Wednesday, February 08, 2017

Do Dopaminergic Impairments Underlie Physical Inactivity in People with Obesity? - PubMed - NCBI

Do Dopaminergic Impairments Underlie Physical Inactivity in People with Obesity? - PubMed - NCBI: Do Dopaminergic Impairments Underlie Physical Inactivity in People with Obesity?
Kravitz AV1, O'Neal TJ2, Friend DM2.
Author information
Abstract
Obesity is associated with physical inactivity, which exacerbates the negative health consequences of obesity. Despite a wide consensus that people with obesity should exercise more, there are few effective methods for increasing physical activity in people with obesity. This lack is reflected in our limited understanding of the cellular and molecular causes of physical inactivity in obesity. We hypothesize that impairments in dopamine signaling contribute to physical inactivity in people with obesity, as in classic movement disorders such as Parkinson's disease. Here, we review two lines of evidence supporting this hypothesis: (1) chronic exposure to obesogenic diets has been linked to impairments in dopamine synthesis, release, and receptor function, particularly in the striatum, and (2) striatal dopamine is necessary for the proper control of movement. Identifying the biological determinants of physical inactivity may lead to more effective strategies for increasing physical activity in people with obesity, as well as improve our understanding of why it is difficult for people with obesity to alter their levels of physical activity.

Saturday, February 04, 2017

Exercise can help adults better cope with ADHD symptoms

Exercise can help adults better cope with ADHD symptoms: Exercise, even a small amount, can help alleviate symptoms of ADHD in adults, according to a new study. About 6 percent of American adults report symptoms consistent with attention deficit hyperactivity disorder, or ADHD, which lead to anxiety, depression, low energy and motivation, poor performance at work or school and also increased traffic accidents.



The study tested 32 young men with elevated ADHD symptoms who cycled at a moderate intensity for 20 minutes on one day, and on another day sat and rested for 20 minutes as a control condition. The participants were asked to perform a task requiring focus both before and after the different conditions, and researchers noted leg movement, mood, attention and self-reported motivation to perform the task.
As a result, researchers found that it was only after the exercise when the participants felt motivated to do the task; they also felt less confused and fatigued and instead felt more energetic. Interestingly, leg movements and performance on the task did not change after the exercise--rather, the exercise helped the young men feel better about doing the task.
These findings are consistent with prior research that shows a single bout of exercise helps people feel more energetic, said O'Connor, who is also co-director of the UGA Exercise Psychology Laboratory. The results suggest that young men who have symptoms of ADHD can benefit psychologically from the short workouts, similar to the benefits enjoyed by typical adults who work out.
"The reduced feelings of confusion and increased motivation to perform a cognitive task suggest that other types of acute exercise also may benefit cognitive performance," added study co-author Kathryn Fritz, a UGA doctoral student who completed the study as part of her master's thesis. "We speculate that a different mode or duration or intensity of exercise, other than a boring cycle ride in a sterile lab, may show larger cognitive effects for those suffering from ADHD symptoms."

Thursday, January 26, 2017

Zinc Supplements Could Help Treat ADHD

Zinc Supplements Could Help Treat ADHD:



An article published in BMC Psychiatry this week shows that zinc supplements could increase the effectiveness of stimulants used to treat children with attention deficit hyperactivity disorder (ADHD).



"The effects of ADHD on individual children differ, but symptoms include inattention, hyperactivity and impulsiveness. Stimulants are the most common treatment prescribed, but recent findings that vitamin and mineral deficiencies correlate with ADHD suggest that dietary supplements could also play a role in disease management.





Researchers from Iran carried out a controlled trial to assess the benefits of prescribing supplementary zinc alongside the more conventional methylphenidate treatment. They found that children taking additional zinc sulphate on a daily basis improved faster than those taking a placebo.
"The efficacy of zinc sulphate to increase the rate of improvement in children, seems to support the role of zinc deficiency in the pathogenesis of ADHD," say the authors."

Thursday, December 22, 2016

New research appears to point to link between vitamin D and autism

New research appears to point to link between vitamin D and autism:

New research has found that a vitamin D deficiency in pregnancy is linked to an increased risk of autism traits in children.

Tuesday, October 04, 2016

Fat vs sugar craving gene?

Scientists discover ‘fat-craving gene’ after hosting all-you-can eat chicken korma buffet. http://tiny.iavian.net/com6

Friday, September 30, 2016

Health Correlator: Niacin turbocharges the growth hormone response to anaerobic exercise: A delayed effect

Health Correlator: Niacin turbocharges the growth hormone response to anaerobic exercise: A delayed effect:



Niacin is also known as vitamin B3, or nicotinic acid. It is an essential vitamin whose deficiency leads to pellagra. In large doses of 1 to 3 g per day it has several effects on blood lipids, including an increase in HDL cholesterol and a marked decreased in fasting triglycerides. Niacin is also a powerful antioxidant.

