Publisher Health

Fish oil supplements are a billion-dollar industry built on a foundation of purported, but not proven, health benefits. Now, new research from a team led by a University of Georgia scientist indicates that taking fish oil only provides health benefits if you have the right genetic makeup.
The study, led by Kaixiong Ye and published in PLOS Genetics, focused on fish oil (and the omega-3 fatty acids it contains) and its effect on triglycerides, a type of fat in the blood and a biomarker for cardiovascular disease.
“We’ve known for a few decades that a higher level of omega-3 fatty acids in the blood is associated with a lower risk of heart disease,” said Ye, assistant professor of genetics in the Franklin College of Arts and Sciences. “What we found is that fish oil supplementation is not good for everyone; it depends on your genotype. If you have a specific genetic background, then fish oil supplementation will help lower your triglycerides. But if you do not have that right genotype, taking a fish oil supplement actually increases your triglycerides.”
Ye’s team, including first author and graduate student Michael Francis, examined four blood lipids (fats) — high-density lipoprotein, low-density lipoprotein, total cholesterol and triglycerides — that are biomarkers for cardiovascular disease. The data for their sample of 70,000 individuals was taken from UK Biobank, a large-scale cohort study collecting genetic and health information from half a million participants.
The team divided the sample into two groups, those taking fish oil supplements (about 11,000) and those not taking fish oil supplements. Then they performed a genome-wide scan for each group, testing for 8 million genetic variants to compare. After running over 64 million tests, their results revealed a significant genetic variant at gene GJB2. Individuals with the AG genotype who took fish oil decreased their triglycerides. Individuals with the AA genotype who took fish oil slightly increased their triglycerides. (A third possible genotype, GG, was not evident in enough study volunteers to draw conclusions.)
Determining your genotype is not as far-fetched as it sounds, thanks to direct-to-consumer genetic testing companies. Companies may not report that specific genetic variant yet, but a tech-savvy consumer should be able to download the raw data and look at the specific position to discover the genotype, according to Ye. The ID for the variant is rs112803755 (A >G).
The study’s findings may also shed light on previous trials, most of which found that fish oil provides no benefit in preventing cardiovascular disease.
“One possible explanation is that those clinical trials didn’t consider the genotypes of the participants,” Ye said. “Some participants may benefit, and some may not, so if you mix them together and do the analysis, you do not see the impact.”
Now that Ye has identified a specific gene that can modify an individual’s response to fish oil supplementation, his next step will be directly testing the effects of fish oil on cardiovascular disease.
“Personalizing and optimizing fish oil supplementation recommendations based on a person’s unique genetic composition can improve our understanding of nutrition,” he said, “and lead to significant improvements in human health and well-being.”
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Materials provided by University of Georgia. Original written by Allyson Mann. Note: Content may be edited for style and length.

In “Hooked,” Michael Moss explores how no addictive drug can fire up the reward circuitry in our brains as rapidly as our favorite foods.In a legal proceeding two decades ago, Michael Szymanczyk, the chief executive of the tobacco giant Philip Morris, was asked to define addiction. “My definition of addiction is a repetitive behavior that some people find difficult to quit,” he responded.Mr. Szymanczyk was speaking in the context of smoking. But a fascinating new book by Michael Moss, an investigative journalist and best-selling author, argues that the tobacco executive’s definition of addiction could apply to our relationship with another group of products that Philip Morris sold and manufactured for decades: highly processed foods.In his new book, “Hooked,” Mr. Moss explores the science behind addiction and builds a case that food companies have painstakingly engineered processed foods to hijack the reward circuitry in our brains, causing us to overeat and helping to fuel a global epidemic of obesity and chronic disease. Mr. Moss suggests that processed foods like cheeseburgers, potato chips and ice cream are not only addictive, but that they can be even more addictive than alcohol, tobacco and drugs. The book draws on internal industry documents and interviews with industry insiders to argue that some food companies in the past couple of decades became