Health benefits of olives and olive oil

The health benefits of olives-- and associated natural products such as olive oil--have long been recognized and touted by proponents of the Mediterranean diet.

However, little was previously known about what specific compounds and biochemical interactions in the fruit contribute to its medical and nutritional benefits such as weight loss and prevention of type 2 diabetes.

A Virginia Tech research team discovered that the olive-derived compound oleuropein helps the body secrete more insulin, a central signaling molecule in the body that controls metabolism. The same compound also detoxifies another signaling molecule called amylin that over-produces and forms harmful aggregates in type 2 diabetes. In these two distinct ways, oleuropein helps prevent the onset of disease.

The findings were recently published in the journal Biochemistry as a Rapid Report, which is reserved for timely topics of unusual interest, according to the journal.

"Our work provides new mechanistic insights into the long-standing question of why olive products can be anti- diabetic," said Bin Xu, lead author, assistant professor of biochemistry in the College of Agriculture and Life Sciences, and a Fralin Life Science Institute affiliate. "We believe it will not only contribute to the biochemistry of the functions of the olive component oleuropein, but also have an impact on the general public to pay more attention to olive products in light of the current diabetes epidemic."

Expectations for a meal have an effect on subsequent feelings of hunger and calorie intake

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Despite eating the same breakfast, made from the same ingredients, people consumed more calories throughout the day when they believed that one of the breakfasts was less substantial than the other.

The research, funded by the Rural and Environment Science and Analytical Services at the Rowett Institute, is the key finding of research led by Steven Brown from Sheffield Hallam University which is being presented today at the annual conference of the British Psychological Society's Division of Health Psychology.

Previous studies have investigated the link between how filling we expect liquids (e.g. drinks) or semi-solids (e.g. smoothies/soups) to be and people's subsequent feelings of hunger up to three hours later.

These initial expectations have also been shown to be an important determinant of how much people eat at a meal provided a short time later. The current research shows that a similar effect can be seen when using solid foods (i.e. an omelette) and that the influence of those expectations is still present after a longer period of time (four hours later and the total day's calorific intake).

A total of 26 participants took part. Over two visits, participants believed they were eating either a two or four egg omelette for breakfast. However, both of the omelettes actually contained three eggs.

When the participants believed that the omelette was smaller they reported themselves to be significantly hungrier after two hours, they consumed significantly more of a pasta lunch and, in total, consumed significantly more calories throughout the day than when the same participants believed that they were eating a larger omelette.

Steven Brown said, "Previous studies have shown that a person's expectations can have an impact on their subsequent feelings of hunger and fullness and, to a degree, their later calorie consumption. Our work builds on this with the introduction of solid food and measured people's subsequent consumption four hours later, a period of time more indicative of the gap between breakfast and lunch.

"We were also able to measure participants' consumption throughout the rest of the day and found that total intake was lower when participants believed that they had eaten a larger breakfast.

"As part of the study, we were able to take blood samples from participants throughout their visits. Having analysed levels of ghrelin, a known hunger hormone, our data also suggest that changes in reported hunger and the differences in later consumption are not due to a differences in participants' physical response to the food.

Therefore, memory for prior consumption, as opposed to physiological factors, may be a better target for investigating why expectations for a meal have an effect on subsequent feelings of hunger and calorie intake."

Eleven new studies suggest 'power poses' don't work

IMAGE: Can holding a power pose, such as standing with your legs wide and hands on hips, improve your life?

Credit: Michigan State University

The claim that holding a "power pose" can improve your life became wildly popular several years ago, fueling the second most-watched TED talk ever but also casting doubts about the science behind the assertion.

Now comes the most definitive evidence to date - a wave of scientific studies spearheaded by a Michigan State University researcher - suggesting that power poses do not improve your life.

"This new evidence joins an existing body of research questioning the claim by power pose advocates that making your body more physically expansive - such as standing with your legs spread and your hands on your hips - can actually make you more likely to succeed in life," said Joseph Cesario, MSU associate professor of psychology.

Cesario co-edits a scientific journal, Comprehensive Results in Social Psychology, that recently published seven studies, all of which attempted - unsuccessfully - to replicate and extend the effects of power pose research. In other words, none of the studies showed positive effects of power poses on any behavioral measure, such as how well you perform in a job interview. The studies were even reviewed by Dana Carney, a University of California Berkeley professor who was one of the authors of the original power pose research.

In addition, Cesario and MSU graduate student David Johnson recently published four new studies testing whether holding power poses impacted important behaviors such as how well you do in a business negotiation. The work, published in the journal Social Psychological and Personality Science, again found no evidence that making yourself expansive mattered at all.

