The Big Picture: Groundbreaking news on boron's nutritional essentiality
by James R. Coughlin, Ph.D.
February 1998

What role does boron play in the delicate balance of animal and human life? Finding a more complete answer was the task that brought together the world's foremost experts on boron and borates - including university researchers, government regulators and producers. These specialists met at the National Academies of Sciences and Engineering in Irvine, California, U.S., in October 1997 at the Second International Symposium on the Health Effects of Boron and its Compounds. James Coughlin, leading nutritional expert and former director of Kraft General Foods, reports.

Not since the First International Symposium, held five years earlier, has such an authoritative group convened to discuss today's knowledge about the fifth element on the periodic table and to determine tomorrow's research needs. In 1992, U.S. Borax and University of California, Irvine's College of Medicine sponsored the first event. From it came a snapshot of what was known about the toxicological, pharmacological and nutritional aspects of boron. This first symposium also sparked worldwide interest in a range of scientific research and set the stage for a much more comprehensive second symposium.

One significant evolution from the first to the second symposium was the greater number and diversity of organizations that came to the table as sponsors.

Government agencies charged with protecting public health recognized the benefit of learning the latest scientific information about boron. In fact, some of their own scientists have been actively engaged in advancing the frontiers of borate science. So it made sense that the Department of Agriculture (USDA), the Environmental Protection Agency (USEPA) and the Food and Drug Administration (USFDA) joined the roster of sponsors for the second symposium.

The world's leading borate producers - including Borax, Etibank and North American Chemical Company - also put their active support behind this second symposium, gaining access to what the world's leading researchers have uncovered, and sharing insight into operational and production exposure scenarios.

Finally, the academic sponsorship list expanded to include the medical faculty of Turkey's Ankara University, while participants burgeoned to nearly 150 experts from eleven countries - all gathered to share research findings and methodologies about boron and to set the research agenda for the future.

Breakthrough in nutritional essentiality: A 'star' is born

If the first symposium breakthrough had to do with who came, the second - and most exciting breakthrough - had to do with what came out of the symposium.

The second symposium reviewed the historical research - from the chemistry and environmental occurrence of boron to its nutritional essentiality and toxicology - in just three days. But the newest findings had to do with boron's nutritional essentiality: research presented at the symposium promises to significantly influence how boron's role as a beneficial nutrient may be recast as an essential nutrient. In fact, as symposium co-chair and former USDA Director of Human Nutrition Walter Mertz, M.D. put it, symposium participants "witnessed the birth of a new trace element that is essential in non-mammalian vertebrate species."

Echoing that sentiment was Janet C. King, Ph.D. director of USDA's Western Human Nutrition Research Center and former chair of the National Academy of Science/Institute of Medicine's (NAS/IOM) Food and Nutrition Board (the group that sets Recommended Dietary Allowances or RDAs for nutrients), who named boron "a new star in the field of nutrition."

How was the new 'star' born? The latest and very promising assessment has to do with three areas: new research regarding dietary intake of boron, the specific role boron plays in normal reproduction and development, and the further research needed to formalize boron's scientific status as an essential element.

Dietary intake

An understanding of normal boron intake is a vital first step to research regarding the practical nutritional importance of boron and to aid in the establishment of an RDA for humans.

New research in this area included two studies. First, Susan L. Meacham, Ph.D. from the Department of Human Nutrition at South Carolina's Winthrop University, and Curtiss D. Hunt, Ph.D. from USDA Grand Forks, North Dakota, measured the boron concentrations of more than 200 commonly consumed foods. They determined the boron intake of various populations in the United States was about a milligram per day.

Second, Charlene Rainey of the Nutrition Research Group presented findings from a five-country study including the United States, Germany, Egypt, Kenya and Mexico to get a more complete picture of customary boron consumption the world over.

Together, the two research reports determined the boron intake of more than 30,000 people around the world. They also recorded the boron content of hundreds of different foods and found that fruits, vegetables, nuts and legumes are the largest contributors.

Function and essentiality

Beyond understanding how much boron is in a healthy diet, researchers also looked at exactly what role boron plays in maintaining and promoting health. At the first symposium, Forrest H. Nielsen, Ph.D. and Dr. Curtiss Hunt of the USDA - the first scientists to study boron's beneficial effects - showed how boron is nutritionally important for humans.

However, it had become apparent that to convincingly demonstrate boron's nutritional essentiality, researchers would have to show that insufficient boron in the diet results in adverse health effects - from those that severely interfere with an organism's quality of life to those that result in death. To accomplish this objective, Borax sponsored new research about how boron impacts the reproduction, early embryonic development and growth of frogs, fish and rodents.

Although boron's importance in energy metabolism, bone health and strength, and brain function, has been established, its impact on reproduction and development constitutes new scientific knowledge. This new knowledge provides a more complete picture of boron's specific functions and builds a firm foundation upon which daily intake requirements can be determined.

At the second symposium, Curtis D. Eckhert, Ph.D. of the University of California, Los Angeles, reported on studies involving zebra fish which demonstrated that boron deficiency significantly reduces embryo survival rate, and that embryonic death begins very early in the post-fertilization period in the absence of sufficient boron.

Another research project presented at the symposium involved a multi-phased study to evaluate the impact of very low boron intake on the growth, development and reproductive performance of frogs. Douglas J. Fort, Ph.D. of the Stover Group in Oklahoma, U.S., concluded that insufficient boron resulted in poor quality embryos - some dead and most developing poorly and dying early - in frogs.

Carl L. Keen, Ph.D. professor and chairman of the University of California, Davis' Department of Nutrition, investigated the potentially adverse effects of boron deficiency in mice and rats. Although the research data show an increase in death rates during early embryo development in rats and mice, these results are not as convincing as those conducted with frogs and fish. It has proven to be more difficult in these mammalian studies to effectively eliminate dietary boron to obtain a true deficiency state in the animals, but new studies will be underway shortly.

Future research

Despite the exciting research findings regarding essentiality, one of the most important functions of the second symposium was to draft a blueprint for future research needs, setting a course for research that is broader in scope and more precise in measurement.

The seeds of this research, planted at the second symposium, will be harvested at a third, and should coincide with the National Academy of Sciences/Institute of Medicine's Food and Nutrition Board setting new recommendations for the essentiality of trace elements like boron.

By all accounts, the second symposium set a new standard for understanding an element that is essential to modern industry, and made great strides towards determining its essentiality to all life on the planet.

Dr. Coughlin is an expert in nutritional toxicology and environmental safety. He is a former director of scientific and regulatory affairs at Kraft General Foods, the largest food company in the United States.