aware of the addictive nature of their products and took drastic steps to avoid accountability, such as shutting down important research into sugary foods and spearheading laws preventing people from suing food companies for damages.PenguinRandomHouseIn another cynical move, Mr. Moss writes, food companies beginning in the late 1970s started buying a slew of popular diet companies, allowing them to profit off our attempts to lose the weight we gained from eating their products. Heinz, the processed food giant, bought Weight Watchers in 1978 for $72 million. Unilever, which sells Klondike bars and Ben & Jerry’s ice cream, paid $2.3 billion for SlimFast in 2000. Nestle, which makes chocolate bars and Hot Pockets, purchased Jenny Craig in 2006 for $600 million. And in 2010 the private equity firm that owns Cinnabon and Carvel ice cream purchased Atkins Nutritionals, the company that sells low-carb bars, shakes and snacks. Most of these diet brands were later sold to other parent companies.“The food industry blocked us in the courts from filing lawsuits claiming addiction; they started controlling the science in problematic ways, and they took control of the diet industry,” Mr. Moss said in an interview. “I’ve been crawling through the underbelly of the processed food industry for 10 years and I continue to be stunned by the depths of the deviousness of their strategy to not just tap into our basic instincts, but to exploit our attempts to gain control of our habits.”A former reporter for The New York Times and recipient of the Pulitzer Prize, Mr. Moss first delved into the world of the processed food industry in 2013 with the publication of “Salt Sugar Fat.” The book explained how companies formulate junk foods to achieve a “bliss point” that makes them irresistible and market those products using tactics borrowed from the tobacco industry. Yet after writing the book, Mr. Moss was not convinced that processed foods could be addictive.“I had tried to avoid the word addiction when I was writing ‘Salt Sugar Fat,’” he said. “I thought it was totally ludicrous. How anyone could compare Twinkies to crack cocaine was beyond me.”But as he dug into the science that shows how processed foods affect the brain, he was swayed. One crucial element that influences the addictive nature of a substance and whether or not we consume it compulsively is how quickly it excites the brain. The faster it hits our reward circuitry, the stronger its impact. That is why smoking crack cocaine is more powerful than ingesting cocaine through the nose, and smoking cigarettes produces greater feelings of reward than wearing a nicotine patch: Smoking reduces the time it takes for drugs to hit the brain.But no addictive drug can fire up the reward circuitry in our brains as rapidly as our favorite foods, Mr. Moss writes. “The smoke from cigarettes takes 10 seconds to stir the brain, but a touch of sugar on the tongue will do so in a little more than a half second, or six hundred milliseconds, to be precise,” he writes. “That’s nearly 20 times faster than cigarettes.”This puts the term “fast food” in a new light. “Measured in milliseconds, and the power to addict, nothing is faster than processed food in rousing the brain,” he added.Mr. Moss explains that even people in the tobacco industry took note of the powerful lure of processed foods. In the 1980s, Philip Morris acquired Kraft and General Foods, making it the largest manufacturer of processed foods in the country, with products like Kool-Aid, Cocoa Pebbles, Capri Sun and Oreo cookies. But the company’s former general counsel and vice president, Steven C. Parrish, confided that he found it troubling that it was easier for him to quit the company’s cigarettes than its chocolate cookies. “I’m dangerous around a bag of chips or Doritos or Oreos,” he told Mr. Moss. “I’d avoid even opening a bag of Oreos because instead of eating one or two, I would eat half the bag.”As litigation against tobacco companies gained ground in the 1990s, one of the industry’s defenses was that cigarettes were no more addictive than Twinkies. It may have been on to something. Philip Morris routinely surveyed the public to gather legal and marketing intelligence, Mr. Moss writes, and one particular survey in 1988 asked people to name things that they thought were addictive and then rate them on a scale of 1 to 10, with 10 being the most addictive.