Intermittent fasting can help manage metabolic disease

 

Popular diet trend could reduce the risk of diabetes and heart disease

Peer-Reviewed Publication

Eating your daily calories within a consistent window of 8-10 hours is a powerful strategy to prevent and manage chronic diseases such as diabetes and heart disease, according to a new manuscript published in the Endocrine Society’s journal, Endocrine Reviews.

Time-restricted eating is a type of intermittent fasting that limits your food intake to a certain number of hours each day. Intermittent fasting is one of the most popular diet trends, and people are using it to lose weight, improve their health and simplify their lifestyles.

“People who are trying to lose weight and live a healthier lifestyle should pay more attention to when they eat as well as what they eat. Time-restricted eating is an easy-to-follow and effective dietary strategy that requires less mental math than counting calories,” said Satchidananda Panda, Ph.D., of the Salk Institute for Biological Studies in La Jolla, Calif. “Intermittent fasting can improve sleep and a person’s quality of life as well as reduce the risk of obesity, diabetes and heart disease.”

In the manuscript, the researchers explore the science behind time-restricted eating, recent clinical studies and the scope for future research to better understand its health benefits. Recent research has revealed that genes, hormones and metabolism rise and fall at different times of the 24-hour day. Aligning our daily habit of when we eat with the body’s internal clock can optimize health and reduce the risk or disease burden of chronic conditions like diabetes, heart disease and liver disease.

“Eating at random times breaks the synchrony of our internal program and make us prone to diseases,” said Panda. "Intermittent fasting is a lifestyle that anyone can adopt. It can help eliminate health disparities and lets everyone live a healthy and fulfilling life."

Weather can affect pain tolerance

Can the weather affect pain from conditions like arthritis or migraine? It may sound like an old superstition – but on some standard quantitative sensory tests, weather-related factors do indeed affect pain tolerance, suggests a study in PAIN®, the official publication of the International Association for the Study of Pain (IASP). 

"Although observational, these findings suggest that weather has a causal, non-linear, dynamic effect on pain tolerance," according to the new research, led by Erlend Hoftun Farbu, PhD student at UiT – The Arctic University of Norway, Tromsø. But it remains unclear if the link between weather and pain involves physiological or psychological factors, or a combination of factors.

Weather-related factors affect two standard pain assessments

The study included participants in the Tromsø Study, an ongoing study of the health of people in that city in Northern Norway, located north of the Arctic Circle. About 19,500 participants, average age 57 years, were evaluated on two quantitative sensory tests, widely used in research studies. The pressure pain tolerance test (PPT) measured the subjects' ability to tolerate pain from steadily increasing pressure applied to the lower leg. The cold pain tolerance test (CPT) measured how long they could tolerate immersion of the hand in cold water.

Results of the pain tolerance tests were analyzed in relation to data on weather conditions - temperature, barometric pressure, precipitation, relative humidity, and wind speed. Associations between pain tolerance and meteorological factors were assessed, along with seasonal or shorter-term variations.

Overall, the PPT results showed no significant seasonal variation and were not strongly related to weather-related variables when considering the whole study period. However, the correlations varied depending on the time period studied. The data suggested “non-random short-term variation” in PPT outcomes – the time frame of short-term variations  in PPT mirrored the time frame of the weather. Additionally, temperature and barometric pressure predicted future PPT values.

In contrast, the CPT results showed clear seasonal variation – subjects were able to tolerate cold-induced pain longer during colder times of year. Cold pain tolerance also varied with weather-related variables. "This fits nicely together with research on cold adaptation," Mr. Farbu comments. "As you get used to cold, you might be able to tolerate more cold.”

He adds, "Temperature and barometric pressure seems to be most strongly related to CPT and PPT, and they predict future PPT. However, the effect of temperature is likely influenced by humidity and wind, as they might alter the heat loss."

Many people, particularly those with chronic pain, believe that weather or weather-related factors can cause or aggravate episodes of pain. While some studies have supported associations between weather and pain, others have reached conflicting results.

"If we are correct about that the relationship is dynamic and non-linear, it might very well explain why many studies find small effects and conflicting results," Mr. Farbu comments. "If an effect is changing over time and you average it over time, you might end up with no effect."

The findings, especially for CPT, "should be considered when planning future studies on pain tolerance," the researchers write. They discuss some ways in which weather might affect pain tolerance. One possible explanation is "central mechanisms," with weather-related variables affecting parts of the brain involved in pain processing. Alternatively, weather might affect people's mental status – as in seasonal depression, for example – which could affect their capacity to endure pain.

