…the beneficial effects of TRE are dose dependent, with greater reductions in body weight, fat mass, and improvement in glucose tolerance when a 9-h protocol was implemented versus 12 and 15 h. The optimal TRE time frame to recommend for people has not been tested. Clear improvements have been noted after 6-, 8-, 9-, and 10-h protocols. It is likely that the greater time restriction would result in greater weight losses, which may maximize the metabolic benefits.
Eating out of phase with daily circadian rhythms induces metabolic desynchrony in peripheral metabolic organs and may increase chronic disease risk. Time-restricted eating (TRE) is a dietary approach that consolidates all calorie intake to 6- to 10-h periods during the active phase of the day, without necessarily altering diet quality and quantity.
TRE reduces body weight, improves glucose tolerance, protects from hepatosteatosis, increases metabolic flexibility, reduces atherogenic lipids and blood pressure, and improves gut function and cardiometabolic health in preclinical studies. This review discusses the importance of meal timing on the circadian system, the metabolic health benefits of TRE in preclinical models and humans, the possible mechanisms of action, the challenges we face in implementing TRE in humans, and the possible consequences of delaying initiation of TRE.
“On a high-sugar diet, we find that the fruit flies’ dopaminergic neurons are less active, because the high sugar intake decreases the intensity of the sweetness signal that comes from the mouth,” Dus said. “Animals use this feedback from dopamine to make predictions about how rewarding or filling a food will be. In the high-sugar diet flies, this process is broken—they get less dopamine neuron activation and so end up eating more than they need, which over time makes them gain weight.”
It is well known that consuming food and drink high in sugar is not great for us, but scientists are continuing to unravel the intricacies of how the sweet stuff drives negative health outcomes. The latest finding comes from researchers at the University of Michigan, who through studies in fruit flies have found that excess amounts of sugar can shut down crucial neural circuits linked to regulating satiety, possibly leading to overeating in humans.
“We took an unbiased approach and searched throughout the body for indicators of damage from sleep deprivation. We were surprised to find it was the gut that plays a key role in causing death,” said senior study author Dragana Rogulja, assistant professor of neurobiology in the Blavatnik Institute at HMS.
The first signs of insufficient sleep are universally familiar. There’s tiredness and fatigue, difficulty concentrating, perhaps irritability or even tired giggles. Far fewer people have experienced the effects of prolonged sleep deprivation, including disorientation, paranoia, and hallucinations.
Total, prolonged sleep deprivation, however, can be fatal. While it has been reported in humans only anecdotally, a widely cited study in rats conducted by Chicago-based researchers in 1989 showed that a total lack of sleep inevitably leads to death. Yet, despite decades of study, a central question has remained unsolved: Why do animals die when they don’t sleep?
Now, Harvard Medical School (HMS) neuroscientists have identified an unexpected, causal link between sleep deprivation and premature death.
From The Lancet Diabetes & Endocrinology (June 2020):
Our findings show that the intensive lifestyle intervention led to significant weight loss at 12 months, and was associated with diabetes remission in over 60% of participants and normoglycaemia in over 30% of participants. The provision of this lifestyle intervention could allow a large proportion of young individuals with early diabetes to achieve improvements in key cardiometabolic outcomes, with potential long-term benefits for health and wellbeing.
Type 2 diabetes is affecting people at an increasingly younger age, particularly in the Middle East and in north Africa. We aimed to assess whether an intensive lifestyle intervention would lead to significant weight loss and improved glycaemia in young individuals with early diabetes.
Between July 16, 2017, and Sept 30, 2018, we enrolled and randomly assigned 158 participants (n=79 in each group) to the study. 147 participants (70 in the intervention group and 77 in the control group) were included in the final intention-to-treat analysis population. Between baseline and 12 months, the mean bodyweight of participants in the intervention group reduced by 11·98 kg (95% CI 9·72 to 14·23) compared with 3·98 kg (2·78 to 5·18) in the control group (adjusted mean difference −6·08 kg [95% CI −8·37 to −3·79], p<0·0001). In the intervention group, 21% of participants achieved more than 15% weight loss between baseline and 12 months compared with 1% of participants in the control group (p<0·0001). Diabetes remission occurred in 61% of participants in the intervention group compared with 12% of those in the control group (odds ratio [OR] 12·03 [95% CI 5·17 to 28·03], p<0·0001). 33% of participants in the intervention group had normoglycaemia compared with 4% of participants in the control group (OR 12·07 [3·43 to 42·45], p<0·0001).
President Trump’s preferred coronavirus treatment is the focus of a new study suggesting it could cause more harm than good, but not everybody agrees. We discuss the fallout as trials around the world are paused and countries diverge over policy advice.
12:12 Are we rushing science?
Coronavirus papers are being published extremely quickly, while normally healthy scientific debate is being blown up in the world’s press. Is there a balancing act between timely research and accurate messaging?
18:49 One good thing
Our hosts pick out things that have made them smile in the last week, including hedgerow brews and a trip into the past using AI.
From the American Journal of Clinical Nutrition (April 22, 2020):
Our findings imply that higher long-term dietary intakes of flavonoids are associated with lower risks of ADRD and AD in US adults.
Our findings provide new evidence that diets higher in flavonols, anthocyanins, and flavonoid polymers are associated with a lower risk of developing ADRD. These associations were sustained after accounting for a variety of potential confounders including key nutrients related to ADRD risk and overall diet quality. Similar findings were seen with AD risk for flavonols and anthocyanins but the association with flavonoid polymers was no longer statistically significant.
