Monday, August 31, 2009

The Heart Scan Blog: Weight loss and vitamin D

The Heart Scan Blog: Weight loss and vitamin D

Weight loss and vitamin D

At the start of her program, Penny's 25-hydroxy vitamin D blood level showed the usual deficiency at 22 ng/ml.

She supplemented with 8000 units of vitamin D. Another 25-hydroxy vitamin D blood level several months later showed a level of 67.8 ng/ml, right on target.

But Penny also began our diet, including the elimination of wheat, cornstarch, and sugars, and, over 6 months, lost 34 lbs.

Now a much trimmer 146 lbs (still more to go!), another vitamin D blood level: 111 ng/ml.

Penny's weight loss means that the vitamin D is distributed in a smaller total volume, particularly a lower volume of fat.

This is a common phenomenon with substantial weight loss: lose weight and the need for vitamin D is reduced. The reduction in dose is roughly proportion to the weight lost. Vitamin D should therefore be reassessed with any substantial change in weight of, say, 10 lbs or more, either up or down, because of the influence of fat on vitamin D blood levels.

Some references on this effect:

Men and women over age 65:
Adiposity in relation to vitamin D status and parathyroid hormone levels: a population-based study in older men and women.

Obese women:
Low 25-hydroxyvitamin D concentrations in obese women: their clinical significance and relationship with anthropometric and body composition variables

Obese children:
Hypovitaminosis D in obese children and adolescents: relationship with adiposity, insulin sensitivity, ethnicity, and season.

African-Americans:
Relationship of vitamin D and parathyroid hormone to obesity and body composition in African Americans.

Although the bulk of the effect is most likely due to sequestration by fatty tissue, perhaps less sun exposure in obese people also contributes:
Body mass index determines sunbathing habits: implications on vitamin D levels.

Vitamin B12 deficiency is associated with coronary...[Clin Chem Lab Med. 2009] - PubMed Result

Vitamin B12 deficiency is associated with coronary...[Clin Chem Lab Med. 2009] - PubMed Result

BACKGROUND: The incidence of coronary artery disease (CAD) is increasing at an alarming rate, especially in developing countries, such as India. It is often advocated that a vegetarian lifestyle could reduce the burden of CAD. However, in spite of a majority of Indians being vegetarians, the incidence of CAD is highest in this population. This may be due to deficiency of vitamin B12, a micronutrient, sourced only from animal products.

RESULTS: We found that vitamin B12 levels were significantly lower in coronary artery disease patients than in controls (p<0.0001). Also, vegetarians were found to have significantly lower vitamin B12 concentrations (p=0.0001) and higher incidence of coronary artery disease (p=0.01). Interestingly, elevated homocysteine levels, a hallmark of vitamin B12 deficiency, was not associated with CAD. In contrast, cysteine levels were significantly higher in CAD patients than in controls (p=0.004). CONCLUSIONS: We believe that, when vitamin B12 is deficient, homocysteine is rapidly metabolized via the transsulfuration pathway leading to increased cysteine levels.

Low plasma vitamin B12 in pregnancy is associated with gestational ‘diabesity’ and later diabetes

SpringerLink - Journal Article

Conclusions/interpretation Maternal vitamin B12 deficiency is associated with increased adiposity and, in turn, with insulin resistance and GDM. Vitamin B12 deficiency may be an important factor underlying the high risk of ‘diabesity’ in south Asian Indians.

Thursday, August 27, 2009

Slashdot Science Story | Depression May Provide Cognitive Advantages

Slashdot Science Story | Depression May Provide Cognitive Advantages

"Paul W. Andrews and J. Anderson Thomson, Jr. argue in Scientific American that although depression is considered a mental disorder, depression may in fact be a mental adaptation which provides real benefits. This is not to say that depression is not a problem. Depressed people often have trouble performing everyday activities, they can't concentrate on their work, they tend to socially isolate themselves, they are lethargic, and they often lose the ability to take pleasure from such activities such as eating and sex. So what could be so useful about depression? "Depressed people often think intensely about their problems," write the authors. "These thoughts are called ruminations; they are persistent and depressed people have difficulty thinking about anything else. Numerous studies have also shown that this thinking style is often highly analytical. They dwell on a complex problem, breaking it down into smaller components, which are considered one at a time." Various studies have found that people in depressed mood states are better at solving social dilemmas and there is evidence that people who get more depressed while they are working on complex problems in an intelligence test tend to score higher on the test (PDF). "When one considers all the evidence, depression seems less like a disorder where the brain is operating in a haphazard way, or malfunctioning. Instead, depression seems more like the vertebrate eye--an intricate, highly organized piece of machinery that performs a specific function.""

