Improving deep sleep may prevent dementia, study finds

As little as 1 per cent reduction in deep sleep per year for people over 60 years of age translates into a 27 per cent increased risk of dementia, according to a study which suggests that enhancing or maintaining deep sleep, also known as slow wave sleep, in older years could stave off dementia.

The study, led by Associate Professor Matthew Pase, from the Monash School of Psychological Sciences and the Turner Institute for Brain and Mental Health in Melbourne, Australia, and published today in JAMA Neurology, looked at 346 participants, over 60 years of age, enrolled in the Framingham Heart Study who completed two overnight sleep studies in the time periods 1995 to 1998 and 2001 to 2003, with an average of five years between the two studies.

These participants were then carefully followed for dementia from the time of the second sleep study through to 2018. The researchers found, on average, that the amount of deep sleep declined between the two studies, indicating slow wave sleep loss with ageing. Over the next 17 years of follow-up, there were 52 cases of dementia. Even adjusting for age, sex, cohort, genetic factors, smoking status, sleeping medication use, antidepressant use, and anxiolytic use, each percentage decrease in deep sleep each year was associated with a 27 per cent increase in the risk of dementia.

“Slow-wave sleep, or deep sleep, supports the ageing brain in many ways, and we know that sleep augments the clearance of metabolic waste from the brain, including facilitating the clearance of proteins that aggregate in Alzheimer’s disease,” Associate Professor Pase said.

“However, to date we have been unsure of the role of slow-wave sleep in the development of dementia. Our findings suggest that slow wave sleep loss may be a modifiable dementia risk factor.”

Associate Professor Pase said that the Framingham Heart Study is a unique community-based cohort with repeated overnight polysomnographic (PSG) sleep studies and uninterrupted surveillance for incident dementia.

“We used these to examine how slow-wave sleep changed with ageing and whether changes in slow-wave sleep percentage were associated with the risk of later-life dementia up to 17 years later,” he said.

“We also examined whether genetic risk for Alzheimer’s Disease or brain volumes suggestive of early neurodegeneration were associated with a reduction in slow-wave sleep. We found that a genetic risk factor for Alzheimer’s disease, but not brain volume, was associated with accelerated declines in slow wave sleep.”

 

Body weight, not red meat, may be the driver of increased systemic inflammation

 

Inflammation is a risk factor for many chronic diseases, including cardiovascular disease (CVD), and the impact of diet on inflammation is an area of growing scientific interest. In particular, recommendations to limit red meat consumption are often based, in part, on old studies suggesting that red meat negatively affects inflammation – yet more recent studies have not supported this.

“The role of diet, including red meat, on inflammation and disease risk has not been adequately studied, which can lead to public health recommendations that are not based on strong evidence,” said Dr. Alexis Wood, associate professor of pediatrics – nutrition at the USDA/ARS Children's Nutrition Research Center at Baylor College of Medicine and Texas Children’s Hospital. “Our team sought to take a closer look by using metabolite data in the blood, which can provide a more direct link between diet and health.”

Wood and her team analyzed cross-sectional data captured from approximately 4,000 older adults participating in the Multi-Ethnic Study of Atherosclerosis (MESA), and recently published their findings in The American Journal of Clinical Nutrition. Cross-sectional data is a useful source of evidence on how diet affects health; it uses data that is observed with free-living people, without attempting to influence their usual lifestyle. In this way, it may be easier to take results from such studies and apply them to non-research settings. In addition to assessing participants’ self-reported food intake and several biomarkers, researchers also measured an array of dietary intake metabolites in blood. Plasma metabolites can help capture the effects of dietary intake as food is processed, digested and absorbed. 

Researchers found that when adjusted for body mass index (BMI), intake of unprocessed and processed red meat (beef, pork or lamb) was not directly associated with any markers of inflammation, suggesting that body weight, not red meat, may be the driver of increased systemic inflammation. Of particular interest was the lack of a link between red meat intake and C-reactive protein (CRP), the major inflammatory risk marker of chronic disease.

“Our analysis adds to the growing body of evidence that indicates the importance of measuring plasma markers, such as metabolites, to track diet and disease risk associations, versus relying on self-reported dietary intake alone,” Wood said. “Our analysis does not support previous observational research associations linking red meat intake and inflammation.”

Because observational studies cannot indicate cause and effect, randomized controlled trials (RCTs) where individuals are randomly assigned to consume a dietary factor of interest or not consume it, are needed as an additional line of evidence to adequately understand if red meat does not alter inflammation. Several RCTs have demonstrated that lean unprocessed beef can be enjoyed in heart-healthy dietary patterns.

“We have reached a stage where more studies are needed before we can make recommendations to limit red meat consumption for reducing inflammation if we want to base dietary recommendations on the most up-to-date evidence,” Wood said. “Red meat is popular, accessible and palatable – and its place in our diet has deep cultural roots. Given this, recommendations about reducing consumption should be supported by strong scientific evidence, which doesn’t yet exist.”

Great news for runners: Improve performance while easing up on sprints

10-20-30 interval training is an effective way to improve running performance and overall health. A new study from the University of Copenhagen demonstrates that this kind of training is just as effective for improving your running times and overall fitness, even if your sprints are only at 80 percent. The researchers hope that the new knowledge can encourage more people to adopt this type of training, which benefits both blood pressure and cholesterol levels.

A group of runners jogs leisurely along a park's trails. Thirty seconds later, they accelerate to a moderate pace for 20 seconds before blasting into a ten-second sprint. 10-20-30 interval running training is a widespread training concept because it is effective at improving running times and fitness levels, even with marked reduction in the amount of training.

Now, new research from the University of Copenhagen’s Department of Nutrition, Exercise and Sports (NEXS) demonstrates that you do not necessarily need to give it all you’ve got in the final ten-second sprint to get into good shape and improve your times.

