Why do many people dislike soy products?

Soy: healthy or unhealthy?

In recent years, plant-based alternatives to animal products have enjoyed increasing popularity: More and more companies are expanding their vegan product range and sales figures are steadily increasing. Soy products such as soy milk, cream and quark or tofu are becoming increasingly popular. With the increasing consumption of soy, however, critical voices are also being raised: Soy is a health concern. In the following article we address this concern and briefly summarize the current scientific state of affairs.

Nutritious food

The soybean is generally characterized by its high protein and nutrient content. It contains all the essential amino acids, i.e. protein building blocks that the body cannot produce itself. If you replace meat and sausage products with the soy product tofu, you consume a lot of monounsaturated and polyunsaturated fatty acids and avoid cholesterol. Natural, not heavily processed soy products such as tofu and tempeh (fermented soybeans) are often low in fat and high in protein and nutrients.


Soy has come under fire mainly because of the so-called isoflavones, secondary plant substances that are structurally similar to the human hormone estrogen and can influence the hormone balance. If there are thyroid diseases, isoflavones can reduce the formation of thyroid hormones. There is no evidence of negative thyroid effects in people who do not have thyroid problems. With regular soy consumption, however, it is recommended to ensure that there is a sufficient iodine balance in the body - the research situation is not yet clear. In general, the content of isoflavones in processed soy products such as tofu, tempeh or soy milk is significantly lower than in pure soybeans.

Cancer risk

The risk of thyroid cancer is reduced by up to 55% in people who eat tofu. Although some websites and researchers warn that the risk of breast cancer is increased with soy consumption, the low breast cancer rates in East and Southeast Asia, where traditionally high levels of soy are consumed, speak against this. Prostate cancer rates are also low in Asian countries. In addition, higher concentrations of possibly protective isoflavones in the prostate were found in Asian men than in Western study participants. Even if, in addition to soy consumption, additional (regional) nutritional, health and environmental factors play a role in the development and prevention of diseases, such findings can be read as important first indications of the effects of different eating habits.

Menopausal symptoms

Another finding from Asia points to additional positive properties of soy: in parts of Asia, women suffer less from hot flashes and classic menopausal symptoms. It is believed that the soy-rich diet gives them more isoflavones, which, due to their similarity to the hormone estrogen, compensate for the drop in hormones during menopause. However, it is generally not advisable to take isolated isoflavones in the form of high-dose food supplements for these and other health reasons.

Heart disease

Because they are cholesterol-free and have a high content of monounsaturated and polyunsaturated fatty acids, soy products are known as "heart-friendly" foods. The risk of cardiovascular disease can be reduced in part by consuming soy. B. could be detected in Japanese women after menopause.


In osteoporosis, calcium is extracted from the bones, causing the bone density to decrease and the bones to be broken down. Soy protein and isoflavones seem to have a positive influence on this process: studies show that fewer cases of osteoporosis occur in people from countries with usually high levels of soy consumption (see note above on regional studies). Regular consumption of soy milk (partially enriched with calcium) can have preventive effects on osteoporosis and prevent bone loss in postmenopausal women.

Official expert opinions

The Federal Institute for Risk Assessment (BfR) states that “the intake of isoflavones as part of a normal soy diet with normal consumption can be regarded as harmless according to the current state of scientific knowledge”. Our scientific advisory board Dr. Markus Keller from the Institute for Alternative and Sustainable Nutrition (IFANE) summarizes the data situation on soy in a similar way:

»Claims about the harmful effects of soy consumption [are] often presented one-sidedly or [are] at least controversial (…). Some of them are based on a single study. Alleged “evidence” on soy-critical websites is often insufficiently researched, cited literature is sometimes poorly or incorrectly reproduced, and studies that indicate possible positive effects of consuming soy products are ignored. As a result, relevant websites and articles should be critically examined. According to the current state of science, the moderate consumption of soy products has more positive than possible negative health effects. However, there is still a need for further research here. "

Conclusion: soy is safe in moderation

One thing is certain: if there is nothing physically against it (such as a thyroid disease or a soy allergy), there is nothing wrong with moderate soy consumption. Tofu and other not-over-processed soy products such as tempeh and soy milk can make a valuable contribution to a healthy plant-based diet. The fact that the consumption of soy is also far less worrying from an environmental point of view than is sometimes emphasized should only be briefly indicated in conclusion:

Around 80% of the world's soy harvest is used as feed for the production of animal products and not for direct human consumption. Negative environmental impacts such as the ongoing clearing of the rainforest to open up further soybean cultivation areas are clearly the result of animal production and consumption. In addition, soy products produced in Europe for direct human consumption (such as these tofu products) are often made from sustainably grown North American or European soybeans: whether from Canada, southern France, Italy, Austria or even southern Germany - Soy does not only grow in South American monocultures.

The concerns have been dispelled, but you are still not quite sure how to make the tasteless tofu delicious? Then take a look at our tofu article.