Debunking Soy Misconceptions

Originating in eastern Asia, soybeans, commonly called soya beans have long been a staple food in the area. These days, South and North America as well as Asia are the main regions where they are grown.

Soybeans are usually eaten whole in Asian cuisines, however, they are usually processed into various items in Western countries. For instance, soy flour, soy protein, soybean oil, tofu, soy milk, edamame, and soy sauce are some of these goods.

Foods containing soy can be nutritious additions to a diet when consumed in moderation. They are low in saturated fat, cholesterol-free, and rich in vitamins, minerals, and antioxidants.

Antioxidants and phytonutrients, which are abundant in soybeans, are linked to several health advantages. Diets incorporating soy have been associated with reduced blood sugar, heart health, menopause symptoms, and possibly even a decreased risk of some cancers.

However, some individuals are skeptical about the health benefits of diets high in soy. For example, some worry that consuming too much soy could impede thyroid function or raise the risk of breast cancer.

For ages, Asian cuisines have used soy as a mainstay. It is also a well-liked meat alternative for vegetarians and vegans due to its high protein content.

Soybeans are considered one of the top sources of plant-based protein, with a protein content ranging from 36% to 56% of their dry weight. A single cup (172 grams) of boiled soybeans contains about 31 grams of protein.

While soy protein is nutritionally valuable, its quality is slightly lower than that of certain animal proteins. The primary proteins in soybeans, glycinin and conglycinin, constitute roughly 80% of the total protein content but may trigger allergic reactions in some individuals.

Consuming soy protein has been associated with a moderate reduction in cholesterol levels. However, despite benefits like this, there are still some soy misconceptions, particularly regarding its effects on health.

Even with its many health benefits, soy has been surrounded by numerous myths. These soy misconceptions have led to confusion and hesitation among consumers about including soy in their diets. 

Let’s address some of the most common misconceptions about soy. Whether it’s concerns about cancer, hormonal impacts, or effects on testosterone levels, we aim to clear the air on soy’s role in a healthy diet.

One soy misconception you may have heard is that if you have a higher-than-average risk of breast cancer, you should avoid soy. On the other hand, you may notice headlines suggesting that it offers illness protection. What is the truth, then?

The notion that soy consumption leads to cancer is unfounded. Numerous scientific studies have shown that moderate soy consumption is safe. These studies revealed soy may even provide protective benefits against certain types of cancer, such as breast and prostate cancer.

Eating soy products including edamame, tofu, and soy nuts is popular among consumers. According to Dr. Mussallem, plant-based protein doesn’t raise your risk of breast cancer.

Soy contains compounds called isoflavones. They are phytoestrogens possessing antioxidant properties. Extensive research has been conducted on these compounds, revealing their potential to reduce cancer risk by inhibiting tumor growth, decreasing inflammation, and disrupting cancer cell signaling pathways.

Although soy and human estrogen share a similar chemical composition, soy binds to estrogen receptors on breast tissue distinctly, possibly suppressing tumor growth.

“Soy consumption after a breast cancer diagnosis not only is a great way for you to get a plant-based protein, it also improves your breast cancer outcomes,” asserts Dr. Mussallem.

In a study involving over 73,000 Chinese women, researchers discovered that those who consumed a minimum of 13 grams of soy protein daily, equivalent to approximately one to two servings, had an 11% lower risk of developing breast cancer compared to those who consumed less than 5 grams.

Furthermore, populations with traditionally high soy intake, notably in Asian countries, exhibit lower rates of certain cancers compared to Western populations, despite soy being a fundamental part of their diet.

The myth that soy impacts women’s hormones is not supported by scientific evidence. Soy is considered safe for consumption by women at all stages of life, including those going through hormonal changes such as menopause. Research suggests that soy may even offer benefits for women experiencing menopausal symptoms.

Studies have shown that soy contains phytoestrogens which have a chemical structure similar to estrogen. However, these phytoestrogens do not exert the same effects as estrogen in the body. Instead, they can act as weak agonists or antagonists of estrogen receptors, depending on various factors such as hormone levels and tissue type.

For some women going through menopause, consuming soy reduces symptoms such as hot flashes and night sweats. This is believed to be due to the ability of isoflavones to modulate estrogen activity in the body. Additionally, foods that contain soy are often rich in nutrients and can contribute to overall health during this stage of life.

Individual responses to soy may vary. While many women may experience relief from menopausal symptoms, others may not notice significant changes. As with any dietary component, moderation is key. You should consult with a healthcare professional before making significant changes to your diet, especially during times of hormonal transition like menopause.

In the realm of fitness, the relationship between soy and testosterone has always been a bit of a contentious topic.

You may have heard that soy consumption lowers testosterone levels in men. However, this claim is not supported by scientific evidence. Several studies investigated the effects of soy consumption on testosterone levels, and the consensus is that moderate soy intake does not have a significant impact on testosterone levels in men.

Soy contains phytoestrogens, such as isoflavones, which are compounds that can interact with estrogen receptors in the body. However, these phytoestrogens do not mimic the effects of estrogen in the same way that natural estrogen does, and they do not have a suppressive effect on testosterone production.

Research suggests that soy consumption is unlikely to affect testosterone levels in men, even when consumed regularly as part of a balanced diet. Furthermore, population studies have not found any association between soy intake and adverse effects on male reproductive health or hormone levels. Soy’s nine necessary amino acids can actually help restore normal testosterone levels.

Overall, the idea that soy consumption lowers testosterone levels in men is a myth. Moderate consumption of soy foods, as part of a varied diet, is safe for men and is not expected to have negative effects on testosterone levels or overall health.

Now that we’ve covered the top soy misconceptions, let’s get into the amount of soy that is safe to consume. Research studies have found that consuming up to 25 to 30% of total protein intake from soy products is generally safe for most individuals.

Here are some examples of what that could look like:

6 oz. Tofu and 1 cup Soy Milk:

·   6 oz. (approximately 170 grams) of tofu typically contains around 18-24 grams of protein.

·   1 cup (240 ml) of soy milk provides approximately 7 grams of protein.

·   Total soy protein intake: 25-31 grams

1 cup Edamame and 3 oz. Tempeh:

·   1 cup (155 grams) of cooked edamame offers about 17 grams of protein.

·   3 oz. (approximately 85 grams) of tempeh contains around 15 grams of protein.

·   Total soy protein intake: 32 grams

1 cup Soy Milk and 1/2 cup Soy Nuts:

·   1 cup (240 ml) of soy milk provides approximately 7 grams of protein.

·   1/2 cup (around 60 grams) of soy nuts offers about 34 grams of protein.

·   Total soy protein intake: 41 grams

These examples show various combinations of soy products that fall within the recommended range of 25 to 30% of total protein intake. It’s important to note that individual protein needs may vary, so it’s essential to consider factors such as age, weight, activity level, and overall health status when determining soy consumption. 

Additionally, consuming a variety of protein sources, including both plant-based and animal-based sources, is recommended to ensure adequate intake of essential amino acids and nutrients. Lastly, soy is a common allergen, if reactions occur consider eliminating soy and check with your doctor.

Navigating the misconceptions about soy and other foods can be overwhelming, and it’s crucial to have clear guidance about your dietary choices. Consulting with a registered dietitian can provide you with personalized support tailored to your needs. 

Schedule an appointment with a remote dietitian through Dietitian Live. Our team of experienced dietitians is here to help you achieve your health objectives. Register now, connect with a registered dietitian, and gain access to a personalized nutrition plan designed to propel you toward improved well-being.