Among niacin’s other effects, when taken in large doses�of 1 to 3 g per day, is an acute elevation in growth hormone secretion. This is a delayed effect, frequently occurring 3 to 5 hours after taking niacin. This effect is independent of exercise.

It is important to note that large doses of 1 to 3 g of niacin are completely unnatural, and cannot be achieved by eating foods rich in niacin. For example, one would have to eat a toxic amount of beef liver (e.g., 15 lbs) to get even close to 1 g of niacin. Beef liver is one of the richest natural sources of niacin.

Thursday, September 29, 2016

Lowering the Bar on the Low-Fat Diet | JAMA | JAMA Network

Lowering the Bar on the Low-Fat Diet | JAMA | JAMA Network:

David S. Ludwig, MD, PhD1

The recent revelation that the sugar industry attempted to manipulate science in the 1960s1 has once again focused attention on the quality of the scientific evidence in the field of nutrition and how best to prevent diet-related chronic disease.



 Beginning in the 1970s, the US government and major professional nutrition organizations recommended that individuals in the United States eat a low-fat/high-carbohydrate diet, launching arguably the largest public health experiment in history. Throughout the ensuing 40 years, the prevalence of obesity and diabetes increased several-fold, even as the proportion of fat in the US diet decreased by 25%. Recognizing new evidence that consumption of processed carbohydrates—white bread, white rice, chips, crackers, cookies, and sugary drinks—but not total fat has contributed importantly to these epidemics, the 2015 USDA Dietary Guidelines for Americans essentially eliminated the upper limit on dietary fat intake.2 However, a comprehensive examination of this massive public health failure has not been conducted. Consequently, significant harms persist, with the low-fat diet remaining entrenched in public consciousness and food policy. In addition, critical scientific questions have been muddled.



[...]




To facilitate this change, the Healthy People 2000 goals included a call to the food industry to increase from 2500 items “to at least 5000 brand items the availability of processed food products that are reduced in fat.” The food industry followed suit, systematically replacing fat in food products with starch and sugar.

As a result of these efforts, dietary fat decreased to near the recommended limit of 30% total energy. But contrary to prediction, total calorie intake increased substantially, the prevalence of obesity tripled, the incidence of type 2 diabetes increased many-fold, and the decades-long decrease in cardiovascular disease plateaued and may reverse, despite greater use of preventive drugs and surgical procedures. However, other changes in diet (such as meals away from home) and lifestyle (such as physical activity level) may have influenced these trends.

Recent research suggests that the focus on dietary fat reduction has directly contributed to this growing burden of chronic disease.2,69 In contrast to older, cross-sectional designs, high-quality prospective observational studies consistently show that total fat intake does not predict change in body fat, after controlling for confounding and reverse causation. Some foods previously relegated to the top of the pyramid because of high fat content (nuts, full-fat yogurt) are associated with lower rates of weight gain than common high-carbohydrate foods (processed grains, potato products, sugary beverages).9 Moreover, meta-analyses of clinical trials report that low-fat diets are inferior to comparisons controlled for treatment intensity, including low-carbohydrate diets,6 Mediterranean diets, and all higher-fat diets. Of particular importance, the major low-fat diet studies, such as the Women’s Health Initiative clinical trial and Look Ahead, failed to reduce risk for heart disease despite use of lower-intensity control conditions. In contrast, the PREDIMED study was terminated early when cardiovascular disease incidence decreased more rapidly than expected in the higher-fat diet groups compared with the low-fat control. Consistent with these findings, men and women adhering to low-fat/high-carbohydrate diets had higher, not lower, rates of premature death, although the type of dietary fats consumed importantly modified risk.7

One reason for the apparent failure of low-fat diets is that they may elicit biological adaptations—increasing hunger, slowing metabolic rate, and other hallmarks of the starvation response—that antagonize ongoing weight loss. Preliminary studies suggest that the reduced insulin secretion with low-carbohydrate and low-glycemic-index diets may attenuate these adaptations, facilitating long-term weight-loss maintenance and reducing diseases associated with hyperinsulinemia (the carbohydrate-insulin model).8

Tuesday, September 20, 2016

Activity trackers my undermine weight loss efforts

Activity Trackers May Undermine Weight Loss Efforts. http://tiny.iavian.net/cfjp

Sunday, September 18, 2016

We’re All Guinea Pigs in a Failed Decades-Long Diet Experiment | VICE | United States

We’re All Guinea Pigs in a Failed Decades-Long Diet Experiment | VICE | United States: Overseas, national health authorities followed America's lead on fat. The results have been similarly grim. Earlier this year, a UK nonprofit called the National Obesity Forum (NOF) published a blistering condemnation of its government's diet and nutrition policies.

