By Guest Nicole
Sitting for hours without moving can slow the flow of blood to our brains, according to a cautionary new study of office workers, a finding that could have implications for long-term brain health. But getting up and strolling for just two minutes every half-hour seems to stave off this decline in brain blood flow and may even increase it.
Delivering blood to our brains is one of those automatic internal processes that most of us seldom consider, although it is essential for life and cognition. Brain cells need the oxygen and nutrients that blood contains, and several large arteries constantly shuttle blood up to our skulls.
Because this flow is so necessary, the brain tightly regulates it, tracking a variety of physiological signals, including the levels of carbon dioxide in our blood, to keep the flow rate within a very narrow range.
Read more: https://www.nytimes.com/2018/08/15/well/move/why-sitting-may-be-bad-for-your-brain.html?rref=collection%2Fsectioncollection%2Fhealth
By Guest Nicole
A new study adds evidence to the argument that exercise can help preserve brain health, particularly in the aging brain.
What makes this study different than most is a wrinkle in its methodology. Unlike many studies that look for a connection between exercise and brain health, this one used a specific way of measuring physical fitness, by testing the participants’ maximum oxygen consumption during aerobic exercise (known as the V02 max test, it’s a method recognized by the American Heart Association as an objective way of analyzing cardiovascular fitness--more reliable than people just self-reporting on how fit they think they are).
Read more: https://www.forbes.com/sites/daviddisalvo/2018/02/20/study-finds-link-between-physical-fitness-and-brain-health/#6cb0e19172c9
By Guest Nicole
Children who eat fish tend to sleep better and score higher on IQ tests, a new study has found.
Using self-administered questionnaires, researchers collected information on fish consumption among 541 Chinese boys and girls ages 9 to 11. Parents reported their children’s sleep duration, how often they awoke at night, daytime sleepiness and other sleep patterns. At age 12, the children took IQ tests.
Read more: https://www.nytimes.com/2017/12/26/well/eat/fish-brain-iq-intelligence-children-kids.html?_r=2
By Guest Nicole
Both sugary, diet drinks correlated with accelerated brain aging
April 20, 2017
Excess sugar -- especially the fructose in sugary drinks -- might damage your brain, new research suggests. Researchers found that people who drink sugary beverages frequently are more likely to have poorer memory, smaller overall brain volume, and a significantly smaller hippocampus. A follow-up study found that people who drank diet soda daily were almost three times as likely to develop stroke and dementia when compared to those who did not.
By Guest Nicole
The differences in men and women even extend to the way our brains are built.
In the largest study yet on sex differences in the physical makeup of the human brain, researchers from the University of Edinburgh in Scotland have shown that men and women do, in fact, have different brain structures and sizes. Women tend to have thicker cortices, which are associated with intelligence, whereas men’s brains tend to be bigger overall. Although these differences can’t prove that men and women behave differently, they could shed light on why some medications work better in men better than women, and vice versa.
Researchers looked at the brains of over 5,200 participants older than 40, roughly half men and half women. This group was part of the larger UK Biobank study, which is in the midst of collecting health data on over 500,000 individuals. For this particular study, patients lay down in a structural magnetic resonance imaging. These MRIs are able to parse out different types of brain tissues, like the neurons and the connections between them, which can give scientists a picture of the various brain regions.
They found that on average, men’s brains were larger. But women’s brains had larger subregions of the cortex—the cortical subregions are discrete parts of this particular brain section associated with memory, sensory input, learning, and making choices. Additionally, there was a lot of variation in the sizes of different brain regions in men; women’s brains tended to be more similar to each other. The research, which hasn’t yet been peer-reviewed, was published in BioArXiv earlier this month.
These findings aren’t brand new. But most neuroscience studies to date only looked at a sample size of a few hundred participants. The thousands of brains here validate a lot of previous work. The fact that men’s brains had more differences among them “fits with a lot of other evidence that seems to point toward males being more variable physically and mentally,” Stuart Ritchie, a psychologist and lead author of the paper, told Science. Similarly, it wasn’t surprising to find that women tended to have thicker cortices over all based on previous findings (paywall).