Wednesday, August 26, 2009

Half of healthcare workers say no to swine flu jab - Healthcare Republic News

Half of healthcare workers say no to swine flu jab - Healthcare Republic News

Most DR.s may reject swine flu vaccine

(HEALTHCARE REPUBLIC) Up to 60% of GPs may choose not to be vaccinated against swine flu, with many concerned about the safety of the vaccine, a GP newspaper survey suggests.

Of 216 GPs who responded to the survey, 29% said they would not opt to receive the swine flu vaccine and a further 29% said they were not sure whether they would or not.

Of those who would refuse vaccination, 71% said they were concerned that the vaccine had not been through sufficient trials to guarantee its safety.

Professor David Salisbury, DoH director of immunisation, toldHealthcare Republic, the website for GP newspaper, that frontline health workers have a duty to themselves regarding vaccination.

‘They have a duty to their patients not to infect their patients and they have a duty to their families,’ he said.

Tuesday, August 18, 2009

Fructose But Not Glucose-Sweetened Beverages Increased Insulin Resistance And Belly Fat In Overweight And Obese People, Study

Fructose But Not Glucose-Sweetened Beverages Increased Insulin Resistance And Belly Fat In Overweight And Obese People, Study

We all know that too much sugar is not good for us, but researchers from the US have discovered that drinks sweetened with fructose as opposed to glucose were significantly more likely to increase insulin resistance and belly fat in obese and overweight people, leading to medical conditions that increased their risk of heart attack and stroke.

The study was the work of Dr Peter Havel, a researcher in the Department of Nutrition at the University of California at Davis, and colleagues, and was published in the April 20 issue of the Journal of Clinical Investigation.

Over the twelve months of 2005, the average American consumed about 64 kg of extra sugar from drinking sweetened soft drinks: this is approximately the weight of an average height, slim American woman.

But although studies in animals have shown that compared with glucose, dietary fructose leads to increased insulin resistance plus higher levels of blood cholesterol and fats, there has been little equivalent research on humans.

Over the 10 weeks of the study, Havel and colleagues showed that human consumption of beverages sweetened with fructose but not glucose can worsen the body's sensitivity to insulin and how it handles fat.

For the study, which involved 32 overweight and obese men and women aged around 50, the participants spent 2 weeks in a closely observed inpatient setting and then 8 weeks in an outpatient setting. Over the two phases they drank beverages sweetened with glucose (15 subjects) or fructose (17 subjects) comprising 25 per cent of their daily calorie intake.

During the 10 weeks in total of the study, participants in both groups put on about the same amount of weight, but only those in the fructose group showed an increase in belly fat.

Also, only the participants in the fructose group became less sensitive to insulin (the hormone that controls how much glucose is in the bloodstream), and developed higher levels of total and LDL or "bad" cholesterol.

The fructose group also showed higher levels of hepatic DNL (de novo lipogenesis, fat that is produced from excess digested carbohydrate) and other signs that their bodies were producing fat differently to the glucose group.

The researchers concluded that:

"These data suggest that dietary fructose specifically increases DNL, promotes dyslipidemia, decreases insulin sensitivity, and increases visceral adiposity in overweight/obese adults."

Monday, August 17, 2009

Omega-3 Polyunsaturated Fatty Acids and Cardiovascular Diseases -- Lavie et al. 54 (7): 585 -- Journal of the American College of Cardiology

Omega-3 Polyunsaturated Fatty Acids and Cardiovascular Diseases -- Lavie et al. 54 (7): 585 -- Journal of the American College of Cardiology:

"Omega-3 polyunsaturated fatty acid ({omega}-3 PUFA) therapy continues to show great promise in primary and, particularly in secondary prevention of cardiovascular (CV) diseases. The most compelling evidence for CV benefits of {omega}-3 PUFA comes from 4 controlled trials of nearly 40,000 participants randomized to receive eicosapentaenoic acid (EPA) with or without docosahexaenoic acid (DHA) in studies of patients in primary prevention, after myocardial infarction, and most recently, with heart failure (HF). We discuss the evidence from retrospective epidemiologic studies and from large randomized controlled trials showing the benefits of {omega}-3 PUFA, specifically EPA and DHA, in primary and secondary CV prevention and provide insight into potential mechanisms of these observed benefits. The target EPA DHA consumption should be at least 500 mg/day for individuals without underlying overt CV disease and at least 800 to 1,000 mg/day for individuals with known coronary heart disease and HF. Further studies are needed to determine optimal dosing and the relative ratio of DHA and EPA {omega}-3 PUFA that provides maximal cardioprotection in those at risk of CV disease as well in the treatment of atherosclerotic, arrhythmic, and primary myocardial disorders."