In its report, the NOF argues that advice to cut back on fat and cholesterol is "the root cause" of Britain's skyrocketing rates of obesity and diabetes. Speaking shortly after the report's publication, Aseem Malhotra, a British cardiologist who consulted on the NOF report, said, "The change in dietary advice to promote low-fat foods is perhaps the biggest mistake in modern medical history.

Along with ripping its government's "failed policies," the NOF report called for a "complete overhaul of dietary advice and public health messaging."

In a recent editorial appearing in the British Journal of Sports Medicine, researcher Zoe Harcombe from the University of the West of Scotland explains that obesity rates among British men and women rose from 2.7 percent in 1972 to 23 percent and 26 percent, respectively, by 1999.

"There are only three macronutrients," Harcombe told VICE, "protein, fat, and carbohydrates." Nearly everything you eat or drink contains one or more of these. And if you followed the government's advice to eat less fat, it's inevitable that your carb consumption would shoot up, she said. That's just what happened at a population level during the 1980s and 90s.

50 Years Ago, Sugar Industry Quietly Paid Scientists To Point Blame At Fat : The Two-Way : NPR

50 Years Ago, Sugar Industry Quietly Paid Scientists To Point Blame At Fat : The Two-Way : NPR:



In the 1960s, the sugar industry funded research that downplayed the risks of sugar and highlighted the hazards of fat, according to a newly published article in JAMA Internal Medicine.

The article draws on internal documents to show that an industry group called the Sugar Research Foundation wanted to "refute" concerns about sugar's possible role in heart disease. The SRF then sponsored research by Harvard scientists that did just that. The result was published in the New England Journal of Medicine in 1967, with no disclosure of the sugar industry funding.



The sugar-funded project in question was a literature review, examining a variety of studies and experiments. It suggested there were major problems with all the studies that implicated sugar, and concluded that cutting fat out of American diets was the best way to address coronary heart disease.



 The authors of the new article say that for the past five decades, the sugar industry has been attempting to influence the scientific debate over the relative risks of sugar and fat.

"It was a very smart thing the sugar industry did, because review papers, especially if you get them published in a very prominent journal, tend to shape the overall scientific discussion," co-author Stanton Glantz told The New York Times.

Thursday, September 15, 2016

Aerobic exercise training increases brain volume in aging humans. - PubMed - NCBI

Aerobic exercise training increases brain volume in aging humans. - PubMed - NCBI: Significant increases in brain volume, in both gray and white matter regions, were found as a function of fitness training for the older adults who participated in the aerobic fitness training but not for the older adults who participated in the stretching and toning (nonaerobic) control group. As predicted, no significant changes in either gray or white matter volume were detected for our younger participants.

CONCLUSIONS:
These results suggest that cardiovascular fitness is associated with the sparing of brain tissue in aging humans. Furthermore, these results suggest a strong biological basis for the role of aerobic fitness in maintaining and enhancing central nervous system health and cognitive functioning in older adults.

Benefits of regular aerobic exercise for executive functioning in healthy populations. - PubMed - NCBI

Benefits of regular aerobic exercise for executive functioning in healthy populations. - PubMed - NCBI: Research suggests that regular aerobic exercise has the potential to improve executive functioning, even in healthy populations. The purpose of this review is to elucidate which components of executive functioning benefit from such exercise in healthy populations. In light of the developmental time course of executive functions, we consider separately children, young adults, and older adults. Data to date from studies of aging provide strong evidence of exercise-linked benefits related to task switching, selective attention, inhibition of prepotent responses, and working memory capacity; furthermore, cross-sectional fitness data suggest that working memory updating could potentially benefit as well. In young adults, working memory updating is the main executive function shown to benefit from regular exercise, but cross-sectional data further suggest that task-switching and post error performance may also benefit. In children, working memory capacity has been shown to benefit, and cross-sectional data suggest potential benefits for selective attention and inhibitory control. Although more research investigating exercise-related benefits for specific components of executive functioning is clearly needed in young adults and children, when considered across the age groups, ample evidence indicates that regular engagement in aerobic exercise can provide a simple means for healthy people to optimize a range of executive functions.

