Calorie Restriction; Muscle Rejuvenation

A study in October 2023 by the National Institue of Aging suggests that a reduction in calories may help rejuvenate muscles and active biological systems that promote health.

• "A 12% reduction in calorie intake is very modest,"

• "This kind of small reduction in calorie intake is doable and may make a big difference in your health."
  "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,"

Tissue and muscle regeneration

A May 2021 study at the Sulk Institute said,

• "Our study uncovers specific factors that are able to accelerate muscle regeneration, as well as revealing the mechanism by which this occurred."

• "Our laboratory previously showed that these factors can rejuvenate cells and promote tissue regeneration in live animals … But how this happens was not previously known."

• "Our laboratory has recently developed novel gene-editing technologies that could be used to accelerate muscle recovery after injury and improve muscle function," he says. "We could potentially use this technology to either directly reduce Wnt4 levels in skeletal muscle or to block the communication between Wnt4 and muscle stem cells."

Klotho and Ageing Muscles

An April 2021 study by the University of Pittsburgh said, 

"Although there are no proven treatments for sarcopenia [age-related loss of skeletal muscle mass and function] yet, there are some pharmaceutical treatments entering clinical trials. Interestingly, many of these act on mechanisms that also involve a protein called Klotho," 

"Evidence suggests that Klotho levels gradually decline with age, and so we wanted to test whether supplementation with Klotho may attenuate the development of sarcopenia."

"Our data suggest that treatment with Klotho may be more effective in slowing the progression of sarcopenia at an earlier time point, rather than rescuing advanced age-related disease, by which time the gene responses seem to be more random," 

"It will be interesting in future studies to determine whether boosting Klotho levels at a younger age could prevent muscle declines into old, and even oldest-old, age.”

Vitamin D and muscle function

An April 2021 study by Garvan Institute of Medical Research, Australia, said

"Our results show there is a clear link between vitamin D deficiency and oxidative capacity in skeletal muscle. They suggest that vitamin D deficiency decreases mitochondrial function, as opposed to reducing the number of mitochondria in skeletal muscle." 

"We are particularly interested to examine whether this reduction in mitochondrial function may be a cause of age related loss in skeletal muscle mass and function."

Muscle Repair and Glucose

An April 2021 study by Tokyo Metropolitan University found that skeletal muscle satellite cells perform better in environments that are low in glucose. 

The researchers noticed also that high glucose had an adverse effect.

Vitamin C and muscle-mass in the over-50s

A March 2021 study by the University of East Anglia said,

• "People over 50 lose up to one per cent of their skeletal muscle mass each year, and this loss is thought to affect more than 50 million people worldwide."

• "It's a big problem, because it can lead to frailty and other poor outcomes such as sarcopenia, physical disability, type-2 diabetes, reduced quality of life and death."

• "We know that Vitamin C consumption is linked with skeletal muscle mass. It helps defend the cells and tissues that make up the body from potentially harmful free radical substances. Unopposed these free radicals can contribute to the destruction of muscle, thus speeding up age-related decline."

• "But until now, few studies have investigated the importance of Vitamin C intake for older people. We wanted to find out whether people eating more Vitamin C had more muscle mass than other people."

• "We studied a large sample of older Norfolk residents and found that people with the highest amounts of vitamin C in their diet or blood had the greatest estimated skeletal muscle mass, compared to those with the lowest amounts.

• "We are very excited by our findings as they suggest that dietary vitamin C is important for muscle health in older men and women and may be useful for preventing age-related muscle loss.

• "This is particularly significant as Vitamin C is readily available in fruits and vegetables, or supplements, so improving intake of this vitamin is relatively straightforward.

• "We found that nearly 60 per cent of men and 50 per cent of women participants were not consuming as much Vitamin C as they should, according to the European Food Safety Agency recommendations.

• "We're not talking about people needing mega-doses. Eating a citrus fruit, such as an orange, each day and having a vegetable side to a meal will be sufficient for most people."

