Showing posts with label evidence-based science. Show all posts
Showing posts with label evidence-based science. Show all posts

Sunday, 15 March 2015

Science Has Worked Out Why Paper Cuts Hurt So Damn Much





Science Has Worked Out Why Paper Cuts Hurt So Damn Much

When people say paper cuts are the worst pain in the world, they might be slightly exaggerating - but why do such tiny cuts actually hurt that much? 

Check out this short video from Scientific American explaining why.


Wednesday, 19 November 2014

Scientists have discovered an on/off switch for ageing cells

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In our bodies, our cells are constantly dividing in order to replenish our lungs, skin, liver and other organs. But most human cells can’t divide forever, and eventually this causes our organs and tissues to degrade as we age.
The "timekeeper" of our cells are telomeres - little DNA caps that sit at the end of our chromosomes, sort of like that plastic bit at the end of your shoelace. Each time a cell divides, these telomeres get shorter and shorter until eventually they're so short the cell can no longer divide. 
But researchers know that there is a way to stop the telomere from wearing down - some cells can produce an enzyme called telomerase, which rebuilds telomeres and lets cells divide indefinitely. However they've struggled to understand why telomerase acts in some cells and not others.
Now researchers from the Salk Institute for Biological Studies in the UShave discovered that telomerase has an on/off switch - and can be present in a cell but not slow down ageing if it's turned off.
“Previous studies had suggested that once assembled, telomerase is available whenever it is needed,” senior author Vicki Lundblad said in a press release. “We were surprised to discover instead that telomerase has what is in essence an ‘off’ switch, whereby it disassembles.” Their research is published in the journal Genes and Development.
It’s a pretty huge breakthrough, because if scientists can now work out how to manipulate this “off” switch, it could help them slow down the ageing process and lead to treatments for age-related diseases. And, interestingly, it may also provide insight into cancer cells, which require telomerase to help them divide uncontrollably.
Lundblad, along with graduate student Timothy Tucey, discovered this switch in yeast, by using a new technique that allowed them to monitor each component of telomerase while a cell grew and divided. 
Each time a cell divides, its genome must be duplicated completely. And the scientists found that while a cell was replicating, telemorase was sitting in a “preassembly” mode, waiting for a molecular subunit to be added once genome duplication was complete.
But surprisingly, as soon as the telemorase was assembled, it quickly disassembled and switched into the “off” position, they discovered. 
The researchers believe that this off switch might help the body keep telomerase at exceptionally low levels inside the cells in order to avoid the uncontrollable cell growth that can lead to cancer. But it could also be the key to helping cells divide for longer.
While it might not seem as though these experiments in a single-celled yeast can tell us much about human cells, much of the initial research on telomerase was done in yeast cells and laid the groundwork for future discoveries in humans.
The next step is to understand more about this switch and how it is involved in ageing and cancer, and then scientists can try to understand how it can be manipulated to keep people healthier for longer.

Tuesday, 14 October 2014

8 Foods Even The Experts Won’t Eat


Food scientists are shedding light on items loaded with toxins and chemicals–and simple swaps for a cleaner diet and supersized health. Experts from different areas of specialty explain why they won’t eat these eight foods.
Clean eating means choosing fruits, vegetables, and meats that are raised, grown, and sold with minimal processing. Often they’re organic, and rarely (if ever) should they contain additives. But in some cases, the methods of today’s food producers are neither clean nor sustainable. The result is damage to our health, the environment, or both. So we decided to take a fresh look at food through the eyes of the people who spend their lives uncovering what’s safe–or not–to eat. ” Their answers don’t necessarily make up a “banned foods” list. But reaching for the suggested alternatives might bring you better health–and peace of mind.

1. The Endocrinologist Won’t Eat: Canned Tomatoes

Fredrick Vom Saal, is an endocrinologist at the University of Missouri who studies bisphenol-A.
The problem: The resin linings of tin cans contain bisphenol-A, a synthetic estrogen that has been linked to ailments ranging from reproductive problems to heart disease, diabetes, and obesity. Unfortunately, acidity (a prominent characteristic of tomatoes) causes BPA to leach into your food. Studies show that the BPA in most people’s body exceeds the amount that suppresses sperm production or causes chromosomal damage to the eggs of animals. “You can get 50 mcg of BPA per liter out of a tomato can, and that’s a level that is going to impact people, particularly the young,” says vom Saal. “I won’t go near canned tomatoes.”
The solution: Choose tomatoes in glass bottles (which do not need resin linings), such as the brands Bionaturae and Coluccio. You can also get several types in Tetra Pak boxes, like Trader Joe’s and Pomi. Exposure to BPA Causes Permanent Damage In OffSpring

2. The Farmer Won’t Eat: Corn-Fed Beef

Joel Salatin is co-owner of Polyface Farms and author of half a dozen books on sustainable farming.The problem: Cattle evolved to eat grass, not grains. But farmers today feed their animals corn and soybeans, which fatten up the animals faster for slaughter. But more money for cattle farmers (and lower prices at the grocery store) means a lot less nutrition for us. A recent comprehensive study conducted by the USDA and researchers from Clemson University found that compared with corn-fed beef, grass-fed beef is higher in beta-carotene, vitamin E, omega-3s, conjugated linoleic acid (CLA), calcium, magnesium, and potassium; lower in inflammatory omega-6s; and lower in saturated fats that have been linked to heart disease. “We need to respect the fact that cows are herbivores, and that does not mean feeding them corn and chicken manure,” says Salatin.
The solution: Buy grass-fed beef, which can be found at specialty grocers, farmers markets, and nationally at Whole Foods. It’s usually labeled because it demands a premium, but if you don’t see it, ask your butcher.


