Walnuts, walnut oil, improve reaction to stress
October 4, 2010
A diet rich in walnuts and walnut oil may prepare the body to deal better with stress, according to a researchers who looked at how these foods, which contain polyunsaturated fats, influence blood pressure at rest and under stress.
Previous studies have shown that omega-3 fatty acids -- like the alpha linolenic acid found in walnuts and flax seeds -- can reduce low density lipoproteins (LDL) -- bad cholesterol. These foods may also reduce c-reactive protein and other markers of inflammation.
"People who show an exaggerated biological response to stress are at higher risk of heart disease," said Sheila G. West, associate professor of biobehavioral health. "We wanted to find out if omega 3-fatty acids from plant sources would blunt cardiovascular responses to stress."
The researchers studied 22 healthy adults with elevated LDL cholesterol. All meals and snacks were provided during three diet periods of six weeks each.
The researchers found that including walnuts and walnut oil in the diet lowered both resting blood pressure and blood pressure responses to stress in the laboratory. Participants gave a speech or immersed their foot in cold water as a stressor. Adding flax seed oil to the walnut diet did not further lower blood pressure. They report their findings in the current issue of the Journal of the American College of Nutrition.
"This is the first study to show that walnuts and walnut oil reduce blood pressure during stress," said West. "This is important because we can't avoid all of the stressors in our daily lives. This study shows that a dietary change could help our bodies better respond to stress."
A subset of the participants also underwent a vascular ultrasound in order to measure artery dilation. Results showed that adding flax oil to the walnut diet significantly improved this test of vascular health. The flax plus walnuts diet also lowered c-reactive protein, indicating an anti-inflammatory effect. According to West, that could also reduce risk of cardiovascular disease.
The researchers used a randomized, crossover study design. Tests were conducted at the end of each six-week diet, and every participant consumed each of the three diets in random order, with a one-week break between. Diets included an "average" American diet -- a diet without nuts that reflects what the typical person in the U.S. consumes each day.
The second diet included 1.3 ounces of walnuts and a tablespoon of walnut oil substituted for some of the fat and protein in the average American diet. The third diet included walnuts, walnut oil and 1.5 tablespoons of flaxseed oil. The three diets were matched for calories and were specifically designed for each participant so that no weight loss or gain occurred. The walnuts, walnut oil, and flax oil were either mixed into the food in such offerings as muffins or salad dressing or eaten as a snack.
About 18 walnut halves or 9 walnuts make up the average serving used by the researchers.
After each diet, the participants underwent two stress tests. In the first test, they received a topic; and they were given two minutes to prepare a three-minute speech, which they presented while being videotaped. The second stressor was a standard physical test of stress consisting of submerging one foot in ice-cold water. Throughout these tests, the researchers took blood pressure readings from the participants.
Results showed that average diastolic blood pressure -- the "bottom number" or the pressure in the arteries when the heart is resting -- was significantly reduced during the diets containing walnuts and walnut oil.
Walnuts are a rich source of fiber, antioxidants, and unsaturated fatty acids, particularly alpha linolenic acid, an omega-3 fatty acid, and these compounds could be responsible for the beneficial effects on blood pressure. Flax oil is a more concentrated source of omega-3 fatty acids than walnut oil, but this study did not test whether flax oil alone could blunt cardiovascular responses to stress.
"These results are in agreement with several recent studies showing that walnuts can reduce cholesterol and blood pressure," noted West. "This work suggests that blood pressure is also reduced when a person is exposed to stress in their daily life."
Also working on this research were Penny Kris-Etherton, Distinguished Professor of nutrition; Laura Cousino Klein, associate professor of biobehavioral health; Andrea Likos Krick, recent doctoral recipient, biobehavioral health; Guixiang Zhao, recent doctoral recipient, nutritional sciences; Rachel M. Ceballos, recent doctoral recipient, biobehavioral health; Todd F. Wojtowicz and Matthew McGuiness, former Penn State undergraduate students; Deborah M. Bagshaw and Paul Wagner, Penn State and Bruce J. Holub, university professor emeritus, University of Guelph, Ontario, Canada.
The California Walnut Commission, Sacramento California, the Heart and Stroke Foundation, Ontario, Canada and the National Institutes of Health supported this research.
Page Update 08.18.2017
The Neurological Basis for Digital Addiction
By Jeanene Swanson 10/06/14
Published at: https://www.thefix.com/content/digital-addictions-are-real-addictions
Increasing evidence shows that texting and internet addiction can negatively affect lives. It's time to treat digital dependence as a real diagnosable disorder
A recent LA Times article named texting the “addiction du jour” for teens, surpassing more traditional ones, like smoking and sex. The statistics are very sobering as they reinforce the dangers of texting while driving. An astonishing 40% of all American teenagers report having been in a car when the driver used a cell phone in a way that put people in danger, according to a Pew survey.