The differences between men and women’s brains were small enough that it’d be impossible for scientists to determine a person’s sex by looking at his or her brain alone. Brain size and composition are characteristics kind of like nose shape: they depend on a lot of different genetic factors, and can take on countless different forms. And although a lot of men have larger noses (and brains) than women, that’s not always the case.
And it’s important to consider that different brain sizes and regions don’t necessarily translate to actual behavioral differences, like intelligence. “Our manuscript is just about describing the differences, and we can’t say anything about the causes of those differences,” Ritchie told New York Magazine. Different environmental and social factors play a huge role in determining the ways we think and interact with each other.
Ritchie is confident, though, that understanding the structural variability can help determine why certain diseases affect men and women differently. Understanding variations in brain structure can help develop better, sex-specific treatments for them.
By Guest Nicole
Memory athletes like Sue Jin Yang — competing here in the 17th annual USA Memory Championship in New York City in 2014 — wear headphones to block out distractions as they memorize the order of decks of cards.
Carolyn Cole/LA Times via Getty Images
There is such a thing as a memory athlete. These are people who can memorize a truly insane amount of information really quickly, like the order of playing cards in a deck in under 20 seconds, or 200 new names and faces in a matter of minutes.
Neuroscientists writing Wednesday in the journal Neuron found these champs of memorization aren't that different from the rest of us.
"We were interested in what differentiates memory champions from normal people, like you and me," says Martin Dresler, a cognitive neuroscientist at the Donders Institute for Brain, Cognition and Behavior at Radboud University in the Netherlands.
Were parts of their brains bigger, for example, or more dense with gray matter?
To find out, Dresler and Boris Nikolai Konrad — a doctoral student in Dresler's lab who happens to be a memory champion himself — rounded up nearly two dozen champs.
"We really took the world's best memorizers — 23 memory champions out of the top 50 of the world. You wouldn't find anywhere in the world people more capable of memorizing stuff than them," says Dresler.
They did MRI scans of their brains, to take a look at the anatomy.
Then they scanned the brains of 23 regular people who were matched in age, gender and even IQ to the memory athletes. When Dresler and his colleagues compared the brain scans, they found no difference. At least, no big, obvious difference.
"That was actually really a bit surprising," he says.
But, when Dresler and his colleagues did functional MRI scans, which measure brain activity by looking at how much blood is going to specific portions of it, they did see a subtle difference in brain activity.
When memory athletes were asked to recite a long list of memorized words, some portions of brain were activating in unison — making 25 connections that seemed particularly significant among different parts of the brain. The scientists didn't see that sort of unified activity in the brains of the regular subjects.
In particular, parts of the brain associated with memory and with spatial learning seemed to be interacting a lot.
That makes sense, when you consider the tricks these athletes had learned to use when they memorize.
They weren't born with extraordinary memorization skills. They had all learned and practiced the same kind of training to develop their seemingly superhuman abilities.
Konrad, the memorizing whiz in Dresler's lab who is also a co-author of the study, started using the memory strategy as a hobby in high school, after watching memory championships on TV. He holds the world record for memorizing faces and names — 201 people in 15 minutes.
"I use my visual memory," says Konrad. If he's trying to remember a person called Miller, he says, "I would picture this person looking at a mill, maybe during a vacation in the Netherlands."
For more abstract memory challenges, like memorizing the exact order of hundreds of digits, he'll build memory palaces. It's a method that's been around since the Greeks and is covered extensively in the book Moonwalking With Einstein by journalist Joshua Foer.
It works by recalling a building or place that is very familiar and charting a mental path through that building.
"The very first one I ever did was in the home of my parents, where I still lived back then when I was still in high school," says Konrad.
Then, he memorizes an order of walking through that house.
"It would start in my room," he says. The first location would be my bed, and the second one would be the shelf above my bed; then it's my desk, the computer on it, the window, the mirror and so on."
