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Glucose restriction can extend normal cell lifespan and impair precancerous cell growth through epigenetic control of hTERT and p16 expression. Li Y, Liu L, Tollefsbol TO. FASEB J. 2009 Dec 17. [Epub ahead of print] PMID: 20019239 doi: 10.1096/fj.09-149328 Cancer cells metabolize glucose at elevated rates and have a higher sensitivity to glucose reduction. However, the precise molecular mechanisms leading to different responses to glucose restriction between normal and cancer cells are not fully understood. We analyzed normal WI-38 and immortalized WI-38/S fetal lung fibroblasts and found that glucose restriction resulted in growth inhibition and apoptosis in WI-38/S cells, whereas it induced lifespan extension in WI-38 cells. Moreover, in WI-38/S cells glucose restriction decreased expression of hTERT (human telomerase reverse transcriptase) and increased expression of p16(INK4a). Opposite effects were found in the gene expression of hTERT and p16 in WI-38 cells in response to glucose restriction. The altered gene expression was partly due to glucose restriction-induced DNA methylation changes and chromatin remodeling of the hTERT and p16 promoters in normal and immortalized WI-38 cells. Furthermore, glucose restriction resulted in altered hTERT and p16 expression in response to epigenetic regulators in WI-38 rather than WI-38/S cells, suggesting that energy stress-induced differential epigenetic regulation may lead to different cellular fates in normal and precancerous cells. Collectively, these results provide new insights into the epigenetic mechanisms of a nutrient control strategy that may contribute to cancer therapy as well as antiaging approaches.

A signalling pathway that influences how sensitive cancer cells are to the beneficial effects of dietary restriction is described in this week's Nature. Dietary restriction - eating less calories while maintaining essential vitamins and minerals - can extend lifespan, and reduce cancer incidence and growth. But some types of cancer cell are more sensitive to the anti-growth effects of dietary restriction than others, Nada Kalaany and David Sabatini report. The effect hinges on the activity of the phosphatidylinositol-3-kinase (PI3K) pathway. If the pathway is active, dietary restriction has no effect on cancer cells. However, if the pathway is inactive, tumours are sensitive to dietary restriction.

DURHAM, N.C. -- Restricting carbohydrates, regardless of weight loss, appears to slow the growth of prostate tumors, according to an animal study being published this week by researchers in the Duke Prostate Center. "Previous work here and elsewhere has shown that a diet light in carbohydrates could slow tumor growth, but the animals in those studies also lost weight, and because we know that weight loss can restrict the amount of energy feeding tumors, we weren't able to tell just how big an impact the pure carbohydrate restriction was having, until now," said Stephen Freedland, M.D., a urologist in the Duke Prostate Center and lead investigator on this study. The researchers believe that insulin and insulin-like growth factor contribute to the growth and proliferation of prostate cancer, and that a diet devoid of carbohydrates lowers serum insulin levels in the bodies of the mice, thereby slowing tumor growth, Freedland said.

Studies have shown that eating a diet that is low in calories can lead to a longer and healthier life. This is known as the Calorie Restriction Optimal Nutrition (CRON) or Calorie Restriction diet (CR). This does not mean a starvation diet, since that would be the opposite of healthy.

Calorie Restriction Diet Plan is being promoted by many medical experts to maintain body weight and size. Calorie restriction diet seems to be one of the most popular diets and it seems to be backed up by great medical results. This is different from fads

Hara hatchi bu, the Okinawan people's habit of eating only till they are 80 percent full, is thought to be one of the secrets of their extraordinary health and longevity. In addition to one of the highest percentages of people in the world who live past 100, Okinawans appear to be less prone to heart disease, diabetes and obesity. Indeed, ever since it was discovered in the 1930s that laboratory rats fed a caloric-restricted (CR) diet lived almost twice as long as their well fed counterparts, scientists have pursued caloric restriction research in the hopes of finding novel strategies for extending human life and preventing disease. Given the growing older population at risk for memory problems and the rising rates of obesity, the role of diet in maintaining peak brain performance has taken on added importance.

