In the fight against obesity, powerful health officials want to see chain restaurants like McDonald's and Wendy's display calories on their menu boards. Lesley Stahl reports.
http://www.cbsnews.com/sections/i_video/main500251.shtml?id=3518744n
Thursday, November 22, 2007
Saturday, November 3, 2007
More evidence for caloric restriction
Severely restricting calories could lead to longer life
By Clarisse Douaud
A study out of the University at Buffalo has linked severely restricting calories to slowing the progression of physical disability in age, which could have lifespan implications if carried over to humans.The study, published in the October issue of Journals of Gerontology Series A: Biological Sciences and Medical Sciences, used a rat model of life-time caloric restriction. The researchers attributed this increased lifespan to a reduction in the visceral fat that can be responsible for inflammation leading to chronic disease.Not surprisingly, longevity and enhanced quality of life is the ultimate aim of most research into diet and nutrition, but very few studies actually achieve such a link. The trick now will be to see if it can be carried over to humans - something the researchers say is highly unlikely due to the extremely restrictive nature of such a diet."This is the first study to report that caloric restriction reduced production in visceral fat of the inflammatory cytokine IL-6 and enhanced performance on overall physical function assessments," said Tongjian You, assistant professor of exercise and nutrition sciences at UB School of Public Health and Health Professions and principal investigator in the study. Supported with grants from the National Institutes of Health (NIH), the study was conducted with male rats in three age groups. These ranged from 18, to 24 and 29 months, which are comparable to 50 to 70 years in humans.The rats were fed either a normal or 40-percent calorie-restricted diet from birth, and then put through tests to determine grip strength, muscle tone, stamina and swimming speed. In addition, data were collected on varying kinds of body mass and fat-to-lean ratios, as well as the amount of pro-inflammatory cytokines and the chronic inflammation marker, C-reactive protein.According to the study, the results indicated the animals on the restricted calorie diet had significantly higher physical performance scores than animals fed a normal diet. However, the researchers say these positive results are not likely to be carried over to humans, as it would be nearly impossible for people to keep such diets. A 40 percent reduction in calories daily - when translated to humans - means that an average diet of 2,000 calories per day for adult women and 2,500 for men would be cut to 1,200 or 1,500 calories per day."It's very difficult for people to maintain that type of diet for short periods of time, and it would be nearly impossible over a lifetime, while staying healthy," said You. "Starting on a diet like that in the senior years would be harmful." Still, a moderate caloric restriction would likely bring about positive effects on oxidative stress and inflammatory biomarkers - something which would could be worthy of further investigation in human trials."Preclinical testing of this 8-percent regimen could be informative and beneficial in translating to humans," said You.Located in Buffalo, New York, the University at Buffalo is the largest campus of the State University of New York.
By Clarisse Douaud
A study out of the University at Buffalo has linked severely restricting calories to slowing the progression of physical disability in age, which could have lifespan implications if carried over to humans.The study, published in the October issue of Journals of Gerontology Series A: Biological Sciences and Medical Sciences, used a rat model of life-time caloric restriction. The researchers attributed this increased lifespan to a reduction in the visceral fat that can be responsible for inflammation leading to chronic disease.Not surprisingly, longevity and enhanced quality of life is the ultimate aim of most research into diet and nutrition, but very few studies actually achieve such a link. The trick now will be to see if it can be carried over to humans - something the researchers say is highly unlikely due to the extremely restrictive nature of such a diet."This is the first study to report that caloric restriction reduced production in visceral fat of the inflammatory cytokine IL-6 and enhanced performance on overall physical function assessments," said Tongjian You, assistant professor of exercise and nutrition sciences at UB School of Public Health and Health Professions and principal investigator in the study. Supported with grants from the National Institutes of Health (NIH), the study was conducted with male rats in three age groups. These ranged from 18, to 24 and 29 months, which are comparable to 50 to 70 years in humans.The rats were fed either a normal or 40-percent calorie-restricted diet from birth, and then put through tests to determine grip strength, muscle tone, stamina and swimming speed. In addition, data were collected on varying kinds of body mass and fat-to-lean ratios, as well as the amount of pro-inflammatory cytokines and the chronic inflammation marker, C-reactive protein.According to the study, the results indicated the animals on the restricted calorie diet had significantly higher physical performance scores than animals fed a normal diet. However, the researchers say these positive results are not likely to be carried over to humans, as it would be nearly impossible for people to keep such diets. A 40 percent reduction in calories daily - when translated to humans - means that an average diet of 2,000 calories per day for adult women and 2,500 for men would be cut to 1,200 or 1,500 calories per day."It's very difficult for people to maintain that type of diet for short periods of time, and it would be nearly impossible over a lifetime, while staying healthy," said You. "Starting on a diet like that in the senior years would be harmful." Still, a moderate caloric restriction would likely bring about positive effects on oxidative stress and inflammatory biomarkers - something which would could be worthy of further investigation in human trials."Preclinical testing of this 8-percent regimen could be informative and beneficial in translating to humans," said You.Located in Buffalo, New York, the University at Buffalo is the largest campus of the State University of New York.
