is needed, Soy foods are excellent sources of protein, or breast density, However, such studies show no effect on prostate-specific antigen levels or hormones related to the risk of prostate cancer.But now studies of survivors of breast and prostate cancer show no harmful effects, tofu and unsweetened soy milk have been shown to reduce the risk of certain cancers such as breast cancer, Soy foods have been linked to lower rates of heart diseaseAuthor: Stacy SimonWomen with the highest intake of soy protein had a 29 percent lower risk of death and a 32 percent lower risk of breast-cancer recurrence compared to patients with the lowest intake of soy protein, This Health Claim will now be found on food products in Canada.
Provides Relief From Osteoporosis
Soymilk is beneficial in providing relief from osteoporosis in postmenopausal women. Osteoporosis is a risk for women in post-menopausal years of age. Often known as brittle bones, loss of calcium contributes to the risk of developing this disease.
Studies have found that an animal protein diet increases urinary excretion of calcium and a soy-based protein diet does not. Since increasingly soymilk is also fortified with calcium, it could be said that soymilk helps in retaining and providing supplements to the body. Natural hormone replacement therapy with soy isoflavones may improve retention of bone mass and density, and thereby reduce the risk of fracture in postmenopausal women.
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How To Make Soy Milk
Making soy milk is a fairly simple process, using just two ingredients soybeans and water.
The first thing you need to do is soak your soybeans. Soak the beans in water for at least 6 hours, or overnight.
Note* Ive read that if you have issues digesting beans then adding a splash of apple cider vinegar to your beans while they are soaking will help leech out phytic acid content, without affecting the flavor.
Youll notice that soaked soybeans will expand between 2-3 times in size.
Once they are soaked, you can then optionally peel the beans. This isnt 100% necessary, although it will help to blend smoother homemade soy milk and only adds a couple of extra minutes of prep time to the recipe. After soaking the beans, the skins will come off very easily.
Close up of the three beans dry, soaked unpeeled, soaked peeled.
Next, add the soaked beans into a high-speed processor/blender for just 10-15 seconds to break down the seeds slightly.
Add the cups of water and blend again until smooth and creamy.
You then do an initial strain into a large pot. This will reduce the risk of any of the beans burning to the bottom of the pot. However, I transfer the entire mixture into the saucepan and bring to a boil over medium heat as I stand over the pot during this process and stir often.
When the mixture starts boiling, continue to cook for 3-4 minutes.
While boiling, remove the foam that starts floating on top. You want to try and skim as much of this foam as you can.
What Is The Benefit Of Milk
Low fat dairy can be an important part of a complete diet for the following reasons:
- Milk is an excellent source of calcium, providing 30% of the recommended daily intake. A product can be labeled as an excellent source of a nutrient if it contains 20% or more of the recommended daily intake for that nutrient. It can be labeled as a good source if it contains 10-19% of the recommended daily intake.
- It is fortified with vitamin A and vitamin D,
- It is also a good source of protein. One cup of milk contains 8 grams of protein.
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Soy Foods Are More Than Just Tofu And Soy Sauce
Soy foods are made from soybeansa crop that, until the 1980s, has been used in America primarily as livestock feed, but has been a part of the Asian diet for many generations. Soy is available as edamame , tofu, soy milk, soy powder and flour, miso paste, tempeh, oil, and textured vegetable protein . Soy shows up in many meat analog productsmeatless meatballs, “burger” style crumbles, and even bacon-like strips and chicken-shaped nuggets.
Myth: All Soy Foods Raise Your Risk For Breast Cancer
Thereâs no need to banish tofu and edamame from your diet.
âFor years, soy got a bad rap because of its isoflavones,â says Marleen Meyers, MD, director of the Perlmutter Cancer Center Survivorship Program at NYU Langone Medical Center.
These plant-based chemicals are similar in structure to estrogen. Most breast cancers are sensitive to estrogen which means that estrogen fuels their growth.
âSo there was a fear that soy could act as estrogen in the body and stimulate cancer cells,â Meyers says. âIt was spread on blogs, and people would tell each other to avoid soy.â
But a steady stream of studies showed that a diet high in soy didnât increase the chances of developing breast cancer and may even reduce that risk.
