You would be hard pressed to do your usual grocery shop and avoid soy. Even some products that would not typically be linked to soy contain some form of this little legume.
However, despite being all over the place, soy faces a lot of controversies.
Today I am looking at some of the big claims made for and against soy and seeing what the science has to say.
Soy products are made from the Glycine Max legumeor, as it is probably more commonly known, the soya bean.
Traditional soy products have raised very few questions regarding their negative impact on health. However, as supermarkets have introduced more and more genetically modified soy products, science has had some questions.
Most of the claims that it can have a negative impact on our health is related to this ‘second generation’ soy; this includes things such as ‘hot-dogs’, tofu burgers and soy-based cheeses or yoghurts.
So, what does science have to say on the matter?
In recent years various studies have been conducted trying to answer the question of is soy bad for you.
Here are some of the most prominent health claims and whether research supports or disproves them.
Claim 1: Soy has a negative impact on thyroid activity
The Science: 14 recent studies conducted on humans revealed that soy products had little (if any) effect on thyroid activity in adults that had a normally functioning thyroid to begin with.
It should be noted that none of these studied directly focused on thyroid activity; however, it was monitored, and no change was seen.
Claim 2: Soy can have a negative impact on heart health
The Science: In terms of the impact soy has on heart health, a meta-analysis did bring together a number of studies that showed that those who ate more soy foods had a lower risk of heart disease.
However, the association between soy products and reduced risk of cardiovascular disease was very weak – basically, it could have come down to loads of different factors.
One thing it does show is that those who did consume more soy did not see a negative impact on their heart health.
Take from that what you will…
Claim 3: Soy can lower testosterone
The Science: Let’s be honest, this is perhaps the most famous controversy surrounding soy. Way back in 2007, a study carried out by the Harvard School of Public Health showed that soy consumption could impact testosterone. Another study in 2011 had very similar results.
However, fear not, you don’t need to throw your soy milk down the drain just yet!
The first of these studies was conducted on overweight-obese men and the second study was conducted on one man who also had type-one diabetes. Basically, once again, we can’t conclusively put the changes in health down to soy.
A more recent meta-analysis showed these earlier studies to be misguided, revealing that soy had little to no impact on testosterone or fertility if not consumed in excess.
Claim 4: Soy can strengthen your bones
The Science: Recent studies have shown that this claim might actually be valid. Researchers believe that soy might have positive impacts on female bone strength and help to counter the negative effects of the menopause.
No harm in protecting yourself for the future, right?
So, what can we take from this?
Soy is quite literally under the microscope at the moment and, if anything, recent studies have had some pretty positive results.
Just as with anything else, soy products should be consumed in moderation,especially those that have been genetically engineered.