It’s not just teens, either. The National Highway Traffic Safety Administration reported that in 2010, 18% of all fatal crashes as well as crashes resulting in an injury were caused by driver distraction. According to the Virginia Tech Transportation Institute, text messaging makes it 23 times more likely that drivers will get into a crash.
Digital media is empty calories. We have to create a digital diet.
It’s an obvious problem that we can’t put our smartphones down long enough to make sure we don’t kill ourselves or someone else while driving. But, why is it such a problem?
Dr. David Greenfield, a pioneer in the field of virtual addiction and founder of the Center for Internet and Technology Addiction in Connecticut, believes that texting is simply a subset of the larger Internet addiction disorder. Internet addiction disorder is not listed in the latest DSM manual (DSM-5, 2013)—however, Internet gaming disorder is listed in the appendix as a disorder requiring further study. According to Greenfield, Internet addiction disorder encompasses everything that uses the Internet—surfing, social media, texting, gaming, porn, and other activities. And while sexting and online sex addiction are still the most prevalent forms of Internet addiction, all types of excessive use can lead to addictive behavior.
“Everyone feels like they lose track of time and space when they use the Internet,” Greenfield says. “That means that it’s psychoactive—in other words, it’s a digital drug.”
“We use it to numb out,” says Nancy Colier, a psychotherapist who writes a blog at the Huffington Post and recently published a book, Inviting a Monkey to Tea: Befriending Your Mind and Discovering Lasting Contentment. “It’s just that we’re addicted to getting out of the moment,” Colier says. “You’re distracting yourself from where you are.” Colier believes that information gathering falls into this realm. While information used to be something “we gathered to create change,” she says, now we use it to “shore up our own identity.” In the quest to constantly feed our desire for information, “we use it to keep people at bay, or to fill ourselves up with something. At the end of all of it, we feel more and more empty.”
“[Texting] helps us to switch off our thoughts about our problems and if we are not thinking about our problems, we are not feeling anything negative,” says Liz Karter, addiction therapist and author of a new book called Working with Women’s Groups for Problem Gambling. “This sense of escapism can become addictive.”
Behaviors that define Internet addiction, according to the Center for Internet Addiction, include compulsive use, a preoccupation with being online, lying or hiding the extent or nature of the Internet use, and an inability to control or curb it. “The symptoms of texting addiction are preoccupation with the digital device, craving to spend more and more time online [or] texting, secretive behavior, [and] mood swings,” Karter says.
Alongside Greenfield, Dr. Kimberly Young is another pioneer in the field. She founded the Center for Internet Addiction in 1995 and she has written multiple books on the disorder, including Caught in the Net, the first to identify Internet addiction. While other countries seem to be ahead of the game in treating and preventing Internet use disorder—Young recently returned from the first International Congress on Internet Addiction Disorders, where Korea, Japan, Germany, China, Italy, and France are leading the way in addressing what they consider to be a significant mental health issue—Young is working to change that here in the US. She has developed the “first empirically-based treatment plan for Internet addiction, showing that [Cognitive Behavioral Therapy - Internet Addiction] is effective for curing various forms of Internet-related problems.”
Who is affected?
Studies suggest that one in eight Americans suffers from problematic Internet use. Those estimates are higher in China, Taiwan, and Korea, where 30% or more of the population may experience problematic use, according to Young’s Center for Internet Addiction.
Teens and young adults under 25 are most susceptible, mainly because the Internet and digital devices are embedded in their culture. Karter calls them “digital natives” while Greenfield refers to them as Generation D. “To them, it’s like a toaster is to me, that’s how they view digital technology,” says Greenfield, who has two sons that are of Generation D. “It’s become that generation’s defining point that separates them from previous ones.”
“Drinking and drugs are the outcasts; this is the ‘in-cast,’” says Colier in reference to teens who buy the latest iPhone instead of beer or drugs. Teens are more affected by peer pressure—as well as having unhealthy role models in many parents who “have drunk the Kool-Aid,” she says.
There’s also the trend of not being able to live in the moment—without broadcasting every detail in text, tweet, or social media share. It speaks to a larger issue, in internet-speak FOMO, also known as the dreaded Fear Of Missing Out. “I can’t say it’s a pathology but it’s an interesting social phenomenon,” Greenfield says. The problem becomes, “you’re not really living [life], you’re transmitting it.”
There is also evidence of co-morbidity. According to the Center for Internet Addiction, national surveys showed that over 70% of Internet addicts also suffered from other addictions: drugs, alcohol, smoking, and sex. Trends show that the majority of Internet addicts suffer from emotional problems like depression, mood disorders, social disorders, and anxiety disorders. Almost 75% of Internet addicts also suffer from relationship problems, and they “use interactive online applications such as social media, virtual communities, video games or online gaming as a safe way of establishing new relationships and more confidently relating to others through the virtual world.”
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