Sunday, August 16, 2009

Low vitamin D levels linked to metabolic syndrome

Low vitamin D levels linked to metabolic syndrome

Increasing blood levels of vitamin D are linked to a lower prevalence of the metabolic syndrome, as well as improved ‘good’ cholesterol levels, says a new study.

According to findings published in the Journal of Clinical Lipidology, the lowest levels of the sunshine vitamin were associated with a 31 per cent prevalence of metabolic syndrome, compared to only 10 per cent for people wit the highest average levels.

The researchers noted that the results do not prove that low vitamin D levels contributes or causes metabolic syndrome, and called for more studies to “assess whether increasing vitamin D intake will improve the metabolic cardiovascular risk factor profile”.

“Although previous surveys have also reported associations between low 25(OH)D concentration and metabolic syndrome components, to our knowledge, the present investigation is the first to report this finding in a sample with a high prevalence of vitamin D dietary supplement users in which frequencies of vitamin D insufficiency and deficiency were low,” wrote the researchers, led by Kevin Maki from Illinois-based Provident Clinical Research

Metabolic syndrome (MetS) is a condition characterised by central obesity, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type-2 diabetes and cardiovascular disease (CVD).

Canada examines vitamin D for swine flu protection

Canada examines vitamin D for swine flu protection:

The Public Health Agency of Canada (PHAC) has confirmed that it will be investigating the role of vitamin D in protection against swine flu, NutraIngredients-USA.com has learned.

The agency started a study last year on the role of vitamin D in severe seasonal influenza, which it said it will now adapt to the H1N1 swine flu virus.

Part of the researchers’ goal is to understand if vitamin D levels are in any way responsible for the fact that most people with seasonal influenza develop a mild illness but a small minority go on to develop severe symptoms.

According to PHAC, results from its study will indicate the extent and nature of the role of vitamin D in sever seasonal influenza. The agency said it would most likely take at least three influenza seasons to be able to recruit a sufficient sample size of individuals with severe disease and controls before the results can be “meaningfully” analyzed.

In addition, PHAC said that epidemiological evidence suggests a role for vitamin D in seasonal influenza in general.

“Influenza infection is correlated geographically and seasonally with levels of solar ultraviolet radiation (Cannell, 2006). Given that vitamin D is synthesisized in our skin on exposure to sunlight, low serum levels of 25(OH) vitamin D in winter months appear to correlate with the occurrence of seasonal influenza in the winter. However a direct causal relationship between low vitamin D levels and the risk of influenza remains to be proven.”

“How vitamin D might protect against influenza infection is not fully understood. However new research suggests that vitamin D induces the production of antimicrobial substances in the body that possess neutralizing activity against a variety of infectious agents including influenza virus (Doss, 2009).”

So, Vitamin D's attributes as the main substance to activate the body's immune system should make it protective against swine flu. Notice also that overweight people have had the highest death rates from swine flu, and also have lower Vit D levels. Low Vitamin D has been related to metabolic syndrome. This puts the lie to the whole "tanning beds are more dangerous than arsenic" garbage the WHO has been pushing lately. When fall comes, and I'm surrounded by sick teenagers, I'll be tanning without fear.

Wednesday, August 05, 2009

Review: Insulin Resistance May Link Metabolic And Cognitive Disorders

Review: Insulin Resistance May Link Metabolic And Cognitive Disorders

Insulin resistance, when tissues in the body lose sensitivity to the hormone that regulates glucose, may underlie both dementia and metabolic disorders such as obesity and diabetes. In a review article, Suzanne Craft, Ph.D., of Veterans Administration Puget Sound Health Care System and University of Washington School of Medicine, Seattle, writes that "considerable progress has been made in establishing relationships among metabolic disorders and late-life dementing illnesses," including through the common foundation of insulin resistance.

"A number of challenges must be addressed as we move forward to determine the key mechanisms underlying these associations," Dr. Craft concludes, including establishing clear definitions of both metabolic and neurological conditions. "Future research aimed at identifying mechanisms that underlie comorbid associations will not only provide important insights into the causes and interdependencies of late-life dementias, but will also inspire novel strategies for treating and preventing these disorders."

