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Showing posts from November, 2010

New vitamin D guidelines, a disappointment

Over the past decade, there has been tremendous excitement in the world of nutrition centered around the "sunshine vitamin " for its association with reducing risk of influenza, osteoporosis, autoimmune diseases, heart disease, and even some cancers such as prostate and breast cancer.   However, this morning, the Institute of Medicine, of the National Academy of Sciences released new  guidelines   for vitamin D   (and calcium) that will come as a disappointment to several researchers who consider the report too conservative to deal with a widespread epidemic. "Vitamin D is  the most common medical condition in the world, believe it or not" said Michael Holick, of Boston University Medical Center, to me in a recent interview. Holick, who routinely prescribes 2000-3000 IU per day to his patients, has studied  Vitamin D for more than 40 years. In the 1970s he was the first to isolate the major circulating form of   Vitamin D  in plasma, 25-hydroxyvitamin D , as well as

HealthCorrelator for Excel 1.0 (HCE): Call for beta testers

This call is closed. Beta testing has been successfully completed. HealthCorrelator for Excel (HCE) is now publicly available for download and use on a free trial basis. For those users who decide to buy it after trying, licenses are available for individuals and organizations. To download a free trial version – as well as get the User Manual, view demo YouTube videos, and download and try sample datasets – visit the HealthCorrelator.com web site.

Food sharing: Hunter-gatherer "health insurance"

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Kim Hill By pure chance (involving a failed attempt to go hiking and a speeding ticket), I found myself at a talk given by anthropologist Kim Hill , speaking on the "Emergence of Human Uniqueness: Characteristics Underlying Behavioral Modernity." I previously wrote an article for Scientific American on an Arizona State University workshop that Hill headed up along with Curtis Marean and Lawrence Krauss last February. Most of Hill's talk was basically the same stuff I wrote about before like that humans are outliers, not unique in any specific way, but contain a combination of non-unique traits that arose through non-unique processes produced a unique outcome -- a "spectacular anomaly." "If aliens from outerspace came to the Earth," Hill said, then they would be questioning humans instantly because we're so dominant in several ways: technologically, agriculturally, population-wise, etc. Some would point to the industrial revolution, but Hill argue

Human traits are distributed along bell curves: You need to know yourself, and HCE can help

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Most human traits (e.g., body fat percentage, blood pressure, propensity toward depression) are influenced by our genes; some more than others. The vast majority of traits are also influenced by environmental factors, the “nurture” part of the “nature-nurture” equation. Very few traits are “innate”, such as blood type. This means that manipulating environmental factors, such as diet and lifestyle, can strongly influence how the traits are finally expressed in humans. But each individual tends to respond differently to diet and lifestyle changes, because each individual is unique in terms of his or her combination of “nature” and “nurture”. Even identical twins are different in that respect. When plotted, traits that are influenced by our genes are distributed along a bell-shaped curve. For example, a trait like body fat percentage, when measured in a population of 1000 individuals, will yield a distribution of values that will look like a bell-shaped distribution. This type of distribu

Chemicals in Store Register Receipts and Fast Food Wrappers

Before the next time you ask a cashier for a receipt, think twice! It might be tainted with bisphenol A, aka BPA. A recent study in Environmental Health Perspectives showed that cashiers had highest BPA exposure because of its use in thermal paper for register receipts in a monomer form that is readily absorbed through skin. BPA is also used as a polymer complex in hard, clear polycarbonate plastic water bottles and as epoxy resins lining aluminum cans. The study raises concerns about widespread exposure to BPA from a variety of sources, especially for women who are pregnant. Although the actual BPA amounts in receipts is so little it may not pose enough risk to worry about, it does raise concerns for people—those behind a register, for example—who are in contact with the thermal paper regularly. The news comes no later than a month after Health Canada officially declared BPA a toxic substance that mimics estrogen, potentially increasing risks of breast cancer and prostate cancer. Add

How our senses help us decide what we eat

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Senses help us select our food. So, this is a blog post about the importance of sensory criteria for selecting food, which was inspired by a day of cooking up goods for the holidays. What makes people choose the foods that they do? This question may seem obvious to yourself--after all, you know what you like--but this is a question posed by food industry scientists ask themselves day in and day out. The science of food selection can get crazy complex when you think of the huge variety of foods that you find at your corner grocery store. Food scientists must continually find new "niches" for products to be placed in the marketplace. How do they do it? The same question can be asked of musicians who endlessly produce new songs that the radio blares as latest hits, but using the same 12 musical notes. Only, in the case of food, scientists only have five notes, or tastes, the "Five-Taste Stimuli": -sweet -sour -bitter -salty -savory (umami - think MSG, mushrooms, tomato