In the study, 19 runners replaced their normal training with 10-20-30 workouts for six weeks. The results came as a surprise:  Half of the group, whom the researchers had instructed to perform at only 80 percent during the final ten-second sprint, achieved as much progress in their running performance and fitness as the group that sprinted at 100 percent.

"The result of the study really came as a surprise. We think that it is related to the fact that training at 80 percent of one’s maximum still gets the heart rate up significantly higher than a runner’s typical training. A higher heart rate leads to improvements in heart function and circulation, as evidenced in their times and fitness levels," says Professor Jens Bangsbo of the Department of Nutrition, Exercise and Sports, who headed the study.    

Sprint 100 percent to achieve the maximum benefit

Over the five-kilometer distance that the researchers tested the 19 runners on, the "slow" group – who sprinted at only 80 percent of their max – achieved an average improvement in their running time of 42 seconds compared to their original time prior to the six-week interval training. Meanwhile, runners in the "fast" group only shaved an average of 24 seconds off of their times. Both groups of runners improved their overall fitness (maximum oxygen uptake) by seven percent.

At first glance, it appears as if holding back somewhat on one’s final sprint carries nothing but advantages. However, as the researchers dug deeper to better understand how the runners' muscles reacted to the two loads, one important difference emerged.

"Only the max group formed more mitochondria, which are the tiny power plants within our cells. They are important for muscular endurance and the ability of our muscles to engage in long-term work. So, if you plan on running a half or full marathon, you’ll need to sprint at 100 percent to achieve the maximum benefit," says Jens Bangsbo.

Effective training for busy lives

It may seem silly to be constantly accelerating and slowing down while out on a run, but consider what you’re missing out on by not doing so. 10-20-30 interval running is a type of workout that, besides improving running times and overall fitness, also comes with a wide range of other health benefits.

This was established in another study by Jens Bangsbo in 2020, in which diabetics lowered their blood sugar and the amount of "dangerous fat" around their organs after ten weeks of 10-20-30 exercise.

"Just as with other high intensity exercises that elevate heart rate, 10-20-30 workouts have a positive effect on health. Among other things, we also see improvements in blood pressure and cholesterol levels. At the same time, interval training is more effective, because you can get into better shape and improve your health in less time than by running at a constant pace," says Bangsbo.

According to Bangsbo, 10-20-30 training  can also feel both easier and more fun.

"Many people find that interval running is more fun due to the changes in pace. And when doing 10-20-30 training , there is also a social element, as runners with different performance level can meet after the ten-seconds period and run together, whichmakes it more enjoyable. With this study, we’ve shown that, even if you "only" run at 80 percent during the sprint, it is still a very effective form of training – which may encourage even more people to opt for this kind of training," concludes Jens Bangsbo.

About 10-20-30 Training:

• 10-20-30 running is intensive interval training where you run: 30 seconds at a slow pace, 20 seconds at a moderate pace and 10 seconds as sprint.
• Each interval takes one minute and is repeated three to five times. A one to four minute break is taken after each block of intervals. The five-minute periods of intervals should be performed one to four times during a workout, depending on your level of fitness.
• The method is characterized by running faster and straining yourself more than you normally would, and by being divided into fixed intervals with built-in breaks. The many changes in pace and increased intensity are the fundamentals of 10-20-30 training and play a crucial role for anyone seeking to improve their overall fitness and performance.
• Beginners should start with a 1 x 5-minute training. For people used to run, start with 2 x 5-minute periods with a 3-4 minute break. As you get used to this type of training, you should increase speed during the 20- and 10-second intervals as well as gradually increase the number of 5-minute intervals and reduce break time.
• To benefit from this type of workout, you will need to do 10-20-30 training  at least twice a week. Beginners should not run more than twice a week at first. Recreational runners can run three times a week, while experienced runners, who may already be accustomed to interval running, can choose to replace up to four training sessions a week with 10-20-30 training  for optimal effect.

About the study

• 19 runners replaced their regular training with 10-20-30 workouts (3-4 5-minute blocks) 3 times a week for 6 weeks. One group performed the 10-second sprint with maximum effort (MAX) and the other with approximately 80% of their maximum effort (SUBMAX).
• What's new in this study is that the runners who ran at 80% of their maximum speed during the 10-second sprint intervals progressed just as much (42 seconds improvement) in 5K performance and also benefited from a 7% increase in overall fitness (maximum oxygen uptake) as the group who ran at a full sprint during the 10 second sprints.
• According to the researchers, the surprising result is probably related to the fact that even "sub-maximum" 10-20-30 training provokes a significantly higher heart rate than a runner's normal training regimen. This is one of the main reasons for participants’ improved health and cardiovascular fitness.
• The study "Similar improvements in 5-km performance and maximal oxygen uptake with sub-maximal and maximal 10-20-30 training in runners, but increase in muscle oxidative phosphorylation occur only with maximal effort training" has been published in the Scandinavian Journal of Medicine & Science in Sports, e-pub.
• The study was conducted by Casper Skovgaard, Danny Christiansen, Alejandro Martinez Rodriguez, Jens Bangsbo.

 

A comprehensive picture of health benefits of eggs

New research provides a broader perspective on the nutritional effects of egg consumption in young, healthy adults

Peer-Reviewed Publication

UNIVERSITY OF CONNECTICUT

Most existing research articles that evaluate the health effects of eggs tend to focus on a more limited range of standard clinical measurements, looking at biomarkers for heart disease, diabetes, body composition, inflammation, immune health, and anemia in isolation, rather than all together. Participants in these studies also tend to have pre-existing risk factors for chronic disease. They typically also follow additional dietary regimen changes like weight loss plans. These factors can complicate interpretations of how eggs affect health markers in the general or young, healthy population.

Andersen and her collaborators conducted a more comprehensive, clinically-focused study that considered many health measurements a doctor would look at during a routine physical.

“It helps to provide a comprehensive picture of the effects of egg intake in a young, healthy population utilizing standard, routine clinical biomarkers,” Andersen says. “We believe that allows for greater translation to the general public.”