Arch Neurol. 2009;66[3]:300-305.

Tuesday, August 04, 2009

Fructose Metabolism By The Brain Increases Food Intake And Obesity

Fructose Metabolism By The Brain Increases Food Intake And Obesity

Elsevier, will publish an important review this week online, by M. Daniel Lane and colleagues at Johns Hopkins, building on the suggested link between the consumption of fructose and increased food intake, which may contribute to a high incidence of obesity and Type 2 diabetes.

[...]

M. Daniel Lane and co-workers at The Johns Hopkins University School of Medicine in Baltimore have now pulled together work, largely in their laboratory (many papers beginning in 2000), dealing with the role of malonyl-CoA in the signaling system in the brain (specifically the hypothalamus) that has inputs into the higher brain centers that determine feeding behavior, most notably appetite. Two papers in the journal PNAS in 2007 and 2008 showed that glucose and fructose act quite differently in the brain (hypothalamus) - glucose decreasing food intake and fructose increasing food intake. Both of these sugars signal in the brain through the malonyl-CoA signaling pathway and have inverse effects on food intake.

Lane commented: "We feel that these findings may have particular relevance to the massive increase in the use of high fructose sweeteners (both high fructose corn syrup and table sugar) in virtually all sweetened foods, most notably soft drinks. The per capita consumption of these sweeteners in the USA is about 145 lbs/year and is probably much higher in teenagers/youth that have a high level of consumption of soft drinks. There is a large literature now that correlates, but does not prove that a culprit in the rise of teenage obesity may be fructose."

The fact that fructose metabolism by the brain increases food intake and obesity risk raises health concerns in view of the large and increasing per capita consumption of high fructose sweeteners, especially by youth.

Monday, August 03, 2009

Omega-3 linked to lower body weight: Study

Omega-3 linked to lower body weight: Study

Increased blood levels of the omega-3 fatty acids EPA and DHA is linked to lower incidence of obesity, suggesting a role for fish oils in weight management.

New findings reported in the British Journal of Nutrition indicate that overweight and obese people have blood levels of omega-3 fatty acids almost 1 per cent lower than people with a healthy weight.

“Our findings suggest that n-3 PUFA may play an important role in weight status and abdominal adiposity,” wrote the researchers, led by Professor Monohar Garg from the University of Newcastle, and president elect of the Nutrition Society of Australia.

Previous studies have implicated omega-3 in protective benefits against obesity, and the new study adds to this small but growing body of evidence. A considerable number of studies already support the benefits of the omega-3 fatty acids eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3) for cardiovascular health, and cognitive health. Other areas of potential for the fatty acids include mood and behaviour, eye health, cancer risk reduction, and improved infant development.

“Previous studies involving children and adolescents have shown a negative correlation between adiposity and plasma omega-3 PUFA and DHA concentrations, but there appears to be a paucity of research in adults,” explained the researchers.

Insulin may be key to fighting Alzheimer's disease - Times Online

Insulin may be key to fighting Alzheimer's disease - Times Online: "Insulin, the hormone that regulates levels of sugar in the blood, may slow or prevent memory loss caused by Alzheimer’s disease, a study suggests.

Researchers examining the effects of diabetes drugs on the brain have found that the medication appears to protect cells responsible for the formation of memory.

The work offers further support for the theory that Alzheimer’s could be caused by a form of diabetes linked to the body’s failure to produce and process insulin effectively.

[...]

Cells in the hippocampus are susceptible to damage caused by amyloid beta-derived diffusible ligands (ADDLs), toxic proteins that build up in people with Alzheimer’s.

ADDLs attack the synapses – the junctions between nerve cells through which impulses pass – which help form memory. After the proteins have attached, the synapses lose their capacity to respond to incoming information, resulting in memory loss.

The researchers discovered that damage to neurons exposed to ADDLs was blocked by insulin, which stopped the proteins from attaching to the cells. The insulin-sensitising drug rosiglitazone enhanced protection afforded by low levels of insulin, the study showed.

William Klein, a professor of neurobiology and physiology at the Weinberg College of Arts and Sciences and a researcher in Northwestern University’s Cognitive Neurology and Alzheimer’s Disease Centre, said: “Therapeutics designed to increase insulin sensitivity in the brain could provide new avenues for treating Alzheimer’s disease.

“Sensitivity to insulin can decline with ageing, which presents a novel risk factor for Alzheimer’s disease. Our results demonstrate that bolstering insulin signalling can protect neurons from harm.”

