Tag Archives: Metabolism

Cover Preview: Scientific American – January 2023

Scientific American – January 2023 issue:

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New Human Metabolism Research Upends Conventional Wisdom about How We Burn Calories

Metabolism studies reveal surprising insights into how we burn calories—and how cooperative food production helped Homo sapiens flourish

How Star Collisions Forge the Universe’s Heaviest Elements

Scientists have new evidence about how cosmic cataclysms forge gold, platinum and other heavy members of the periodic table

This Spiritual Tradition Could Be the Most Poetic Bereavement Therapy Ever Documented

A mourning ritual of dialogues with the dead speaks to the fragility of theological diversity

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Preview: New Scientist Magazine – Oct 8, 2022

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  • CULTURE – Nuclear review: Oliver Stone’s paean to a nuclear future
  • FEATURES – Why ancient Nubia is finally emerging from Egypt’s long shadow
  • FEATURES – Did magnetism shape the universe? An epic experiment suggests it did
  • FEATURES – How hacking your metabolism can help you burn fat and prevent disease

Preview: New Scientist Magazine – March 12

COVER STORIES

  • FEATURES Martin Rees interview: Elon Musk could spawn the first post-humans
  • FEATURES Creatures living in our cities are evolving in some surprising ways
  • FEATURES Middle-age spread isn’t down to metabolism, but we know how to beat it

Research: ‘The Science Of Healthy Aging’ (Scripps)

Although growing older comes with a number of major life changes, science can help inform the things we do in the here in and now to forestall the most serious features of the aging self, promoting healthspan and not just lifespan.

Summer 2021
  • Build Muscle – Muscle mass is one the best predictors of health and longevity. Muscle tissue is known to release its own chemicals called myokines, which can have benefits that span cognition, immunity and anti-cancer activity. By performing regular, resistance-based exercise that prioritizes strength, we can delay the loss of bone density and risk of physical injuries.
  • Vitamin D – Commonly known as the sunshine vitamin, vitamin D is in fact a critical hormone that helps maintain healthy bones, boost our immune system and improve our cardiovascular function. With age, the production of vitamin D in the skin can become less efficient, so if we don’t spend enough time outdoors, our risk of vitamin D deficiency may increase.
  • Neurodegenerative Diseases – One of the most unsettling aspects of aging is the potential for neurodegenerative disease. These conditions are increasingly prevalent in those with diabetes, suggesting that the brain’s blood flow and energy supply may be compromised. Research indicates that regular physical exercise, a healthy whole foods diet and staying intellectually active could at least slow the rate of decline.
  • Mindfulness – As we get older, major arteries can become thicker and less flexible, leading to increased blood pressure and undue strain on the heart. A regular mindfulness practice such as yoga or meditation has been shown to stem the release of stress hormones like cortisol and adrenaline. By freeing us from this “fight-or-flight” state, this habit can improve blood flow and reduce the risk of heart attack and stroke.
  • Stay Social – As social animals, maintaining a strong sense of community and close personal relationships into old age are underestimated contributors to longevity. While social isolation in seniors can result in significant physical and mental decline, research suggests that close loved ones offer important emotional support and behavioral modifications that can overcome periods of high stress.
  • Metabolism – “My metabolism is slowing down!” That’s what we often hear, as the aging body becomes less effective at using energy, placing us at risk of obesity and type 2 diabetes. By maintaining our muscle mass and reducing sugar consumption, we can support hormonal health, preserve our metabolism and keep our vitality into those advanced years. As scientists continue to find ways to extend our lives, paying attention to these keys to healthy aging can help increase the quality of those extra years.

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Exercise: The Evolution Of Human Physical Activity

Human physical activities differ significantly from other species. How, when and why did these capabilities evolve? What adaptations underlie them? And how did the evolution of human physical activity affect other key human characteristics that have advanced our species?

Herman Pontzer explores the evolution of human metabolism and its role in our evolution and health. From an evolutionary perspective, life is a game of turning energy into offspring. The strategies that species use to acquire energy, in the form of food, and allocate energy to the essential tasks of growth, maintenance, movement, and reproduction, are incredibly diverse and reflect the ecological pressures and opportunities encountered. There is a deep evolutionary history of the human metabolic strategy and our divergence from other apes.

Timeline: 00:00 – Start 01:38 – The Evolution of Human Metabolism  

More from: CARTA: The Evolution of Human Physical Activity (https://www.uctv.tv/carta-physical-ac…)

Diet Studies: Benefits Of “Time-Restricted Eating” (TRE) Improve With Greater Time Restriction

From iScience / Cell.com (June 26, 2020):

iScience June 26 2020…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.