To memorize abstract information, like a list of numbers, he would translate numbers into images and then distribute them along the mental path through his house.
For example, to memorize my phone number, which starts with "1202," Konrad transforms pairs of numbers into images, using something called the Major System.
The combination "1-2," for example, brings to mind (for him) a dinosaur, Konrad says. "So I would then picture a dinosaur standing on my bed," says Konrad. "It's a weird image. That's why it sticks."
"And then, 0-2 would be a sun. So, I would picture the sun illuminating the shelf over my bed," he says. And so on.
In a second part of their study, Konrad and Dresler recruited 51 university students, and had one-third of them do memory palace training for six weeks — once a week in person with Konrad, and half an hour a day at home on the computer. (If you want to give it whirl, here you go.)
Another group did a different kind of memory training, and the last group did nothing special.
Then, they were brought into the lab and were asked to memorize a list of words, like "night, car, yardstick," and so on.
The researchers used functional MRI machines to scan the brains of subjects as they rested, and again as they recited the list of words.
In the group that did memory palace training, Konrad, Dresler and their colleagues found that the volunteers' brain activity had changed to become more like that of the champions of memorization. This was the case when they were reciting words, but also when they were at rest.
"We showed that, indeed, the brain is somehow driven into the patterns you see in memory champions," says Dresler.
The subjects came back into the lab four months after training and got a new list of words to memorize. The ones who had done memory palace training did really well compared to the others, and their brains were still connecting in that new way.
"Not only during a task, but even in the complete absence of any memory-related activity, we see this effect — that memory champions differ from matched controls, and that after memory training your brain shows similar patterns," says Dresler.
"There are very few actual studies of people with remarkably superior memory who compete in these memory contests. This is by far the largest," says Roddy Roediger, a psychologist with Washington University in St Louis.
Roediger has studied people with exceptional memory for a long time. He says people knew that something different had to be going on inside the brains of these people.
"These people are the first to really uncover what that something may be," he says.
But this method of memory training is not the key to unlocking intelligence. In fact, it doesn't even seem to be the key to unlocking overall memory capability.
For example, Roediger knows a man capable of playing dozens of games of chess at the same time, while blindfolded.
"He had never heard of memory palaces," says Roediger.
There are also people who have memorized the Bible in its entirety and can recite portions of it on demand. And there are others who have a condition known as Highly Superior Autobiographical Memory, where they remember every day of their lives in sometimes excruciating detail.
"And yet, when you put them in memory tasks that memory competitors can do very easily, they can't do them any easier than you or I could," says Roediger. "So that's a real mystery."
The same limitations apply to people who have trained their memories.
If, for example, you ask the chess player or a Bible memorizer to remember a long list of words, says Roediger, "none of them can do that." Their techniques are specific to their tasks.
And, he says, intense memory training doesn't cure everyday forgetfulness.
"They forget the milk on the way home from work just like we do," says Roediger.
Boris Nikolai Konrad says it has been years since he forgot something on his grocery list. But every now and then he does slip up with someone's name — and that's a moment people don't let him forget.
By Guest Nicole
Using a sauna may be more than just relaxing and refreshing. It may also reduce the risk for Alzheimer’s disease and other forms of dementia, a new study suggests.
Researchers in Finland analyzed medical records of 2,315 healthy men ages 42 to 60, tracking their health over an average of about 20 years. During that time, they diagnosed 204 cases of dementia and 123 cases of Alzheimer’s disease.
The study, in Age and Ageing, controlled for alcohol intake, smoking, blood pressure, diabetes and other health and behavioral factors. It found that compared with men who used a sauna once a week, those who used a sauna four to seven times a week had a 66 percent lower risk for dementia and a 65 percent lower risk for Alzheimer’s disease.
The senior author, Jari Antero Laukkanen, a professor of clinical medicine at the University of Eastern Finland, said that various physiological mechanisms may be involved. Sauna bathing may, for example, lead to reduced inflammation, better vascular function or lowered blood pressure.