"There is currently little reason to continue to strongly believe," Cesario said, "that holding these expansive poses will meaningfully affect people's lives, especially the lives of the low-status or powerless people."

Led by Carney and Amy Cuddy from Harvard University, the original power pose study, in 2010, suggested that holding such poses can make you more likely to succeed in life, especially if you are "chronically powerless because of lack of resources, low hierarchical rank or membership in a low-power social group."

Cuddy's June 2012 TED talk, now with more than 42 million views, argued that "power posing" - or standing in a posture of confidence, even when we don't feel confident - will boost feelings of confidence and will have an impact on one's chances for success, such as in a job interview.
When you're alone before the interview, Cuddy recommends, hold a power pose for two minutes - whether that's standing with hands on hips, leaning over a table with your fingertips on the surface, or perhaps seated with your feet on the table and your arms folded behind your head.

"Share [this science] with people, because the people who can use it the most are the ones with no resources and no technology and no status and no power," Cuddy concludes the TED talk. "Give it to them because they can do it in private. They need their bodies, privacy and two minutes, and it can significantly change the outcomes of their life."

But the new research stands in stark contrast to Cuddy's claim. Cesario's research and the findings from the journal he co-edits do find that holding power poses makes people feel more powerful, but that's where the effect ends.

"Feeling powerful may feel good, but on its own does not translate into powerful or effective behaviors," Cesario said. "These new studies, with more total participants than nearly every other study on the topic, show - unequivocally - that power poses have no effects on any behavioral or cognitive measure."

In several of the experiments by MSU's Cesario and Johnson, for example, participants watched Cuddy's TED talk, held a power pose and then completed a negotiation task with another participant. The participants who held the power poses did no better than their partners.

In addition, the seven studies that appear in a special issue of Comprehensive Results in Social Psychology also fail to replicate the power pose effects.

"Based on the papers in the special issue, and prior replication attempts, one could conclude that the power pose effect on behavioral outcomes does not replicate," the researchers, including Cesario and Dana Carney, write in the journal.

Carney puts it even more bluntly in a previously posted statement on her website: "As evidence has come in over these past 2-plus years, my views have updated to reflect the evidence. As such, I do not believe that power pose effects are real."

Metabolically healthy obese and underweight individuals still have higher heart disease risk

Individuals who are metabolically healthy obese and underweight are at a higher risk of heart disease compared to metabolically healthy normal weight individuals, according to the largest study to date comparing weight and metabolic status to cardiovascular risk, published today in the Journal of the American College of Cardiology. Normal weight individuals with metabolic abnormalities showed similar risk as those who were healthy obese and healthy underweight.

Obesity, an established risk factor for heart disease, has increased globally over the past 40 years. This study aimed to examine the association between "metabolically healthy" obese individuals and their risk for coronary heart disease, cerebrovascular disease, heart failure and peripheral vascular disease. Three metabolic abnormalities were taken into consideration during the study: diabetes, hypertension and hyperlipidemia. A metabolically healthy person was classified as having no metabolic abnormalities.

The researchers compared electronic health records of 3.5 million British adults obtained through The Health Improvement Network from 1995 to 2015, with a five-year follow up period. The individuals were initially free from heart disease and divided into four body size phenotypes using body mass index (calculated by dividing body weight by height): underweight (BMI less than 18.5), normal weight (more than 18 but less than 25), overweight (more than 25 but less than 30) and obese (more than 30). The study also factored in age, sex, smoking status and social deprivation (determined based on income, education and employment).

"This is the largest prospective study of the association between body size phenotypes - including metabolically healthy obesity - with or without metabolic abnormalities and a range of cardiovascular disease events," said lead study author Rishi Caleyachetty, MBBS, PhD, research fellow at the Institute of Applied Health Research, University of Birmingham. "Compared to normal weight individuals with no metabolic abnormalities, individuals who are 'metabolically healthy' obese were at higher risk of coronary heart disease, cerebrovascular disease and heart failure. Individuals who are normal weight can also have metabolic abnormalities, and be at high risk for cardiovascular disease events."

Approximately 15 percent of participants were classified as obese with no metabolic abnormalities. These individuals were most likely to be younger, male, current smokers and socially deprived. Those who were metabolically healthy obese had an increased risk of developing coronary heart disease, cerebrovascular disease and heart failure compared to individuals with normal weight and no metabolic abnormalities. Metabolically healthy obese individuals had a decreased risk of peripheral vascular disease compared to normal weight individuals with no metabolic abnormalities.

