Science headlines, Dec 2009 — See the full post at http://www.nutritioninvestigator.org/. There you will find links to published articles.
SUMMARY -
1. How inflammation causes cancer – [Remember trans-fats in margarine, food from 4-legged animals, and stress all contribute to inflammation] Switching normal cells into a transformed phenotype that is characterized by uncontrolled growth is central to the development of cancer. Iliopoulos et al. describe an epigenetic switch: a stable phenotypic change, retained through multiple generations in proliferating cells, which is not due to changes in DNA sequence. Immortalized cells from mammary epithelial tissue were transformed by overexpressing Src, a protein tyrosine kinase; activation of Src for just 5 min produced cells that adopted a transformed phenotype and maintained it for at least 12 generations. Activating Src led to an increase in activity of the transcription factor NF-B, a central mediator of inflammatory responses. A key target of NF-B in this system was Lin28, an RNA-binding protein that inhibits the accumulation of the microRNA let-7. In turn, let-7 reduces levels of interleukin-6 (IL-6), an inflammatory cytokine thought to contribute to human cancers. IL-6 signals through its receptor to activate NF-B, thus creating a positive feedback loop. Disruption of any step in the loop resulted in loss of transformation. The authors note that the signaling events defined in this study are known to be associated with certain human cancers. Thus, the epigenetic switch they describe could allow a transient inflammation to produce a long-lasting cancerous effect analogous to mutation of a tumor suppressor gene or activation of an oncogene.
2. Diet of your personal ancestors reduces your risk of diabetes and heart disease – What’s for Dinner? Researchers Seek Our Ancestors’ Answers, Ann Gibbons- Sixteen researchers from multiple disciplines chewed on the question of whether there is an ideal diet for humans as part of a recent workshop on evolution and modern diseases. Those focusing on diet hoped to test the common belief that diseases such as obesity, diabetes, and high blood pressure arise because our bodies are poorly adapted to the modern diet, rich in fat, sugar, and salt. After comparing emerging evidence from ancient humans and diverse modern cultures, the researchers concluded that many factors—including genes, sex, ancestry, and fetal and childhood conditions—influence how we digest foods and store fat. Physiological stress in mothers can leave lingering imprints on descendants for generations. So although it’s true that humans evolved to eat a diet relatively high in protein and low in carbohydrates and fat, there’s no single Paleolithic prescription for better health. The agricultural revolution favored people lucky enough to have gene variants that helped them digest milk, alcohol, and starch. Those mutations therefore spread among farmers. But other populations remained more carnivorous, such as the Saami of frigid northern Norway, whose ancestors herded reindeer. Among Saami ancestors, genes to digest meat and fat efficiently were apparently favored. One gene variant, for example, makes living Saami less likely to get uric acid kidney stones—common in people who eat high-protein diets—than are people whose ancestors were vegetarian Hindus and lack this gene variant… But when ethnic groups abandon traditional lifestyles and rapidly adopt Western diets, they often suffer.
3. Nation of flab – Obesity is edging ahead of smoking as a health hazard in the United States, say researchers at the National Bureau of Economic Research in Cambridge, Massachusetts.
A team led by Susan Stewart, a researcher who studies aging, has come up with some hard numbers on the skyrocketing problem: In the past 15 years, smoking has decreased by 20%, but the number of fat Americans has increased by 48%. By 2020, the team calculates that obesity will rob an 18-year-old of 0.7 years of life on average and 0.9 years of “quality of life.”
The average gain for an individual from not smoking—0.3 years—is more than offset by the loss of more than a year from weight gain, the authors reported last week in The New England Journal of Medicine. Even if obesity increases level off to as little as 0.15% per year, they’ll swamp overall gains from nonsmoking by 2020.
4. Nobelist Eric Kandel on cognitive therapy instead of antidepressants – [See the posters at Nutrition Investigator about the benefits of exercise and SAMe for good spirits in 2010] Q: You’ve said that the 20th century saw the merging of psychology and biology. What recent advances excite you? Until quite recently, there has been very little hard data [on the effectiveness of psychotherapy]. In the last 20 years, people have done … systematic studies that show that cognitive behavioral therapy is as good if not better than selective serotonin uptake inhibitors in moderate depression. Moreover, imagistic studies in obsessive-compulsive neurosis and depression have shown an abnormality in the brain. That’s remarkable progress.