“Overall relaxation and well-being can be another reason,” he added, though the findings were only an association. “We need more studies to clarify mechanisms and confirm our findings.”
By Guest Nicole
It’s that time of year again. On November 6th, most of the United States will participate in that semi-annual ritual of changing the clocks by an hour. In the fall we gain an hour of sleep time, or an hour of loafing around on a Sunday morning…how bad could it be?
Our circadian clock is an elaborate system of chemical signals and hormonesreacting to all sorts of environmental inputs such as light, feeding, and even temperature. The system is quite elegant, with many interconnected parts that when working well keeps us healthy with brains and metabolism in tip top condition. We can compare the circadian system to an orchestra playing a symphony…if everyone is playing the same piece, well-timed and in tune, it sounds wonderful, but if one horn is off pitch, the whole experience can be ruined.
Sleep is necessary for the brain to wash away the build-up of toxic byproducts of cell metabolism accumulated over the day. Without sleep, we very quickly lose the ability to function. The effects of acute total sleep deprivation are very obvious. In folks with bipolar disorder it can cause a manic episode and seizures in those with epilepsy. Long term, even low level sleep deprivation can contribute to a myriad of bad health effects, such as obesity, depression, and dementia. It also increases risks of heart attacks and motor vehicle accidents. While one hour difference a couple times a year seems small, evidence shows us that the delicate human circadian clock doesn’t adjust well to the abrupt difference in time.
When looking at the acute affects of the one hour transition of daylight savings, there are a host of papers showing negative effects on workplace injuries, productivity, traffic accidents, and heart attacks. But what about mental health? Older papers remark on no changes in suicidal behaviors or increase in inpatient or outpatient admissions during DST changes, but large Scandinavian registries over decades give us the ability to get a bigger picture of daylight savings in spring and fall and mental health. Overall admissions could balance out if each transition (forward or backward) has different effects on major depressive disorder or mood disorders with more seasonal components.
It seems that the single hour change is not disruptive enough to lead to an increase hospitalization for bipolar manic episodes in this Finnish study (whereas there are cases of mania caused by bigger time shifts due to air travel). However, less dramatic but negative behavioral effects are seen in children during the days following daylight savings switches.
One hour of change in the timing of the day (that, in the fall, is often looked upon favorably as ‘that extra hour of sleep’) theoretically has it’s most debilitating consequences for those with depressive disorders. We don’t understand all the intricacies of circadian rhythm and mood problems, but we do know there are many therapies involving light, sleep deprivation, early awakening, and circadian advance to an “early to bed, early to rise” sleep schedule can effectively help treat depression. Sleeping later in the morning is associated with depression, particularly in women. It makes sense, then, that a government proscribed regimen of sleeping later could increase the risk of depression, and a recent large study seems to confirm this, with an 11% increase in hospitalizations for depression in the weeks after the daylight savings transition to standard time in Denmark. Autumn daylight savings in the high latitudes shortens the effective light in the working day, with biologic and psychological effects.
The one hour time change, even adding an hour of needed sleep, can be detrimental to the brain’s delicate circadian clock. It acts as one more stressor to the myriad of stress in our modern daily schedules. Given that daylight savings time may not even save energy, it’s a wonder that we subject ourselves to the disruption twice a year.
By Guest Nicole
Telling small lies desensitizes our brains to the associated negative emotions and may encourage us to tell bigger lies in future
October 24, 2016
University College London
Telling small lies desensitizes our brains to the associated negative emotions and may encourage us to tell bigger lies in future, reveals new research.
Researchers have shown that self-serving lies gradually escalate, and they have revealed how this happens in our brains.
Credit: © pathdoc / Fotolia
Telling small lies desensitises our brains to the associated negative emotions and may encourage us to tell bigger lies in future, reveals new UCL research funded by Wellcome and the Center for Advanced Hindsight.