The Liver, high blood sugar and muscle loss

A March 2021 study by Monash University said, 

"The ageing-related diseases of skeletal muscle loss and type 2 diabetes are very prevalent and are a huge societal and economic burden. We have known for some time that the ageing-related diseases of skeletal muscle loss and type 2 diabetes were linked but we didn't know how.”

"Our studies demonstrate that the liver is a critical control point for muscle protein metabolism; a discovery that is quite surprising. We believe that our new findings highlight the need to examine the role of skeletal muscle atrophy in type 2 diabetes more closely in human clinical populations."

Strength Training - Getting Started

I am a fan of the Starting Strength programme to get started with strength training.

Protein intake, muscle mass, ageing

A March 2020 study by the University of Birmingham said,

• "We know that older people show a blunted response to muscle building when consuming a certain amount of protein. Therefore, older individuals need to eat more protein to get the same muscle building response as younger and middle-aged people."

• "Another way to help muscles make better use of dietary protein is to perform regular exercise".

• "Most people are reaching the Recommended Daily Allowance of protein, but our results show that a one-size-fits-all guideline for protein intake isn't appropriate across all age groups. Simply saying older people should eat more protein isn't really enough either. We need a more sophisticated and individualised approach that can help people understand when and how much protein to consume to support muscle mass."

Muscle Mass in the Arms and Legs

In a July 2019 study by University of São Paulo’s Medical School said,

• “We evaluated the body composition of this group, focusing on appendicular muscle mass, subcutaneous fat and visceral fat. We then sought to determine which of these factors could predict mortality in the ensuing years. We concluded that the key factor was the amount of appendicular lean mass,”

• “According to the most widely used criteria [appendicular lean mass in kg divided by height squared in m], most of the individuals identified as having sarcopenia are lean. However, our sample had a higher-than-average BMI [body mass index], so we substituted muscle mass for fat mass. Subjects with muscle mass that was 20% below average were classified as having sarcopenia,” 

• “We then conducted a number of statistical analyses to detect differences between the subjects who died and those who remained alive, particularly, whether it was possible to predict a person’s death on the basis of body composition measured by the DXA examination,” 

• “We found that other parameters also negatively influenced mortality in the men, statistically reducing the significance of appendicular muscle mass. In the women, however, muscle mass stood out as a key factor and hence had more influence,”

• “The rapid and significant transition from a protective estrogenic environment to a deleterious hypoestrogenic environment, which is particularly adverse for the cardiovascular system, may make the protective metabolic role of skeletal muscles, including the production of anti-inflammatory cytokines, more important in the postmenopause period. This hormone change is far less abrupt in men,” 

Fluid Intelligence, Age, Fat & Muscle

A December 2017 study by Iowa State University said,

"Chronological age doesn't seem to be a factor in fluid intelligence decreasing over time … It appears to be biological age, which here is the amount of fat and muscle."

"Further studies would be needed to see if people with less muscle mass and more fat mass are more likely to develop Alzheimer's disease, and what the role of the immune system is,"

."If you eat alright and do at least brisk walking some of the time, it might help you with mentally staying quick on your feet,"

Resistance Training or Endurance Training?

An April 2017 study by Division of Mathematics, Science, and Health Careers; Department of Science, Manchester Community College, Manchester, CT concluded, in part, that, “resistance training … was more effective than endurance training.”

Protein Drinks and Muscle Recovery

A September 2019 study by the University of Lincoln found, “neither whey-protein based shakes nor milk-based formulas enhanced the rate of muscle recovery following resistance training when compared to a carbohydrate-only drink.”

"While proteins and carbohydrates are essential for the effective repair of muscle fibres following intensive strength training, our research suggests that varying the form of protein immediately following training does not strongly influence the recovery response or reduce muscle pain.

"We would hypothesise that well balanced daily nutrition practices would influence recovery from delayed onset muscle soreness to a greater extent."