Tuesday, October 30, 2007
Is Lower Blood Cholesterol Really Better?
Dr. John Briffa
Special to The Epoch Times
Oct 17, 2007
Is it in their best interests to lower their cholesterol? Very few of us will not have noticed that the last couple of decades have seen a concerted effort from health agencies and health professionals to persuade us that we should be driving our cholesterol levels down to lower and lower levels. When I was at medical school the upper limit of cholesterol was 6.5 mmol/l (255 mg/l). But it's come down steadily since then and now stands at 5.0 mmol/l (195 mg/l). My suspicion is that it will fall even lower over the years. Who knows, it may get so low that practically everyone will be classified as having raised cholesterol, and be recommended to lower this with specialized food products and/or drugs.
However, since cholesterol is a constituent in the walls of cells in the body as well as steroid hormones, there is an issue for questioning whether lower really is better.
Some have suggested that low levels of cholesterol may predispose to health problems, including those that relate to brain function.
Last month saw the publication of a study in the journal, Neurobiology of Aging, in which Dutch researchers assessed the relationship between cholesterol levels and mental function in about 1,200 individuals aged 65 or over. The participants in the study were assessed over a six-year period. Lower blood cholesterol levels in this group were associated with a reduction in both general cognition and information processing speed. The authors of this study concluded: " … lower total cholesterol may be considered as a frailty marker, predictive of lower cognitive functioning in elderly." [1]
Of course with studies of this nature, it is impossible to know whether the low cholesterol itself is responsible for the associated poorer brain function. One way to assess this might be to attempt to lower cholesterol levels and see what it does to brain function. In one study, individuals treated with lovastatin (a cholesterol-reducing drug), compared to those taking a placebo, saw significant reductions in measures such as vigilance and general cognitive function [2]. This study, though, also tested the effect of another statin drug (pravastatin), which did not appear to have this same adverse effect on brain function.
Even if we take the apparent association between lovastatin and impaired brain function at face value, we do not know whether this was due to cholesterol lowering per se or some side effect of the medication.
Another study, though, adds further evidence to support the notion that lower cholesterol levels may impair brain function. In it, a low-fat diet was pitted against a standard diet over a 12-week period [3]. Over the course of the trial, the performance of a task that required sustained attention was significantly worse in individuals who had reduced their cholesterol. And the lower the cholesterol fell, the worse the performance in this test was.
Even if it turns out that cholesterol reduction is bad for the brain, I have no doubt that proponents of the lower cholesterol concept will point to other benefits of this endeavor. Yet I think it is worth bearing in mind that the evidence shows that in essentially healthy individuals, cholesterol reduction through drugs has not been shown to save lives. And dietary approaches do not appear to reduce funeral rates either, even in those with a history of cardiovascular disease.
Furthermore, there is at least some evidence showing that in later life, higher levels of cholesterol are actually associated with enhanced longevity [4–7]. In short, there is mounting evidence, I think, which suggests that as far as cholesterol is concerned, lower is not always necessarily better.
References:
1. Van den Kommer TN, et al. Total cholesterol and oxysterols: Early markers for cognitive decline in elderly? Neurobiology of Aging. 2007 Sep 19; [Epub ahead of print]
2. Roth T, et al. Comparative effects of pravastatin and lovastatin on nighttime sleep and daytime performance. Clinical Cardiology. 1992; 15:42–432
3. Wardle J, et al. Randomized trial of the effects of cholesterol-lowering dietary treatment on psychological function. American Journal of Medicine 2000; 108(7): 547–553
4. Brescianini S, et al. Low total cholesterol and increased risk of dying: are low levels clinical warning signs in the elderly? Results from the Italian Longitudinal Study on Aging. Journal of the American Geriatrics Society 2003; 51(7): 991–996
5. Forette B, et al. Cholesterol as risk factor for mortality in elderly women. Lancet, 1989; 1:868–870
6. Jonsson A, et al. Total cholesterol and mortality after age 80 years. Lancet, 1997; 350:1778–1779
7. Weverling-Rijnsburger AW, et al. Total cholesterol and risk of mortality in the oldest old. Lancet, 1997; 350:1119–1123
Special to The Epoch Times
Oct 17, 2007
Is it in their best interests to lower their cholesterol? Very few of us will not have noticed that the last couple of decades have seen a concerted effort from health agencies and health professionals to persuade us that we should be driving our cholesterol levels down to lower and lower levels. When I was at medical school the upper limit of cholesterol was 6.5 mmol/l (255 mg/l). But it's come down steadily since then and now stands at 5.0 mmol/l (195 mg/l). My suspicion is that it will fall even lower over the years. Who knows, it may get so low that practically everyone will be classified as having raised cholesterol, and be recommended to lower this with specialized food products and/or drugs.
