Harmful effects of the consumption of soy and derivatives
For years we have been selling through different advertising campaigns that both the soy as popular derivative products such as soy milk, are healthy and adequate products from a nutritional point of view for the different benefits and properties they provide. But the reality according to the existing scientific studies is very different.
Although it is true, as we mentioned in a previous article, soy milk provides omega-3 fatty acids, isoflavones rich in plant estrogens, lecithin, B vitamins, essential amino acids and minerals such as calcium and phosphorus, Different scientific studies only confirm that, despite its nutritional wealth, it is a drink whose consumption would be little or not really advised.
Therefore, before consuming the popular soy beverage, we want to analyze what are its detrimental effects, since both short and long term would be really dangerous both for our body and for our own health.
The main negative effects of soy consumption and its derivatives
Endocrine disorders
Soy is rich in genistein, a protein that causes alterations of the pancreas and thyroid. Different scientific studies have described an increase in the hormone thyrotropin (pituitary TSH) in response to its antithyroid action, causing hypothyroidism, diffuse goiter and subacute autoimmune thyroiditis (1).
Since genistein inhibits thyroid peroxidase, it causes irreversible damage to the enzymes that synthesize the thyroid hormones. To give just one example, in 1988 Dr. Theodore Kay (from the Faculty of Medicine of the University of Kyoto) found that people fed with soy - mostly children and women - suffer from an enlarged thyroid.
In addition, there is evidence that a long-term consumption can increase the risk of thyroid cancer, while those children fed soy formulas have twice as much diabetes.
Alterations in fertility
Although this section is within the different endocrine alterations produced by soy consumption, we want to make a separate section to be able to analyze it in depth.
We must not forget that soy contains phytoestrogens, whose action is combined with other endocrine disruptors and xenoestrogens, responsible for alterations in sexual behavior, sex hormones, decreased fertility and androgens.
In the case of men, not only both androgens and fertility are reduced, but also genistein and daidzein found in soybeans are genotoxic compounds for sperm. In turn, phytoestrogens cause swelling, fluid retention and breast development (gynecomastia).
If the consumption of soy occurs from childhood, precocious puberty and congenital anomalies of the male genital tract may appear. In fact, the highest incidence of this type of defect has been found in male babies born to vegetarian mothers who consume large amounts of soy (2).
Alterations of the immune system
Soy is rich in genistein, a protein that exerts an immunosuppressive effect, producing atrophic alterations of the thymus. In fact, an even normal consumption of soy products during pregnancy and breastfeeding has been linked to the onset of autoimmune diseases in children.
Allergic alterations
It is known that soy protein produces different allergic alterations, generating almost 30% of serious reactions, as well as being a cause of alopecia.
Alterations in DNA, and malformations at birth
Different scientific studies have described alterations of the natural repairing mechanisms of chromosomal alterations, as well as negative alterations of DNA (3).
In case of pregnancy, different investigations carried out by the John Hopkins University have concluded that there is a potential connection between the consumption of isoflavones during pregnancy, birth defects (such as hypospadias, cryptorchidism, spina bifida, absence of some organ, miscarriage and deformed legs) and thyroid disorders.
Alterations of the nervous system
A scientific study carried out by the Hawaiian Epidemiology Center for more than 3 decades on 7,000 men found that the more soy they consumed, the worse their mental abilities were.
Experts also indicate that take amounts of soybeans approximate to 25 gr. of soy milk per day can lead to cognitive problems. In this regard, the National Institute on Aging reported findings that revealed that soy consumption in two or more servings a week resulted in poor cognitive performance and low brain weight.
Alterations of behavior
There is evidence that a long-term consumption of products derived from soy causes an increase in stress and anxiety, aggressive behavior and in turn a decrease in social behaviors.
Not only does it not prevent cancer, but it increases the risk of suffering from it
For years the industry producing soy and soy products has publicized that it is a food that prevents cancer. However, in the scientific literature we can find cases that show that, in reality, not only does it not prevent it, but it can promote gynecological and thyroid cancers, pancreatic cancer, breast cancer and childhood leukemia.
In the industrial processing of soybeans, a carcinogenic substance known as lisinealin is produced, while the solvents used leave other residues such as hexane, which is also carcinogenic (4).
