Boron in Human Health: Evidence for Dietary Recommendations and Public Policies

Abstract

For over twenty years boron has been of interest to investigators confirming the safety and essentiality of the element in humans. Fruits, vegetables, nuts, and pulses are natural sources of boron in the diet which world wide averages about 1-3 mg daily for most adults. In boron-rich regions of Turkey drinking water sources with 29 mg boron/liter are consumed without harmful effects. The European Union established a safe drinking water standard of 1.0 mg boron/ litre a level difficult for some regions to achieve. Safe standards are difficult to establish due to limited information and widely varying boron concentrations in food and water, high exposures in boron-rich regions or occupational settings and voluntary intakes, for example, of boron containing products. Current research implicates boron as an essential nutrient in humans demonstrating healthful effects in cellular functions associated with osteoporosis, arthritis, inflammation and cancer. Proposed mechanisms of action implicate that boron, found in cells as boric acid, participates in important membrane functions and intracellular signaling cascades. Traditionally, biochemical mechanisms associated with health- fully beneficial effects are needed for nutrients to meet the criteria for essentiality in humans. While boron meets the traditional criteria to be determined essential in humans the research process has provided additional insight into essential- ity for boron insight that essentiality for trace elements may based on different criteria. The study of boron in living systems provides a more fundamentally important role by demonstrating functions for trace elements differing from those needed to confirm essentiality previously for carbon based compounds, i.e., carbohydrates, lipids, proteins, and vitamins in human nutrition. To conclude, boron can be a model element to introduce a new field of study, elementomics. Further studies from boron-rich areas are needed to determine essentiality, dietary requirements, metabolic functions, therapeutic applications, economic benefits and important public policies for boron, a biologically important trace element.