‘Good’ Cholesterol May Not Be So Great After All

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iStock

Bad news for good cholesterol: A Danish study published in European Heart Journal finds that people with extremely high high-density lipoprotein (HDL, often called “good” cholesterol) levels face a higher, not lower, risk of death.

Cholesterol as a substance is neither good nor bad, but an important part of our body chemistry. Like most things, in moderation, it's fine; the health risks set in once our levels get out of whack. Scientists and doctors have long understood cholesterol as a sort of angel-on-one-shoulder, devil-on-the-other situation, in which low-density lipoprotein (LDL) is harmful and HDL is helpful. HDL mediates LDL's negative effects, which means that having more HDL is good.

Or at least that's what we thought.

Researchers pulled health information on 116,000 people from the Copenhagen City Heart Study and the Copenhagen General Population Study, then cross-checked it against death reports from the Danish Civil Registration System. They followed study subjects for six years, during which more than 10,500 people died. 

What they found surprised them. Extremely high levels of HDL were associated with significantly greater risks of death than normal levels—68 percent higher for women and a staggering 106 percent for men. Men with very high HDL (one step down from "extremely high") were 36 percent more likely to die.

"These results radically change the way we understand 'good' cholesterol. Doctors like myself have been used to congratulating patients who had a very high level of HDL in their blood. But we should no longer do so, as this study shows a dramatically higher mortality rate," co-author Børge Nordestgaard of the University of Copenhagen said in a statement.

Before we get too worried, it's worth noting that these extremely high HDL levels were incredibly rare, affecting only 0.4 percent of male participants and 0.3 percent of women. The researchers say these people were also more likely to share unusual genetic variants. It's possible that these genes and not the cholesterol are responsible for their higher mortality rates.

Some elements of our ideas about cholesterol still held true. People with extremely low HDL levels also faced an increased mortality risk.

The safest levels seemed to be right in the middle, at 1.9 mmol/L for men and 2.4 mmol/L for women. 

More research is needed, as this study focused exclusively on white Danish people and only looked at correlation, not causation. 

Still, Nordestgaard said, "It appears that we need to remove the focus from HDL as an important health indicator in research, at hospitals and at the general practitioner. These are the smallest lipoproteins in the blood, and perhaps we ought to examine some of the larger ones instead."

One Good Reason Not to Hold in a Fart: It Could Leak Out of Your Mouth

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iStock/grinvalds

The next time you hold in a fart for fear of being heard by polite company, just remember this: It could leak out of your mouth instead of your butt. Writing on The Conversation, University of Newcastle nutrition and dietetics professor Clare Collins explains that pent-up gas can pass through your gut wall and get reabsorbed into your circulation. It's then released when you exhale, whether you like it or not.

“Holding on too long means the build up of intestinal gas will eventually escape via an uncontrollable fart,” Collins writes. In this case, the fart comes out of the wrong end. Talk about potty mouth.

A few brave scientists have investigated the phenomenon of flatulence. In one study, 10 healthy volunteers were fed half a can of baked beans in addition to their regular diets and given a rectal catheter to measure their farts over a 24-hour period. Although it was a small sample, the results were still telling. Men and women let loose the same amount of gas, and the average number of “flatus episodes” (a single fart, or series of farts) during that period was eight. Another study of 10 people found that high-fiber diets led to fewer but bigger farts, and a third study found that gases containing sulphur are the culprit of the world’s stinkiest farts. Two judges were tapped to rate the odor intensity of each toot, and we can only hope that they made it out alive.

Scientific literature also seems to support Collins’s advice to “let it go.” A 2010 paper on “Methane and the gastrointestinal tract” says methane, hydrogen sulfide, and other gases that are produced in the intestinal tract are mostly eliminated from the body via the anus or “expelled from the lungs.” Holding it in can lead to belching, flatulence, bloating, and pain. And in some severe cases, pouches can form along the wall of the colon and get infected, causing diverticulitis.

So go ahead and let it rip, just like nature intended—but maybe try to find an empty room first.

[h/t CBS Philadelphia]

A Chemical in Spider Venom Could Be a Key to Killing Skin Cancer Cells

Alan Couch, Flickr // CC BY 2.0
Alan Couch, Flickr // CC BY 2.0

Despite their formidable reputation in the eyes of arachnophobes, spiders contribute to human society in a number of positive ways. On a practical level, they can reduce the population of insects in your home by trapping them for meals. Outdoors, they keep pests from destroying gardens and crops, making sure we don't slip into a period of famine and anarchy. In the lab, scientists have identified a number of chemicals in their venom as possible building blocks for medicines treating everything from pain to muscular dystrophy.

That field of study has led to a promising discovery. In Australia, researchers have isolated one particular compound in a funnel-web spider's venom that can diminish skin cancer cells.

Scientists at QIMR Berghofer and the University of Queensland began studying the Australian funnel-web spider known as Hadronyche infensa after a similar Brazilian arachnid, Acanthoscurria gomesiana, was shown to carry a peptide in its venom called gomesin that has cancer-fighting properties. Identifying a similar peptide in the Australian spider, the researchers demonstrated that the chemical was effective in killing skin cancer cells while leaving healthy skin cells alone.

The peptide was tested on human melanoma cells, eradicating the majority of them. In mice, it also slowed the growth of the melanomas. The peptide was even effective in killing cells found in facial tumors of Tasmanian devils, a marsupial susceptible to an aggressive form of skin cancer transmittable through biting. The results were published in the journal Scientific Reports.

These peptides are able to be manipulated, taking on different properties as scientists alter amino acids to create new and potentially more potent versions. It’s hoped that this line of research will lead to the development of treatments for skin cancer in humans.

It's something to think about the next time you consider swatting a spider—though if you happen to reside in Australia and see the funnel-web variety, you might not have a choice. While there are 35 different species of funnel-webs of varying potency, some are so formidable that their fangs can pierce fingernails, and their venom is able to kill a human in less than 15 minutes.

[h/t New Atlas]

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