3. The Toxicologist Won’t Eat: Microwave Popcorn

Olga Naidenko, is a senior scientist for the Environmental Working Group.

The problem: Chemicals, including perfluorooctanoic acid (PFOA), in the lining of the bag, are part of a class of compounds that may be linked to infertility in humans, according to a recent study from UCLA. In animal testing, the chemicals cause liver, testicular, and pancreatic cancer. Studies show that microwaving causes the chemicals to vaporize–and migrate into your popcorn. “They stay in your body for years and accumulate there,” says Naidenko, which is why researchers worry that levels in humans could approach the amounts causing cancers in laboratory animals. DuPont and other manufacturers have promised to phase out PFOA by 2015 under a voluntary EPA plan, but millions of bags of popcorn will be sold between now and then.
The solution: Pop organic kernels the old-fashioned way: in a skillet. For flavorings, you can add real butter or dried seasonings, such as dillweed, vegetable flakes, or soup mix. Make it organic and use coconut oil. If You’re Still Eating Microwave Popcorn, You’re Not Fully Grasping The Health Consequences

4. The Farm Director Won’t Eat: Nonorganic Potatoes

Jeffrey Moyer is the chair of the National Organic Standards Board.

The problem: Root vegetables absorb herbicides, pesticides, and fungicides that wind up in soil. In the case of potatoes–the nation’s most popular vegetable–they’re treated with fungicides during the growing season, then sprayed with herbicides to kill off the fibrous vines before harvesting. After they’re dug up, the potatoes are treated yet again to prevent them from sprouting. “Try this experiment: Buy a conventional potato in a store, and try to get it to sprout. It won’t,” says Moyer, who is also farm director of the Rodale Institute (also owned by Rodale Inc., the publisher of Prevention). “I’ve talked with potato growers who say point-blank they would never eat the potatoes they sell. They have separate plots where they grow potatoes for themselves without all the chemicals.”

The solution: Buy organic potatoes. Washing isn’t good enough if you’re trying to remove chemicals that have been absorbed into the flesh. Budget tip: Organic potatoes are only $1 to $2 a pound, slightly more expensive than conventional spuds.

5. The Fisheries Expert Won’t Eat: Farmed Salmon

Dr. David Carpenter, director of the Institute for Health and the Environment at the University at Albany, published a major study in the journal Science on contamination in fish.
The problem: Nature didn’t intend for salmon to be crammed into pens and fed soy, poultry litter, and hydrolyzed chicken feathers. As a result, farmed salmon is lower in vitamin D and higher in contaminants, including carcinogens, PCBs, brominated flame retardants, and pesticides such as dioxin and DDT. According to Carpenter, the most contaminated fish come from Northern Europe, which can be found on American menus. “You could eat one of these salmon dinners every 5 months without increasing your risk of cancer,” says Carpenter, whose 2004 fish contamination study got broad media attention. “It’s that bad.” Preliminary science has also linked DDT to diabetes and obesity, but some nutritionists believe the benefits of omega-3s outweigh the risks. There is also concern about the high level of antibiotics and pesticides used to treat these fish. When you eat farmed salmon, you get dosed with the same drugs and chemicals.
The solution: Switch to wild-caught Alaska salmon. If the package says fresh Atlantic, it’s farmed. There are no commercial fisheries left for wild Atlantic salmon. Farmed Fish vs. Wild Fish: How Healthy
Is The Fish At Your Favorite Grocery?

6. The Cancer Researcher Won’t Drink: Milk Produced With Artificial Hormones

Rick North is project director of the Campaign for Safe Food at the Oregon Physicians for Social Responsibility and former CEO of the Oregon division of the American Cancer Society.

The problem: Milk producers treat their dairy cattle with recombinant bovine growth hormone (rBGH or rBST, as it is also known) to boost milk production. But rBGH also increases udder infections and even pus in the milk. It also leads to higher levels of a hormone called insulin-like growth factor in milk. In people, high levels of IGF-1 may contribute to breast, prostate, and colon cancers. “When the government approved rBGH, it was thought that IGF-1 from milk would be broken down in the human digestive tract,” says North. “There’s not 100 percent proof that this is increasing cancer in humans,” admits North. “However, it’s banned in most industrialized countries.”
The solution: Buy raw milk or check labels for rBGH-free, rBST-free, produced without artificial hormones, or organic milk. These phrases indicate rBGH-free products. Why Do Humans Still Drink Milk?

