Soy has been touted as a healthy food group for as long as I’ve been around.

Phytoestrogens are plant derived compound found in a wide variety of foods, most notably soy. They’re naturally present in many other foods including lentils, oats, peanuts, cashews, garlic, cabbage, fennel, apples, coffee, beer, dairy, and meat. Phytoestrogens have long been part of our traditional diet, so we’re adapted to them. They help to regulate and metabolise estradiol (our strongest estrogen). For example, phytoestrogens protect and buffer estrogen receptors and they promote the healthy detoxification of estrogen.

The good news…

Soy, in the presence of high estrogen, can have an anti-estrogen effect. Thus make periods lighter and improve estrogen-excess such as PMS, Endometriosis, PCOS and heavy periods. They also have been shown to protect against breast cancer (even though breast cancer is an estrogen related cancer).   Soy is so strong that too much soy can stop periods and impair fertility.

Conversely, in the presence of low estrogen, soy has a pro-estrogen effect, which I probably harmless at low dose, but men and children should avoid too much soy. Soy’s pro-estrogen effect can be beneficial in post-menopausal women or those with low estrogens leading into peri-menopause.

The bad news…

Soy is commonly hidden in our foods and are listed as these ingredients: Soy lecithin, soy protein concentrate, soy protein isolate, texturized vegetable protein, hydrolyzed vegetable protein or any other phrase containing the word “soy.”

It’s cheap and it’s a common filler in packaged foods. It’s in everything from chewing gum, chocolate and bread to microwave meals, frozen pizzas and processed meat.

• 95% of the world Soy is GMO and “Round Up Ready”. If you’re not sure why this is an issue you should read more on GMO and Glyphosates.
• Soy’s isoflavones inactivate the enzyme that makes thyroid hormone (thyroid peroxidase), so it can suppress thyroid hormone. That’s less likely to be a problem when there is sufficient iodine.
• Infants fed on soy formula have been found to have a phytoestrogen intake six to 11 times higher than adults on a high-phytoestrogen diet, this can be dangerous levels for their age and sex.
• Researchers from King’s College London warned women should also avoid eating too much soy if they are trying to fall pregnant, citing soy can sabotage sperm on its journey to the egg.
• In a study of 99 men, those with the highest soy intake had 41 million less sperm per millilitre than those who ate no soy. 

So, where does this leave us in the safe vs not safe debate on soy?

If you’re preparing this correctly, buying only an organic non GMO soy bean source… then I can’t see a problem if you’re a women with diagnosed low estrogen or high estrogen.

If you’re pregnant, have thyroid issues, are an infant or child or a male, I would avoid this food group due to its impact on hormones and fertility.