ScienceDaily (May 26, 2009) - A protein that plays a key role in tumor formation, oxygen metabolism and inflammation is involved in a pathway that extends lifespan by dietary restriction. The finding, which appears in the May 22, 2009 edition of the online journal PLoS Genetics, provides a new understanding of how dietary restriction contributes to longevity and cancer prevention and gives scientists new targets for developing and testing drugs that could extend the healthy years of life.

"Researchers from the University of Alabama at Birmingham (UAB) have discovered that restricting consumption of glucose, the most common dietary sugar, can extend the life of healthy human-lung cells and speed the death of precancerous human-lung cells, reducing cancer's spread and growth rate. The research has wide-ranging potential in age-related science, including ways in which calorie-intake restriction can benefit longevity and help prevent diseases like cancer that have been linked to aging, said principal investigator Trygve Tollefsbol, Ph.D., D.O., a professor in the Department of Biology. "These results further verify the potential health benefits of controlling calorie intake." Tollefsbol said. "Our research indicates that calorie reduction extends the lifespan of healthy human cells and aids the body's natural ability to kill off cancer-forming cells.

"ScienceDaily (Dec. 17, 2009) - Researchers from the University of Alabama at Birmingham (UAB) have discovered that restricting consumption of glucose, the most common dietary sugar, can extend the life of healthy human-lung cells and speed the death of precancerous human-lung cells, reducing cancer's spread and growth rate. The research has wide-ranging potential in age-related science, including ways in which calorie-intake restriction can benefit longevity and help prevent diseases like cancer that have been linked to aging, said principal investigator Trygve Tollefsbol, Ph.D., D.O., a professor in the Department of Biology. "These results further verify the potential health benefits of controlling calorie intake." Tollefsbol said. "Our research indicates that calorie reduction extends the lifespan of healthy human cells and aids the body's natural ability to kill off cancer-forming cells.""

"ScienceDaily (Dec. 26, 2009) - Going back for a second dessert after your holiday meal might not be the best strategy for living a long, cancer-free life say researchers from the University of Alabama at Birmingham. That's because they've shown exactly how restricted calorie diets -- specifically in the form of restricted glucose -- help human cells live longer. They found that the normal cells lived longer, and many of the precancerous cells died, when given less glucose. Gene activity was also measured under these same conditions. The reduced glucose caused normal cells to have a higher activity of the gene that dictates the level of telomerase, an enzyme that extends their lifespan and lower activity of a gene (p16) that slows their growth. Epigenetic effects (effects not due to gene mutations) were found to be a major cause in changing the activity of these genes as they reacted to decreased glucose levels. "Western science is on the cusp of developing a pharmaceutical fountain of youth" said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "This study confirms that we are on the path to persuading human cells to let us to live longer, and perhaps cancer-free, lives.""

Eggs distinctly modulate plasma carotenoid and lipoprotein subclasses in adult men following a carbohydrate-restricted diet. Mutungi G, Waters D, Ratliff J, Puglisi M, Clark RM, Volek JS, Fernandez ML. J Nutr Biochem. 2009 Apr 13. [Epub ahead of print] PMID: 19369056 We previously reported that carbohydrate restriction (CR) (10-15% en) during a weight loss intervention lowered plasma triglycerides (TG) by 45% in male subjects (P<.05). However, only those subjects from the EGG group presented higher concentrations of these two carotenoids in plasma, which were correlated with the higher concentra

Dietary cholesterol from eggs increases plasma HDL cholesterol in overweight men consuming a carbohydrate-restricted diet. Mutungi G, Ratliff J, Puglisi M, Torres-Gonzalez M, Vaishnav U, Leite JO, Quann E, Volek JS, Fernandez ML. J Nutr. 2008 Feb;138(2):272-6. PMID: 18203890 Carbohydrate-restricted diets (CRD) significantly decrease body weight and independently improve plasma triglycerides (TG) and HDL cholesterol (HDL-C) . [..] Eighteen subjects were classified as having the metabolic syndrome (MetS) at the beginning of the study, whereas 3 subjects had that classification at the end. These results suggest that including eggs in a CRD results in increased HDL-C while decreasing the risk factors associated with MetS.