“Smoking was given an 8.5, nearly on par with heroin,” Mr. Moss writes. “But overeating, at 7.3, was not far behind, scoring higher than beer, tranquilizers and sleeping pills. This statistic was used to buttress the company’s argument that cigarettes might not be exactly innocent, but they were a vice on the order of potato chips and, as such, were manageable.”But processed foods are not tobacco, and many people, including some experts, dismiss the notion that they are addictive. Mr. Moss suggests that this reluctance is in part a result of misconceptions about what addiction entails. For one, a substance does not have to hook everyone for it to be addictive. Studies show that most people who drink or use cocaine do not become dependent. Nor does everyone who smokes or uses painkillers become addicted. It is also the case that the symptoms of addiction can vary from one person to the next and from one drug to another. Painful withdrawals were once considered hallmarks of addiction. But some drugs that we know to be addictive, such as cocaine, would fail to meet that definition because they do not provoke “the body-wrenching havoc” that withdrawal from barbiturates and other addictive drugs can cause.The American Psychiatric Association now lists 11 criteria that are used to diagnose what it calls a substance use disorder, which can range from mild to severe, depending on how many symptoms a person exhibits. Among those symptoms are cravings, an inability to cut back despite wanting to, and continuing to use the substance despite it causing harm. Mr. Moss said that people who struggle with processed food can try simple strategies to conquer routine cravings, like going for a walk, calling a friend or snacking on healthy alternatives like a handful of nuts. But for some people, more extreme measures may be necessary.“It depends where you are on the spectrum,” he said. “I know people who can’t touch a grain of sugar without losing control. They would drive to the supermarket and by the time they got home their car would be littered with empty wrappers. For them, complete abstention is the solution.”

A new analysis suggests that schools and colleges, large companies and other organizations that want to keep themselves safe with frequent mass testing should think beyond their own personnel.By dedicating a substantial portion of their tests to people in the surrounding community, they can reduce the number of Covid-19 cases among their members by as much as 25 percent, researchers report in a new paper, which has not yet been published in a scientific journal.“It’s natural in an outbreak for people to become self-serving, self-focused,” said Dr. Pardis Sabeti, a computational biologist at Harvard University and the Broad Institute who led the analysis. But she added, “If you’ve been in enough outbreaks, you just understand that testing in a box doesn’t makes sense. These things are communicable, and they’re coming in from the community.”The study has “really profound implications, especially if others can replicate it,” said David O’Connor, a virologist at the University of Wisconsin, Madison, who was not involved in the analysis but reviewed a draft of the paper.Early in the pandemic, when testing resources were in short supply, many colleges proposed intensive, expensive testing regimens focused entirely on their own campuses. When they sought Dr. Sabeti’s advice, she said, she told them they ought to test friends, relatives and neighbors of their students and employees as well.It was not an easy idea to sell without data on its effectiveness, so Dr. Sabeti and her colleagues developed an epidemiological model to simulate how a virus might spread through a midsize institution, Colorado Mesa University, and what would happen under different testing policies. They found that allocating some tests to community contacts would significantly reduce the expected number of Covid cases on campus.C.M.U. now offers free tests to all of its students’ self-reported contacts, and runs a testing site that is open to local residents, according to Amy Bronson, a co-chair of the university’s Covid-19 task force and an author of the paper.And in November, the University of California, Davis, began offering free coronavirus tests to anyone who lives or works in that city.“A virus does not respect geographic boundaries,” said Brad Pollock, an epidemiologist at U.C. Davis who directs the project. “It is ludicrous to think that you can get control of an acute infectious respiratory disease like Covid-19, in a city like Davis that hosts a very large university, without coordinated public health measures that connect both the university and the community.”

A 10-week muscle-building and dietary program involving 50 middle-aged adults found no evidence that eating a high-protein diet increased strength or muscle mass more than consuming a moderate amount of protein while training. The intervention involved a standard strength-training protocol with sessions three times per week. None of the participants had previous weightlifting experience.
Published in the American Journal of Physiology: Endocrinology and Metabolism, the study is one of the most comprehensive investigations of the health effects of diet and resistance training in middle-aged adults, the researchers say. Participants were 40-64 years of age.