The research, published in Nature Neuroscience, provides the first empirical evidence that self-serving lies gradually escalate and reveals how this happens in our brains.
The team scanned volunteers' brains while they took part in tasks where they could lie for personal gain. They found that the amygdala, a part of the brain associated with emotion, was most active when people first lied for personal gain. The amygdala's response to lying declined with every lie while the magnitude of the lies escalated. Crucially, the researchers found that larger drops in amygdala activity predicted bigger lies in future.
"When we lie for personal gain, our amygdala produces a negative feeling that limits the extent to which we are prepared to lie," explains senior author Dr Tali Sharot (UCL Experimental Psychology). "However, this response fades as we continue to lie, and the more it falls the bigger our lies become. This may lead to a 'slippery slope' where small acts of dishonesty escalate into more significant lies."
The study included 80 volunteers who took part in a team estimation task that involved guessing the number of pennies in a jar and sending their estimates to unseen partners using a computer. This took place in several different scenarios. In the baseline scenario, participants were told that aiming for the most accurate estimate would benefit them and their partner. In various other scenarios, over- or under-estimating the amount would either benefit them at their partner's expense, benefit both of them, benefit their partner at their own expense, or only benefit one of them with no effect on the other.
When over-estimating the amount would benefit the volunteer at their partner's expense, people started by slightly exaggerating their estimates which elicited strong amygdala responses. Their exaggerations escalated as the experiment went on while their amygdala responses declined.
"It is likely the brain's blunted response to repeated acts of dishonesty reflects a reduced emotional response to these acts," says lead author Dr Neil Garrett (UCL Experimental Psychology). "This is in line with suggestions that our amygdala signals aversion to acts that we consider wrong or immoral. We only tested dishonesty in this experiment, but the same principle may also apply to escalations in other actions such as risk taking or violent behaviour."
Dr Raliza Stoyanova, Senior Portfolio Developer, in the Neuroscience and Mental Health team at Wellcome, said: "This is a very interesting first look at the brain's response to repeated and increasing acts of dishonesty. Future work would be needed to tease out more precisely whether these acts of dishonesty are indeed linked to a blunted emotional response, and whether escalations in other types of behaviour would have the same effect."
Materials provided by University College London. Note: Content may be edited for style and length.
Neil Garrett, Stephanie C Lazzaro, Dan Ariely, Tali Sharot. The brain adapts to dishonesty. Nature Neuroscience, 2016; DOI: 10.1038/nn.4426
Cite This Page:
University College London. "How lying takes our brains down a 'slippery slope': Telling small lies desensitizes our brains to the associated negative emotions and may encourage us to tell bigger lies in future." ScienceDaily. ScienceDaily, 24 October 2016. <www.sciencedaily.com/releases/2016/10/161024134012.htm>.
By Guest Nicole
Do you see what I see? Not necessarily with these optical illusions! When you look at an image, your brain takes that information into perception. Sometimes, an image can trick the brain into perceiving it differently from what the picture actually is, creating an optical illusion.
Take a look at the following 10 images to find out if you can see the two images masking as one.
Is It a Man Playing a Horn or Woman’s Face?
When you stare at this black and white image, do you see woman’s face with hair on the right side of it or a man playing a horn? If you can’t see the man, look at the black shape. See him now?
Is It a Rabbit or a Duck?
If you look at this image one way, the two rectangular shapes on the left could be a duck’s bill. But if you look at it another way, those shapes might appear to you as a pair of rabbit ears.
Do You See One Face or Two?
When staring at this image, you might see two silhouettes facing each other. Look again and you may just see one face staring at a candlestick.
Do You See a Stream or People?
Some people may see a rushing stream going down a mountain in this picture, but if you take a closer look at that stream, you may see it as people wearing white robes. What do you see?
Is It a Frog or Horse?
At first glance, this image may just look like an illustration of a horse. However, if you tilt your head to the left you might see a frog sitting on a lily pad instead.
Is It a Vase or Two Faces?