The study compared eating no eggs, three egg whites per day, and three whole eggs per day. Participants could prepare the eggs however they preferred.

Andersen found that blood samples showed a significant increase in choline, an essential nutrient found in egg yolks, when participants ate whole eggs daily. Choline intake has been associated with increases in a metabolite known as TMAO, which is linked to heart disease. But Andersen’s study found that TMAO did not change in this population despite increases in choline.

“That’s kind of the best-case scenario,” Andersen says. “We want to have rich amounts of this important nutrient, but not increase this metabolite that could potentially promote cardiovascular disease.”

The researchers did not see any adverse changes in inflammation or blood cholesterol levels either. They also found that eating whole eggs had less of a negative impact on markers associated with diabetes risk than eating egg whites.

Overall, participants had greater nutrient density in their diet when consuming the whole eggs, in addition to higher hematocrit – a measure of red blood cell density in the blood, which can be lowered in anemia.

 

More than just carbs: starchy vegetables play an integral role in meeting nutrition needs

 

Healthy examples of starch include whole grains, beans, legumes, bananas, and cooked and cooled starches.

A perspective recently published in Frontiers in Nutrition underscores the unique role starchy vegetables play as a vital vehicle for essential nutrients. The Dietary Guidelines for Americans currently recommend that most adults consume five to six cups (or cup equivalents) of starchy vegetables each week to help meet their total vegetable goals.1 Yet, as confusion around “good versus bad carbs” persists among consumers, there is a risk of starchy vegetable avoidance in favor of other carbohydrate foods perceived as equally or more nutritious – or even carbohydrate avoidance all together.

Using menu model analyses, nutrition expert Keith Ayoob, EdD, RDN, Associate Professor Emeritus, Albert Einstein College of Medicine, demonstrates the real-world implications of eliminating starchy vegetables in the diet and swapping them for grain-based foods. The results? Replacing starchy vegetables with grain-based alternatives, including whole-grain foods, for one day led to a 21% decrease in potassium, a 17% decrease in vitamin B6, an 11% drop in vitamin C and a 10% reduction in fiber.

"It’s tempting to think of all carbohydrate foods as interchangeable,” says Ayoob. “But these foods are categorized within different food groups for a reason – perhaps most importantly, they tend to have vastly different vitamin and mineral contents.” Compared to grains, starchy vegetables like potatoes tend to be higher in potassium, designated a nutrient of public health concern by the Dietary Guidelines for Americans because inadequate intake is associated with increased health risks.1 They can also provide an excellent source of vitamin C.2

Additionally, though neither group is considered a major protein source, the protein quality in potatoes is notably higher than the protein quality of grains, comparable in quality (as measured by “biological value”) to the protein in egg and milk.3,4 And though food choices from both groups can help add fiber to the diet, grains offer unique nutritional benefits as well, typically offering more thiamin, zinc and vitamin E.

“As is so often the case in the world of nutrition, guidance comes down to balance, variety and moderation – which might sound boring, but all three would benefit most people's eating styles,” Ayoob adds. “It’s important to get the right mix of vegetables and grains and include both starchy and non-starchy vegetables to help ensure we’re meeting both our macronutrient and micronutrient needs.”

In addition to demonstrating key differences in the nutrient contributions of starchy vegetables and grain-based foods, the perspective discusses distinctions in each food group’s chemical structure, culinary applications, economic benefits and cultural relevance.

Ayoob notes, “It’s also important to recognize that some cultural groups traditionally use certain carb-containing foods over others. That’s why more research is needed to understand how different carbohydrate food choices impact diet quality and what culturally appropriate foods should be encouraged to help close any nutrient gaps.”

Menu Model Details

Dr. Ayoob analyzed two, one-day menu models to assess the nutrient contributions from both starchy vegetables and grain-based foods to the daily diet.

A ~2,000-calorie “foundation” menu was used to reflect the dietary recommendations within the 2020-2025 Dietary Guidelines for Americans and in alignment with the USDA’s “Food Pattern Models.” This menu included both grain-based foods and white potatoes, as a nutritionally representative food from the starchy vegetable category.  In this foundational diet, white potatoes were included at breakfast in the form of hashbrowns and at dinner in the form of a baked potato.

A ~2,000-calorie menu with 100% of starchy vegetables replaced with grain-based foods was used as a comparison. This menu replaced the hashbrowns at breakfast with an additional slice of whole wheat bread and the baked potato at dinner with white rice.

Limitations of these menu modeling results include the fact that potatoes were the only starchy vegetable incorporated into the foundational menu, and modeling was limited to a single day. Additional modeling reflecting other culturally relevant starchy vegetable options and preparations over a longer period would help to further elucidate nutritional implications of starchy vegetable avoidance or carbohydrate food swapping behaviors.

Full details can be found in the published article, “Carbohydrate confusion and dietary patterns: unintended public health consequences of ‘food swapping,’” in Frontiers in Nutrition (https://doi.org/10.3389/fnut.2023.1266308). Funding was provided by Potatoes USA; the funder had no impact on the peer review process and final manuscript.

References

1U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. [Internet]. Available from: https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf

2U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, 2019. fdc.nal.usda.gov/fdc-app.html#/food-details/170030/nutrients

3Camire, ME, Kubow, S, and Donnelly, DJ. Potatoes and human health. Crit Rev Food Sci Nutr. (2009) 49:823–40. doi: 10.1080/10408390903041996

4Hoffman, JR, and Falvo, MJ. Protein–Which is Best? J Sports Sci Med. (2004) 3:118

Heated yoga may reduce depression symptoms

 

 In a randomized controlled clinical trial of adults with moderate-to-severe depression, those who participated in heated yoga sessions experienced significantly greater reductions in depressive symptoms compared with a control group.

The results of the trial, which was led by investigators at Massachusetts General Hospital (MGH), a founding member of Mass General Brigham (MGB), and was published in the Journal of Clinical Psychiatry, indicate that heated yoga could be a viable treatment option for patients with depression.

