The decision to eat soy containing foods as a phytoestrogen source during the menopausal transition is a controversial one. You will find some sources that recommend it and others don't. Let's break this down.
Soy is a phytoestrogen source. It is the highest source of isoflavones. It contains the main isoflavones Daidzein and Genistein.
Isoflavones need to be converted to the active form "equol". This is done in the digestive microbiome. Most Asian women's digestive system is capable of this conversion. Unfortunately, less than a 1/3 of American women can do this.
It is the most genetically engineered crop on the planet. Roughly 94% is GM. GM foods are heavily sprayed with herbicides and pesticides such as glyphosate. Which makes them unfavourable to consume.
Soy is a goitrogen. Women transitioning into menopause are at a greater risk of thyroid dysfunction. Thyroid related issues such as hypothyroidism double at this stage of life. Goitrogens reduce the thyroid's ability to function and should be avoided at this stage of life especially if you or someone in your family has a thyroid condition.
Soy contains phytates. Phytates are also called antinutrients as they bind to minerals and make them unabsorbable. Key minerals that may be impacted include iron, iodine, calcium, magnesium, and zinc.
Soy contains an enzyme inhibitor - Trypsin inhibitor. This impacts your ability to digest protein and carbohydrates and may cause digestive symptoms such as bloating and flatulence.
Soy is a very common allergen. It is one of the big top 4 foods that cause allergies or intolerances.
Although I don't recommend soy consumption, some women are looking for a compromise. If you want to consume soy please search high and low for an organic version. Next, I would recommend eating it as it has been traditionally eaten in Japan. This is mostly small portion sizes of fermented soy such as natto, miso, and tempeh. (Fermenting soy reduces the number of goitrogens, phytates, and enzyme inhibitors it contains.)
And avoiding consuming the highly processed soy alternatives we often find in western supermarkets such as soy protein isolate (this doesn't even contain the desired phytoestrogens as they are removed with processing), fake meat products made out of hydrolyzed vegetable protein, or textured vegetable protein.