In this popular optical illusion you might see a vase. Another person might look at it and see two silhouettes of faces. Do you see how the curves of the vase could form the shape of a face and vice versa?
Do You See an Old Man, an Old Woman, or a Girl?
Your eye might show you one, two or even three different images in this complex optical illusion. Do you see the large nose and mustache of a man who is wearing a hat? Perhaps you see the young girl wearing a hat who is looking away on her left. Or, you might see the old woman, also wearing a hat, who is facing to the left.
Are the Circles Intertwining or Concentric?
Do these circles look like they’re intertwining to you? Now, take another look and try to pinpoint the locations in which the circles meet. If you can’t find them, don’t worry. These circles are actual concentric and only have the illusion of intertwining with one another.
Are the Circles Moving?
Staring still at this image will show you two stationary circles with a black dot in the middle of the inner circle. Stare at the dot, but start moving your head closer to the image, and then pull it away. Did you see the circles move?
Do You See an Elderly Man and Woman or a Young Man and Woman?
When you look at this image do you see two elderly people gazing at each other? If not, you might see two people wearing sombreros while sitting down set against a larger scene. The man is playing the guitar. These people’s bodies make out the silhouettes of the elderly couple’s faces.
By Guest Nicole
WEDNESDAY, Aug. 10, 2016 (HealthDay News) -- Could too much weight be bad for the brain as well as the belly?
New research suggests that being overweight or obese may trigger premature aging of the middle-aged brain.
The study centered on how carrying excess weight might affect the brain's white matter, which facilitates communication between different brain regions.
White matter tissue is known to shrink with age. But the new study found that the amount of white matter in the brain of a 50-year-old overweight/obese person was comparable to that of a 60-year-old lean person.
"Obesity is associated with a host of biological processes that are seen in normal aging," said study author Lisa Ronan, a research associate in the department of psychiatry at the University of Cambridge in England. "And therefore we hypothesized that obesity may in fact compound the effects of aging that we see in the brain. This is what we found."
Ronan stressed that it's "too early to tell" what this really means. "However, it is possible that being overweight may raise the risk of developing disorders related to neurodegeneration such as Alzheimer's disease or dementia," she said.
Still, the study didn't prove obesity causes premature brain aging. And, Ronan noted that "there were no differences in cognitive ability between overweight and obese people and their lean counterparts."
Ronan and her colleagues focused on nearly 500 men and women between the ages of 20 and 87. All were residents of the Cambridge region and in good mental health.
About half were "lean" (at a body mass index or BMI between 18.5 and 25). Nearly a third were "overweight" (BMI 25 to 30), and about 20 percent were "obese" (BMI over 30). Body mass index is a measure of body fat based on weight in relation to height.
Initial white matter measurements generally revealed that overweight/obese participants had notably reduced white matter volume compared with lean participants.
And an age breakdown revealed that a middle-aged participant who was either overweight or obese had a white matter volume comparable in size to that of a middle-aged lean participant a decade older.
The study authors stressed that the 10-year white matter difference was only seen among those middle-aged and older, not among participants in their 20s or 30s. This, they said, suggests that the brain may become increasingly vulnerable to the impact of excess weight as people grow older.
"At the moment, we really don't know what might be driving the correlation between an increased BMI and lower white matter volume," noted Ronan.
"Indeed, it is not yet clear whether being overweight/obese may cause brain changes, or whether brain changes may in some way cause an increase in adiposity (excess weight)," she added.
"Until we understand the mechanism that relates BMI to brain changes, it is not easy to say whether losing weight will in some way act to mitigate the effects we reported," she said. "This is something that we are currently investigating."
The findings were published recently in the Neurobiology of Aging journal.
Dr. Yvette Sheline is director of the Center for Neuromodulation in Depression and Stress at the University of Pennsylvania's Perelman School of Medicine. She described Ronan's study as "interesting from several perspectives."
But, Sheline noted that the study had a few "limitations," which might explain why the research team didn't observe any relationship between reduced white matter volume and poorer memory and thinking.