In the eight-week trial, 80 participants were randomized into two groups: one that received 90-minute sessions of Bikram yoga practiced in a 105°F room and a second group that was placed on a waitlist (waitlist participants completed the yoga intervention after their waitlist period). A total of 33 participants in the yoga group and 32 in the waitlist group were included in the analysis.

Participants in the intervention group were prescribed at least two yoga classes per week, but overall, they attended an average of 10.3 classes over eight weeks.

After eight weeks, yoga participants had a significantly greater reduction in depressive symptoms than waitlisted participants, as assessed through what’s known as the clinician-rated Inventory of Depressive Symptomatology (IDS-CR) scale.

Also, investigators observed that 59.3% of yoga participants had a 50% or greater decrease in symptoms, compared with 6.3% of waitlist participants. Moreover, 44% in the yoga arm achieved such low IDS-CR scores that their depression was considered in remission, compared with 6.3% in the waitlist arm.

Depressive symptoms were reduced even in participants who received only half of the prescribed yoga “dose,” suggesting that heated yoga sessions just once a week could be beneficial.

“Yoga and heat-based interventions could potentially change the course for treatment for patients with depression by providing a non-medication–based approach with additional physical benefits as a bonus,” says lead author Maren Nyer, PhD, director of Yoga Studies at the Depression Clinical and Research Program at Massachusetts General Hospital and an assistant professor of Psychiatry at Harvard Medical School.

“We are currently developing new studies with the goal of determining the specific contributions of each element—heat and yoga—to the clinical effects we have observed in depression.”

Participants rated the heated yoga sessions positively, and they experienced no serious adverse effects associated with the intervention.

“Future research is needed to compare heated to nonheated yoga for depression to explore whether heat has benefits over and above that of yoga for the treatment of depression, especially given the promising evidence for whole body hyperthermia as a treatment for major depressive disorder,” says senior author David Mischoulon, MD, PhD, Director, Depression Clinical and Research Program at Massachusetts General Hospital.

Women with a heart healthy diet in midlife are less likely to report cognitive decline later

 Women with diets during middle age designed to lower blood pressure were about 17 percent less likely to report memory loss and other signs of cognitive decline decades later, a new study finds.

Led by researchers from NYU Grossman School of Medicine, the new findings suggest that a mid-life lifestyle modification – adoption of the Dietary Approaches to Stop Hypertension, or DASH diet – may improve cognitive function later in life for women, who make up more than two-thirds of those diagnosed with Alzheimer’s disease, the most prevalent form of dementia.

The findings, published online today in the journal Alzheimer's & Dementia , have implications for the approximately 6.5 million Americans over age 65 diagnosed with Alzheimer’s disease in 2022. That number is expected to more than double by 2060.

“Subjective complaints about daily cognitive performance are early predictors of more serious neurocognitive disorders such as Alzheimer’s,” said Yu Chen, PhD, MPH, professor in the Department of Population Health and senior author of the study. “With more than 30 years follow-up, we found that the stronger the adherence to a DASH diet in midlife, the less likely women are to report cognitive issues much later in life.” 

The DASH diet includes a high consumption of plant-based foods that are rich in potassium, calcium, and magnesium and limits saturated fat, cholesterol, sodium, and sugar. Longstanding research shows that high blood pressure, particularly in midlife, is a risk factor for cognitive decline and dementia.

How the Study was  Conducted

The investigators analyized data from 5,116 of the more than 14,000 women enrolled in the NYU Women’s Health Study, one of the longest running studies of its kind that examines the impact of lifestyle and other factors on the development of the most common cancers among women, as well as other chronic conditions.

The researchers queried the study participants’ diet using questionnaires between 1985 and 1991 at study enrollment when the participants were, on average, 49 years old. The participants were followed for more than 30 years (average age of 79) and then asked to report any cognitive complaints. Participants that did not return questionnaires were contacted by phone.

Self-reported cognitive complaints were assessed using six validated standard questions that are indicative of later mild cognitive impairment, which leads to dementia. These questions were about difficulties in remembering recent events or shopping lists, understanding spoken instructions or group conversation, or navigating familier streets.

Of the six cognitive complaints, 33 percent of women reported having more than one. Women who adhered most closely to the DASH diet had a 17 percent reduction in the odds of reporting multiple cognitive complaints.

“Our data suggest that it is important to start a healthy diet in midlife to prevent cognitive impairment in older age”, said Yixiao Song , a lead author of the study.

“Following the DASH diet may not only prevent high blood pressure, but also cognitive issues,” said Fen Wu, PhD, an senior associate research scientist and co-led the study.

According to the investigators, future research is needed across multiple racial and ethnic groups to determine the generalizability of the findings.

More than 7,500 daily steps prior to surgery is associated with lower risk of postoperative complications

 

IMAGE: 

PHYSICAL ACTIVITY LOWERS RISK OF POSTOPERATIVE COMPLICATIONS.

 

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CREDIT: AMERICAN COLLEGE OF SURGEONS

Key takeaways 

• Using Fitbit activity tracking data, researchers identified patients who might be at higher risk of postoperative complications. Fewer daily steps were associated with a higher rate of complications postoperatively.  

• The odds of complications within 90 days after hospital discharge were reduced by half if a patient took more than 7,500 steps a day before the operation, after adjusting for the complexity of the procedure, comorbidities, and other factors.  

CHICAGO (October 20, 2023): Patients who recorded more walking activity prior to surgery, regardless of complexity of the operation or their health status, showed 51% reduced odds for postoperative complications than less active patients, according to research findings being presented at the American College of Surgeons (ACS) Clinical Congress 2023. 

