Stretching more effective than walking to lower high blood pressure

 

A new University of Saskatchewan (USask) study has found that stretching is superior to brisk walking for reducing blood pressure in people with high blood pressure or who are at risk of developing elevated blood pressure levels.

Walking has long been the prescription of choice for physicians trying to help their patients bring down their blood pressure. High blood pressure (hypertension) is a leading risk factor for cardiovascular disease and among the top preventable risk factors affecting overall mortality.

This new finding, published December 18, 2020 in the Journal of Physical Activity and Health, shows that stretching should be part of a well-rounded treatment plan for people wrestling with hypertension.

"Everyone thinks that stretching is just about stretching your muscles," said kinesiology professor Dr. Phil Chilibeck (PhD), a co-author of the study. "But when you stretch your muscles, you're also stretching all the blood vessels that feed into the muscle, including all the arteries. If you reduce the stiffness in your arteries, there's less resistance to blood flow," he said, noting that resistance to blood flow increases blood pressure.

While previous studies have shown stretching can reduce blood pressure, the USask research is the first to pit walking against stretching in a head-to-head comparison in the same group of study participants.

Chilibeck and colleagues randomly assigned 40 older men and women (mean age 61) to two groups for the eight-week study period: one did a whole-body stretching routine for 30 minutes a day, five days a week, and the other group walked briskly for the same amount of time and frequency. All participants had elevated blood pressure, or stage 1 hypertension, at the start of the study.

Before and after the study, Chilibeck and colleagues measured participants' blood pressure while they were sitting, lying down, and over 24 hours using a portable monitor--widely considered the gold standard for accurate blood pressure measurement. Stretching resulted in bigger reductions in blood pressure across all three types of measurement. The walkers did, however, lose more body fat off their waist in the eight-week study.

People who are walking to reduce their high blood pressure should continue to do so, but also add in some stretching sessions, according to Chilibeck.

"I don't want people to come away from our research thinking they shouldn't be doing some form of aerobic activity. Things like walking, biking, or cross- country skiing all have a positive effect on body fat, cholesterol levels, and blood sugar."

While the study protocol had participants stretching for 30 minutes at a time, Chilibeck suspects the same benefits can be achieved by doing a shorter routine that emphasizes the larger muscle groups in the legs, particularly the quadriceps and hamstrings. Yoga produces similar reductions in blood pressure, he said.

The beauty of stretching, said Chilibeck, is that it's so easy to incorporate into a person's daily routine. You're not at the mercy of the weather and it's easy on your joints--a big plus for people with osteoarthritis. And it doesn't require a big commitment of time, another barrier to exercise for many people. "When you're relaxing in the evening, instead of just sitting on the couch, you can get down on the floor and stretch while you're watching TV," he said.

Chilibeck and colleagues are now seeking funding to do a larger study involving more participants. They'd like to expand the scope beyond blood pressure measurement to explore some of the physiological reasons behind why stretching reduces blood pressure--such as arterial stiffness and changes in the body's nervous system resulting from stretching.

Stress, depression and poor health behaviors can negatively affect the body's immune response to vaccination

 While we wait for our turn to get vaccinated against SARS-CoV-2, we could -- and probably should -- use the time to make sure we bring our healthiest emotional and physical selves to the treatment, a new review of previous research suggests.

Ohio State University researchers reviewed 49 vaccine studies in humans dating back 30 years that document how stress, depression and poor health behaviors can negatively affect the body's immune response to vaccination, and how improving health factors can enhance that response.

The impaired immune responses tended to fall into three categories -- interference with the development of antibodies against the pathogen, more rapid erosion of antibody protection that does develop, or intensification of vaccination's side effects.

The steady stress of navigating our disrupted routines and social lives during the pandemic may have set us back when it comes to maintaining healthy behaviors, the researchers say. They report on recent data from across the world documenting higher depressive and anxiety symptoms and more insomnia during lockdown, increased alcohol sales and overeating, and fewer average step counts recorded by Fitbits.

There is good news: The power to make improvements that give us the best chance for a healthy response to the coronavirus vaccine is almost completely in our control. Managing stress through exercise and mindfulness meditation, getting enough sleep, quitting or curbing tobacco use and improving our diets -- even in the short term, right around the time of vaccination -- could influence how our bodies respond, the evidence suggests. And for those struggling with depression, now would be a good time to seek professional help.