Sheline said Ronan's team "only looked at obesity as an overall measure and didn't take into account the distribution of fat." She also noted that some studies have suggested that obesity centered around the waist does tend to have a worse effect on thinking than other types of obesity.
"Also, this study didn't actually follow people over time, so their conclusions are limited by having measures from only one time point," Sheline added.
There's more on obesity's impact on health at the U.S. National Heart, Lung, and Blood Institute.
SOURCES: Lisa Ronan, Ph.D., research associate, department of psychiatry, University of Cambridge, Cambridge, England; Yvette Sheline, M.D., professor, psychiatry, radiology and neurology, and director, Center for Neuromodulation in Depression and Stress, University of Pennsylvania Perelman School of Medicine, Philadelphia; July 27, 2016, Neurobiology of Aging
Last Updated: Aug 10, 2016
By Guest Nicole
MRI scans found infants who drank more of it had more brain tissue, study found.
TUESDAY, May 3, 2016 (HealthDay News) -- Breast milk may help promote brain growth in premature infants, a new study found.
"The brains of babies born before their due dates usually are not fully developed," explained senior investigator Dr. Cynthia Rogers, an assistant professor of child psychiatry at Washington University in St. Louis.
"But breast milk has been shown to be helpful in other areas of development, so we looked to see what effect it might have on the brain," Rogers said in a university news release.
"With MRI scans, we found that babies fed more breast milk had larger brain volumes. This is important because several other studies have shown a correlation between brain volume and cognitive development," she said.
The study included 77 infants born at least 10 weeks early, with the average being 14 weeks premature. Brain scans were conducted on the infants at about the time when they would have been born if delivered at full term.
The scans revealed that infants whose daily diets included at least 50 percent breast milk had more brain tissue and cortical-surface area than those who received much less breast milk.
The findings were to be presented Tuesday at the Pediatric Academic Societies annual meeting, in Baltimore. Research presented at meetings is considered preliminary until published in a peer-reviewed journal.
By Guest Nicole
Scientists report that diet rich in omega-3 fatty acids can reverse the damage
April 22, 2016
University of California - Los Angeles
Consuming fructose, a sugar that's common in the Western diet, alters hundreds of genes that may be linked to many diseases, life scientists report. However, they discovered good news as well: an important omega-3 fatty acid known as DHA seems to reverse the harmful changes produced by fructose.
A range of diseases -- from diabetes to cardiovascular disease, and from Alzheimer's disease to attention deficit hyperactivity disorder -- are linked to changes to genes in the brain. A new study by UCLA life scientists has found that hundreds of those genes can be damaged by fructose, a sugar that's common in the Western diet, in a way that could lead to those diseases.
However, the researchers discovered good news as well: An omega-3 fatty acid known as docosahexaenoic acid, or DHA, seems to reverse the harmful changes produced by fructose.
"DHA changes not just one or two genes; it seems to push the entire gene pattern back to normal, which is remarkable," said Xia Yang, a senior author of the study and a UCLA assistant professor of integrative biology and physiology. "And we can see why it has such a powerful effect."
DHA occurs naturally in the membranes of our brain cells, but not in a large enough quantity to help fight diseases.
"The brain and the body are deficient in the machinery to make DHA; it has to come through our diet," said Fernando Gomez-Pinilla, a UCLA professor of neurosurgery and of integrative biology and physiology, and co-senior author of the paper.
DHA strengthens synapses in the brain and enhances learning and memory. It is abundant in wild salmon (but not in farmed salmon) and, to a lesser extent, in other fish and fish oil, as well as walnuts, flaxseed, and fruits and vegetables, said Gomez-Pinilla, who also is a member of UCLA's Brain Injury Research Center.
Americans get most of their fructose in foods that are sweetened with high-fructose corn syrup, an inexpensive liquid sweetener made from corn starch, and from sweetened drinks, syrups, honey and desserts. The Department of Agriculture estimates that Americans consumed an average of about 27 pounds of high-fructose corn syrup in 2014. Fructose is also found is in most baby food and in fruit, although the fiber in fruit substantially slows the body's absorption of the sugar -- and fruit contains other healthy components that protect the brain and body, Yang said.