Individuals who fell into the underweight BMI category with zero metabolic abnormalities were also at an increased risk for cerebrovascular disease, heart failure and peripheral vascular disease. These risks may be due to smoking-related diseases such as chronic obstructive pulmonary disease and lung cancer. Underweight individuals who did not smoke were not found to have a risk for cerebrovascular disease.

Senior authors Neil Thomas, PhD, and Krish Nirantharakumar, MD, of the Institute of Applied Health Research, University of Birmingham noted that the data shows that at a population level, metabolically healthy obese is not a harmless condition and increases risk of cardiovascular events.

"With an impending obesity epidemic, examination of specific cardiovascular outcomes in this way is timely and highly significant," said Jennifer Bea, PhD, assistant professor of medicine with the University of Arizona's Collaboratory for Metabolic Disease Prevention and Treatment in an accompanying editorial. "[This study] confirmed that obesity without metabolic abnormality is not benign. Even with no evident metabolic dysfunction, obese individuals were not 'healthy.'"

Long sitting periods may be just as harmful as daily total

A new study finds that it isn't just the amount of time spent sitting, but also the way in which sitting time is accumulated during the day, that can affect risk of early death.

The study, published online today in Annals of Internal Medicine, found that adults who sit for one to two hours at a time without moving have a higher mortality rate than adults who accrue the same amount of sedentary time in shorter bouts.

"We tend to think of sedentary behavior as just the sheer volume of how much we sit around each day," said Keith Diaz, PhD, associate research scientist in the Department of Medicine at Columbia University Medical Center (CUMC) and lead investigator of the study. "But previous studies have suggested that sedentary patterns--whether an individual accrues sedentary time through several short stretches or fewer long stretches of time--may have an impact on health."

The researchers used hip-mounted activity monitors to objectively measure inactivity during waking time over a period of seven days in 7,985 black and white adults over age 45. (The participants were taking part in the REGARDS study, a national investigation of racial and regional disparities in stroke.)

On average, sedentary behavior accounted for 77 percent of the participants' waking hours, equivalent to more than 12 hours per day. Over a median follow-up period of four years, 340 of the participants died. Mortality risk was calculated for those with various amounts of total sedentary time and various sedentary patterns. Those with the greatest amount of sedentary time--more than 13 hours per day--and who frequently had sedentary bouts of at least 60 to 90 consecutive minutes had a nearly two-fold increase in death risk compared with those who had the least total sedentary time and the shortest sedentary bouts.

The researchers also found that participants who kept most of their sitting bouts to less than 30 minutes had the lowest risk of death. "So if you have a job or lifestyle where you have to sit for prolonged periods of time, we suggest taking a movement break every half hour. This one behavior change could reduce your risk of death, although we don't yet know precisely how much activity is optimal," Dr. Diaz said.

The study was the largest to link objectively measured sedentary time and sedentary patterns with mortality risk.

"This study adds to the growing literature on how dangerous long periods of sitting are for our health, and underscores a growing awareness among clinicians and researchers that sitting really is the new smoking," said study co-author Monika Safford, MD, chief of the Division of General Internal Medicine and the John J. Kuiper Professor at Weill Cornell Medicine, and an internist at NewYork-Presbyterian/Weill Cornell Medical Center. "We need creative ways to ensure that we not only cut back on the total amount we sit, but also increase regular interruptions to sitting with bursts of activity." Dr. Safford is the PI on one of the REGARDS ancillary studies and provided the cardiac events data for this paper.

Small increases in physical activity reduce immobility, disability risks in older adults

Adding 48 minutes of moderate exercise per week is associated with improvements in overall physical functioning and decreases in risks of immobility in older adults who are sedentary, finds a new study led by researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University.

In the study, published in PLOS ONE on Aug. 18, the researchers evaluated how different doses of exercise for adults age 70-89 would impact the benefits. While the researchers saw improvements in all participants who added some physical activity to their routine, those who got more exercise saw greater changes. The work is part of the Lifestyle Interventions and Independence for Elders (LIFE) study.

"These are people who want to live healthy, independent lives and are at risk for losing that. Maintaining functional independence for older adults is an important public health issue. In our first LIFE study, we confirmed that regular exercise can help improve physical function and prevent mobility loss. Now we see that small increases can have big impacts," said first and corresponding author Roger A. Fielding, senior scientist and director of the Nutrition, Exercise Physiology, and Sarcopenia Laboratory at the USDA HNRCA.