Eggs modulate the inflammatory response to carbohydrate restricted diets in overweight men. Ratliff JC, Mutungi G, Puglisi MJ, Volek JS, Fernandez ML. Nutr Metab (Lond). 2008 Feb 20;5:6. PMID: 18289377 Carbohydrate restricted diets (CRD) consistently lower glucose and insulin levels and improve atherogenic dyslipidemia [decreasing triglycerides and increasing HDL cholesterol (HDL-C)]. We have previously shown that male subjects following a CRD experienced significant increases in HDL-C only if they were consuming a higher intake of cholesterol provided by eggs compared to those individuals who were taking lower concentrations of dietary cholesterol. Here, as a follow up of our previous study, we examined the effects of eggs (a source of both dietary cholesterol and lutein) on adiponectin, a marker of insulin sensitivity, and on inflammatory markers in the context of a CRD. Conclusion A CRD with daily intake of eggs decreased plasma CRP and increased plasma adiponectin compared to a CRD without eggs. These findings indicate that eggs make a significant contribution to the anti-inflammatory effects of CRD, possibly due to the presence of cholesterol, which increases HDL-C and to the antioxidant lutein which modulates certain inflammatory responses.

Tumours with PI3K activation are resistant to dietary restriction. Nada Y. Kalaany & David M. Sabatini Nature. Published online 11 March 2009 doi:10.1038/nature07782

Demark-Wahnefried W, Price DT, Polascik TJ, Robertson CN, Anderson EE, Paulson DF, Walther PJ, Gannon M, Vollmer RT. Pilot study of dietary fat restriction and flaxseed supplementation in men with prostate cancer before surgery: exploring the effects o

Looking at journals of animal farm science, studies for increasing USDA Grades of beef and Marbling Scores (MS) have yielded some interesting perspectives regarding vitamin A and its role in controlling obesity. Do Americans get enough vitamin A? The beef industry has figured out that better grades and thus higher market value can be achieved by restricting vitamin A in the food fed to commercial cows. In fact, by depleting liver stores and restricting the content in food, the grade of meat and percentage of intramuscular (IM) fat increase quite substantially. Better yield for livestock owners. Higher levels of blood glucose (BG) are also associated with lower vitamin A status and higher marbling.

Increased dietary protein consumed at breakfast leads to an initial and sustained feeling of fullness during energy restriction compared to other meal times. Heather J. Leidy, Mandi J. Bossingham, Richard D. Mattes and Wayne W. Campbell British Journal of Nutrition (2009), 101:798-803 Cambridge University Press doi:10.1017/S0007114508051532

Pilot study of dietary fat restriction and flaxseed supplementation in men with prostate cancer before surgery: exploring the effects on hormonal levels, prostate-specific antigen, and histopathologic features.\nDemark-Wahnefried W, Price DT, Polascik TJ, Robertson CN, Anderson EE, Paulson DF, Walther PJ, Gannon M, Vollmer RT.\nUrology. 2001 Jul;58(1):47-52.\nPMID: 11445478 \ndoi:10.1016/S0090-4295(01)01014-7  

Calorie-restricted diets are thought to protect against cancer and slow tumor growth, and a new study published in this week's Nature begins to tease out why the measure works for some tumors, and not for others. For almost a century, researchers have known that fasting helps animals live longer and avoid some cancers, "but which type of cancers would be amenable to this approach, from a therapeutic standpoint, is still an open question," said Pier Paolo Pandolfi, a cancer geneticist at Harvard Medical School and Beth Israel Deaconess Cancer Center in Boston, Mass., who was not involved in the study. The study is exciting because it is one of the first to start answering that question at the genetic level, he said.

Long-term consumption of a carbohydrate-restricted diet does not induce deleterious metabolic effects. Grieb P, K?apcin'ska B, Smol E, Pilis T, Pilis W, Sadowska-Krepa E, Sobczak A, Bartoszewicz Z, Nauman J, Stan'czak K, Langfort J. Nutr Res. 2008 Dec;28(12):825-33. PMID: 19083495 doi:10.1016/j.nutres.2008.09.011 These results indicate that long-term (>1 year) compliance with a low-CHO high-fat "optimal diet" does not induce deleterious metabolic effects and does not increase the risk for cardiovascular disease, as evidenced by maintenance of adequate glycemic control and relatively low values for conventional cardiovascular risk factors.