EarthSpin

Dogma vs. data: Rethinking linoleic acid

11/03/2022 by Stacy W. Kish

Humans have evolved to eat a variety of foods. No one component is entirely bad or entirely good. Many diets popular today, approach nutrition through a narrow, simplified lens. Every decade one component of our diet is placed center stage as the villain that is responsible for all of our woes. In recent decades, the spotlight has been turned on fats.

Fat is essential, providing a source of energy and a feeling of satiety. There are essential fatty acids that humans cannot produce, including linoleic acid (omega- 6) and alpha-linolenic acid (omega-3). Both fatty acids are obtained from the food we eat and play a critical role in major cellular events, including metabolism, inflammation, cell differentiation, and cell death. Some dietitians and nutritionists have advocated for eating an equal amount of omega-6 and omega-3 fatty acids, resulting in a 1:1 ratio. This diet is presumed to mimic the ancient human diet, though no definitive data supports what early humans actually ate consistently. The modern American diet ranges from a value of 10:1 to 15:1.

The overarching nutritional message has been that the modern diet suffers from an “omega imbalance.” The imbalance is a ‘concern,’ because omega-6 fatty acids, which skews the index to higher numbers, have been assumed to promote poor health outcomes and disease, including increased ‘bad’ cholesterol (LDL), inflammation, and coronary heart disease. Surprisingly, no randomized controlled clinical trials actually support any of these claims.

The concept of the omega-6:omega-3 ratio is “flawed and unhelpful,” says William Harris, professor of basic biomedical sciences at the University of South Dakota, in Vermillion, South Dakota, USA.

Harris is the founder and president of the Fatty Acid Research Institute, a non-profit research and education organization created to further the study of fatty acids and disease. To expand on Harris’s point, measuring the ratio is difficult because each fatty acid appears as various species in different ratios in different reservoirs in the body. According to Harris, this simple metric has “both theoretical and practical complications” that create fundamental misunderstandings that have cascaded through the field. He has published numerous articles describing the lack of scientific validation to support using this ratio as an indicator of healthful diet.

Martha Belury, Carol S. Kennedy professor of human nutrition in the Department of Human Sciences at the Ohio State University, Columbus, Ohio, USA, concurs with Harris’s assessment. She believes it is time to move away from the omega-6:omega-3 ratio and re-evaluate the benefits of the much maligned omega-6 fat.

“Science and health are short-changed if we oversimplify,” said Belury. “While omega-3 has an important role in health, omega-6 has a pivotal role to play as well. This is an important message for consumers and practitioners.”

Posted in Food, Nutrition and Health |

Mapping the Membrane: New proteomic technique reveals secrets of dendrite development

10/18/2022 by Stacy W. Kish

The research team mapped the surface proteins present in cerebellar purkinje cells and discovered key players in the growth and development of the cells’ elaborate dendritic arbors. Image courtesy Luo lab.

NeuroOmics technology lets researchers label and capture cell-surface proteins in intact, live tissue — opening opportunities to understand complex cellular interactions and future drug targets.

Purkinje cells are large neurons that form in the cerebellum, the small compact portion of the brain behind the cerebrum. Intricate, dendritic trees extend from each cell, forming a convoluted branching pattern that resembles a sea fan. Dysfunction of Purkinje cells has been linked to neurological symptoms, such as tremors, irregular muscle movement and hyperreactivity.

Purkinje cells’ elaborate dendrites play an integral role in neuronal communication, by receiving and integrating synaptic impulses that are coordinated by proteins scattered across the surface of the cell. Despite this integral role in neural computation, an understanding of the development of these elaborate dendrites remains elusive. A study published online in the October issue of Neuron applies a new technology to profile the proteins present on the surface of Purkinje cells to gain a better understanding of their role in dendrite development and neuronal communication.

Cell-surface proteins stick out of the cell membrane, like antennae on a building. By protruding into the surrounding environment, the proteins play a critical role in intercellular communication, like the highly orchestrated interactions between the different cell types in the nervous systems of mammals. Most techniques for studying these proteins are unable to quantify and profile the proteins in the diverse cell-type mosaic of the mammalian brain.

“Cell surface proteins are like little machines on the outside surface of cells that mediate communication between different types of cells,” said study lead author Andrew Shuster, a postdoc at Harvard University and former member of the Luo lab. “We were interested in developing a method to profile the entire coat of cell surface proteins in healthy tissue that has not been approachable by other methods.”

Posted in Medicine |

Hobby-Eberly Telescope reaches 25th anniversary milestone

10/17/2022 by Stacy W. Kish

The Hobby-Eberly telescope (HET) at The University of Texas at Austin’s McDonald Observatory has reached a milestone — 25 years of service. One of the world’s largest optical telescopes, the HET captures light from stars and distant galaxies to help astronomers solve the mysteries of the cosmos.

“This year marks an important milestone for the Hobby-Eberly telescope,” said Taft Armandroff, the Director of McDonald Observatory and HET Board Chair. “The HET provides the resources that our faculty, students, and researchers from partner institutions use to do cutting-edge science.”

First dedicated in 1997, the HET rotates on a cushion of air to train its 11-meter (433-inch) honeycombed mirror 55 degrees above the horizon to scan the universe. The telescope received an upgrade in 2016, expanding its field-of-view to capture a section of the night sky 120 times larger than before. With the upgrade, the HET has been instrumental in some remarkable discoveries.

Posted in Physics |

Fish Heads, Fish Heads: For Biosurfactant Production

09/19/2022 by Stacy W. Kish

Biosurfactants are compounds produced by some bacteria that replicate the properties of petroleum-based surfactants.
While many research studies have explored different bacteria grown on different medium, fish waste is proving to be a viable option to grow microbes for industrial-scale biosurfactant production.
The Scottish start-up company, Eco Clean Team, has partnered with a researcher at the University of St. Andrews to develop a pilot project for scaling biosurfactant production with fish oil from the local aquaculture industry.
While many hurdles remain, the biosurfactant industry and fish peptone industry are both on the upswing.

In 2010, Deep Water Horizon released over 130 million gallons of oil, the equivalent to 200 Olympic-sized swimming pools, into the Gulf of Mexico. Twenty years earlier, the Exxon Valdez oil tanker ran aground in Alaska, releasing 11 million gallons of oil into Prince William Sound.

Oil spills harm marine plants and animals, and render seafood unsafe to eat. Environmental remediators apply different techniques, including skimming and burning, to remove oil pollution from the water’s surface; however, synthetic dispersants created using petrochemicals, paradoxically, are the best means of clean-up. They reduce the opportunity for the contaminant to reach the shoreline by dispersing the oil and breaking it up into smaller droplets that are easier for microbes to consume. However, research shows synthetic surfactants are often toxic to marine organisms, changing their behavior, physiology, and reproduction patterns. These adverse effects raise concerns about which is worse for the environment — the dispersants applied to break up an oil slick or the oil itself.

Synthetic surfactants are a common class of molecules found in laundry and dishwashing detergents, among other household products. They are ubiquitous in our lives, yet they rarely garner the negative attention of an oil spill, because they are typically unseen. Although, in many instances synthetic surfactants are more pervasive and insidious to the environment.

Posted in Blinding People with Science, Food |

« Newer Posts - Older Posts »