Postoperative complications typically occur in about 30% of patients,1 and about half of all complications occur after the patient leaves the hospital.2 

“Fitbits and other wearable devices could potentially be linked to Electronic Health Records (EHRs) and have that data be something that surgeons consider when planning perioperative care for their patients,” said lead study author Carson Gehl, a second-year medical student at the Medical College of Wisconsin in Milwaukee. “This could really come to fruition to improve postoperative outcomes.” 

Researchers analyzed health data for 475 people participating in the All of Us Research Program — a National Institutes of Health-sponsored program focusing on the relationship between lifestyle, biology, and environment in diverse populations — who used a Fitbit device, worn like a watch, that measured their daily steps. This is the only population-level study to explore the association between physical activity, as measured by a Fitbit, and 90-day postoperative complications, according to the study authors. 

“We used the combination of EHRs and Fitbit data to uncover how to potentially improve surgical outcomes. In our study, we looked at how many steps patients recorded on any given day, which is a proxy for physical activity,” Gehl said.  

“However, the fitness data wasn’t limited to the immediate preoperative period. The length of their activity record could be six months or several years before surgery. This is more reflective of chronic physical activity habits, versus the physical activity in the immediate preoperative period.” 

Participants underwent a wide range of operations, including general surgery, orthopedic surgery, and neurosurgery, and were an average age of 57 years old. Women comprised 74.7% of participants, and 85.2% of participants were White.  

Key findings 

• About 12.6% of study participants experienced a complication within 90 days of surgery. 

• The odds of experiencing a complication within 30 days after surgery were 45% less (odds ratio 0.55) if patients took more than 7,500 steps per day prior to surgery than if their Fitbit recorded fewer than 7,500 steps.  

• After adjusting for comorbidities, BMI, sex, race, and complexity of the operation, the odds of experiencing a complication were 51% lower (odds ratio 0.49) if patients had Fitbit data showing they had walked more than 7,500 steps per day before surgery.  

“If we find people who are at high risk, using these Fitbit tools, we could monitor them more closely following their procedure because that allows us to catch problems before they progress beyond control,” Gehl said. “Another goal of our research is to modify physical activity in the preoperative period and improve postoperative outcomes. We need more studies and evidence to answer that question.” 

A limitation of the study was that available Fitbit data came from a less diverse group of patients. Fitbit is a device worn like a watch to self-track sleep, physical activity, and heart rate data. Study participants had to have their own Fitbit device, which limits the generalizability of the study results.  

Study co-authors are Nathaniel B. Verhagen; Tahseen Shaik; Xin Yang, PhD; Bradley W. Taylor; Ugwuji N. Maduekwe, MD, FACS; and Anai Kothari, MD, MS.   

The study was funded by the National Institutes of Health. 

Citation: Gehl CJ, et al. Wearable Device/Smart Watch Activity Trackers as a Tool for Surgical Risk Stratification, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2023. 

______________________  

1 Dharap SB, Barbaniya P, Navgale S. Incidence and Risk Factors of Postoperative Complications in General Surgery Patients. Cureus. 2022 Nov 1;14(11):e30975. 

2 Wick, Elizabeth C., et al. Readmission Rates and Cost Following Colorectal Surgery. Diseases of the Colon & Rectum. 54(12):1475-1479; Dec. 2011. 

Red meat consumption associated with increased type 2 diabetes risk

 People who eat just two servings of red meat per week may have an increased risk of developing type 2 diabetes compared to people who eat fewer servings, and the risk increases with greater consumption, according to a new study led by researchers from Harvard T.H. Chan School of Public Health. They also found that replacing red meat with healthy plant-based protein sources, such as nuts and legumes, or modest amounts of dairy foods, was associated with reduced risk of type 2 diabetes.

The study will be published on Thursday, October 19, in The American Journal of Clinical Nutrition.

“Our findings strongly support dietary guidelines that recommend limiting the consumption of red meat, and this applies to both processed and unprocessed red meat,” said first author Xiao Gu, postdoctoral research fellow in the Department of Nutrition.

While previous studies have found a link between red meat consumption and type 2 diabetes risk, this study, which analyzed a large number of type 2 diabetes cases among participants being followed for an extended period of years, adds a greater level of certainty about the association.

Type 2 diabetes rates are increasing rapidly in the U.S. and worldwide. This is concerning not only because the disease is a serious burden, but it also is a major risk factor for cardiovascular and kidney disease, cancer, and dementia.

For this study, the researchers analyzed health data from 216,695 participants from the Nurses’ Health Study (NHS), NHS II, and Health Professionals Follow-up Study (HPFS). Diet was assessed with food frequency questionnaires every two to four years, for up to 36 years. During this time, more than 22,000 participants developed type 2 diabetes.

The researchers found that consumption of red meat, including processed and unprocessed red meat, was strongly associated with increased risk of type 2 diabetes. Participants who ate the most red meat had a 62% higher risk of developing type 2 diabetes compared to those who ate the least. Every additional daily serving of processed red meat was associated with a 46% greater risk of developing type 2 diabetes and every additional daily serving of unprocessed red meat was associated with a 24% greater risk.

The researchers also estimated the potential effects of substituting one daily serving of red meat for another protein source. They found that substituting a serving of nuts and legumes was associated with a 30% lower risk of type 2 diabetes, and substituting a serving of dairy products was associated with a 22% lower risk.

“Given our findings and previous work by others, a limit of about one serving per week of red meat would be reasonable for people wishing to optimize their health and wellbeing,” said senior author Walter Willett, professor of epidemiology and nutrition.

In addition to health benefits, swapping red meat for healthy plant protein sources would help reduce greenhouse gas emissions and climate change, and provide other environmental benefits, according to the researchers.

Other Harvard Chan School authors included Frank Sacks and Frank Hu.

The NHS, NHS II, and HPFS are supported by the National Institute of Health (grants UM1 CA186107, U01 CA176726, and U01 CA167552).

