On a spring day after the storms have receded, farmers throughout America’s breadbasket plant acre upon acre of soybeans. The bean is a current staple of many farms, and it became a favored crop partly due to the effects of climate change. Image by Lynn Betts, USDA Natural Resources Conservation Service.
Soy, a legume with a long history, has seen an exponential increase of use in the last 35 years. Researchers find the bean to be an endless source of new paradigms for exploration.
The thrust to understand the soybean could not have come at a better time. North American cultivation of soy increased in acreage during the last 25 years, in part, due to climate change.
Soy is a subject of research in multiple disciplines (e.g. biofuels, medicinals, diet aids, and insecticides as well). The bean has been a staple in the Asian diet for thousands of years, and researchers from around the globe are attempting to unlock a boundless future.
Research on soy’s potential to help feed the world hinges upon understanding the effects of phytoestrogens.
Soy and Conflicting Health Benefits
When compared to the West, Asian communities suffer far fewer incidences of heart disease, cancer and dementia, and soy stands as one reason.
However, western cultures show limited dietary advantages when utilizing soy consistently. The reasons for the discrepancies seem mysterious.
Presently, using soy across the general population as a prophylaxis for heart disease, Alzheimer’s disease, and certain cancers may be years in the future, so plant scientists work feverishly to unlock the bean’s secrets.
Present phytochemicals associated with soy include tocopherol-type molecules (vitamin E), omega-fatty acids (the healthy fats), polyphenols (estrogen-mimics), and lesser amounts of other phytochemicals.
The benefits derived from the soybean reduce the effects of oxidative stress upon the body. Oxidative stress works by releasing damaging free radicals upon the body’s most sensitive parts—the circulatory system, the nervous system, and DNA.
The Phytochemicals of Soy—a Source for Confusion
A question puzzling researchers was: What are the major components in soy that battle the free radicals of oxidative stress? Presently, scientists regard the polyphenols as a major avenue addressing oxidative stress. However in the last 40 years, publications on the legume have given the benefits of soy a confusing picture.
Soy, Polyphenols, and Estrogen
The polyphenols possess endocrine-disrupting properties: The molecules behave similarly to estrogen. Although a complete inventory of soy’s polyphenols remains incomplete, two polyphenols and one metabolite standout: Genistein, Daidzen, and Equol (metabolite).
Genistein molecule is a molecular constituent of cancer chemotherapy and is major soy phytoestrogen. Molecule drawn with Chem Draw 14. Image copyright by John A. Jaksich, all rights reserved.
Genistein, the most common polyphenol component in soy, inhibits free radicals.
The medical establishment currently uses Genistein in cancer chemotherapy. Because the molecule is an estrogen-mimic, researchers believed it warranted further investigation.
Scientists discovered that Genistein could cross the blood-brain-barrier and induce biochemical changes in the brain.
The findings suggest genistein warrants closer scrutiny by the scientific community for other potential benefits.
Daidzen: Slows Tumor Growth Less Effectively
Daidzen molecule found in soy to a lesser degree than genistein. The molecule plays a role in tumor migration. Molecule drawn with Chem Draw 14. Image copyright by John A. Jaksich, all rights reserved.
Daidzen is one reason for the mixed picture given to the soybean.
Daidzen slows tumor growth less effectively than Genistein, so it doesn’t provide as much support for soy as a beneficial foodstuff or proactive nutrient.
However, when viewing the molecule, Daidzen, in the context of all the bean’s constituents and metabolites, there seems to be more to the picture.
Equol, a soy metabolite, is found in excess when the positive aspects of soy are present. Molecule drawn with Chem Draw 14. Image copyright by John A. Jaksich, all rights reserved.
Equol is the phytoestrogen metabolite of Daidzen that resembles the two prior molecules.
Equol is disproportionately found to a greater degree in individuals who benefit most from soy’s phyto-arsenal.
The metabolite influences the brain-gut axis; its presence in the GI tract aids in the way that the brain responds to soy.
Given the fact that many of soy’s phytochemicals remain uncategorized, scientists will not eliminate Daidzen or any other ‘molecule’ from the list of compounds that produce soy’s lasting effects.