"In summary, it is unlikely that one singular mechanism can explain the variations in pain tolerance observed," Mr. Farbu and coauthors conclude. "[I]t is more probable that this is the net result of many, possibly antagonistic, mechanisms."

Click here to read “To tolerate weather and to tolerate pain two sides of the same coin? The Tromsø Study 7”

Sticking to low-fat dairy may not be the only heart healthy option

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New research amongst the world’s biggest consumers of dairy foods has shown that those with higher intakes of dairy fat - measured by levels of fatty acids in the blood - had a lower risk of cardiovascular disease compared to those with low intakes. Higher intakes of dairy fat were not associated with an increased risk of death.

Researchers then combined the results of this study in just over 4,000 Swedish adults with those from 17 similar studies in other countries, creating the most comprehensive evidence to date on the relationship between this more objective measure of dairy fat consumption, risk of cardiovascular disease (CVD) and death.

Dr Matti Marklund from The George Institute for Global Health, Johns Hopkins Bloomberg School of Public Health, and Uppsala University said that with dairy consumption on the rise worldwide, a better understanding of the health impact was needed.

“Many studies have relied on people being able to remember and record the amounts and types of dairy foods they’ve eaten, which is especially difficult given that dairy is commonly used in a variety of foods.

“Instead, we measured blood levels of certain fatty acids, or fat ‘building blocks’ that are found in dairy foods, which gives a more objective measure of dairy fat intake that doesn’t rely on memory or the quality of food databases,” he added.

“We found those with the highest levels actually had the lowest risk of CVD. These relationships are highly interesting, but we need further studies to better understand the full health impact of dairy fats and dairy foods.”

Dairy and dairy product consumption in Sweden is among the highest worldwide. An international collaboration between researchers in Sweden, the US and Australia assessed dairy fat consumption in 4150 Swedish 60-year-olds by measuring blood levels of a particular fatty acid that is mainly found in dairy foods and therefore can be used to reflect intake of dairy fat.

They were then followed up for an average of 16 years to see how many had heart attacks, strokes and other serious circulatory events, and how many died from any cause during this time.

After statistically adjusting for other known CVD risk factors including things like age, income, lifestyle, dietary habits, and other diseases, the CVD risk was lowest for those with high levels of the fatty acid (reflecting high intake of dairy fats). Those with the highest levels had no increased risk of death from all causes.

Dr Marklund added that the findings highlight the uncertainty of evidence in this area, which is reflected in dietary guidelines.

“While some dietary guidelines continue to suggest consumers choose low-fat dairy products, others have moved away from that advice, instead suggesting dairy can be part of a healthy diet with an  emphasis on selecting certain dairy foods - for example, yoghurt rather than butter - or avoiding sweetened dairy products that are loaded with added sugar,” he said.

Combining these results with 17 other studies involving a total of almost 43,000 people from the US, Denmark, and the UK confirmed these findings in other populations.

“While the findings may be partly influenced by factors other than dairy fat, our study does not suggest any harm of dairy fat per se,” Dr Marklund said.

Lead author Dr Kathy Trieu from The George Institute for Global Health said that consumption of some dairy foods, especially fermented products, have previously been associated with benefits for the heart.

“Increasing evidence suggests that the health impact of dairy foods may be more dependent on the type - such as cheese, yoghurt, milk, and butter - rather than the fat content, which has raised doubts if avoidance of dairy fats overall is beneficial for cardiovascular health,” she said.

“Our study suggests that cutting down on dairy fat or avoiding dairy altogether might not be the best choice for heart health.”

“It is important to remember that although dairy foods can be rich in saturated fat, they are also rich in many other nutrients and can be a part of a healthy diet. However, other fats like those found in seafood, nuts, and non-tropical vegetable oils can have greater health benefits than dairy fats,” Dr Trieu added.

MIND diet linked to better cognitive performance

 

Study finds diet may contribute to cognitive resilience in the elderly

Aging takes a toll on the body and on the mind. For example, the tissue of aging human brains sometimes develops abnormal clumps of proteins that are the hallmark of Alzheimer’s disease. How can you protect your brain from these effects?

Researchers at Rush University Medical Center have found that older adults may benefit from a specific diet called the MIND diet even when they develop these protein deposits, known as amyloid plaques and tangles. Plaques and tangles are a pathology found in the brain that build up in between nerve cells and typically interfere with thinking and problem-solving skills.

Developed by the late Martha Clare Morris, ScD, who was a Rush nutritional epidemiologist, and her colleagues, the MIND diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. Previous research studies have found that the MIND diet may reduce a person’s risk of developing Alzheimer’s disease dementia.