[...]

Sergio Ferreira, another member of the research team and a professor of biochemistry in Rio de Janeiro, added: “Recognising that Alzheimer’s disease is a type of brain diabetes points the way to novel discoveries that may finally result in disease-modifying treatments for this devastating disease.” "

Being overweight does affect your libido. But small changes can jump-start your sex drive.

Being overweight does affect your libido. But small changes can jump-start your sex drive.

How Too Much Weight Hampers Sex Drive

According to a recent study conducted by Binks and his colleagues at Duke, up to 30% of obese people seeking help controlling their weight indicate problems with sex drive, desire, performance, or all three. Often, the latest research shows, these problems can be traced to physical conditions that co-exist with obesity.

"Medical conditions such as high cholesterol and insulin resistance [an early indicator of type 2 diabetes] do have the ability to impact sexual performance, which in turn impacts desire, particularly in men," says Andrew McCollough, MD, director of sexual health and male infertility at NYU Medical Center in New York.

Because both conditions can cause the tiny arteries in the penis to shut down, particularly when vessel-clogging fatty deposits begin to form, McCollough says impotence or erectile dysfunction is often the result.

"A man who has problems having an erection is going to lose his desire for sex in not too long a time," says McCollough.

Men aren't alone with sex problems caused by poor blood flow. Research shows overweight women's sex drive and desire are affected by the same problem.

"We are beginning to see that the width of the blood vessels leading to the clitoris [the area of the vagina most closely related to sexual response] in women are affected by the same kind of blockages that impact blood flow to the penis," says Susan Kellogg, PhD, director of sexual medicine at the Pelvic and Sexual Health Institute of Graduate Hospital in Philadelphia.

When this happens, says Kellogg, a woman's body is far less responsive, and a drop in desire is not far behind.

Complicating matters further for both sexes: The more body fat you have, the higher your levels of a natural chemical known as SHBG (short for sex hormone binding globulin). It's aptly named because it binds to the sex hormone testosterone. Doctors theorize that the more testosterone that is bound to SHBG, the less there is available to stimulate desire.

What can you do to improve your physical conditioning for sex? Plenty. Experts say losing as few as 10 pounds can often free up testosterone and almost immediately give a boost to your love life.

Evidence that Low Carb Diets are Better for Diabetics - Second Opinions, UK

Evidence that Low Carb Diets are Better for Diabetics - Second Opinions, UK

Surender K Arora and Samy I McFarlane. The case for low carbohydrate diets in diabetes management. Nutrition & Metabolism 2005, 2:16 doi:10.1186/1743-7075-2-16

Abstract (provisional)
A low fat, high carbohydrate diet in combination with regular exercise is the traditional recommendation for treating diabetes. Compliance with these lifestyle modifications is less than satisfactory, however, and a high carbohydrate diet raises postprandial plasma glucose and insulin secretion, thereby increasing risk of CVD, hypertension, dyslipidemia, obesity and diabetes. Moreover, the current epidemic of diabetes and obesity has been, over the past three decades, accompanied by a significant decrease in fat consumption and an increase in carbohydrate consumption.

This apparent failure of the traditional diet, from a public health point of view, indicates that alternative dietary approaches are needed. Because carbohydrate is the major secretagogue of insulin, some form of carbohydrate restriction is a prima facie candidate for dietary control of diabetes.

Evidence from various randomized controlled trials in recent years has convinced us that such diets are safe and effective, at least in short-term. These data show low carbohydrate diets to be comparable or better than traditional low fat high carbohydrate diets for weight reduction, improvement in the dyslipidemia of diabetes and metabolic syndrome as well as control of blood pressure, postprandial glycemia and insulin secretion. Furthermore, the ability of low carbohydrate diets to reduce triglycerides and to increase HDL is of particular importance.

Resistance to such strategies has been due, in part, to equating it with the popular Atkins diet. However, there are many variations and room for individual physician planning. Some form of low carbohydrate diet, in combination with exercise, is a viable option for patients with diabetes. However, the extreme reduction of carbohydrate of popular diets (<30g/day) cannot be recommended for a diabetic population at this time without further study.

On the other hand, the dire objections continually raised in the literature appear to have very little scientific basis. Whereas it is traditional to say that more work needs to be done, the same is true of the assumed standard low fat diets which have an ambiguous record at best. We see current trends in the national dietary recommendations as a positive sign and an appropriate move in the right direction.