Favors the appearance of breast cancer
Although we discussed this issue in the previous section, we wanted to open a special space dedicated to this topic, mainly because one of the supposed advantages or benefits of soy consumption for women is the presumed prevention of breast cancer.
However, we must bear in mind that soy is rich in phytoestrogens, so it could be linked to an increased risk of breast cancer. This was verified by Cornell University, which showed that high levels of estrogen in the long term are linked to the increased risk of breast cancer. It seems that these carcinogenic effects are even greater in premenopausal women (5).
Appearance of uterine fibroids and menarche
A study conducted in the Enviromental Health Perspective, which lasted 4 years and involved 50,000 women, found that women who were fed soy milk in their childhood had a 25% higher incidence of uterine fibroids at 35 years .
In 2011, the results of a scientific study showed that girls fed in childhood with soy have a 25% higher risk of early menarche (ie, early adolescence) (6).
Does not prevent osteoporosis
It seems that also the claim that soy prevents osteoporosis is completely false, since it is actually a vegetable product that not only blocks the absorption of calcium, but causes a deficit of vitamin D.
Why is Asia one of the continents with the lowest levels of osteoporosis? Not because of soy consumption, but because their diet is richer in vitamin D, from other foods such as seafood, bacon, and broths made with bones (very rich in calcium).
Appearance of kidney stones
Soy is rich in oxalates, which can not be metabolized by our body and are eliminated in the urine. A recent study conducted by the Washington State University (in Spokane), has shown that oxalates bind to calcium in the kidneys, which can lead to the formation of kidney stones. Therefore, the consumption of soy is not recommended in people at risk of calculations.
So, is not it safe to consume soy?
We must bear in mind that there are no foods that are one hundred percent beneficial or harmful. Also, in most cases, The problem of soybean comes from consuming soybeans and derivatives obtained from transgenic crops.
Luckily, according to European regulations collected in Genetically Modified Organisms, like any other food, If the soybean is transgenic, it must be indicated in the product package, so every time we go to buy a soy product or derivative, it is best to look at its labeling. It is likely that you will find a notice of the type "produced from non-transgenic soybean", or perhaps "contains transgenic soy".
However, The best way to ensure that you consume soy one hundred percent safe is to opt for products from organic farming.
On the other hand, we must also pay special attention to daily amountsthat we consume of soybeans, given that no matter how much it is not transgenic and even comes from organic farming, if we spend in its consumption we will notice its negative effects, and it will not be so beneficial for health. Studies indicate that Do not exceed 3 daily servings of soy or derivatives per day, while to notice the effects of isoflavones (especially in men), we must exceed 12 daily rations. References (1) Endocrine disorders:
- Suppressive effects of genistein and daidzein on pituitary-thyroid axis in orchidectomized middle-aged rats
- Goitrogenic and estrogenic activity of soy isoflavones
(2) Alterations in fertility:
- I am, phyto-oestrogens and male reproductive function: a review
- An unusual case of gynecomastia associated with soy product
- Potential detrimental effects of a phytoestrogen-rich diet on male fertility in mice
(3) Alterations in DNA and malformations at birth:
- Genistein and daidzein induces cell proliferation and their metabolites cause oxidative DNA damage in relation to isoflavone-induced cancer of estrogen-sensitive organs
- Adverse effects on female development and reproduction in CD-1 mice following neonatal exposure to the phytoestrogen genistein at environmentally relevant doses
- Neonatal exposure to genistein disrupts ability of female mouse reproductive tract to support preimplantation embryo development and implantation
- A maternal vegetarian diet in pregnancy is associated with hypospadias.The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood
(4) It increases the risk of some types of cancer:
- Genistein and daidzein induces cell proliferation and their metabolites cause oxidative DNA damage in relation to isoflavone-induced cancer of estrogen-sensitive organs
- Genistein induces topoisomerase IIbeta- and proteasome-mediated DNA sequence rearrangements: Implications in infant leukemia
(5) It favors the appearance of breast cancer:
- Maternal genistein exposure mimics the effects of estrogen on mammary gland development in female mouse offspring
- Maternal genistein exposure mimics the effects of estrogen on mammary gland development in female mouse offspring
(6) It favors the appearance of uterine fibroids and menarche:
- Early-life I am exposure and age at menarche