Now a study has shown that participants in the study who followed the MIND diet moderately later in life did not have cognition problems, according to a paper published on Sept. 14 in the Journal of Alzheimer’s Disease.

“Some people have enough plaques and tangles in their brains to have a postmortem diagnosis of Alzheimer’s disease, but they do not develop clinical dementia in their lifetime,” said Klodian Dhana, MD, PhD, lead author of the paper and an assistant professor in the Division of Geriatrics and Palliative Medicine in the Department of Internal Medicine at Rush Medical College .

“Some have the ability to maintain cognitive function despite the accumulation of these pathologies in the brain, and our study suggests that the MIND diet is associated with better cognitive functions independently of brain pathologies related to Alzheimer’s disease.

In this study, the researchers examined the associations of diet—from the start of the study until death—brain pathologies and cognitive functioning in older adults who participated in the Rush Alzheimer’s Disease Center’s ongoing Memory and Aging Project, which began in 1997 and includes people living in greater Chicago. The participants were mostly white without known dementia, and all of them agreed to undergo annual clinical evaluations while alive and brain autopsy after their death.

The researchers followed 569 participants, who were asked to complete annual evaluations and cognitive tests to see if they had developed memory and thinking problems. Beginning in 2004, participants were given an annual food frequency questionnaire about how often they ate 144 food items in previous year.

Using the questionnaire answers, the researchers gave each participant a MIND diet score based on how often the participants ate specific foods. The MIND diet has 15 dietary components, including 10 “brain-healthy food groups” and five unhealthy groups — red meat, butter and stick margarine, cheese, pastries and sweets, and fried or fast food.

To adhere to and benefit from the MIND diet, a person would need to eat at least three servings of whole grains, a green leafy vegetable and one other vegetable every day — along with a glass of wine — snack most days on nuts, have beans every other day or so, eat poultry and berries at least twice a week and fish at least once a week. A person also must limit intake of the designated unhealthy foods, limiting butter to less than 1 1/2 teaspoons a day and eating less than a serving a week of sweets and pastries, whole fat cheese, and fried or fast food.

Based on the frequency of intake reported for the healthy and unhealthy food groups, the researchers calculated the MIND diet score for each participant across the study period. An average of the MIND diet score from the start of the study until the participant’s death was used in the analysis to limit measurement error. Seven sensitivity measures were calculated to confirm accuracy of the findings.

“We found that a higher MIND diet score was associated with better memory and thinking skills independently of Alzheimer's disease pathology and other common age-related brain pathologies. The diet seemed to have a protective capacity and may contribute to cognitive resilience in the elderly.” Dhana said.

“Diet changes can impact cognitive functioning and risk of dementia, for better or worse,” he continued. “There are fairly simple diet and lifestyle changes a person could make that may help to slow cognitive decline with aging, and contribute to brain health.”

 

Patients with implanted medical devices should keep their smart phones and watches at least six inches away

 After reports of smart phone and watch interference with implanted medical devices, investigators affiliated with the Center for Devices and Radiological Health (CDRH) at the US Food and Drug Administration conducted a study that supports the FDA recommendation that patients keep any consumer electronic devices that may create magnetic interference, including cell phones and smart watches, at least six inches away from implanted medical devices, in particular pacemakers and cardiac defibrillators. Their findings appear in Heart Rhythm, the official journal of the Heart Rhythm Society, the Cardiac Electrophysiology Society, and the Pediatric & Congenital Electrophysiology Society, published by Elsevier.

"Ensuring the safety of our nation's medical devices is a cornerstone of our consumer protection mission, especially as technology continues to advance," explained lead investigator Seth J. Seidman, MS, Research Electrical Engineer and EMC Program Advisor with the CDRH. "As part of this work, the agency reviewed recently published articles describing the possibility that certain newer cell phones, smart watches, and other consumer electronics with high field strength magnets may temporarily affect the normal operation of implanted electronic medical devices, such as pacemakers and implantable defibrillators. Based on our review, we decided to conduct our own testing to confirm and help inform appropriate recommendations for patients and consumers."

Cardiac implanted electronic devices are intended to support heart rhythm disorders, such as slow or fast heart rates. Implantable pacemakers and cardioverter defibrillators (ICDs) include a "magnet mode" designed to be used when a patient is undergoing a procedure where electromagnetic interference is possible, or when suspension of the device is necessary for medical treatment. However, this feature can also be triggered accidentally from strong magnetic fields greater than 10G, which can change how the device works and could result in serious harm to the patient.

Historically, magnets strong enough to trigger this magnet mode were very large and identifiable, such as stereo speakers or electronic motors in cordless tools. With the advent of small rare-earth magnets, however, strong magnetic fields can be found in headphones, door locks, or small phone speakers.