However, since cholesterol is a constituent in the walls of cells in the body as well as steroid hormones, there is an issue for questioning whether lower really is better.
Some have suggested that low levels of cholesterol may predispose to health problems, including those that relate to brain function.
Last month saw the publication of a study in the journal, Neurobiology of Aging, in which Dutch researchers assessed the relationship between cholesterol levels and mental function in about 1,200 individuals aged 65 or over. The participants in the study were assessed over a six-year period. Lower blood cholesterol levels in this group were associated with a reduction in both general cognition and information processing speed. The authors of this study concluded: " … lower total cholesterol may be considered as a frailty marker, predictive of lower cognitive functioning in elderly." [1]
Of course with studies of this nature, it is impossible to know whether the low cholesterol itself is responsible for the associated poorer brain function. One way to assess this might be to attempt to lower cholesterol levels and see what it does to brain function. In one study, individuals treated with lovastatin (a cholesterol-reducing drug), compared to those taking a placebo, saw significant reductions in measures such as vigilance and general cognitive function [2]. This study, though, also tested the effect of another statin drug (pravastatin), which did not appear to have this same adverse effect on brain function.
Even if we take the apparent association between lovastatin and impaired brain function at face value, we do not know whether this was due to cholesterol lowering per se or some side effect of the medication.
Another study, though, adds further evidence to support the notion that lower cholesterol levels may impair brain function. In it, a low-fat diet was pitted against a standard diet over a 12-week period [3]. Over the course of the trial, the performance of a task that required sustained attention was significantly worse in individuals who had reduced their cholesterol. And the lower the cholesterol fell, the worse the performance in this test was.
Even if it turns out that cholesterol reduction is bad for the brain, I have no doubt that proponents of the lower cholesterol concept will point to other benefits of this endeavor. Yet I think it is worth bearing in mind that the evidence shows that in essentially healthy individuals, cholesterol reduction through drugs has not been shown to save lives. And dietary approaches do not appear to reduce funeral rates either, even in those with a history of cardiovascular disease.
Furthermore, there is at least some evidence showing that in later life, higher levels of cholesterol are actually associated with enhanced longevity [4–7]. In short, there is mounting evidence, I think, which suggests that as far as cholesterol is concerned, lower is not always necessarily better.
References:
1. Van den Kommer TN, et al. Total cholesterol and oxysterols: Early markers for cognitive decline in elderly? Neurobiology of Aging. 2007 Sep 19; [Epub ahead of print]
2. Roth T, et al. Comparative effects of pravastatin and lovastatin on nighttime sleep and daytime performance. Clinical Cardiology. 1992; 15:42–432
3. Wardle J, et al. Randomized trial of the effects of cholesterol-lowering dietary treatment on psychological function. American Journal of Medicine 2000; 108(7): 547–553
4. Brescianini S, et al. Low total cholesterol and increased risk of dying: are low levels clinical warning signs in the elderly? Results from the Italian Longitudinal Study on Aging. Journal of the American Geriatrics Society 2003; 51(7): 991–996
5. Forette B, et al. Cholesterol as risk factor for mortality in elderly women. Lancet, 1989; 1:868–870
6. Jonsson A, et al. Total cholesterol and mortality after age 80 years. Lancet, 1997; 350:1778–1779
7. Weverling-Rijnsburger AW, et al. Total cholesterol and risk of mortality in the oldest old. Lancet, 1997; 350:1119–1123
Sunday, October 28, 2007
Twist and Ouch
Important information for all of us, not just athletes.