The team assessed participants’ strength, lean-body mass, blood pressure, glucose tolerance and several other health measures before and after the program. They randomized participants into moderate- and high-protein diet groups. To standardize protein intake, the researchers fed each person a freshly cooked, minced beef steak and carbohydrate beverage after every training session. They also sent participants home with an isolated-protein drink to be consumed every evening throughout the 10 weeks of the study.
“The moderate-protein group consumed about 1.2 grams of protein per kilogram of body weight per day, and the high-protein group consumed roughly 1.6 grams per kilogram per day,” said Colleen McKenna, a graduate student in the division of nutritional sciences and registered dietician at the University of Illinois Urbana-Champaign who led the study with U. of I. kinesiology and community health professor Nicholas Burd. The team kept calories equivalent in the meals provided to the two groups with additions of beef tallow and dextrose.
The study subjects kept food diaries and McKenna counseled them every other week about their eating habits and protein intake.
In an effort led by U. of I. food science and human nutrition professor Hannah Holscher, the team also analyzed gut microbes in fecal samples collected at the beginning of the intervention, after the first week — during which participants adjusted to the new diet but did not engage in physical training — and at the end of the 10 weeks. Previous studies have found that diet alone or endurance exercise alone can alter the composition of microbes in the digestive tract.

One-third of the Earth’s surface is covered by more than 11,000 grass species — including crops like wheat, corn, rice and sugar cane that account for the bulk of the world’s agricultural food production and important biofuels. But grass is so common that few people realize how diverse and important it really is.
Research published today in the journal Nature provides insights that scientists could use not only to improve crop design but also to more accurately model the effects of climate change. It also offers new clues that could help scientists use leaf fossils to better interpret the climate of the ancient past.
The study’s senior author is Lawren Sack, a UCLA professor of ecology and evolutionary biology and one of the world’s most influential scientific researchers.
The research determined that grass with narrow leaves and high numbers of veins should be better able to withstand the drier conditions expected in the future. That finding should enable scientists to better predict grass species’ ability to tolerate cold and drought — important for conserving species amidst climate change. It also suggests that scientists who are breeding agricultural grasses to better survive cold climates and drought should turn their focus toward varieties with smaller leaves and more large veins.
From other types of plants, scientists have learned that leaf size is an important factor in how plants adapt to their environments. But until now, it was not known how thousands of species of grass could exist in so many diverse environments, and whether leaf size might play a role.
“Grass leaf blades can vary in size from a few square millimeters for grasses of the high Andes to more than a square meter for tropical bamboos,” Sack said.

Researchers have developed a new microscopy technique that can acquire 3D super-resolution images of subcellular structures from about 100 microns deep inside biological tissue, including the brain. By giving scientists a deeper view into the brain, the method could help reveal subtle changes that occur in neurons over time, during learning, or as result of disease.
The new approach is an extension of stimulated emission depletion (STED) microscopy, a breakthrough technique that achieves nanoscale resolution by overcoming the traditional diffraction limit of optical microscopes. Stefan Hell won the 2014 Nobel Prize in Chemistry for developing this super-resolution imaging technique.
In Optica, The Optical Society’s (OSA) journal for high impact research, the researchers describe how they used their new STED microscope to image, in super-resolution, the 3D structure of dendritic spines deep inside the brain of a living mouse. Dendric spines are tiny protrusions on the dendritic branches of neurons, which receive synaptic inputs from neighboring neurons. They play a crucial role in neuronal activity.
“Our microscope is the first instrument in the world to achieve 3D STED super-resolution deep inside a living animal,” said leader of the research team Joerg Bewersdorf from Yale School of Medicine. “Such advances in deep-tissue imaging technology will allow researchers to directly visualize subcellular structures and dynamics in their native tissue environment,” said Bewersdorf. “The ability to study cellular behavior in this way is critical to gaining a comprehensive understanding of biological phenomena for biomedical research as well as for pharmaceutical development.”
