In our more and more health-conscious society, a brand new fad eating regimen appears to pop up each few years. Atkins, Zone, Ketogenic, Vegetarian, Vegan, South Beach, Raw — with so many selections and scientific proof to again every, it is arduous to know what’s wholesome and what’s not. One message, nevertheless, has remained all through: saturated fat are unhealthy.
A brand new Columbia University examine reveals why.
While medical doctors, nutritionists and researchers have recognized for a very long time that saturated fat contribute to some of the main causes of dying within the United States, they have not been capable of decide how or why extra saturated fat, akin to these launched from lard, are poisonous to cells and trigger all kinds of lipid-related illnesses, whereas unsaturated fat, akin to these from fish and olive oil, may be protecting.
To discover solutions, Columbia researchers developed a brand new microscopy method that enables for the direct monitoring of fatty acids after they have been absorbed into residing cells. The method entails changing hydrogen atoms on fatty acids with their isotope, deuterium, with out altering their physicochemical properties and behavior like conventional methods do. By making the swap, all molecules constituted of fatty acids may be noticed inside residing cells by a complicated imaging method referred to as stimulated Raman scattering (SRS) microscopy.
What the researchers discovered utilizing this system could have vital impact on each the understanding and remedy of weight problems, diabetes and heart problems.
Published on-line December 1st in Proceedings of the National Academy of Sciences (PNAS), the staff studies that the mobile course of of constructing the cell membrane from saturated fatty acids leads to patches of hardened membrane by which molecules are “frozen.” Under wholesome circumstances, this membrane must be versatile and the molecules fluidic.
The researchers defined that the stiff, straight, lengthy chains of saturated fatty acids rigidify the lipid molecules and trigger them to separate from the remainder of the cell’s membrane. Under their microscope, the staff noticed that these lipid molecules then accumulate in tightly-packed “islands,” or clusters, that do not transfer a lot — a state they name “solid-like.” As extra saturated fatty acids enter the cell, these islands develop in dimension, creating growing inelasticity of the membrane and step by step damaging the complete cell.
“For a long time, we believed that all cell membrane is liquid-like, allowing embedded proteins to change their shape and perform reactions,” mentioned Principal Investigator Wei Min, a professor of chemistry. “Solid-like membrane was hardly observed in living mammalian cells before. What we saw was quite different and surprising.”
Lipid molecules constituted of unsaturated fatty acids alternatively bear a kink of their chains, Min mentioned, which makes it inconceivable for these lipid molecules to align intently with one another as saturated ones do. They proceed to maneuver round freely somewhat than forming stationary clusters. In their motion, these molecules can jostle and slide in between the tightly-packed saturated fatty acid chains.
“We found that adding unsaturated fatty acids could ‘melt’ the membrane islands frozen by saturated fatty acids,” mentioned First Author Yihui Shen, a graduate pupil in Min’s lab. This new mechanism, she mentioned, can partly clarify the helpful impact of unsaturated fatty acids and how unsaturated fat like these from fish oil may be protecting in some lipid issues.
The examine represents the primary time researchers had been capable of visualize the distribution and dynamics of fatty acids in such element inside residing cells, Shen added, and it revealed a beforehand unknown poisonous bodily state of the saturated lipid accumulation inside mobile membranes.
“The behavior of saturated fatty acids once they’ve entered cells contributes to major and often deadly diseases,” Min mentioned. “Visualizing how fatty acids are contributing to lipid metabolic disease gives us the direct physical information we need to begin looking for effective ways to treat them. Perhaps, for example, we can find a way to block the toxic lipid accumulation. We’re excited. This finding has the potential to really impact public health, especially for lipid related diseases.”
Materials offered by Columbia University. Note: Content could also be edited for type and size.