7. The Biotech Specialist Who Won’t Eat Conventional Soy: GMO Unfermented Soy

Michael Harris is biotech specialist who has directed several projects within the biotech sector including those for genetically engineered food. He has been a consultant, manager and director for companies such as Xenon Pharmaceuticals and Genon Corporation.

The problem: Genetically engineered food is a cause of great concern due to the manipulation of DNA and genetic code including transfers from one species to another. Fermented Soy Is The Only Soy Food Fit for Human Consumption and since almost 90% of soy in the world is genetically modified, if you are not ensuring sources are organic, long-term health problems are inevitable, especially since soy has been found to affect hormonal balance and even cause cancer.
The solution: Check labels to ensure soy is Non-GMO or organic and never consume unfermented sources. If possible contact the company to find out exactly where the Non-GMO soy was obtained.

8. The Organic-Foods Expert Won’t Eat: Conventional Apples

Mark Kastel, a former executive for agribusiness, is codirector of the Cornucopia Institute, a farm-policy research group that supports organic foods.
The problem: If fall fruits held a “most doused in pesticides contest,” apples would win. Why? They are individually grafted (descended from a single tree) so that each variety maintains its distinctive flavor. As such, apples don’t develop resistance to pests and are sprayed frequently. The industry maintains that these residues are not harmful. But Kastel counters that it’s just common sense to minimize exposure by avoiding the most doused produce, like apples. “Farm workers have higher rates of many cancers,” he says. And increasing numbers of studies are starting to link a higher body burden of pesticides (from all sources) with Parkinson’s disease.
The solution: Buy organic apples or apples from a farmer that you trust!

Wednesday, 23 July 2014

Is Laughter the Best Medicine?

There's some scientific evidence that "Take two jokes and call me in the morning" is a worthwhile prescription. But not much.

By Susan Brink

We all want to believe that laughter is good for what ails us, but the science backing that up is thin. Most studies have been small and have relied on self-reported assessments.





Still, a rollicking good guffaw can't hurt. Or can it? There are rare instances of laughter prompting an asthma attack and even rarer instances of it triggering a stroke. And though this hasn't been part of a formal study, one researcher speculates that if you're surrounded by people laughing inappropriately—finding, say, a cockfight hilarious—it increases stress.
However, a few studies relying on laboratory testing do show some benefits.
"A good belly laugh leads to the release of endorphins from the brain," says Michael Miller, director of the Center for Preventive Cardiology at the University of Maryland Medical Center in Baltimore.
That release sets off a cascade of heart-healthy biological events. Endorphins, pleasure-inducing neurotransmitters, activate receptors on the surface of the endothelium, the layer of flat cells lining blood vessels. That leads to the release of nitric oxide, which widens blood vessels—increasing blood flow, lessening inflammation, inhibiting platelet clumping, and reducing the formation of cholesterol plaque.
A 2005 study by Miller measured the blood flow of 20 volunteers before and after watching a funny movie and a sad movie. After the sad movie, blood flow was more restricted in 14 of the 20 viewers. But after the movie that made them laugh, average blood flow increased by 22 percent.
"The best laugh is one that brings tears to our eyes," says Miller, author of Heal Your Heart: The Positive Emotions Prescription to Prevent and Reverse Heart Disease, scheduled for publication by Rodale Press in September. His prescription: at least 30 minutes of exercise at least three times a week—and 15 minutes of daily laughter.
You Have to Laugh Out Loud
Funding for laughter and humor research is low—so low that when Mary Bennett, director of the Western Kentucky University School of Nursing, wanted to look into the effect of laughter on the immune system, she found herself scrounging, asking other researchers for vials and other equipment from their labs. "It's really hard to get taken seriously when you say you study laughter," she says.
But her study of 33 healthy women, published in 2003, showed that those who laughed at a humorous movie had higher levels of natural killer cell activity, which increased their ability to fight off disease. However, the effect was seen only in the subjects who laughed out loud, not in those who quietly watched the comedy.
A study in Japan that also used laboratory findings found that laughter could improve anti-inflammatory factors in the blood of people who have rheumatoid arthritis.
But the bulk of the research on laughter and health depends on subjective studies and not on evidence-based science. And some studies are contradictory. One study of 70 depressed elderly women found that laughter yoga was just as effective as exercise therapy in improving mood, as measured by self-satisfaction reports by subjects. Humor and laughter may improve muscle tone, though only when someone is laughing, and some studies do show that a good laugh can help reduce stress hormones. But other studies show that laughter doesn't affect those hormones, according to a review of the literature published by Bennett.
No doubt, a New Yorker cartoon, a good joke, or an hour spent with the Marx Brothers can feel therapeutic. But when Bennett, who has spent much of her career studying laughter and poring over the research literature, is asked whether laughter cures or prevents any disease, her quick answer is a simple "No."
Still, she adds, "I think it's a useful adjunct of real medicine. If you're going through something like chemotherapy, anything you can do to help you stay sane through something that nasty will help."