Going deeper
Conventional STED microscopy is most often used to image cultured cell specimens. Using the technique to image thick tissue or living animals is a lot more challenging, especially when the super-resolution benefits of STED are extended to the third dimension for 3D-STED. This limitation occurs because thick and optically dense tissue prevents light from penetrating deeply and from focusing properly, thus impairing the super-resolution capabilities of the STED microscope.
To overcome this challenge, the researchers combined STED microscopy with two-photon excitation (2PE) and adaptive optics. “2PE enables imaging deeper in tissue by using near-infrared wavelengths rather than visible light,” said Mary Grace M. Velasco, first author of the paper. “Infrared light is less susceptible to scattering and, therefore, is better able to penetrate deep into the tissue.”
The researchers also added adaptive optics to their system. “The use of adaptive optics corrects distortions to the shape of light, i.e., the optical aberrations, that arise when imaging in and through tissue,” said Velasco. “During imaging, the adaptive element modifies the light wavefront in the exact opposite way that the tissue in the specimen does. The aberrations from the adaptive element, therefore, cancel out the aberrations from the tissue, creating ideal imaging conditions that allow the STED super-resolution capabilities to be recovered in all three dimensions.”
Seeing changes in the brain
The researchers tested their 3D-2PE-STED technique by first imaging well-characterized structures in cultured cells on a cover slip. Compared to using 2PE alone, 3D-2PE-STED resolved volumes more than 10 times smaller. They also showed that their microscope could resolve the distribution of DNA in the nucleus of mouse skin cells much better than a conventional two-photon microscope.
After these tests, the researchers used their 3D-2PE-STED microscope to image the brain of a living mouse. They zoomed-in on part of a dendrite and resolved the 3D structure of individual spines. They then imaged the same area two days later and showed that the spine structure had indeed changed during this time. The researchers did not observe any changes in the structure of the neurons in their images or in the mice’s behavior that would indicate damage from the imaging. However, they do plan to study this further.
“Dendritic spines are so small that without super-resolution it is difficult to visualize their exact 3D shape, let alone any changes to this shape over time,” said Velasco. “3D-2PE-STED now provides the means to observe these changes and to do so not only in the superficial layers of the brain, but also deeper inside, where more of the interesting connections happen.”
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Materials provided by The Optical Society. Note: Content may be edited for style and length.

Increased allergic reactions may be tied to the corticotropin-releasing stress hormone (CRH), suggests a study published this month in the International Journal of Molecular Sciences. These findings may help clarify the mechanism by which CRH induces proliferation of mast cells (MC) — agents involved in the development of allergies in the human nasal cavity.
“In my daily practice, I meet many patients with allergies who say their symptoms worsened due to psychological stress,” states lead researcher Mika Yamanaka-Takaichi, a graduate student of the Department of Dermatology, Osaka City University, “This is what led me to do this research.”
Together with Professor Daisuke Tsuruta of the same department, they hypothesized that due to its role in inducing MC degranulation in human skin, “CRH may also be involved in stress-aggravated nasal allergies,” says Professor Tsuruta.
When the team added CRH to a nasal polyp organ culture, they saw a significant increase in the number of mast cells, a stimulation both of MC degranulation and proliferation, and an increase of stem cell factor (SCF) expression, a growth factor of mast cells, in human nasal mucosa- the skin of the nasal cavity. In exploring possible therapeutic angles, “we saw the effect of CRH on mast cells blocked by CRHR1 gene knockdown, CRHR1 inhibitors, or an addition of SCF neutralizing antibodies,” states Dr. Yamanaka-Takaichi.
In vivo, the team found an increase in the number of mast cells and degranulation in the nasal mucosa of mouse models of restraint stress, which was inhibited by the administration of CRHR1 inhibitor, antalarmin.
“In addition to understanding the effects stress has on our allergies, we have also found promising therapeutic potential in candidates like antalarmin,” adds Dr. Yamanaka-Takaichi, “And this is wonderful news for my patients.”
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Materials provided by Osaka City University. Note: Content may be edited for style and length.