When Will We Understand the True Benefits of the Soybean?
As scientists continue delving into the riches of soy, its universal use may come when we delineate how the gut-brain axis differs among those who eat the legume. Soy has been a diet staple for years, and its continued cultivation should reap answers.
Being a fitness guy, i would love to hear the opinion of meeting the daily dose of protein from soy , curd and legumes. in the bodybuilding world i hear a lot of chatter on soy inducing more estrogen into the blood and such. being one of the top biological value of 73. i think its a good source of protein, is there any digestion issue of consuming as much as 300 grams per day
Good day, Guptha!
You pose interesting questions. To the best of my knowledge, soy is well tolerated in men, but there may be a caveat or two. (Please consult your personal MD–I do not practice medicine.)
However, the complete avoidance of beef may pose problems in vitamin B-complex. The other issue deals with individuals diagnosed with hypothyroidism–of which (in men) I am unsure.
However, to the best of my knowledge, soy is well tolerated in men.
Best to you
John, You’ve certainly presented a lot of good information here. Soy has bombarded our consciousness since sometime in the 2nd half of the 20th century. You know it has to be good for many uses. Having said that, I’m not a fan. Not simply because of the GMO business, though that is disconcerting to me. But also because of soy’s association with uric acid, which substance is also associated with gout. And, besides, I don’t like it when any item out there is rather forced down our throats. Especially when it is done somewhat deceptively. For instance, you’ve doubtless noticed that there is this kind of generic cooking oil on your grocery shelf. Being of the same twist of mind as I am, you’ve doubtless read the label. Soybean oil. Why don’t they declare that openly on the bottle, instead of calling it “vegetable” oil? They feel people wouldn’t buy the oil if they knew it is soy. Sneaky, evasive tactics. Point made. Keep writing informative articles, old boy! We love ’em.
Coming from a purely non-scientific mind, my knowledge of soy is based on newspaper and magazine articles. I have also read that many scientists believe most, if not all, of the world’s soy is GMO, that there is no pure soy, and the problem with this is showing in children who are maturing early. My grandchildren’s pediatrician recommended soy milk when they struggled with breast milk and formula and I worry about early maturity and other problems I’ve read about in articles. Do you have any thoughts on soy as an alternative formula for babies and its possible long-term effects considering the GMO issue? What are your thoughts on the claims that there is no natural soy left, that it has all been genetically modified? (Please forgive me if I phrased this incorrectly–I’m not sure if I’m using the correct scientific terms here).
Good day, Darla!
While much of what you have mentioned is true, so my immediate thoughts for your grandchildren would be to get a second opinion in terms of soy-based formula. A good, prevention-focused MD would be able to address the issues.
Much of soy is GMO (greater than 60 percent). There seems to be ‘evidence’ that early-onset of puberty occurs in a certain percentage of children who consume soy–however there are many chemicals in the environment that mimic estrogen, as well.
I am sorry to hear that grandchildren are suffering,
John
Thank you for your help!
Soy may be all you say, but it is almost all GMO and carries a HUGE glyphosate residue with it rendering any benefits null.
Change that and your hopes may be realized.
Best Wishes,
Doug
Hello Mr. McKee,
The fact that soybeans have a ‘large’ weed-killer fingerprint tells me that technology is ‘doing its best’ to keep agriculture humming at increased efficiency. Considering what other alternatives may await–glyphosate is one of the safer bets. Scientists are human beings like you and me– we are not perfect nor do we wish harm upon our fellow-individuals.
It is bad that we continue to snipe at what one another because no can agree with the politics of the moment. Technology is all that we presently have to keep society from being fragmented further. If I knew of a way to keep any and all of us safe from bad aspects of the present world –I would be the first to do so. Otherwise, I do my best.
Thank you and best to you,
John
To say that almost all soy is GMO is true, but very deceptive. The vast majority of soy is not eaten by humans, but is used as animal feed and in industry. In terms of soy consumed by humans, non-GMO soy is quite prevalent (conventional and Organic options).