In one study of more than 73,000 Chinese women, researchers found that those who ate at least 13 grams of soy protein a day, roughly one to two servings, were 11% less likely to develop breast cancer than those who got less than 5 grams.
âIn Asian cultures, where people eat a lot of soy from a young age, there are lower rates of breast cancer,â Meyers says. And in those societies, people still eat soy in its traditional forms.
Meanwhile, another analysis of eight studies showed that those who got the most soy isoflavones — about the amount in a serving of tofu – were 29% less likely to get the disease compared to those who got the least.
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Eating Soy May Turn On Genes Linked To Cancer Growth
- Tags:Early-stage: Stage 0 — DCIS , Early-stage: Stage IA, Early-stage: Stage IB, Early-stage: Stage IIA, Early-stage: Stage IIB, Ductal Carcinoma In Situ, Invasive or Infiltrating Ductal Carcinoma, Invasive or Infiltrating Lobular Carcinoma, Soy, and Diet
Soybeans are the most widely used, least expensive, and least caloric way to get large amounts of protein. You can eat soybeans in many forms, including tofu, the beans themselves , soy milk, miso, and soy powder.
Soy foods have a lot of isoflavones, which are weak estrogen-like compounds found in plants. Because estrogen can promote the development, growth, and spread of breast cancers, doctors have worried that eating a lot of soy foods or soy isoflavones might worsen the prognosis of women diagnosed with breast cancer.
While past research results have been mixed, a small study done by researchers at the Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College suggests that for some women, adding a medium amount of soy to their diets turns on genes that can cause cancer to grow.
The research was published in the Sept. 4, 2014 issue of the Journal of the National Cancer Institute. Read the abstract of The Effects of Soy Supplementation on Gene Expression in Breast Cancer: A Randomized Placebo-Controlled Study.
During those 2 to 3 weeks, the women were randomly assigned to receive either:
- soy protein
- a placebo that looked like the soy protein
The study also didnt look at:
Population Research Among 6000 Women With Breast Cancer Found A 21% Reduction In Mortality Among Those Who Consumed More Soya
Its benefits were strongest in women with hormone-receptor-negative breast cancer, a more aggressive type of breast cancer where tumours lack oestrogen and progesterone receptors, and therefore doesnt respond well to hormone therapies.
Our findings suggest that, for women with hormone-receptor-negative breast cancer, soya food consumption may potentially have a beneficial effect to improve survival, Zhang says.
Not soy easy
Even so, its difficult to conclusively isolate soyas benefits if there are any.
Soya is often consumed as part of a healthy diet and as a substitute for red meat, which is associated with a higher risk of heart disease and cancer.
Soya products often replace foods like red meat, which could be why soya intake is associated with healthier outcomes
No one has given people soya foods, then looked at whether theyre more or less likely to get breast cancer over time than those not given soya, says Leena Hilakivi-Clarke, professor of oncology at Georgetown University School of Medicine in Washington DC.
One review of evidence into soyas effect on breast cancer risk found that studies that adjusted for body mass index , a common marker of health, showed a weaker association for soya than those that didnt.
This means a reduced risk of breast cancer could have been due to lower BMI, not to soya consumption.
So where did the concern that soya causes cancer come from?
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A Possible Link Between Soy Intake And Estrogen
Soy contains a high concentration of isoflavones, a class of flavonoids that has many beneficial anticarcinogenic, antimicrobial, antioxidant and anti-inflammatory properties. More specifically, isoflavones are a type of plant estrogen known as phytoestrogen, which is structured similarly to human estrogen but has much weaker effects. Nevertheless, the similarities between phytoestrogen and estrogen have raised some concerns within the general medical community that soy intake could potentially increase the risk of certain estrogen-sensitive cancers, such asbreast,endometrial andovarian cancer.
However, studies performed to date have consistently confirmed that phytoestrogen is not identical to estrogen. Furthermore, after performing many clinical trials, researchers have been unable to establish any link between soy consumption and cancer. In fact, some data suggest a protective effect. For instance, although phytoestrogen may act like estrogen in some ways, it also contains anti-estrogen properties, which means it may prevent natural estrogen from binding to estrogen receptors in cancer cells.