Food scientists from Nanyang Technological University, Singapore (NTU Singapore) have made an antibacterial gel bandage using the discarded husks of the popular tropical fruit, durian.
Known as the “King of Fruits” in Southeast Asia, the durian has a thick husk with spiky thorns which is discarded, while the sweet flesh surrounding the seeds on the inside is considered a delicacy.
By extracting high-quality cellulose from the durian husks and combining it with glycerol — a waste by-product from the biodiesel and soap industry — NTU scientists created a soft gel, similar to silicon sheets, which can be cut into bandages of various shapes and sizes.
They then added the organic molecules produced from baker’s yeast known as natural yeast phenolics, making the bandage deadly to bacteria.
Developed by Professor William Chen, the Director of NTU’s Food Science and Technology Programme, the innovation was published recently in ACS Sustainable Chemistry & Engineering, a peer-reviewed journal of the American Chemistry Society.
Conventional hydrogel patches are commonly available at pharmacies, usually used to cover wounds from surgery to minimise the formation of excessive scar tissue, resulting in a softer and flatter scar. The patch keeps the skin hydrated instead of drying up when conventional band-aid or gauze bandages are used.

An international team of scientists has found evidence that SARS-CoV-2, the virus that causes COVID-19, infects cells in the mouth. While it’s well known that the upper airways and lungs are primary sites of SARS-CoV-2 infection, there are clues the virus can infect cells in other parts of the body, such as the digestive system, blood vessels, kidneys and, as this new study shows, the mouth. The potential of the virus to infect multiple areas of the body might help explain the wide-ranging symptoms experienced by COVID-19 patients, including oral symptoms such as taste loss, dry mouth and blistering. Moreover, the findings point to the possibility that the mouth plays a role in transmitting SARS-CoV-2 to the lungs or digestive system via saliva laden with virus from infected oral cells. A better understanding of the mouth’s involvement could inform strategies to reduce viral transmission within and outside the body. The team was led by researchers at the National Institutes of Health and the University of North Carolina at Chapel Hill.
“Due to NIH’s all-hands-on-deck response to the pandemic, researchers at the National Institute of Dental and Craniofacial Research were able to quickly pivot and apply their expertise in oral biology and medicine to answering key questions about COVID-19,” said NIDCR Director Rena D’Souza, D.D.S., M.S., Ph.D. “The power of this approach is exemplified by the efforts of this scientific team, who identified a likely role for the mouth in SARS-CoV-2 infection and transmission, a finding that adds to knowledge critical for combatting this disease.”
The study, published online March, 25, 2021 in Nature Medicine, was led by Blake M. Warner, D.D.S., Ph.D., M.P.H., assistant clinical investigator and chief of NIDCR’s Salivary Disorders Unit, and Kevin M. Byrd, D.D.S., Ph.D., at the time an assistant professor in the Adams School of Dentistry at the University of North Carolina at Chapel Hill. Byrd is now an Anthony R. Volpe Research Scholar at the American Dental Association Science and Research Institute. Ni Huang, Ph.D., of the Wellcome Sanger Institute in Cambridge, U.K., and Paola Perez, Ph.D., of NIDCR, were co-first authors.
Researchers already know that the saliva of people with COVID-19 can contain high levels of SARS-CoV-2, and studies suggest that saliva testing is nearly as reliable as deep nasal swabbing for diagnosing COVID-19. What scientists don’t entirely know, however, is where SARS-CoV-2 in the saliva comes from. In people with COVID-19 who have respiratory symptoms, virus in saliva possibly comes in part from nasal drainage or sputum coughed up from the lungs. But according to Warner, that may not explain how the virus gets into the saliva of people who lack those respiratory symptoms.
“Based on data from our laboratories, we suspected at least some of the virus in saliva could be coming from infected tissues in the mouth itself,” Warner said.