“Red meat intake and risk of type 2 diabetes in a prospective cohort study of US females and males,” Xiao Gu, Jean-Philippe Drouin-Chartier, Frank M. Sacks, Frank B. Hu, Bernard Rosner, Walter C. Willett, The American Journal of Clinical Nutrition, October 19, 2023, doi: 10.1016/j.ajcnut.2023.08.021

What drives obesity - diets high in fat? Carbohydrates? Actually, it’s everything – and fructose is at the center

Nutrition experts have recognized for many years that western diets rich in fats and sugar may be behind the cause of obesity, but debate has reigned over the primary culprit - intake of too many calories? Specific foods such as carbohydrates or fat? This has led to some groups recommending reducing sugar, some reducing carb intake, while others believe the key is reducing high fat-foods. 

A paper published today in the research journal Obesity suggests these theories are not incompatible with each other, and that they can all be brought together in one unified pathway that centers around one true driver: fructose.

According to Richard Johnson, MD, University of Colorado Anschutz Medical Campus researcher, and his colleagues, the primary problem in obesity is fructose, which is present in table sugar and high fructose corn syrup. Fructose can also be made in the body from carbohydrates (particularly glucose). When fructose is metabolized, it lowers the active energy in the body (known as ATP, or adenosine triphosphate) which causes hunger and food intake.

What Johnson calls the “fructose survival hypothesis” brings together most of the dietary hypotheses of obesity, including the two that have been most incompatible with each other– the energy balance theory, which proposes too much food (and primarily fat) drives obesity, and the carbohydrate-insulin model, which puts carbohydrates at the center of weight gain.

“Essentially, these theories, which put a litany of metabolic and dietary drivers at the center of the obesity epidemic, are all pieces of a puzzle unified by one last piece: fructose,” says Johnson. “Fructose is what triggers our metabolism to go into low power mode and lose our control of appetite, but fatty foods become the major source of calories that drive weight gain.”

To unify these theories in particular, Johnson says we can look to hibernating animals as an example. When we’re hungry and low on active energy, we go into survival mode. Animals know to forage for food when energy levels begin to fall; why bears eat fruit to prepare for winter. Fruits are high-fructose foods, and fructose significantly stifles active energy. Fat acts as stored energy, but eating high-fructose foods blocks the replacement of active energy from fat storage, keeping active energy low like a bear preparing for a long winter’s nap.

“This theory views obesity as a low-energy state,” says Johnson. “Identifying fructose as the conduit that redirects active energy replacement to fat storage shows that fructose is what drives energy imbalance, which unites theories.”

While more work is needed to fully validate this unifying hypothesis, this is a hopeful first step in potentially identifying more targeted preventions for obesity and related metabolic imbalance management.

Calorie restriction in humans builds strong muscle and stimulates healthy aging genes

 

NIH study suggests a small reduction in daily calories is beneficial for wellness

Peer-Reviewed Publication

NIH/NATIONAL INSTITUTE ON AGING

 

IMAGE: 

THE RESEARCH FOUND CALORIE RESTRICTION IMPROVES MUSCLE HEALTH AND OFFERS ADDITIONAL HEALTH BENEFITS.

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CREDIT: ILLUSTRATION COURTESY OF NIA.

 

Reducing overall calorie intake may rejuvenate your muscles and activate biological pathways important for good health, according to researchers at the National Institutes of Health and their colleagues. Decreasing calories without depriving the body of essential vitamins and minerals, known as calorie restriction, has long been known to delay the progression of age-related diseases in animal models. This new study, published in Aging Cell, suggests the same biological mechanisms may also apply to humans.

Researchers analyzed data from participants in the Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE), a study supported by the National Institute on Aging (NIA) that examined whether moderate calorie restriction conveys the same health benefits seen in animal studies. They found that during a two-year span, the goal for participants was to reduce their daily caloric intake by 25%, but the highest the group was able to reach was a 12% reduction. Even so, this slight reduction in calories was enough to activate most of the biological pathways that are important in healthy aging.

"A 12% reduction in calorie intake is very modest," said corresponding author and NIA Scientific Director Luigi Ferrucci, M.D., Ph.D. "This kind of small reduction in calorie intake is doable and may make a big difference in your health."

The research team next sought to understand the molecular underpinnings of the benefits seen in limited, previous research of calorie restriction in humans. One study showed that individuals on calorie restriction lost muscle mass and an average of 20 pounds of weight over the first year and maintained their weight for the second year. However, despite losing muscle mass, calorie restriction participants did not lose muscle strength, indicating calorie restriction improved the amount of force generated by each unit of muscle mass, called muscle specific force.

For the current study, scientists used thigh muscle biopsies from CALERIE participants that were collected when individuals joined the study and at one-year and two-year follow ups.

To figure out which human genes were impacted during calorie restriction, the scientists isolated messenger RNA (mRNA), a molecule that contains the code for proteins, from muscle samples. The team determined the protein sequence of each mRNA and used the information to identify which genes originated specific mRNAs. Further analysis helped the scientists establish which genes during calorie restriction were upregulated, meaning the cells made more mRNA; and which were downregulated, meaning the cells produced less mRNA. The researchers confirmed calorie restriction affected the same gene pathways in humans as in mice and non-human primates. For example, a lower caloric intake upregulated genes responsible for energy generation and metabolism, and downregulated inflammatory genes leading to lower inflammation.

"Since inflammation and aging are strongly coupled, calorie restriction represents a powerful approach to preventing the pro-inflammatory state that is developed by many older people," said Ferrucci.

Heart disease risk, prevention and management redefined

Interactions among obesity, Type 2 diabetes, chronic kidney disease and cardiovascular disease drive the new approach, says new American Heart Association presidential advisory

Peer-Reviewed Publication

AMERICAN HEART ASSOCIATION

Advisory Highlights:

• A new American Heart Association presidential advisory identifies the strong connections among cardiovascular disease (CVD), kidney disease, Type 2 diabetes and obesity, and suggests redefining CVD risk, prevention and management.
• The advisory defines cardiovascular-kidney-metabolic (CKM) syndrome for the first time.
• CKM syndrome ranges from Stage 0, or no risk factors and an entirely preventive focus, to Stage 4, the highest-risk stage with cardiovascular disease. Stage 4 may also include kidney failure.
• The advisory urges use of a new tool that will predict someone’s likelihood of heart attack, stroke and/or heart failure in 10 and 30 years.