For the LIFE study, the researchers analyzed data from 1,635 men and women age 70-89 over an average of 2.6 years. Half were randomly assigned to a program of walking and walking-based strength, flexibility and balance training; half participated in health education workshops. All had low levels of physical functioning at the start and reported fewer than 20 minutes per week of regular physical activity in the month prior to starting the study. Participants were evaluated at baseline, six, 12, and 24 months. The researchers relied on movement monitors and self-reporting to measure physical activity outside study sessions.

Changes in activity were significantly greater in the physical activity intervention group than the health education group from baseline through 24 months. There was a continuous, graded effect with the greatest benefits seen in the participants who engaged in at least 48 minutes of physical activity per week. The greater differences were also associated with prevention of major mobility loss.

"Our goal was to have participants walking up to 150 minutes per week. To see benefits at 48 minutes is encouraging. We wanted the physical activity sessions to include exercise that participants could do outside of the study, and we hope that learning of these results might motivate others to try to make safe, incremental changes to their activity levels. Reducing muscle loss, functional decline, and loss of independence are important to anyone, at any age, and at any physical ability," said Fielding.

The researchers acknowledge limitations of this study, including examining the different quantities of exercise participation achieved in the LIFE study participants and not specifically prescribing different amounts of exercise to different study groups. In addition, there were differences in the measured absolute amounts of exercise performed when comparing objective activity monitoring using a wearable "device" and self-report of physical activity.

Whole grains decrease colorectal cancer risk, processed meats increase the risk

Eating whole grains daily, such as brown rice or whole-wheat bread, reduces colorectal cancer risk, with the more you eat the lower the risk, finds a new report by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF). This is the first time AICR/WCRF research links whole grains independently to lower cancer risk.

Diet, Nutrition, Physical Activity and Colorectal Cancer also found that hot dogs, bacon and other processed meats consumed regularly increase the risk of this cancer. There was strong evidence that physical activity protects against colon cancer.

"Colorectal cancer is one of the most common cancers, yet this report demonstrates there is a lot people can do to dramatically lower their risk," said Edward L. Giovannucci, MD, ScD, lead author of the report and professor of nutrition and epidemiology at the Harvard TH Chan School of Public Health. "The findings from this comprehensive report are robust and clear: Diet and lifestyle have a major role in colorectal cancer."

The new report evaluated the scientific research worldwide on how diet, weight and physical activity affect colorectal cancer risk. The report analyzed 99 studies, including data on 29 million people, of whom over a quarter of a million were diagnosed with colorectal cancer.

Other factors found to increase colorectal cancer include:

• Eating high amounts of red meat (above 500 grams cooked weight a week), such as beef or pork
• Being overweight or obese
• Consuming two or more daily alcoholic drinks (30 grams of alcohol), such as wine or beer

Lowering Risk with Fiber, Activity and Grains
 
The report concluded that eating approximately three servings (90 grams) of whole grains daily reduces the risk of colorectal cancer by 17 percent.

It adds to previous evidence showing that foods containing fiber decreases the risk of this cancer.
For physical activity, people who are more physically active have a lower risk of colon cancer compared to those who do very little physical activity. Here, the decreased risk was apparent for colon and not rectal cancer.

In the US, colorectal cancer is the third most common cancer among both men and women, with an estimated 371 cases diagnosed each day. AICR estimates that 47 percent of US colorectal cancer cases could be prevented each year through healthy lifestyle changes.

Notes Giovannucci: "Many of the ways to help prevent colorectal cancer are important for overall health. Factors such as maintaining a lean body weight, proper exercise, limiting red and processed meat and eating more whole grains and fiber would lower risk substantially. Moreover, limiting alcohol to at most two drinks per day and avoidance or cessation of smoking also lower risk."

Fish, Fruits and Vegetables, Emerging Evidence
 
The report found other links between diet and colorectal cancer that were visible but not as clear. There was limited evidence that risk increases with low intake of both non-starchy vegetables and fruit. A higher risk was observed for intakes of less than 100 grams per day (about a cup) of each.
Links to lowering risk of colorectal cancer was with fish and foods containing vitamin C. Oranges, strawberries and spinach are all foods high in vitamin C.

The research continues to emerge for these factors, but it all points to the power of a plant-based diet, says Alice Bender, MS, RDN, AICR Director of Nutrition Programs. "Replacing some of your refined grains with whole grains and eating mostly plant foods, such as fruits, vegetables and beans, will give you a diet packed with cancer-protective compounds and help you manage your weight, which is so important to lower risk."

"When it comes to cancer there are no guarantees, but it's clear now there are choices you can make and steps you can take to lower your risk of colorectal and other cancers," said Bender.