Here’s a few longer stories to inspire New Year’s resolve to better health. Follow the links to full articles at Science magazine.
SUMMARY -
1. How inflammation causes cancer – [Remember trans-fats in margarine, food from 4-legged animals, and stress all contribute to inflammation] Switching normal cells into a transformed phenotype that is characterized by uncontrolled growth is central to the development of cancer. Iliopoulos et al. describe an epigenetic switch: a stable phenotypic change, retained through multiple generations in proliferating cells, which is not due to changes in DNA sequence. Immortalized cells from mammary epithelial tissue were transformed by overexpressing Src, a protein tyrosine kinase; activation of Src for just 5 min produced cells that adopted a transformed phenotype and maintained it for at least 12 generations. Activating Src led to an increase in activity of the transcription factor NF-B, a central mediator of inflammatory responses. A key target of NF-B in this system was Lin28, an RNA-binding protein that inhibits the accumulation of the microRNA let-7. In turn, let-7 reduces levels of interleukin-6 (IL-6), an inflammatory cytokine thought to contribute to human cancers. IL-6 signals through its receptor to activate NF-B, thus creating a positive feedback loop. Disruption of any step in the loop resulted in loss of transformation. The authors note that the signaling events defined in this study are known to be associated with certain human cancers. Thus, the epigenetic switch they describe could allow a transient inflammation to produce a long-lasting cancerous effect analogous to mutation of a tumor suppressor gene or activation of an oncogene.
2. Diet of your personal ancestors reduces your risk of diabetes and heart disease – What’s for Dinner? Researchers Seek Our Ancestors’ Answers, Ann Gibbons- Sixteen researchers from multiple disciplines chewed on the question of whether there is an ideal diet for humans as part of a recent workshop on evolution and modern diseases. Those focusing on diet hoped to test the common belief that diseases such as obesity, diabetes, and high blood pressure arise because our bodies are poorly adapted to the modern diet, rich in fat, sugar, and salt. After comparing emerging evidence from ancient humans and diverse modern cultures, the researchers concluded that many factors—including genes, sex, ancestry, and fetal and childhood conditions—influence how we digest foods and store fat. Physiological stress in mothers can leave lingering imprints on descendants for generations. So although it’s true that humans evolved to eat a diet relatively high in protein and low in carbohydrates and fat, there’s no single Paleolithic prescription for better health. The agricultural revolution favored people lucky enough to have gene variants that helped them digest milk, alcohol, and starch. Those mutations therefore spread among farmers. But other populations remained more carnivorous, such as the Saami of frigid northern Norway, whose ancestors herded reindeer. Among Saami ancestors, genes to digest meat and fat efficiently were apparently favored. One gene variant, for example, makes living Saami less likely to get uric acid kidney stones—common in people who eat high-protein diets—than are people whose ancestors were vegetarian Hindus and lack this gene variant… But when ethnic groups abandon traditional lifestyles and rapidly adopt Western diets, they often suffer.
3. Nation of flab – Obesity is edging ahead of smoking as a health hazard in the United States, say researchers at the National Bureau of Economic Research in Cambridge, Massachusetts.
A team led by Susan Stewart, a researcher who studies aging, has come up with some hard numbers on the skyrocketing problem: In the past 15 years, smoking has decreased by 20%, but the number of fat Americans has increased by 48%. By 2020, the team calculates that obesity will rob an 18-year-old of 0.7 years of life on average and 0.9 years of “quality of life.”
The average gain for an individual from not smoking—0.3 years—is more than offset by the loss of more than a year from weight gain, the authors reported last week in The New England Journal of Medicine. Even if obesity increases level off to as little as 0.15% per year, they’ll swamp overall gains from nonsmoking by 2020.
4. Nobelist Eric Kandel on cognitive therapy instead of antidepressants - [See the posters at Nutrition Investigator about the benefits of exercise and SAMe for good spirits in 2010] Q: You’ve said that the 20th century saw the merging of psychology and biology. What recent advances excite you? Until quite recently, there has been very little hard data [on the effectiveness of psychotherapy]. In the last 20 years, people have done … systematic studies that show that cognitive behavioral therapy is as good if not better than selective serotonin uptake inhibitors in moderate depression. Moreover, imagistic studies in obsessive-compulsive neurosis and depression have shown an abnormality in the brain. That’s remarkable progress.
Happy New Year!
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