 Health experts are redefining cardiovascular disease (CVD) risk, prevention and management, according to a new American Heart Association presidential advisory published today in the Association’s flagship journal Circulation.

Various aspects of cardiovascular disease that overlap with kidney disease, Type 2 diabetes and obesity support the new approach. For the first time, the American Heart Association defines the overlap in these conditions as cardiovascular-kidney-metabolic (CKM) syndrome. People who have or are at risk for cardiovascular disease may have CKM syndrome.

The new approach detailed in the presidential advisory includes:

• CKM syndrome stages ranging from 0, or no risk factors and an entirely preventive focus, to Stage 4, the highest-risk stage with established cardiovascular disease. Stage 4 may also include kidney failure. Each stage correlates to specific screenings and therapies.
• Screening for and addressing social factors that impact health.
• Collaborative care approaches among multiple specialties to treat the whole patient.
• Suggested updates to the algorithm, or risk calculator, that helps health care professionals predict a person’s likelihood of having a heart attack or stroke. The update adds a risk prediction for heart failure, which estimates risk for “total cardiovascular disease” — heart attack, stroke and/or heart failure.
• The writing group suggest the updated algorithm provide both 10- and 30-year cardiovascular disease risk estimates.

According to the American Heart Association’s 2023 Statistical Update, 1 in 3 U.S. adults have three or more risk factors that contribute to cardiovascular disease, metabolic disorders and/or kidney disease. CKM affects nearly every major organ in the body, including the heart, brain, kidney and liver. However, the biggest impact is on the cardiovascular system, affecting blood vessels and heart muscle function, the rate of fatty buildup in arteries, electrical impulses in the heart and more.

“The advisory addresses the connections among these conditions with a particular focus on identifying people at early stages of CKM syndrome,” said Chiadi E. Ndumele, M.D., Ph.D., M.H.S., FAHA, writing committee chair and an associate professor of medicine and director of obesity and cardiometabolic research in the division of cardiology at Johns Hopkins University in Baltimore. “Screening for kidney and metabolic disease will help us start protective therapies earlier to most effectively prevent heart disease and best manage existing heart disease.”

CKM syndrome is a consequence of the historically high prevalence of obesity and Type 2 diabetes in both adults and youth, according to the advisory. Type 2 diabetes and obesity are metabolic conditions — the “M” in CKM — that are also risk factors for cardiovascular disease. Moreover, the most common cause of death for people with Type 2 diabetes and chronic kidney disease is cardiovascular disease.

“We now have several therapies that prevent both worsening kidney disease and heart disease,” Ndumele said. “The advisory provides guidance for health care professionals about how and when to use those therapies, and for the medical community and general public about the best ways to prevent and manage CKM syndrome.”

With multiple conditions to manage, Ndumele noted fragmented care is a concern in treating patients with CKM syndrome, particularly for those with barriers to care. “The advisory suggests ways that professionals from different specialties can better work together as part of one unified team to treat the whole patient.” Additionally, the advisory emphasizes the importance of systematically screening for and addressing social factors that act as determinants, or drivers, of health, such as nutrition insecurity and opportunities for exercise,  as key aspects of optimal CKM syndrome care.”

A companion article published with the presidential advisory, a new American Heart Association scientific statement, “A Synopsis of the Evidence for the Science and Clinical Management of Cardiovascular-Kidney-Metabolic (CKM) Syndrome,”, documents the evidence for the writing committee’s proposed approach. The scientific statement brings together evidence from current guidelines and large research studies and describes where gaps remain in knowledge needed to further improve CKM health.

CKM screening, stages and treatment

CKM-related screening is intended to detect cardiovascular, metabolic and kidney health changes early; identify social and structural barriers to care; and prevent progression to the next stage of CKM syndrome.

The advisory addresses care for adults. However, studies suggest CKM syndrome is progressive and begins early in life. Therefore, the advisory aligns with the American Academy of Pediatrics’ recommendations for children and youth to have annual assessments of weight, blood pressure, and mental and behavioral health, starting at age 3.

Stage 0 – No CKM risk factors. The goal at this stage is preventing CKM syndrome by achieving and maintaining ideal health based on the American Heart Association’s Life’s Essential 8 recommendations. The recommendations include healthy eating, physical activity and sleep habits; avoiding nicotine; and maintaining optimal weight, blood pressure, blood sugar and cholesterol levels. The advisory suggests screening adults in Stage 0 every three to five years to assess blood pressure, triglycerides, HDL (good) cholesterol and blood sugar.

Preventing unhealthy weight gain is important for CKM syndrome prevention because of the connection of obesity to Type 2 diabetes, high blood pressure and high triglycerides. At all stages, the advisory proposes yearly measurement of waist circumference and body mass index. Healthy lifestyle behaviors are also encouraged at every stage.

Stage 1 – Excess body fat and/or an unhealthy distribution of body fat, such as abdominal obesity, and/or impaired glucose tolerance or prediabetes. Support for healthy lifestyle changes (healthy eating and regular physical activity) and a goal of at least 5% weight loss in people with Stage 1 are suggested, with treatment for glucose intolerance if needed. Screening every two to three years is advised to assess blood pressure, triglycerides, cholesterol and blood sugar.