Impact of aerobic exercise training on cognitive functions and affect associated to the COMT polymorphism in young adults

Impact of aerobic exercise training on cognitive functions and affect associated to the COMT polymorphism in young adults: Physical fitness can serve as a means to enhance cognitive functioning by modulating particular aspects of brain functioning. However, mechanisms underlying this modulating effect remain widely unresolved. To examine the impact and to clarify the mechanisms of physical fitness training in a young and healthy population, it was investigated whether an increase in fitness would result in improvements in executive control processes and positive and negative affect. Moreover, genotype of the Val158Met polymorphism in catechol-O-methyltransferase (COMT) as an index of relative central dopamine bioavailability was determined to elucidate dopamine tuning efficiency and its association with performance in the applied cognitive tasks. Seventy-five individuals participated and underwent an incremental fitness test to assess physical fitness. An exercising group subsequently engaged in a 17�weeks running training consisting of three running sessions at moderate to high, individually adjusted intensities. Associated with increased fitness improved cognitive flexibility and cognitive control were observed, whereas working memory remained unaffected. In runners, Val/Val participants improved cognitive performance to a greater extent compared to individuals carrying a Met allele. From the present results it is concluded that an increase in physical fitness provides a means to improve cognitive functioning via dopaminergic modulation.

Research highlights

► Increased physical fitness is associated with improved cognitive functions. ► Increased physical fitness is accompanied by a gain in positive affect. ► The beneficial effect of increased physical fitness seems to be mediated by dopaminergic modulation.

The sugar conspiracy | Ian Leslie | Society | The Guardian

The sugar conspiracy | Ian Leslie | Society | The Guardian:



Although Keys had shown a correlation between heart disease and saturated fat, he had not excluded the possibility that heart disease was being caused by something else. Years later, the Seven Countries study’s lead Italian researcher, Alessandro Menotti, went back to the data, and found that the food that correlated most closely with deaths from heart disease was not saturated fat, but sugar.

Tuesday, September 13, 2016

The Science of Smart: A Surprising Way To Improve Executive Function - Secret Life of Scientists and Engineers — Secret Life of Scientists and Engineers | PBS

The Science of Smart: A Surprising Way To Improve Executive Function - Secret Life of Scientists and Engineers — Secret Life of Scientists and Engineers | PBS:



 There is one surprising but well-supported way to improve executive function in both children and adults, however: aerobic exercise. A just-published review of the relevant research, appearing in the journal Psychonomic Bulletin and Review, concludes that “ample evidence indicates that regular engagement in aerobic exercise can provide a simple means for healthy people to optimize a range of executive functions.”

NY Times. How the Sugar Industry Shifted Blame to Fat

NY Times. How the Sugar Industry Shifted Blame to Fat
The sugar industry paid scientists in the 1960s to play down the link between sugar and heart disease and promote saturated fat as the culprit instead, newly released historical documents show.
The internal sugar industry documents, recently discovered by a researcher at the University of California, San Francisco, and published Monday in JAMA Internal Medicine, suggest that five decades of research into the role of nutrition and heart disease, including many of today’s dietary recommendations, may have been largely shaped by the sugar industry.
“They were able to derail the discussion about sugar for decades,” said Stanton Glantz, a professor of medicine at U.C.S.F. and an author of the JAMA paper.
The documents show that a trade group called the Sugar Research Foundation, known today as the Sugar Association, paid three Harvard scientists the equivalent of about $50,000 in today’s dollars to publish a 1967 review of research on sugar, fat and heart disease. The studies used in the review were handpicked by the sugar group, and the article, which was published in the prestigious New England Journal of Medicine, minimized the link between sugar and heart health and cast aspersions on the role of saturated fat.
Even though the influence-peddling revealed in the documents dates back nearly 50 years, more recent reports show that the food industry has continued to influence nutrition science.
Last year, an article in The New York Times revealed that Coca-Cola, the world’s largest producer of sugary beverages, had provided millions of dollars in funding to researchers who sought to play down the link between sugary drinks and obesity. In June, The Associated Press reported that candy makers were funding studies that claimed that children who eat candy tend to weigh less than those who do not.
The Harvard scientists and the sugar executives with whom they collaborated are no longer alive. One of the scientists who was paid by the sugar industry was D. Mark Hegsted, who went on to become the head of nutrition at the United States Department of Agriculture, where in 1977 he helped draft the forerunner to the federal government’s dietary guidelines. Another was Dr. Fredrick J. Stare, the chairman of Harvard’s nutrition department.