"When we think of vaccine efficacy, we often think of the vaccine itself. My motivation was to draw attention to the fact that we bring important factors to the table as well -- and those factors are modifiable," said Annelise Madison, first author of the paper and a graduate student in clinical psychology at Ohio State.

"If we can address them now, when most of the world has yet to receive the vaccine, we have the chance to make our response to the vaccine quicker, more robust and lasting."

A number of the studies reviewed were led by senior author Janice Kiecolt-Glaser, director of Ohio State's Institute for Behavioral Medicine Research and a professor of psychiatry and psychology in the College of Medicine. Kiecolt-Glaser and her late husband, immunologist Ronald Glaser, were pioneers in mind-body research that showed how stress impairs physical health in a variety of ways, primarily by hampering the human immune response.

The review is accepted for publication in the journal Perspectives on Psychological Science.

The studies in this review investigated the effects of psychological factors and behaviors on the immune response to a range of vaccine types, such as influenza, hepatitis B, typhoid and pneumonia. Because many findings have been consistent across responses to different vaccines, the team considered them likely to be relevant to the SARS-CoV-2 vaccine.

Kiecolt-Glaser pointed to a few of her past studies that illustrate the varying effects of different types of stress on human responses to vaccination.

In a study of medical students' immune response to a highly effective hepatitis B vaccine, all students eventually developed antibodies -- but the students who were more stressed or anxious about exams coinciding with the inoculations took significantly longer to develop protective antibodies.

Research on older adults' response to a pneumococcal pneumonia vaccine showed that though all study participants initially developed antibodies quickly, the antibody response diminished over the next three to six months in those who were chronically stressed caregivers looking after spouses with dementia.

"These findings suggest that with the COVID-19 vaccine, when people are more stressed and more anxious, it may take a little longer to develop antibodies, so they should probably allow a little more time before they assume they're protected," Kiecolt-Glaser said. "Another possibility is that stress may erode protection more rapidly."

Her lab's past research has also shown that older adults -- who are considered at higher risk for severe COVID-19 symptoms -- sometimes don't respond well to flu vaccines. In one study, only 20% of stressed adults who were age 71 or older developed antibodies after a flu shot.

Additional studies in her lab showed that people who were depressed experienced post-vaccination side effects of lethargy, malaise and irritability for a longer period of time than people who were not depressed.

Side effects are normal -- the vaccination is training the immune system to recognize a pathogen by initiating an inflammatory response that can make us feel sick -- but they can cause some people to avoid vaccines.

"Side effects are from an inflammatory response to the vaccine, which is a good thing," Kiecolt-Glaser said. "You want to see a strong response to the vaccine. That's one reason we know the vaccine is effective. On the other hand, the absence of a response doesn't mean it's not effective."

According to previous research, a range of interventions may help us all get the most out of the COVID-19 vaccine: Massage and expressive writing for stress management, short- and long-term physical activity including 25 minutes of arm exercises before injection, and nutritional supplementation all helped increase antibody response or reduce side effects in past studies.

"And when you know you're going to get the vaccine the next day, try to get a good night's sleep. Just one night, and going in fully rested, can be helpful," Kiecolt-Glaser said.

Though we may be suffering from health-advice fatigue 10 months after the first lockdown, Madison said now may be the most important time to heed the experts' recommendations.

"I know it can be difficult day in and day out during the pandemic to keep prioritizing things we know we should do," she said. "But we could use this time as a wake-up call. These are important health behaviors to keep engaging in, especially as we're preparing to get vaccinated -- which is a really good thing."

MIND and Mediterranean diets associated with later onset of Parkinson's disease

A new study from UBC researchers suggests a strong correlation between following the MIND and Mediterranean diets and later onset of Parkinson's disease (PD). While researchers have long known of neuroprotective effects of the MIND diet for diseases like Alzheimer's and dementia, this study is the first to suggest a link between this diet and brain health for Parkinson's disease (PD).

The MIND diet combines aspects of two very popular diets, the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet.

"The study shows individuals with Parkinson's disease have a significantly later age of onset if their eating pattern closely aligns with the Mediterranean-type diet. The difference shown in the study was up to 17 years later in women and eight years later in men," says Dr. Silke Appel-Cresswell of the Pacific Parkinson's Research Centre, the Djavad Mowafaghian Centre for Brain Health and the Division of Neurology in the UBC Faculty of Medicine. "There is a lack of medications to prevent or delay Parkinson's disease yet we are optimistic that this new evidence suggests nutrition could potentially delay onset of the disease."