The investigators tested the magnetic field output of all iPhone 12 and Apple Watch 6 models at varying distances from the devices. They found that all the devices have static magnetic fields significantly greater than 10G in close proximity, high enough to place implanted cardiac devices into magnet mode. However, when a separation distance of six inches or more is maintained, the phones and watches will not trigger magnet mode.

"Because of these results, we are taking steps to provide information for patients and healthcare providers to ensure they are aware of potential risks and can take simple proactive and preventive measures like keeping consumer electronics, such as certain cell phones and smart watches, six inches away from implanted medical devices and not carrying consumer electronics in a pocket over the medical device," advised Mr. Seidman.

"We believe the risk to patients is low and the agency is not aware of any adverse events associated with this issue at this time. However, the number of consumer electronics with strong magnets is expected to increase over time. Therefore, we recommend people with implanted medical devices talk with their healthcare providers to ensure they understand this potential risk and the proper techniques for safe use. The FDA will continue to monitor the effects of consumer electronics on the safe operation of medical devices," noted Mr. Seidman.

MMR and Tdap vaccines strengthen protection against severe COVID-19

 Vaccines are designed to induce a strong and long-lasting immune response through the creation of memory T cells and B cells. The Measles-Mumps-Rubella (MMR) vaccine, given during early childhood, and Tetanus-Diphtheria-Pertussis (Tdap) vaccine, given every 10 years, are known to elicit a protective response against the diseases from which the vaccines get their names. But these vaccines may have an unexpected bonus: It's possible that they also elicit cross-reactive memory T cells capable of responding to protein targets called antigens that are present in other microbes that cause diseases -- including the viral antigens in SARS-CoV-2. The concept is that pre-existing memory T cells generated by prior MMR or Tdap vaccination and activated by SARS-CoV-2 infection give the immune system a head start in responding to SARS-CoV-2, thereby lowering the risk of severe COVID-19.

To investigate whether the MMR and Tdap vaccines provide additional protection against COVID-19, researchers at Brigham and Women's Hospital conducted laboratory-based analyses using sensitive, new techniques to detect and characterize T cell responses to antigens. They applied these techniques to measure the response of T cells isolated from the blood of COVID-19 convalescent patients and patients vaccinated against COVID-19 to antigens from SARS-CoV-2 and the MMR and Tdap vaccines. Teaming up with collaborators at Cleveland Clinic, they also leveraged a large, well-annotated cohort of COVID-19 patients and found that prior MMR or Tdap vaccination was associated with decreased disease severity. Their results are published in Med.

"Our Cleveland Clinic colleagues observed an association where individuals with COVID-19 who had either MMR or Tdap vaccines had a much lower frequency of going to the intensive care unit or dying," said co-author Andrew Lichtman, MD, PhD, an immunologist and senior investigator in the Brigham's Department of Pathology and professor of Pathology at Harvard Medical School. "Although previous smaller studies suggested a similar link, our in-depth epidemiological analyses, together with our basic research results, suggest that these commonly given vaccines may protect against severe disease."

"During the COVID-19 pandemic, we know that there was a marked decline in routine vaccinations for children and adolescents," said corresponding author Tanya Mayadas, PhD, a senior scientist in the Brigham's Department of Pathology and professor of Pathology at Harvard Medical School. "Our findings emphasize the importance of routine vaccination for children and adults. We know vaccines protect against devastating diseases, and we're now seeing growing evidence that some of them provide a degree of protection against severe COVID-19 disease."

The team's investigation was jumpstarted by an unexpected observation. Mayadas, her postdoctoral fellow Vijaya Mysore, PhD, and colleagues noted in laboratory experiments using COVID-19 convalescent blood that whenever they observed a heightened T cell response to SARS-CoV-2 proteins, they also saw a heightened response to proteins from MMR and Tdap, which they had been using as controls. This was observed with both COVID-19 convalescent and uninfected individuals vaccinated against SARS-CoV-2. This connection was made by the team's use of highly efficient antigen-presenting cells (described in a recently published Nature Communications paper) derived from blood, loaded with SARS-CoV-2, MMR or Tdap antigens, and co-cultured with T cells from the same individual. Using single-cell RNA sequencing and analysis of T cell antigen receptors, the team observed that the antigen receptors on many of the T cells from individuals who had recovered from COVID-19 that responded to proteins from SARS-CoV-2 (Spike-S1 and Nucleocapsid) were identical to the antigen receptors on T cells that responded to MMR and Tdap proteins. This discovery indicated the presence of T cell clones that can respond to both SARS-CoV-2 antigens and the MMR and Tdap vaccine antigens.