Stage 2 – Metabolic risk factors and kidney disease. Stage 2 includes people with Type 2 diabetes, high blood pressure, high triglycerides or kidney disease, and indicates a higher risk for worsening kidney disease and heart disease. The goal of care at this stage is to address risk factors to prevent progression to cardiovascular disease and kidney failure. Treatment may include medications to control blood pressure, blood sugar and cholesterol. In those with chronic kidney disease and in some people with Type 2 diabetes, SGLT2 inhibitors are advised to protect kidney function and reduce the risk of heart failure. SGLT2 inhibitors are a class of prescription medicines that are FDA-approved for use with diet and exercise to lower blood sugar in adults with Type 2 diabetes. Glucagon-like peptide 1 (GLP-1) receptor agonists are also suggested for consideration in people with Type 2 diabetes to help reduce high glucose, facilitate weight loss and reduce risk for CVD. Other therapies to prevent worsening kidney function are also advised. Screening suggestions for Stage 2 CKM syndrome align with AHA/ACC guidelines, which include yearly assessment of blood pressure, triglycerides, cholesterol, blood sugar and kidney function.

For those with increased risk of kidney failure based on kidney function assessments, more frequent kidney screening is recommended.

Stage 3 – Early cardiovascular disease without symptoms in people with metabolic risk factors or kidney disease or those at high predicted risk for cardiovascular disease. The goal of care in Stage 3 is to intensify efforts to prevent people who are at high risk of progressing to symptomatic cardiovascular disease and kidney failure. This may involve increasing or changing medications, and additional focus on lifestyle changes. The writing committee advises coronary artery calcium (CAC) measurement in some adults to assess narrowing of the arteries when treatment decisions are unclear. CAC screening is used to guide decisions about cholesterol-lowering statin therapy. Test results indicating asymptomatic heart failure should lead to intensified therapy to prevent heart failure symptoms.

The advisory also describes CKM syndrome regression, an important concept and public health message in which people making healthy lifestyle changes and achieving weight loss may regress to lower CKM syndrome stages and a better state of health. The best opportunity for patients to experience regression is in Stages 1, 2 and 3. Some may see improvements in glucose control, cholesterol and blood pressure levels, weight, kidney function and types of heart dysfunction.

Stage 4 – Symptomatic cardiovascular disease in people with excess body fat, metabolic risk factors or kidney disease. Stage 4 CKM syndrome is divided into two subcategories: (4a) for those without kidney failure or (4b) for those with it. In this stage, people may have already had a heart attack or stroke or may already have heart failure. They also may have additional cardiovascular conditions such as peripheral artery disease or atrial fibrillation. The goal of care is individualized treatment for cardiovascular disease with consideration for CKM syndrome conditions.

Predicting Risk

A critical step in assessing risk and managing CKM syndrome is updating the risk prediction algorithm to help health care professionals predict cardiovascular disease in a way that includes CKM components: cardiovascular disease, chronic kidney disease and metabolic disorders.

The Pooled Cohort Equation, the current risk calculator for atherosclerotic cardiovascular disease, established in 2013, estimates the risk of a heart attack or stroke in the next 10 years for people ages 40-75. It includes health and demographic factors about a person and is used to guide lifestyle recommendations and treatment decisions for people at risk for cardiovascular disease. The risk factors are age, sex and race (as white, Black and other); cholesterol levels; and systolic blood pressure. The equation also includes yes/no responses to whether a person is receiving treatment for high blood pressure Type 2 diabetes, or smokes cigarettes.

The advisory proposes updating the risk calculator to include measures of kidney function, Type 2 diabetes control (using blood test results instead of a yes/no response) and social determinants of health for a more comprehensive risk estimate. Kidney function assessments include a measure of how well the kidneys filter waste from the blood and urine albumin levels, a measure of how well the kidneys reabsorb protein. Individual health measures in addition to demographic information will allow the calculator to produce an individual’s total CVD risk estimate.

The writing group recommends the risk calculator updates be expanded to assess risk in people as young as age 30 and to calculate both 10- and 30-year CVD risk. More comprehensive CVD risk assessment at younger ages will allow for earlier preventive strategies to mitigate progression to advanced stages of CKM syndrome. In the long term, this will help to reduce gaps in treatment and health equity and improve outcomes.

Calls to Action

The advisory calls for systemic changes to optimize CKM health.

“There is a need for fundamental changes in how we educate health care professionals and the public, how we organize care and how we reimburse care related to CKM syndrome,” Ndumele said. “Key partnerships among stakeholders are needed to improve access to therapies, to support new care models and to make it easier for people from diverse communities and circumstances to live healthier lifestyles and to achieve ideal cardiovascular health.”

Investing in research is important for advancing CKM care. Key research gaps include:

1. better understanding the pathways leading to heart disease in CKM syndrome;
2. better understanding of why some people may advance more quickly along CKM stages, while others may progress more slowly; and
3. understanding the best way to use newer therapies with multiple effects on CKM syndrome, including to improve metabolic factors such as obesity and Type 2 diabetes, and to reduce worsening kidney disease and prevent heart disease.

Co-authors and their disclosures are listed in the manuscript.

This presidential advisory was prepared by the volunteer writing group on behalf of the American Heart Association. Presidential advisories and scientific statements promote greater awareness about cardiovascular diseases and stroke and help facilitate informed health care decisions. They outline what is known about a topic and what areas need additional research. While scientific statements and advisories inform the development of guidelines, they do not make treatment recommendations. American Heart Association guidelines provide official clinical practice recommendations.

The Association receives funding primarily from individuals. Foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers, and the Association’s overall financial information are available here.

Additional Resources:

• Available multimedia is on the right column of the news release link https://newsroom.heart.org/news/heart-disease-risk-prevention-and-management-redefined?preview=fd8230bbebab3e1f9144f5ee1d5f3308
• After Oct. 9, view the  presidential advisory and scientific statement online.
• AHA news release: Simple blood test may predict future heart, kidney risk for people with Type 2 diabetes (August 2023)
• AHA/ACC Clinical Guideline: Symptom relief and healthy habits are top goals for treating chronic heart disease (July 2023)
• AHA news release: $150,000 awarded to research race in clinical algorithms (August 2023)
• Follow AHA/ASA news on X (formerly Twitter) @HeartNews.