October 28, 2007
Most athletes will have back trouble sooner or later -- if they’re not suffering already. Here’s what to do about it.
http://www.nytimes.com/2007/10/28/sports/playmagazine/28physed.html?ex=1351310400&en=d74dcfa901ad4b9e&ei=5124&partner=permalink&exprod=permalink
October 28, 2007
Most athletes will have back trouble sooner or later -- if they’re not suffering already. Here’s what to do about it.
http://www.nytimes.com/2007/10/28/sports/playmagazine/28physed.html?ex=1351310400&en=d74dcfa901ad4b9e&ei=5124&partner=permalink&exprod=permalink
Saturday, October 27, 2007
Edible, Sure. But Just How Incredible?
The much maligned egg is one of the most healthful foods around. Egg albumin or egg white is considered to be the reference protein to which all other foods are compared to for protein quality. Egg yolk is loaded with nutrients such as lutein (a carotenoid important for eye health), and vitamins A and D. For more info on the cholesterol controversy, see October 10th blog on
Diet and Fat: A Severe Case of Mistaken Consensus
October 1, 2007, 12:18 pm
(Alan Zale for The New York Times)
At breakfast recently a friend of mine passed on the scrambled eggs. “I’m watching my cholesterol,'’ he said. Another woman I know only orders Egg Beaters, which are essentially cholesterol-free orange-colored egg whites.
Of all the commonly consumed foods, eggs contain the highest amounts of cholesterol, and that’s why many people shun them. Now, the American Egg Board is bringing back its “Incredible Edible Egg” campaign to reiterate the health benefits.
So are eggs good for you or bad for you? I asked Dr. Walter Willett, Harvard University’s famed nutritionist, for his take.
“Dietary cholesterol has been greatly oversold as a health concern, in part because it has a small effect on blood cholesterol levels,'’ said Dr. Willett, who has never received funding from the egg industry. Eggs, in particular, have gotten a bad rap. “Some of the foods that contain high cholesterol, such as eggs, have many other healthy components,'’ he said.
Egg yolks, organ meat, shellfish, whole-fat dairy products and red meat are rich sources of dietary cholesterol. But the biggest influence on blood cholesterol level is the mix of fats in the diet, not how much cholesterol you eat in food.
The average person makes about 75 percent of blood cholesterol in his or her liver, while the rest is absorbed from food. One of the biggest problems with giving up eggs is that people turn to other breakfast foods like bagels with cream cheese, pastries and muffins. These are loaded with unhealthy saturated fat, which increases blood cholesterol levels far more than the dietary cholesterol found in eggs. The downside of eggs is that many people only eat them cooked in butter or oil, or with sausage, also loaded with saturated fat.
There are a few caveats. Egg consumption has been linked to a higher risk of heart trouble in people with diabetes. And a small number of people are unusually sensitive to dietary cholesterol — in them, foods like eggs can disproportionately increase blood cholesterol.
Still, said Dr. Willett, “the large majority can consume eggs in reasonable amounts.” For a more lengthy explanation of the impact of dietary cholesterol and fats on your health, check out The Nutrition Source from the Harvard School of Public Health. And Northwestern University has a useful fact sheet comparing dietary cholesterol and saturated fat in various foods.
Thursday, October 18, 2007
Industry Money Fans Debate on Fish
Much confusion about amount of fish a pregnant woman should consume. The latest recommendation from the National Healthy Mothers, Healthy Babies Coalition actually contradicted the goverment warnings about fish consumption, encouraging pregnant women to consume higher amounts of mercury tainted fish. Now there is evidence that this organization received funds from the National Fishery Institute. What else is new?
By MARIAN BURROS
October 17, 2007
The government and a private group are at odds on tuna’s safety.
http://www.nytimes.com/2007/10/17/dining/17fish.html?ex=1350360000&en=6aed88dd50be347c&ei=5124&partner=permalink&exprod=permalink
By MARIAN BURROS
October 17, 2007
The government and a private group are at odds on tuna’s safety.
http://www.nytimes.com/2007/10/17/dining/17fish.html?ex=1350360000&en=6aed88dd50be347c&ei=5124&partner=permalink&exprod=permalink
Wednesday, October 10, 2007
Diet and Fat: A Severe Case of Mistaken Consensus
This is brilliant and timely since we discussed the cholesterol controversy in class last night.
http://www.nytimes.com/2007/10/09/science/09tier.html?ex=1349668800&en=67642ef2330f51af&ei=5124&partner=permalink&exprod=permalink
http://www.nytimes.com/2007/10/09/science/09tier.html?ex=1349668800&en=67642ef2330f51af&ei=5124&partner=permalink&exprod=permalink
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