In a second analysis, Mayadas and colleagues teamed up with investigators at Cleveland Clinic to examine the epidemiological evidence. The Cleveland Clinic team performed a retrospective cohort study using data from more than 75,000 patients seen at the Cleveland Clinic Health System in Ohio or Florida who had tested positive for COVID-19 between March 8, 2020, and March 31, 2021. The team used a statistical method known as overlap propensity score weighting to compare two disease severity outcomes (COVID-related hospitalization and COVID-related admission to the intensive care unit or death) for patients who had been vaccinated against MMR or Tdap and those who had not. They found that patients who had previously been vaccinated for MMR had a 38 percent decrease in hospitalization and a 32 percent decrease in ICU admission/death. Similarly, patients previously vaccinated for Tdap had 23 percent and 20 percent decreased rates, respectively, of these outcomes.

"Beyond learning about the potential benefits of the MMR and Tdap vaccines in the context of COVID-19, this study provides a blueprint for accelerating research," said co-author Lara Jehi, MD, MHCDS, Chief Research Information Officer of the Cleveland Clinic Health System. "Biomedical hypotheses generated in the laboratory can be explored through robust clinical and epidemiological research in well-curated, real-world data such as the Cleveland Clinic COVID Registry. Knowledge learned through this collaboration is much more than the sum of our individual parts."

The authors note that while their laboratory-based findings are strengthened by the epidemiological observations, further work is needed to assess the association between the MMR and Tdap vaccinations and severity of COVID-19 disease to determine if the relationship is a causal one. Prospective studies of vaccination and patient outcomes may help distinguish correlation from causation.

"With regards to COVID-19 vaccines, our findings predict that although MMR and Tdap are not a substitute for COVID-19 vaccines they may afford greater and more durable protection, possibly against emerging spike variants than the COVID-19 vaccine alone," said Mayadas. "And in areas where the COVID-19 vaccines are not available, they could protect infected individuals from developing severe disease."

Standing more may help prevent chronic diseases

 Insulin is a key hormone in energy metabolism and blood sugar regulation. Normal insulin function in the body may be disturbed by e.g. overweight, leading to decreased insulin sensitivity and increased risk of developing type 2 diabetes and cardiovascular diseases. In a Finnish collaborative study of Turku PET Centre and UKK institute, the researchers noticed that standing is associated with better insulin sensitivity. Increasing the daily standing time may therefore help prevent chronic diseases.

Type 2 diabetes is one the most common lifestyle diseases worldwide, and its onset is usually preceded by impaired insulin sensitivity, i.e. insulin resistance. This refers to a state in which the body does not react to insulin normally, and the blood glucose levels rise.

Lifestyle has a strong impact on insulin resistance and the development of type 2 diabetes, and regular physical activity is known to have an important role in the prevention of these issues. However, so far, little is known about the impact of sedentary behaviour, breaks in sitting, and standing on insulin resistance.

In a study of Turku PET Centre and UKK institute, the researchers investigated the associations between insulin resistance and sedentary behaviour, physical activity and fitness in inactive working-age adults with an increased risk of developing type 2 diabetes and cardiovascular diseases. In the study published in Journal of Science and Medicine in Sport, the researchers observed that standing is associated with better insulin sensitivity independently of the amount of daily physical activity or sitting time, fitness level, or overweight.

"This association has not been shown before. These findings further encourage replacing a part of daily sitting time with standing, especially if physical activity recommendations are not met," says Doctoral Candidate Taru Garthwaite from the University of Turku.

Body Composition Strongly Associated with Insulin Sensitivity

The study also emphasises the importance of healthy body composition on metabolic health. The results show that increased body fat percentage was a more important factor in terms of insulin sensitivity than physical activity, fitness, or the amount of time spent sitting. Standing, on the other hand, was associated with insulin sensitivity independently, irrespective of body composition.

"Regular exercise is well known to be beneficial for health. It seems that physical activity, fitness, and sedentary behaviour are also connected to insulin metabolism, but indirectly, through their effect on body composition," Taru Garthwaite explains.

Causal effects cannot yet be predicted based on this study, but according to Garthwaite, the results suggest that increasing daily standing time may help in prevention of lifestyle diseases if physical activity recommendations are not met.

Next, the researchers aim to investigate how changes in daily activity and sedentariness impact cardiovascular and metabolic disease risk factors and metabolism by comparing two groups in an intervention study of a longer duration.

"Our aim is to study if reducing daily sitting time by an hour has an impact on energy metabolism and fat accumulation in liver and the whole body, for example, in addition to insulin sensitivity and blood sugar regulation," says Garthwaite.