- – Juvenal, Roman poet, circa 60 AD
Monthly Archives: July 2013
Release your kung fu grip on that salad plate. Maybe a milkshake isn’t as bad as you think – at least not for your brain.
For nearly a decade, researchers have been honing in on a link between diabetes and Alzheimer’s disease. People with diabetes are twice as likely to get the disease. The problem, studies suggest, is impaired insulin function, the hallmark of diabetes.
Insulin dysregulation starves neurons of glucose, their primary energy source. It weakens blood vessels, mucking up delicate brain circulation. Some research implies that normal insulin levels tamp down sticky proteins that clump up in neuron-killing brain lesions. Messed-up insulin levels might break down that safeguard, actually setting the stage for protein buildup.
But a new study that uses tissue from dead brains and images from live ones questions the assumption that diabetes leads to Alzheimer’s.
Two groups were involved in the study, lead by Dr. Madhav Thambisetty of the National Institute on Aging. One consisted of 197 participants enrolled in the Baltimore Longitudinal Study of Aging. While alive, these folks had oral glucose tolerance tests, which measure how the body responds to a sugar blast. When they died, they had a brain autopsy. The second group included 53 living subjects who had the same test, and also an imaging exam showing whether there was any Alzheimer’s pathology in their brain.
Short answer: There were no correlations between any level of impaired insulin function and the presence of amyloid plaques – the protein clumps that destroy brain cells in Alzheimer’s disease. Neither diabetes nor its younger siblings, pre-diabetes or insulin resistance, showed any relation at all to the physical signs of Alzheimer’s.
So should we celebrate this conclusion with a double mocha latte binge? Maybe not. Dr. Thambisetty qualified his findings by saying most of the subjects didn’t experience the years of insulin dysregulation probably needed to cause that kind of damage. Just last week, a neuroscientist found that insulin in the brain seems to impair the way neurons connect to each other. And there’s still that pesky worldwide finding that diabetes doubles your Alzheimer’s risk.
Like most things in life, science sometimes presents conflicting views. But this finding doesn’t change the fact that what’s good for your heart, your lungs, your muscles, your cancer risk, your stroke risk, is also good for your brain.
Exercise, happy plate, no ashtray: Good. Junk food slurping, couch surfing, tobacco smoking: Bad
It seems the ancients had it right: A sound mind arises from a sound body.
“You gain strength, courage, and confidence by every experience in which you really stop to look fear in the face. You must do the thing which you think you cannot do.”
– Eleanor Roosevelt
(and I really am at a dog show this weekend)
….. here’s a really great comic
by Zen Pencils artist Gavin Aung Than. He’s taken the “Welcome to Science” quotes by Phil Plait – better known as The Bad Astronomer – and given them a wonderful visual life. (Click on the link for the entire comic strip)
Mr. Plait’s blog is Bad Astronomy, at Slate.
And more amazing inspirational cartoons on art, being, fear, and courage at Zen Pencils.
“A lot of people forget how important it is to be creative. We get caught up in getting ahead and in day-to-day minutiae. But creativity is a fundamental mode of expression, as is being tenacious and standing by your own convictions and passions, even if it’s not the ‘popular’ choice.”
In a groundbreaking study destined to flip the entire cosmos on its head, testosterone has been found to make women smarter.
Alright. It was just a tiny bit smarter. And the smart-test administered was a shopping list. And the women who took it only remembered 1.6 more things after 26 weeks of testosterone.
I’ve never heard testosterone referred to as the “IQ hormone.” Maybe the “Hey girls, watch me jump off this shed with a knife in my teeth” hormone. Or the “I am going to throw you down on this bed and pound it into a pile of splinters beneath you” hormone. But smart?
Testosterone does bring an element of reckless abandon to manhood, improving pain tolerance, increasing risk-taking behavior, bulking muscles, and serving up a heapin’ helpin’ of aggression. From an evolutionary standpoint this makes lots of sense. If you’re going to throw a puny little sharp stick at a mastodon leg, you better have some guts. Crazy crazy guts. And some serious T-fueled bravado to make excuses about how often you come back empty-handed, bashed-up, hungry, and horny.
Meanwhile, back at the cave, we women – afloat as we were in collaboration-building estrogen – were strapping babies on our backs, foraging far afield, hauling home sacks of roots and nuts and berries and turning it all into dinner. Looking for healing herbs to bind up those manly mastodon wounds. And maybe some kind of pretty nice-smelling flower or a fluffy new cattail pillow.
Given these primal – but still ingrained – differences, I was very surprised at the study of 90 postmenopausal women who got a little brain boost from 6 months of transdermal testosterone gel. Women who used the gel were able to remember about 2 more words on the International Shopping List Test than they did before they gelled up. Women who used a placebo gel still forgot about the same number of items.
According to lead author Susan R. Davis, of Australia’s Monash University, the uptick in memory, though small, should be enough to prompt a bigger investigation of how testosterone might improve cognition in post-menopausal women.
Because, after all, life hasn’t changed much since the cave-days. Even we memory-ravaged old ladies must still range far afield every day, gathering food for the tribe, hauling it home, and turning it into something tasty, applying band-aids to scraped knees and broken hearts, and buying flowers and pillows.
