We are searching data for your request:
Obesity: Membranes of fat cells determine health risks
Being overweight, i.e. obese, can have serious health consequences. A Finnish twin study analyzed the effects of body fat on health, focusing on the so-called metabolic syndrome.
Obesity is considered a critical risk factor for a variety of diseases. The so-called metabolic syndrome is particularly dangerous for overweight people, which is characterized by obesity, high blood pressure (hypertension), insulin resistance (consequence of type II diabetes) and changes in blood fat values (dyslipidemia). Researchers at the VTT Technical Research Center of Finland have now unraveled the mechanism by which an increased body fat percentage promotes the occurrence of the metabolic syndrome.
In the long-term study with 21 pairs of Finnish twins, one of whom was overweight, the researchers at the VTT Technical Research Center of Finland analyzed the effects of body fat on health. The connection with the occurrence of the metabolic syndrome was a focus of the investigation. The researchers found that the individually different adaptability of the fat cell membrane plays a key role in the health problems caused by overweight and obesity. In the next step, the researchers hope to be able to influence the adaptability of the membrane of the fat cells, because in their investigations they also discovered a gene that causes the cell membrane to reshape.
Different membrane structures for overweight and nominal weight According to the researchers at the VTT Technical Research Center of Finland, the changes in the fat cells form the basis for the negative health consequences of being overweight and obese. As part of their study with 21 pairs of Finnish twins, the VTT scientists found out how the altered fat cells can lead to serious health problems. The connection with the metabolic syndrome, which is the main risk factor for cardiovascular diseases and heart attacks in Germany, formed a focus of the study. Since the participating identical twins were equipped with the same genetic makeup, genetic influences could be largely excluded. The researchers found that the membrane structure of the fat cells in the overweight twins differed significantly from their leaner siblings. While the diet of the overweight twins contained significantly smaller amounts of polyunsaturated fatty acids than their siblings, the proportion of unsaturated fatty acids in their fatty tissue was unexpectedly significantly higher than that of the leaner study participants, the scientists report in the online edition of the specialist magazine "PLoS Biology".
Cell membranes in overweight people are restructured. Since the identified polyunsaturated fatty acids have a significant influence on the membrane structure of the fat cells and help to increase elasticity and permeability, the researchers suspect that "it is a coping mechanism" with the help of which it functions the cell membrane should be preserved even when the cells are extremely expanded. Although the membrane structure of the overweight and slim twins was fundamentally different, the VTT researchers were unable to find any differences in functionality. The experts explained that due to the increased proportion of unsaturated fatty acids in the cell membranes, their function was retained even in the overweight. However, additional analyzes show that the adaptability of the cells can only be guaranteed to a certain point and that the functionality of the membrane breaks down at the latest with the onset of the metabolic syndrome, report Matej Orešič from the VTT Technical Research Center of Finland and colleagues.
Omega-6 fatty acids favor the occurrence of inflammation.Although none of the overweight twins examined had already developed a metabolic syndrome, the excessive or incorrect intake of food increased the formation of fat deposits on the legs, hips, abdomen and buttocks - excess nutrients were found in the fat cells of the Body stored. The lipids contained in the cell membranes determine, among other things, the permeability and adaptability of the membrane. The higher the proportion of polyunsaturated fatty acids in the membrane structure, the higher the permeability. According to the researchers at the VTT, a distinction must be made between the various unsaturated fatty acids. Thus, with the help of the increased omega-6 fatty acid content in the cell membranes of the overweight people, the functionality can be maintained, but the omega-6 fatty acids in turn cause a significant proportion of the negative health effects of being overweight, report the VTT researchers. Unlike the omega-3 fatty acids in the cell membranes of the normal-weight study participants, the omega-6 fatty acids act as messenger substances in the human organism that trigger a defense reaction. This promotes inflammation in the body - especially in the fatty tissue - which in turn can lead to further health impairments, write Matej Orešič and colleagues.
Individual differences in the membranes of the fat cells According to the researchers, there are significant individual differences in the response of the fat cells to the increased food intake. “We think it is likely that the threshold of the cells is genetically determined,” explained the VTT experts. Both the restructuring of the cell membrane and the maximum storage capacity of the fat cells vary from person to person, which also explains why some overweight people have significant health problems, while others live relatively carefree with their fat deposits. Once the membrane of the fat cells has reached its capacity limit, the fat cells cannot absorb any more nutrients and the excess fat is stored in other organs such as muscles, liver or pancreas. Fat metabolism disorders are one of the consequences and those affected are at risk of metabolic syndrome in the long term, the experts report. According to Kirsi H. Pietiläinen (Obesity Research Unit, Helsinki University Central Hospital), Antonio Vidal-Puig (University of Cambridge) and Matej Orešič, this is associated with numerous health risks - especially in the area of cardiovascular diseases.
Preventing the restructuring of the fat cell membrane But even before the membrane of the fat cells reaches its limits, there is obviously a restructuring at the level of the unsaturated fatty acids contained. According to the international team of researchers led by Matej Orešič, the functionality of the membrane can be maintained despite the considerable expansion, but the increased omega-6 fatty acid concentration in turn promotes the occurrence of inflammation - especially in the adipose tissue of the human organism. The “coping mechanism” therefore has a serious disadvantage: “There is an increase in inflammation”, which in turn is considered an essential factor in the development of the metabolic syndrome, explained Matej Orešič. According to the researchers, maintaining a healthy membrane structure of the fat cells is therefore crucial in order to minimize the health risks of being overweight. Even in obese people, the cell membrane should predominantly contain omega-3 fatty acids instead of the health-threatening omega-6 fatty acid. According to the VTT researchers, what may seem difficult to influence at first glance may soon be possible. Because Matej Orešič and colleagues were able to identify a gene in their study that can cause a restructuring of the cell membrane. "The big news is that we can manipulate the process," concluded the international research group in the online edition of the specialist magazine "PLoS Biology". (fp)
Bowel type crucial for obesity?
Being overweight can promote cancer
Infants: Vials increase risk of being overweight
Naturopathy: birch bark against obesity
Gerd Altmann / Dieter Petereit, Pixelio.de