The findings are reported by Mari Hakala and Paul Breslin of Monell Chemical Sciences Center in Philadelphia, Pennsylvania and appear in the September 19th issue of Current Biology, published by Cell Press.
Compounds known as glucosinolates are present in a variety of vegetables included in the human diet (especially Cruciferous vegetables), but these compounds can block the formation of organic iodine and the transport of iodine into the thyroid. Iodine is necessary for proper thyroid function, and in geographic regions where inorganic iodine levels are low, endemic goiter (enlarged thyroid) can arise in response to the need to maintain levels of thyroid hormone. In such circumstances, thyroid toxins such as glucosinolates can exacerbate problems with thyroid function. Deficiencies in thyroid function can result in retarded sexual maturation and mental retardation in low-iodine regions (typically, remote areas far from the sea).
Past work has suggested that evolution of the TAS2R family of bitter taste receptors has been shaped by the potential advantage of avoiding certain toxic compounds in plants, but the evidence thus far has been based on findings that used synthetic bitter compounds. For example, past work showed that people possessing genetically different versions of a particular TAS2R receptor exhibit correspondingly different sensitivities to the bitter compounds phenylthiocarbamide (PTC) and propylthiouracil (PROP), which resemble glucosinolates.
In the new work, researchers were able to show that different genetic versions of this same receptor, known as hTAS2R38, specifically determine people's perception of plants that synthesize glucosinolates. In their experiments, the researchers divided a test array of vegetables into those that contain glucosinolates, such as broccoli and turnips, and those that do not contain known glucosinolates. The researchers found that individuals possessing two copies of a "sensitive" version of the hTAS2R38 gene rated the glucosinolate-containing vegetables as 60% more bitter than did subjects possessing two copies of an "insensitive" version of the receptor gene. In comparison, individuals possessing one copy of each version of the gene rated the bitterness of glucosinolate-containing vegetables at an intermediate level.
The researchers found that the differences in bitterness perception by the "sensitive" and "insensitive" hTAS2R38 groups reached statistical significance for six vegetables: watercress, mustard greens, turnip, broccoli, rutabaga, and horseradish.
Though iodine supplementation aids significantly in ameliorating thyroid problems in low-iodine areas, the researchers note that over 1 billion people worldwide are at risk, in principle, for thyroid insufficiency--this reflects the likelihood that strong selective pressures in the past have shaped our ability to detect anti-thyroid compounds and avoid them, especially in low-iodine regions. The new findings illustrate the importance of individual taste receptor genes in shaping our perception of foods and, the researchers point out, show that variation in even a single gene can impact how people perceive an entire family of vegetables.
Heidi Hardman | EurekAlert!
Scientists enlist engineered protein to battle the MERS virus
22.05.2017 | University of Toronto
Insight into enzyme's 3-D structure could cut biofuel costs
19.05.2017 | DOE/Los Alamos National Laboratory
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.
Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...
22.05.2017 | Event News
17.05.2017 | Event News
16.05.2017 | Event News
22.05.2017 | Materials Sciences
22.05.2017 | Life Sciences
22.05.2017 | Physics and Astronomy