Along with improvements in healthcare and medical technology, the aging of the baby boom generation will result in an unprecedented rise in the number of older Americans (1, 2). Currently, there are >50 million Americans aged ≥65 y, and that is projected to more than double by 2060 (3). A consequence of this increase in older adults is the escalation of age-related diseases (4, 5). Alzheimer disease (AD) and related dementias (ADRD), a group of symptoms in which there is progressive deterioration in cognitive function severe enough to interfere with a person’s daily living activities, are regarded as among the most significant public health challenges largely affecting adults aged >65 y (6). AD is the most common form of dementia, making up ∼60–80% of dementia cases. Currently, 5.8 million Americans are living with AD, and by 2050 that is projected to escalate to 14 million (7).
Compared with usual diet, moderate certainty evidence supports modest weight loss and substantial reductions in systolic and diastolic blood pressure for low carbohydrate (eg, Atkins, Zone), low fat (eg, Ornish), and moderate macronutrient (eg, DASH, Mediterranean) diets at six but not 12 months. Differences between diets are, however, generally trivial to small, implying that people can choose the diet they prefer from among many of the available diets (fig 6) without concern about the magnitude of benefits.
The worldwide prevalence of obesity nearly tripled between 1975 and 2018.1 In response, authorities have made dietary recommendations for weight management and cardiovascular risk reduction.23 Diet programmes—some focusing on carbohydrate reduction and others on fat reduction—have been promoted widely by the media and have generated intense debates about their relative merit. Millions of people are trying to lose weight by changing their diet. Thus establishing the effect of dietary macronutrient patterns (carbohydrate reduction v fat reduction v moderate macronutrients) and popular named dietary programmes is important.
Biological and physiological mechanisms have been proposed to explain why some dietary macronutrient patterns and popular dietary programmes should be better than others. A previous network meta-analysis, however, suggested that differences in weight loss between dietary patterns and individual popular named dietary programmes are small and unlikely to be important.4 No systematic review and network meta-analysis has examined the comparative effectiveness of popular dietary programmes for reducing risk factors for cardiovascular disease, an area of continuing controversy.
“Having normal body weight is crucial in the prevention of type 2 diabetes, regardless of genetic predisposition.”
“The results suggest that type 2 diabetes prevention by weight management and healthy lifestyle is critical across all genetic risk groups.”
“Overall, the results indicate that a favorable lifestyle should be universally recommended in the prevention of type 2 diabetes, regardless of genetic predisposition, thus supporting current public health guidelines,”
We examined the joint association of genetic predisposition, obesity and unfavourable lifestyle with incident type 2 diabetes using a case-cohort study nested within the Diet, Cancer and Health cohort in Denmark. The study sample included 4729 individuals who developed type 2 diabetes during a median 14.7 years of follow-up, and a randomly selected cohort sample of 5402 individuals.
Obesity (BMI ≥ 30 kg/m2) and unfavourable lifestyle were associated with higher risk for incident type 2 diabetes regardless of genetic predisposition (p > 0.05 for GRS–obesity and GRS–lifestyle interaction). The effect of obesity on type 2 diabetes risk (HR 5.81 [95% CI 5.16, 6.55]) was high, whereas the effects of high genetic risk (HR 2.00 [95% CI 1.76, 2.27]) and unfavourable lifestyle (HR 1.18 [95% CI 1.06, 1.30]) were relatively modest.
Patients with osteoarthritis of the knee who underwent physical therapy had less pain and functional disability at 1 year than patients who received an intraarticular glucocorticoid injection.
Osteoarthritis of the knee is a leading cause of disability.1 Current management is typically limited to the treatment of symptoms until late stages of arthritis lead to knee replacement.2 Intraarticular glucocorticoid injections are commonly used as a primary treatment for osteoarthritis of the knee,3 but there are conflicting reports regarding the extent and duration of the relief of symptoms with this therapy.4-6 Complications from these injections occur infrequently but include joint infection,7 accelerated degradation of articular cartilage,8 and subchondral insufficiency fractures.9
The physical therapy intervention, which is described in the protocol,26 included instructions and images for exercises, joint mobilizations, and the clinical reasoning underlying the priorities, dosing, and progression of treatment. During a typical clinical session, the physical therapist would implement hands-on, manual techniques immediately before the patient performed reinforcing exercises to help the patient perform the movements with little or no pain. For example, if a patient could not fully extend or flex the knee, or those movements were painful, the physical therapist would use a hands-on, passive mobilizing technique to repeatedly move the knee to reduce stiffness while altering the mechanics of the technique to avoid pain. The patient would then perform repeated active knee movements in the same direction.
From a MedPage Today online article (April 2, 2020):
This relationship between higher glucose levels and poorer cognitive functioning extended beyond just CASI z-score, as well, Cukierman-Yaffe noted. Higher HbA1c levels were also tied to significantly poorer performance in other psychological tests, including the clock making test of executive functioning, test of discriminative ability, and for the test of verbal fluency.
Poorer glycemic control was tied to cognitive decline following a lacunar stroke in a prospective cohort study.
Among 942 individuals with type 2 diabetes who had a lacunar stroke, every 1% higher HbA1c was tied to a 0.06 drop in cognitive function at baseline measured by Cognitive Assessment Screening Instrument (CASI) z-score (95% CI -0.101 to -0.018), reported Tali Cukierman-Yaffe, MD, MSc, of Sheba Medical Center and the Sackler School of Medicine of Tel Aviv University in Israel.