Time-Restricted Eating

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.

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Obesity Study: “Late Night Snacking” Older Adults – Higher Fat Levels Than Early Eaters On Same Diet

From a PLOS Biology Journal study (Feb 20, 2020):

Snacking Before you sleep Keeps on the Fat PLOS Biology April 2020
Schematic: Late-evening snacking interacts with the circadian rhythm of metabolism to inhibit LO.

The major finding of this study is that the timing of feeding over the day leads to significant differences in the metabolism of an equivalent 24-h nutritional intake. Daily timing of nutrient availability coupled with daily/circadian control of metabolism drives a switch in substrate preference such that the late-evening Snack Session resulted in significantly lower LO compared to the Breakfast Session. 

Developed countries are experiencing an epidemic of obesity that leads to many serious health problems, foremost among which are increasing rates of type 2 diabetes, metabolic syndrome, cardiovascular disease, and cancer. While weight gain and obesity are primarily determined by diet and exercise, there is tremendous interest in the possibility that the daily timing of eating might have a significant impact upon weight management [13]. Many physiological processes display day/night rhythms, including feeding behavior, lipid and carbohydrate metabolism, body temperature, and sleep.

PLOS Biology StudiesThese daily oscillations are controlled by the circadian clock, which is composed of an autoregulatory biochemical mechanism that is expressed in tissues throughout the body and is coordinated by a master pacemaker located in the suprachiasmatic nuclei of the brain (aka the SCN [1,4]). The circadian system globally controls gene expression patterns so that metabolic pathways are differentially regulated over the day, including switching between carbohydrate and lipid catabolism [1,3,59]. Therefore, ingestion of the same food at different times of day could lead to differential metabolic outcomes, e.g., lipid oxidation (LO) versus accumulation; however, whether this is true or not is unclear.

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Fasting Activates Sirtuin Signaling Proteins (SIRT1), Accelerating Cell Repair

Sirtuins are a family of signaling proteins involved in metabolic regulation. SIRT1 (along with SIRT6 and SIRT7) are proteins are employed in DNA repair.

 

Sirtuins - SIRT1 Activator Nature Reviews Drug Discovery

From Wikipedia:

Sirtuins are a class of proteins that possess either mono-ADP-ribosyltransferase, or deacylase activity, including deacetylase, desuccinylase, demalonylase, demyristoylase and depalmitoylase activity. The name Sir2 comes from the yeast gene ‘silent mating-type information regulation 2‘, the gene responsible for cellular regulation in yeast.

From in vitro studies, sirtuins are implicated in influencing cellular processes like aging, transcription, apoptosis, inflammation and stress resistance, as well as energy efficiency and alertness during low-calorie situations. As of 2018, there was no clinical evidence that sirtuins affect human aging.

Aging

Although preliminary studies with resveratrol, an activator of deacetylases such as SIRT1, led some scientists to speculate that resveratrol may extend lifespan, there was no clinical evidence for such an effect, as of 2018.

In vitro studies shown that calorie restriction regulates the plasma membrane redox system, involved in mitochondrial homeostasis, and the reduction of inflammation through cross-talks between SIRT1 and AMP-activated protein kinase (AMPK), but the role of sirtuins in longevity is still unclear, as calorie restriction in yeast could extend lifespan in the absence of Sir2 or other sirtuins, while the in vivo activation of Sir2 by calorie restriction or resveratrol to extend lifespan has been challenged in multiple organisms.

 

Healthy Diets: “The Science Behind Fasting – Ketosis” (Infographic)

The Science Behind Fasting - Ketosis
Cellular Cleanup Crew Fasting and caloric restriction both can ramp up autophagy, a kind of cellular housekeeping. When cells are in famine mode and don’t have to break down food, they pause their usual tasks and stop dividing. Instead, they work on repairing and recycling damaged components, and cleaning out dead or harmful cell matter. Alison Mackey/Discover

…It seems fasting triggers a dramatic switch in the body’s metabolism, according Discover Magazine logoto a paper Mattson and colleagues published in February in the experimental biology journal FASEB. In humans, fasting for 12 hours or more drops the levels of glycogen, a form of cellular glucose. Like changing to a backup gas tank, the body switches from glucose to fatty acids, a more efficient fuel. The switch generates the production of ketones, which are energy molecules that are made in the liver. “When the fats are mobilized and used to produce ketones, we think that is a key factor in accruing the health benefits,” says Mattson.

Read more at Discover Magazine