In a study of 176 participants, researchers looked at adherence to these types of diets, characterized by reduced meat intake and a focus on vegetables, fruits, whole grains and healthy fats, and the age of PD onset. They found that close adherence to these diets coincided with later onset of PD in women of up to 17.4 years, and 8.4 years in men. The MIND diet showed a more significant impact on women's health, whereas the Mediterranean diet did for the men. The differences in these two diets are subtle, but could serve as clues to the impacts specific foods and micronutrients may have on brain health.

The different effects of diet adherence between sexes are noteworthy as approximately 60 per cent of those diagnosed with Parkinson's disease are men.

"If we understand the sex differences between the MIND diet and Mediterranean diet then we might better understand the sex differences that drive Parkinson's disease in the first place," says lead researcher Avril Metcalfe-Roach, a PhD student at UBC's Michael Smith Laboratories.

These findings springboard to other research questions that could have significant impacts on the understanding of PD.

"It drives home the connection between the gut and the brain for this disease," says Dr. Brett Finlay, professor in the departments of biochemistry and molecular biology, and microbiology and immunology at UBC. "It also shows it's not just one disease that healthy eating can affect, but several of these cognitive diseases."

The research team plans to further examine the potential connection between the microbiome and its effect on the brain.

"There is so much benefit to eating healthy," says Metcalfe-Roach. "It is in everybody's best interest to try to keep your microbiome healthy, to try and eat a rich variety of plant-based and other healthy foods. This study provides even more evidence for what we already know--that we should be trying to eat healthy and taking care of ourselves."

Best to engage in vigorous exercise and get a good night's sleep in the 24 hours before vaccination

 Decades of research show that depression, stress, loneliness, and poor health behaviors can weaken the body's immune system and lower the effectiveness of certain vaccines. A new report accepted for publication in Perspectives on Psychological Science suggests that the same may be true for the new COVID-19 vaccines that are in development and the early stages of global distribution. Fortunately, it may be possible to reduce these negative effects with simple steps like exercise and sleep.

Vaccines are among the safest and most effective advances in medical history, protecting society from a wide range of otherwise devastating diseases, including smallpox and polio. The key to their success, however, is ensuring that a critical percentage of the population is effectively vaccinated to achieve so-called herd immunity.

Even though rigorous testing has shown that the COVID-19 vaccines approved for distribution in the United States are highly effective at producing a robust immune response, not everyone will immediately gain their full benefit. Environmental factors, as well as an individual's genetics and physical and mental health, can weaken the body's immune system, slowing the response to a vaccine.

This is particularly troubling as the novel coronavirus continues to rage across the world, trigging a concurrent mental health crisis as people deal with isolation, economic stressors, and uncertainty about the future. These challenges are the same factors that have been previously shown to weaken vaccine efficacy, particularly among the elderly.

"In addition to the physical toll of COVID-19, the pandemic has an equally troubling mental health component, causing anxiety and depression, among many other related problems. Emotional stressors like these can affect a person's immune system, impairing their ability to ward off infections," said Annelise Madison, a researcher at The Ohio State University and lead author on the paper. "Our new study sheds light on vaccine efficacy and how health behaviors and emotional stressors can alter the body's ability to develop an immune response. The trouble is that the pandemic in and of itself could be amplifying these risk factors."

Vaccines work by challenging the immune system. Within hours of a vaccination, there is an innate, general immune response on the cellular level as the body begins to recognize a potential biological threat. This frontline response by the immune system is eventually aided by the production of antibodies, which target specific pathogens. It is the continued production of antibodies that helps to determine how effective a vaccine is at conferring long-term protection.

"In our research, we focus most heavily on the antibody response, though it is just one facet of the adaptive immune system's response," said Janice Kiecolt-Glaser, director of the Institute for Behavioral Medicine Research at The Ohio State University and senior author on the paper.

The good news, according to the researchers, is that the COVID-19 vaccines already in circulation are approximately 95% effective. Even so, these psychological and behavioral factors can lengthen the amount of time it takes to develop immunity and can shorten the duration of immunity.

"The thing that excites me is that some of these factors are modifiable," said Kiecolt-Glaser. "It's possible to do some simple things to maximize the vaccine's initial effectiveness."

Based on prior research, one strategy the researchers suggest is to engage in vigorous exercise and get a good night's sleep in the 24 hours before vaccination so that your immune system is operating at peak performance. This may help ensure that the best and strongest immune response happens as quickly as possible.