Men? Not hunting mastodon anymore. But still jumping off sheds, playing with knives and turning bed frames into splinters.
“We’ve all heard that a million monkeys banging on a million typewriters will eventually reproduce the entire works of Shakespeare. Now, thanks to the Internet, we know this is not true.”
Vaccines cause autism.
Genetically modified food causes autism.
Gluten causes autism.
Well, actually, no they don’t. And now we can add one more thing to the ever-growing list of things that don’t cause autism: mercury. This finding has 30 years of fact to back it up.
The Seychelles are an idyllic cluster of islands in the Indian Ocean, east of Madagascar. As you might expect, residents eat a lot of fish – 10 times more fish annually, in fact, than Europeans consume. So, according to new research published in the journal Epidemiology, the archipelago is the ideal place to study the relationship between prenatal fish-sourced mercury exposure and autism
Mercury finds its way into the ocean not only from man-made pollution, but from natural sources like volcanos, geothermal activity, and natural deposits. Released from fossil fuel burning, it can drift through the air for up to a year before precipitating out – often over the globe’s oceans. It’s dense, so it sinks to the bottom, coats algae, and gets gobbled up by plankton.
Fish consumption is a great way to study mercury in humans because we’re the super-predators who eat the secondary predators who eat the bottom-feeders who feast on the mercury-laden plankton.
The 30-year Seychelles Child Development Study has followed almost 2,000 children from birth, correlating the mercury levels found in their hair with scores on communication and behavioral tests and with their teachers’ observations.
Short answer: There wasn’t any relationship between mercury, cognition, and behavior, even when the team looked back at babies’ very first hair samples – the hair that grew while they were still inside Mom.
According to lead investigator Dr. Philip Davidson, the Seychelles study could be the last word on the mercury-autism debate. “This study shows no consistent association in children with mothers with mercury levels that were 6-10 times higher than those found in the U.S. and Europe … if it does not exist here, then it probably does not exist.”
So, moms-to-be, you don’t have to feel guilty about that Chilean sea bass dinner. Unless of course you contemplate how your craving contributes to the death throes of an endangered species.
Oops.. Wait a minute. Hold on to your mother-guilt… This just in....
It seems Mom’s own antibodies could be programming her unborn baby for autism. Apparently about 25% of mothers with an autistic child produce “antibrain antibodies” that can slide through the placenta and into a fetal brain. There they attack regions associated with learning, memory, and communication, according to the paper, published in Translational Psychiatry.
When pregnant monkeys were injected with the antibodies, many of their babies behaved abnormally, didn’t develop well socially, and some of them grew abnormally large brains – a trait that’s been observed in some humans with autism.
I wonder how Jenny McCarthy will take that one.
Listen up, gals. Quit hiding behind that fake diagnosis of sex addiction. It turns out your mother was right all along. You’re just a ho.
Yes, the Diagnostic and Statistical Manual (DSM for short), the revered book of official psychiatric diagnoses, has eliminated “hypersexual disorder” as a real mental illness. And a (lady) researcher at UCLA thinks she knows why. Sex addiction is probably all in your head.
Researchers at UCLA probed some dirty minds to find out. Fifty-two volunteers aged 18-39 years old, all of whom reported difficulty with sexual fantasies and behaviors, participated. EEGs measured their brain waves while they looked at a series of pictures. Some were designed to elicit the most primal cravings for sexual contact – like the super-hot one of your man doing a load of laundry without being asked. Others were not so hot – like dismembered people, skiing people, and, of course, people actually having sex.
“Brain response was only related to the measure of sexual desire,” Dr. Prause said. “In other words, hypersexuality does not appear to explain brain responses to sexual images any more than just having a high libido.”
And in OTHER words… you’re just a horn dog.
Anyway…. I’m not convinced. Studies have linked hypersexual behavior in adulthood with sexual abuse in childhood. And just last week, this study by University of Wisconsin researchers Leslie Seltzer and Dr. Seth Pollack seemed to bolster those findings. Little girls who’ve been abused don’t crank out cortisol, the stress-response chemical. Instead, their brains and bodies flood with oxytocin – the hormone of attachment.
Maybe the most well-known oxytocin scenarios are birth and breastfeeding, when Mom’s oxytocin flood promotes baby-bonding. But oxytocin – the “love hormone” – plays a similar role in all intimate relationships. The more involved you become with a partner, the more ocytocin you release and the more attachment you crave. New love and orgasm trigger a deluge of the stuff.
When the researchers asked a group of 8-11-year-olds to do some complicated math and make a speech, the non-abused boys and girls AND the abused boys produced cortisol. The abused girls made none at all. But their oxytocin levels went through the roof, actually tripling from baseline.
So how come? Are they adapting to stress in the most evolutionarily positive way possible? Ms. Seltzer suggest that answer is yes. Sexual abuse seems to physiologically prime girls for pair-bonding.
And that brings us back to sexual addiction. Abused girls are at heightened risk for early sexual behavior, teen pregnancy, and hooking up with aggressive, violent men. While the DSM symptoms for hypersexual disorder don’t specifically include these, a key criteria is repetitive sexual behavior in response to life stresses. This ties in rather nicely with early sexual activity, pregnancy, and choosing a dangerous jerk for a boyfriend.
Take that one with you to the bar next time.