To test the effects of fructose and DHA, the researchers trained rats to escape from a maze, and then randomly divided the animals into three groups. For the next six weeks, one group of rats drank water with an amount of fructose that would be roughly equivalent to a person drinking a liter of soda per day. The second group was given fructose water and a diet rich in DHA. The third received water without fructose and no DHA.
After the six weeks, the rats were put through the maze again. The animals that had been given only the fructose navigated the maze about half as fast than the rats that drank only water -- indicating that the fructose diet had impaired their memory. The rats that had been given fructose and DHA, however, showed very similar results to those that only drank water -- which strongly suggests that the DHA eliminated fructose's harmful effects.
Other tests on the rats revealed more major differences: The rats receiving a high-fructose diet had much higher blood glucose, triglycerides and insulin levels than the other two groups. Those results are significant because in humans, elevated glucose, triglycerides and insulin are linked to obesity, diabetes and many other diseases.
The research team sequenced more than 20,000 genes in the rats' brains, and identified more than 700 genes in the hypothalamus (the brain's major metabolic control center) and more than 200 genes in the hippocampus (which helps regulate learning and memory) that were altered by the fructose. The altered genes they identified, the vast majority of which are comparable to genes in humans, are among those that interact to regulate metabolism, cell communication and inflammation. Among the conditions that can be caused by alterations to those genes are Parkinson's disease, depression, bipolar disorder, and other brain diseases, said Yang, who also is a member of UCLA's Institute for Quantitative and Computational Biosciences.
Of the 900 genes they identified, the researchers found that two in particular, called Bgn and Fmod, appear to be among the first genes in the brain that are affected by fructose. Once those genes are altered, they can set off a cascade effect that eventually alters hundreds of others, Yang said.
That could mean that Bgn and Fmod would be potential targets for new drugs to treat diseases that are caused by altered genes in the brain, she added.
The research also uncovered new details about the mechanism fructose uses to disrupt genes. The scientists found that fructose removes or adds a biochemical group to cytosine, one of the four nucleotides that make up DNA. (The others are adenine, thymine and guanine.) This type of modification plays a critical role in turning genes "on" or "off."
The research is published online in EBioMedicine, a journal published jointly by Cell and The Lancet. It is the first genomics study of all the genes, pathways and gene networks affected by fructose consumption in the regions of the brain that control metabolism and brain function.
Previous research led by Gomez-Pinilla found that fructose damages communication between brain cells and increases toxic molecules in the brain; and that a long-term high-fructose diet diminishes the brain's ability to learn and remember information.
"Food is like a pharmaceutical compound that affects the brain," said Gomez-Pinilla. He recommends avoiding sugary soft drinks, cutting down on desserts and generally consuming less sugar and saturated fat.
Although DHA appears to be quite beneficial, Yang said it is not a magic bullet for curing diseases. Additional research will be needed to determine the extent of its ability to reverse damage to human genes.
The paper's lead author is Qingying Meng, a postdoctoral scholar in Yang's laboratory. Other co-authors are Zhe Ying, a staff research associate in Gomez-Pinilla's laboratory, and colleagues from UCLA, the National Institutes of Health and Icahn School of Medicine at Mount Sinai in New York.
Yang's research is supported by the National Institutes of Health (grant R01DK104363), as is Gomez-Pinilla's (R01DK104363 and R01NS050465).
The above post is reprinted from materials provided by University of California - Los Angeles. Note: Materials may be edited for content and length.
Americans get most of their fructose in foods that are sweetened with high-fructose corn syrup, an inexpensive liquid sweetener made from corn starch, and from sweetened drinks, syrups, honey and desserts. The Department of Agriculture estimates that Americans consumed an average of about 27 pounds of high-fructose corn syrup in 2014.
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