"Prior research suggests that psychological and behavioral interventions can improve vaccine responsiveness. Even shorter-term interventions can be effective," said Madison. "Therefore, now is the time to identify those at risk for a poor immune response and intervene on these risk factors."

Higher coffee intake may be linked to lower prostate cancer risk

Each additional daily cup associated with reduction in risk of nearly 1%

BMJ

Research News

    SHARE

 PRINT  E-MAIL

Drinking several cups of coffee every day may be linked to a lower risk of developing prostate cancer, suggests a pooled data analysis of the available evidence, published in the online journal BMJ Open.

Each additional daily cup of the brew was associated with a reduction in relative risk of nearly 1%, the findings indicate.

Prostate cancer is the second most common cancer, and the sixth leading cause of cancer death in men. Nearly three out of four cases occur in the developed world, and since the 1970s, new cases of the disease have risen sharply in Asian countries, including Japan, Singapore, and China.

Coffee consumption has been linked to a lower relative risk of liver, bowel, and breast cancers, but as yet, there is no conclusive evidence for its potential role in prostate cancer risk reduction.

In a bid to advance understanding of the issue, the researchers trawled research databases for relevant cohort studies published up to September 2020.

They pooled the data from 16: 15 reported on the risk of prostate cancer associated with the highest, compared with the lowest, coffee consumption; 13 reported on the risk associated with an additional daily cup. The highest level of consumption ranged from 2 to 9 or more cups a day; the lowest level ranged from none to fewer than 2 cups a day.

The included studies were carried out in North America (7), Europe (7) and Japan (2). They included more than 1 million men (1,081, 586) of whom 57,732 developed prostate cancer.

Compared with the lowest category of coffee consumption, the highest category was associated with a reduction in prostate cancer risk of 9%. And each additional daily cup was associated with a reduction in risk of 1%.

Further refining the analysis to localised and advanced prostate cancer, showed that compared with the lowest intake, the highest intake was associated with a 7% lower risk of localised prostate cancer, and a 12%-16% lower risk for advanced and fatal prostate cancer, respectively.

The researchers acknowledge that because of the observational design of the included cohort studies, unmeasured or uncontrolled factors in the original studies may have skewed the pooled risk estimate.

The amount of coffee drunk may also have been misclassified as it depended on recall. And the type of coffee and brewing methods varied among the studies. The design and methods of the included studies also varied, so caution in interpreting the findings is warranted, they say.

Nevertheless, there are plausible biological explanations for their findings, they highlight.

Coffee improves glucose metabolism, has anti-inflammatory and antioxidant effects, and affects sex hormone levels, all of which may influence the initiation, development and progression of prostate cancer, they point out.

And they conclude: "This study suggests that increased coffee consumption may be associated with a reduced risk of prostate cancer. Further research is still warranted to explore the underlying mechanisms and active compounds in coffee.

"If the association is further proved to be a causal effect, men might be encouraged to increase their coffee consumption to potentially decrease the risk of prostate cancer."

Using cannabis while trying to conceive may reduce pregnancy chances

 Women who use marijuana could have a more difficult time conceiving a child than women who do not use marijuana, suggests a study by researchers at the National Institutes of Health. Marijuana use among the women's partners--which could have influenced conception rates--was not studied. The researchers were led by Sunni L. Mumford, Ph.D., of the Epidemiology Branch in NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development. The study appears in Human Reproduction.

The women were part of a larger group trying to conceive after one or two prior miscarriages. Women who said they used cannabis products--marijuana or hashish--in the weeks before pregnancy, or who had positive urine tests for cannabis use, were around 40% less likely to conceive per monthly cycle than women who did not use cannabis. The authors noted that although the findings suggest cannabis could affect women's fertility, they should be tempered with caution as the study observed a relatively small number of cannabis users. However, the authors say their results suggest that women trying to conceive should exercise caution with cannabis use until more definitive evidence is available.

The researchers analyzed data from a broader study of more than 1,200 women ages 18 to 40 with one or two pregnancy losses. The women participated in the study for up to six monthly cycles while attempting pregnancy and throughout pregnancy if conception occurred. After enrolling in the study, the women responded to a questionnaire asking if they had used marijuana, pot, or hashish in the past 12 months, with responses ranging from never, rarely, occasionally, sometimes, often, to daily. Each woman also provided urine samples for analysis when they first entered the study and after six months if they did not conceive or at the time of positive pregnancy test if they conceived.