What happens on a high omega-6 diet

A while back I wrote a review of Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We Can Do about Them . Susan Allport's book goes into the history of how omega-3s were discovered and what they'll mean for us in the future. A controversial topic of the book is how omega-6 (king) and omega-3 (queen) compete for space in eicosanoid pathways. The omega-6s, the king, are the greater competitor and more inflammatory, while the omega-3, the queen, are a lesser competitor and less inflammatory. She goes on about this relationship between omega-6 and omega-3 and gives examples from nature of how both the oils are found and used -- omega-3s in leaves (leaf fats), omega-6s in seeds (seed fats); omega-3s eaten more often in summer months, omega-6s in winter months by animals. The omega-6s are thought to bring on extra fat for warmth, for storage, for hibernation. It's all pretty interesting stuff. And again, as I said, a bit controversial. Now, in a new article

Your mind as an anabolic steroid

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The figure below, taken from Wilmore et al. (2007), is based on a classic 1972 study conducted by Ariel and Saville . The study demonstrated the existence of what is referred to in exercise physiology as the “placebo effect on muscular strength gains”. The study had two stages. In the first stage, fifteen male university athletes completed a 7-week strength training program. Gains in strength occurred during this period, but were generally small as these were trained athletes. In the second stage the same participants completed a 4-week strength training program, very much like the previous one (in the first stage). The difference was that some of them took placebos they believed to be anabolic steroids. Significantly greater gains in strength occurred during this second stage for those individuals, even though this stage was shorter in duration (4 weeks). The participants in this classic study increased their strength gains due to one main reason. They strongly believed it would happe

Resveratrol influences belly fat behavior

Fat can not only be unsightly, but if it’s sitting on your belly, may also contribute to overproduction of signaling hormones called adipokines, which are linked to metabolic changes that can worsen health. New research from Aarhus University has found that abdominal adipose tissue extracted from overweight adults, and then exposed to resveratrol, exhibited reduced adipokine production. According to these authors, "small interfering molecules such as resveratrol are, in this matter, hypothesized to possess beneficial effects and might improve the metabolic profile in human obesity." The scientists obtained the abdominal adipose tissue via liposuction from seven women and one man, ages 43-55, who had body mass indexes categorized as overweight. All subjects were Caucasian, healthy and not on any medication that could confound the results. Because previous studies in rodents have shown that calorie restriction reduces production of adipokines by activating an enzyme called Sirt

Middle-aged Mice fed BCAAs live longer

Scientists are actively seeking aging-intervention strategies to help people maintain their youth in anticipation of a sharp rise in the elderly population – due to the "baby boomer" generation – and an unprecedented number of elderly in North America and throughout the developed world. Now, a new study in the October issue of Cell Metabolism reports that middle-aged, male mice given a cocktail of branched-chain amino acids (BCAAs) – leucine, isoleucine, valine – in their drinking water lived an average of 12 percent longer (869 days compared to 774 days) than middle-aged, male mice drinking regular water. The scientists, from Milan University, found that the BCAA-fed mice exhibited similar changes as those seen with calorie restriction or resveratrol supplementation, showing an increase in longevity-gene SIRT1 activity and an increase in cardiac and skeletal muscle mitochondria levels. The treated mice also showed improved exercise endurance and motor coordination, and had

My tour of Yale biotech facilities

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I had the good fortune of touring Yale University's biotech facilities today, including the 2007-built Yale Stem Cell Center, with its director as our guide: cell biology professor Haifan Lin, PhD . Walking through a high-tech stem cell facility with Lin was nothing like I expected. Lin was incredibly personable, and he and his staff took us through their labs and offices with a sense of enjoyment and courtesy if introducing us as friends to their home -- "come on into my lab, here's our million-dollar microscope, there's our genomic analyzer, would you like some tea?" OK, so Lin didn't actually offer us tea, but he might as well have with his ultra-nice Chinese hospitality. On the tour, there were only three of us, all journalists, so it lended to opportunity of intimate discussion and questions. Lin generously answered everything we wanted him to and with a genuine excitement about it. He shared that he had an appreciation for what we science writers do, s

New Paradigms and the Future of Medicine

What is the future of medicine and how will we get there? On Monday morning, as part of New Horizons of Science at Yale, Director of Institutes of Systems Biology Lee Hood discussed the advent of 21st-century medicine: p4 medicine . What are paradigm changes in biology leading to p4, or proactive medicine? There are several changes needed and all overlap and interconnect, but the main drivers in the process are: - bringing engineering to biology through high throughput biology - the human genome project - cross-disciplinary biology - systems biology "What's fascinating is that these four paradigm changes are creating a new foundation in medicine," says Dr. Hood. "And they were each met with skepticism." What does p4 medicine represent? predictive, preventive, personalized, participatory (p4). In other words, it's the taking of genomics and systems biology to finally unravel the complexity of pathology and seeking out preventive and personalized strategies o

High-heat cooking will AGE you, if you eat food deep-fried with industrial vegetable oils

