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, 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 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 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.