A total of 62 women (5%) either had a positive urine test or responded that they had used cannabis before conception.

For each monthly cycle, women who had used cannabis while trying to conceive were 41% less likely to conceive than non-users. Similarly, a smaller proportion of cannabis users than non-users became pregnant during the study--42% versus 66%. The authors found no differences in miscarriage rates between users and non-users who had achieved pregnancy.

The authors noted that, compared to non-users, cannabis users also had differences in reproductive hormones involved in ovulation. These differences could potentially have influenced their likelihood of conception. Specifically, users had higher levels of luteinizing hormone and a higher proportion of luteinizing hormone to follicle stimulating hormone.

###

Reference

Mumford SL et al. Cannabis use while trying to conceive: a prospective cohort study evaluating associations with fecundability, live birth, and pregnancy loss. Human Reproduction. 2020. 
doi:10.1093/humrep/deaa355

The paper can be found online after publication at: 
https://academic.oup.com/humrep/article-lookup/doi/10.1093/humrep/deaa355

Diets rich in healthy and plant-based foods = gut microbes linked to a lower risk of illnesses, heart disease

A large-scale international study using metagenomics and blood chemical profiling has uncovered a panel of 15 gut microbes associated with lower risks of common conditions such as obesity and type 2 diabetes. The study has been published today in Nature Medicine from researchers at King's College London, Massachusetts General Hospital (MGH), Harvard T.H. Chan School of Public Health, the University of Trento, Italy, and health start-up company ZOE.

The PREDICT 1 (Personalized Responses to Dietary Composition Trial 1) analyzed detailed data on the composition of participants' gut microbiomes, their dietary habits, and cardiometabolic blood biomarkers. It uncovered strong links between a person's diet, the microbes in their gut (microbiome) and their health.

Researchers identified microbes that positively or negatively correlate 'good' and 'bad' with an individual's risk of certain serious conditions such as diabetes, heart disease and obesity. Surprisingly, the microbiome has a greater association to these markers than other factors, such as genetics. Some of the identified microbes are so novel that they have not yet been named.

The researchers defined a "healthy" diet as one that contained a mix of foods associated with a lower risk of chronic disease. They found that trial subjects who ate such a diet, or one rich in plants, were more likely to have high levels of specific 'good' gut microbes which are associated with a low risk of common illnesses. The researchers also found microbiome-based biomarkers of obesity as well as markers for cardiovascular disease and impaired glucose tolerance, which are key risk factors for COVID. These findings can be used to help create personalized eating plans designed specifically to improve one's health.

Dr. Sarah Berry, Reader in Nutrition Sciences at King's College London said, "As a nutritional scientist, finding novel microbes that are linked to specific foods, as well as metabolic health, is exciting. Given the highly personalised composition of each individuals' microbiome, our research suggests that we may be able to modify our gut microbiome to optimize our health by choosing the best foods for our unique biology."

For example, the findings reveal that having a microbiome rich in Prevotella copri and Blastocystis species was associated with maintaining a favorable blood sugar level after a meal. Other species were linked to lower post-meal levels of blood fats and markers of inflammation.

Professor Tim Spector, Epidemiologist from King's College London, who started the PREDICT study program and is scientific founder of ZO, said: "When you eat, you're not just nourishing your body, you're feeding the trillions of microbes that live inside your gut."

Nicola Segata, PhD, professor and principal investigator of the Computational Metagenomics Lab at the University of Trento, Italy and leader of the microbiome analysis in the study, said: "We were surprised to see such large, clear groups of what we informally call 'good' and 'bad' microbes emerging from our analysis. It is also exciting to see that microbiologists know so little about many of these microbes that they are not even named yet. This is now a big area of focus for us, as we believe they may open new insights in the future into how we could use the gut microbiome as a modifiable target to improve human metabolism and health."

PREDICT is the largest in-depth nutritional study in the world. PREDICT 1 was an international collaboration to study links between diet, the microbiome, and biomarkers of cardiometabolic health. The researchers gathered microbiome sequence data, detailed long-term dietary information, and results of hundreds of cardiometabolic blood markers from just over 1,100 participants in the U.S. and the U.K. PREDICT 2 completed its primary investigations in 2020 with a further 1,000 U.S participants, and PREDICT 3 launched a few months ago.