As I said before on this blog, I am yet to be convinced that grilled meat is truly unhealthy in the absence of leaky gut problems. I am referring here to high heat cooking-induced Maillard reactions (browning) and the resulting advanced glycation endproducts (AGEs). Whenever you cook a food in high heat, to the point of browning it, you generate a Maillard reaction. Searing and roasting meat usually leads to that. Elevated levels of serum AGEs presumably accelerate the aging process in humans. This is supported by research with uncontrolled diabetics, who seem to have elevated levels of serum AGEs. In fact, a widely used measure in the treatment of diabetes, the HbA1c (or percentage of glycated hemoglobin) , is actually a measure of endogenous AGE formation. (Endogenous = generated by our own bodies.) Still, evidence that a person with an uncompromised gut can cause serum levels of AGEs to go up significantly by eating AGEs is weak, and evidence that any related serum AGE increases lea

Why do we make bad decisions? It's evolution, stupid.

In the afternoon session of New Horizons in Science at Yale, psychology professor Laurie Santos delivered a compelling talk on the origins of human irrationality. Santos studies comparative cognition in primates including humans, chimps, various monkeys, and (my favorite animal) lemurs! There isn't too much about rationality that we don't share with the rest of the primate family. What makes humans different in irrationality? Well, actually, a lot of us are indeed similarly stupid to most monkeys -- cognitively speaking, because of biases, heuristics, errors in judgment. It's amazing that we can even become adult humans at all, says Santos. Her research delves into what causes us to be irrational, our "cognitive dissonance." Cognitive dissonance, it turns out, is shaped by decisions and preferences that lead to our decision making. And, she presented examples of experiments of how they found in adults and children that preferences change dependent on prior decisi

What microbes in our soil (not dirt!) mean to us

Most people have no idea just how large the role of microbes play as a part in our world, in our soil, in our bodies. That was the introduction we received on the subject from Yale professor Jo Handelsman at New Horizons in Science (as part of #sciwri10). As a molecular, cellular and developmental biologist, Handelsman takes issue with any scientist or science writer who dares refer to the world's largest organ as simply "dirt" (a mistake I've already made and won't make again). In human health, microbes do a lot more than we thought, says Handelsman. There are interesting associations of feelings like anger and different composition of human gut microbiota. Microbes or microbial products or microbial interactions with host tissues are also shown in animals to be linked to diseases including obesity, diabetes, etc. (apart from genetics and diet). We are "microbial organisms"! says Handelsman, noting that our bodies contain 10 times more microbes than ce

On the Hunt for Neuropsychiatric Disorder Genes

Next speaker up at New Horizons in Science is co-director of Yale's Neurogenetics Program Matthew State , a child psychiatrist who describes himself as a gene hunter . The genes he seeks out are those that may be linked to child neuropsychiatric disorders including autism, Tourette , and obsessive-compulsive disorders. What he and other researchers use as a tool is high-throughput, high-resolution genomic analysis, which is so fast that in the near future we may know quite a bit more about many of the chromosomal rearrangements linked to several genetics disorders. However, he says, "we still have not been able to find a single common variation" in gene sequence that explains any of the child psychiatric disorders. But, he expresses a certain excitement about the future of genomics analysis because of fast technologies. What he predicts is that rare gene variations, or rare combinations of gene variations, will finally explain the etiology of the child psychiatric disorde

Deep-brain stimulation for depression

On Sunday morning at New Horizons in Science at Yale -- after some coffee for brain stimulation -- we were treated to our first science talk of the day: on deep-brain stimulation as a treatment for severe depression. Emory University professor of psychiatry and neurology Helen Mayberg, MD , showed us several brain scans she uses to study moods and neural networks. She can tell from these neural images whether you're glad, mad or sad. Then, she targets areas of the brain with what she describes as an "implantation of a very, small wire... with electrodes on the end." The electrodes are guided to wherever she wants it in the brain and an IPG is implanted in the chest. Dr. Mayberg worried about the safety of acute stimulation of areas of the brain. What happens if you stimulate the hypothalamus and it causes a drop in blood pressure? But she couldn't rely on surgeons as "gatekeepers," so she performed intra-operative safety testing. During the testing, patients

Amino acids in skeletal muscle: Are protein supplements as good as advertised?

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When protein-rich foods, like meat, are ingested they are first broken down into peptides through digestion. As digestion continues, peptides are broken down into amino acids, which then enter circulation, becoming part of the blood plasma. They are then either incorporated into various tissues, such as skeletal muscle, or used for other purposes (e.g., oxidation and glucose generation). The table below shows the amino acid composition of blood plasma and skeletal muscle. It was taken from Brooks et al. (2005), and published originally in a classic 1974 article by Bergström and colleagues . Essential amino acids, shown at the bottom of the table, are those that have to be consumed through the diet. The human body cannot synthesize them. (Tyrosine is essential in children; in adults tryptophan is essential.) The data is from 18 young and healthy individuals (16 males and 2 females) after an overnight fast. The gradient is a measure that contrasts the concentration of an amino acid in mu