To explore this possibility, the researchers surveyed oral tissues from healthy people to identify mouth regions susceptible to SARS-CoV-2 infection. Vulnerable cells contain RNA instructions for making “entry proteins” that the virus needs to get into cells. RNA for two key entry proteins — known as the ACE2 receptor and the TMPRSS2 enzyme — was found in certain cells of the salivary glands and tissues lining the oral cavity. In a small portion of salivary gland and gingival (gum) cells, RNA for both ACE2 and TMPRSS2 was expressed in the same cells. This indicated increased vulnerability because the virus is thought to need both entry proteins to gain access to cells.

Dining out is a popular activity worldwide, but there has been little research into its association with health outcomes. Investigators looked at the association between eating out and risk of death and concluded that eating out very frequently is significantly associated with an increased risk of all-cause death, which warrants further investigation. Their results appear in the Journal of the Academy of Nutrition and Dietetics, published by Elsevier.
Eating out is a popular activity. The US Department of Agriculture recently estimated that Americans’ daily energy intake from food away from home increased from 17 percent in 1977-1978 to 34 percent in 2011-2012. At the same time, the number of restaurants has grown steadily, and restaurant-industry sales are forecasted to increase significantly.
Although some restaurants provide high-quality foods, the dietary quality for meals away from home, especially from fast-food chains, is usually lower compared with meals cooked at home. Evidence has shown that meals away from home tend to be higher in energy density, fat, and sodium, but lower in fruits, vegetables, whole grains, and protective nutrients such as dietary fiber and antioxidants.
“Emerging, although still limited, evidence suggests that eating out frequently is associated with increased risk of chronic diseases, such as obesity and diabetes and biomarkers of other chronic diseases,” explained lead investigator Wei Bao, MD, PhD, assistant professor, Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA. “However, little is known about the association between eating meals away from home and risk of mortality.
Investigators analyzed data from responses to questionnaires administered during face-to-face household interviews from 35,084 adults aged 20 years or older who participated in the National Health and Nutritional Examination Survey 1999-2014. Respondents reported their dietary habits including frequency of eating meals prepared away from home. “We linked these records to death records through December 31, 2015, looking especially at all-cause mortality, cardiovascular mortality, and cancer mortality,” noted first author Yang Du, MD, PhD candidate, Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA.
During 291,475 person-years of follow-up, 2,781 deaths occurred, including 511 deaths from cardiovascular disease and 638 deaths from cancer. After adjustment for age, sex, race/ethnicity, socioeconomic status, dietary and lifestyle factors, and body mass index, the hazard ratio of mortality among participants who ate meals prepared away from home very frequently (two meals or more per day) compared with those who seldom ate meals prepared away from home (fewer than one meal per week) was 1.49 (95% CI 1.05 to 2.13) for all-cause mortality, 1.18 (95% CI 0.55 to 2.55) for cardiovascular mortality, and 1.67 (95% CI 0.87 to 3.21) for cancer mortality.
“Our findings from this large nationally representative sample of US adults show that frequent consumption of meals prepared away from home is significantly associated with increased risk of all-cause mortality,” commented Dr. Du.
“This is one of the first studies to quantify the association between eating out and mortality,” concluded Dr. Bao. “Our findings, in line with previous studies, support that eating out frequently is associated with adverse health consequences and may inform future dietary guidelines to recommend reducing consumption of meals prepared away from home.”
“The take-home message is that frequent consumption of meals prepared away from home may not be a healthy habit. Instead, people should be encouraged to consider preparing more meals at home,” concluded the investigators.
Future studies are still needed to look more closely at the association of eating out with death from cardiovascular disease, cancer, dementia, and other chronic diseases.
“It is important to note that the study design for this research examines associations between frequency of eating meals prepared away from home and mortality. While encouraging clients to consider preparing healthy meals at home, registered dietitian nutritionists might also focus on how selections from restaurant menus can be healthy. Tailoring strategies to each client by reviewing menus from restaurants they frequent can help them make healthy food choices,” added co-investigator Linda G. Snetselaar, PhD, RDN, LD, FAND, professor and chair, Preventive Nutrition Education, Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA, and Editor-in-Chief of the Journal of the Academy of Nutrition and Dietetics.