Saturday, September 10, 2016

Reversing impaired kidney function in diabetics may be possible with ketogenic diet

 Reversing impaired kidney function in diabetics may be possible with the ketogenic diet. The researchers at Mount Sinai Medical School found that the ketogenic diet, a style of eating based on high-fat and low-carbohydrate intake, may be beneficial in reversing kidney function. The researchers studied mice that were genetically predisposed to have type 1 or type 2 diabetes. The mice went on to develop diabetic kidney damage. Half of the mice were put on the ketogenic diet and the other half served as controls. After eight weeks, molecular indicators of kidney damage were reversed in the mice on the ketogenic diet, along with kidney pathology in mice with type 2 diabetes. http://www.belmarrahealth.com/reversing-impaired-kidney-function-diabetics-may-possible-ketogenic-diet/

Reversing impaired kidney function in diabetics may be possible with ketogenic diet

 Reversing impaired kidney function in diabetics may be possible with the ketogenic diet. The researchers at Mount Sinai Medical School found that the ketogenic diet, a style of eating based on high-fat and low-carbohydrate intake, may be beneficial in reversing kidney function. The researchers studied mice that were genetically predisposed to have type 1 or type 2 diabetes. The mice went on to develop diabetic kidney damage. Half of the mice were put on the ketogenic diet and the other half served as controls. After eight weeks, molecular indicators of kidney damage were reversed in the mice on the ketogenic diet, along with kidney pathology in mice with type 2 diabetes. http://www.belmarrahealth.com/reversing-impaired-kidney-function-diabetics-may-possible-ketogenic-diet/

Tuesday, August 30, 2016

PLOS ONE: The Ketogenic Diet and Hyperbaric Oxygen Therapy Prolong Survival in Mice with Systemic Metastatic Cancer

PLOS ONE: The Ketogenic Diet and Hyperbaric Oxygen Therapy Prolong Survival in Mice with Systemic Metastatic Cancer:



Ketogenic Diet alone significantly decreased blood glucose, slowed tumor growth, and increased mean survival time by 56.7% in mice with systemic metastatic cancer.

PLOS ONE: The Ketogenic Diet and Hyperbaric Oxygen Therapy Prolong Survival in Mice with Systemic Metastatic Cancer

PLOS ONE: The Ketogenic Diet and Hyperbaric Oxygen Therapy Prolong Survival in Mice with Systemic Metastatic Cancer:



Ketogenic Diet alone significantly decreased blood glucose, slowed tumor growth, and increased mean survival time by 56.7% in mice with systemic metastatic cancer.

Sunday, August 14, 2016

High Carbohydrate Intake Worse than High Fat for Blood Lipids

High Carbohydrate Intake Worse than High Fat for Blood Lipids:

Recent data presented at the World Heart Federation’s World Congress of Cardiology & Cardiovascular Health 2016 (WCC 2016) in Mexico City last month may radically change our perspective on how carbohydrates and different types of fats affect blood cholesterol and other lipid biomarkers. The presentation was based on data from the Prospective Urban Rural Epidemiological (PURE) study. The data have not been published yet, and the results are only available in an abstract

[...]

In the above study, the only benefit of a high carbohydrate diet was a lowering of TC and LDL-C. However, the effect on other lipid biomarkers such as HDL-C, TG, and ApoB/ApoA ratio may be harmful.

A diet rich in SFAs raised TC and LDL-C but lowered TG while a diet rich in MUFAs improved all lipid biomarkers. A diet high in PUFAs had a mixed effect on lipid biomarkers.

The study suggests that placing carbohydrates at the bottom of the food pyramid based on their effect on blood cholesterol was a mistake. In fact, the data show that replacing dietary carbohydrates with different types of fat may improve lipid profile.

In an interview on Medscape, Dr. Mahshid Dehghan, the principal author of the abstract said (3):

To summarize our findings, the most adverse effect on blood lipids is from carbohydrates; the most benefit is from consumption of monounsaturated fatty acids; and the effect of saturated and polyunsaturated fatty acids are mixed. I believe this is a big message that we can give because we are confusing people with a low-fat diet and all the complications of total fat consumption, and WHO and AHA all suggest 55% to 60% of energy from carbohydrates.

Today, most experts agree that diets high in SFAs or refined carbohydrates are not be recommended for the prevention of heart disease. However, it appears that carbohydrates are likely to cause a greater metabolic damage than SFAs in the rapidly growing population of people with metabolic abnormalities associated with obesity and insulin resistance.

I assume we all agree that partially hydrogenated fats (trans-fats) should be avoided. However, the singular focus on reducing the intake of SFAs, and dietary fats in general, may have been counterproductive and promoted the rapidly growing popularity of refined carbohydrates. The recent nutritional data from the PURE study clearly suggest that it is time to shift our focus away from reducing fat in our diet toward reduced consumption of carbohydrates.