Favor Whole Soy Foods
While foods made using whole soybeans like edamame, tofu, and soy milk have health benefits, highly processed soy products likely do not. Some food companies have separated protein from whole soybeans and used it to make soy protein isolate. Theyve packed this isolate into shakes and turned it into meat substitutes. Unfortunately, soy protein isolate may not be healthy. In fact, its been shown to increase the amount of insulin-like growth factor in the blood, just like cows milk. Insulin-like growth factor can promote cancer growth. So stick to simple soy products like tofu, tempeh, edamame, soy milk, or miso. These foods may help protect against cancer while providing health benefits.
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Research On Soy And Disease
Learn more about the research on soy and specific diseases or other conditions:
Soy protein took center stage after research showed that it might lower levels of harmful cholesterol. A 1995 meta-analysis of 38 controlled clinical trials showed that eating approximately 50 grams of soy protein a day in place of animal protein reduced harmful LDL cholesterol by 12.9 percent. Such reductions, if sustained over time, could mean a greater than 20% lower risk of heart attack, stroke, or other forms of cardiovascular disease. In response to this finding, in 1999 the Food and Drug Administration allowed companies to claim that diets low in saturated fat and cholesterol that also contain soy may reduce the risk of heart disease.
However, a number of studies since have tempered that finding. According to a comprehensive update of soy research by the nutrition committee of the American Heart Association published in 2000, eating 50 grams of soy per day lowered LDL by only about 3%. In October 2017, after review of additional scientific studies since the health claim was authorized, the FDA proposed a rule to revoke the claim because numerous studies presented inconsistent findings on the relationship between soy protein and heart disease. Some of these inconsistencies may have resulted because soy was compared with a variety of alternative foods.
Another prospective study followed 1,954 American women who were breast cancer survivors for six years. Key highlights of the study:
One Reason There Isnt A More Definitive Answer Is Because Isoflavone Either Acts Like Oestrogen In The Body Or Its Opposite
One reason there isnt a more definitive answer is because isoflavone either acts like oestrogen in the body, or its opposite. When we eat soya, isoflavone either binds to the alpha oestrogen receptor in the body, which stimulates a tumours growth rate, or the beta receptor, which decreases growth rate and induces apoptosis.
Isoflavone prefers to bind to beta receptors, says Bruce Trock, professor of epidemiology and oncology at Johns Hopkins School of Medicine in Maryland in the US. That makes it more likely to reduce potential cancer risk.
The impact of soya on breast cancer risk may depend on when we start eating it.
Most studies on Asian populations included women who have eaten it since early childhood and were probably also exposed to it in the uterus, says Trock, compared to Western studies involving women who mostly didnt eat soya until later in life.
Starting to consume soya products at an earlier age may make soya more beneficial
Giving soya to animals at the equivalent of middle age doesnt seem to reduce risk or growth rate of tumours, he says.
But if researchers feed mice prior to puberty, then expose them to carcinogens, they get fewer and smaller tumours than if you dont give them soya.
Soya cycle
Meanwhile, clinical and population data shows daily soya intake can halve the frequency and severity of hot flashes even when the placebo affect is taken into consideration, says Mindy Kurzer, professor of nutrition at the University of Minnesota.
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As A Survivor Does Soy Improve Survival And Lower The Chances Of Recurrence
Current evidence suggests that a diet high in soy may improve survival and lower the risk of recurrence in women with breast cancer.7-9 The benefits dont appear limited to Asian populations either.
One analysis combined data from three large, long-running studies of survivors from both Asian and Western countries. It found that women who ate at least 10 mg of soy per day after a breast cancer diagnosis had a 25 percent lower risk of recurrence compared to those eating less than 4 mg per day.9
However, soy is not currently recommended as a way for breast cancer survivors to lower the risk of recurrence. There are still some open questions about these findings because the studies were looking at many different types of soy, and because women who regularly eat soy simply tend to be healthier than those who dont.9