If you do heavy physical work or weight training, you’ll not only make your body more muscled and stronger, but you’ll also make it last longer. Muscle mass extends life expectancy write researchers at the David Geffen School of Medicine in the American Journal of Medicine.
Researchers used to think that overweight elderly people had a higher risk of dying, but recent studies have shown that both overweight and underweight elderly people are more likely to die. More and more epidemiologists are therefore coming to the conclusion that it’s not bodyweight that determines how long you are likely to live, but lean body mass.
In other words: the muscles.
Preethi Srikanthan tested this theory by examining data on 3695 over 55s gathered for the National Health and Nutrition Examination Survey III.
Srikanthan followed the participants from the period 1989-1994 until 2004. When the study started the men were over 55 and the women older than 65.
Srikanthan noted which of the participants died in the 10-16-year period.
There was no relationship between the participants’ amount of non-muscle mass and their survival chances, Srikanthan discovered when he divided the participants into four equal-sized groups (quartiles) on the basis of their non-muscle mass, and then calculated their mortality risk.
The figure below shows this.
But when Srikanthan divided the participants into quartiles based on muscle mass, he did find a relationship. Participants with lots of muscle mass were 20 percent less likely to die than participants with little muscle mass.
Srikanthan is not sure how muscle mass increases our survival chances. Perhaps it protects against high glucose levels, perhaps it reduces the amount of dangerous fat in the body, or perhaps muscles produce protective substances. But he does have a word of advice.
“Get up and start moving”, the researcher said in an interview with Christopher Intagliata of Scientific American. [scientificamerican.com Mar 20, 2014]
Clinical study to assess the efficacy and safety of a citrus polyphenolic extract of red orange, grapefruit, and orange (Sinetrol-XPur) on weight management and metabolic parameters in healthy overweight individuals.
The present study investigated the efficacy and safety effects of Sinetrol-XPur (polyphenolic citrus dry extract) in weight management; metabolic parameters; and inflammatory, glycemic and oxidative status. In a 12-week, randomized, double-blind, placebo-controlled trial, Sinetrol-XPur was given to overweight subjects twice daily with meals in the tested group (N?=?47) versus a placebo group (N?=?48). Waist and hip circumference and abdominal fat were decreased in the Sinetrol-XPur group as compared with the placebo group (p?< ?0.0001) (-5.71% vs. -1.56% for waist, -4.71% vs. -1.35% for hip and -9.73% vs. -3.18% for fat). Inflammatory markers were reduced (C-reactive protein: -22.87% vs. +61%; fibrinogen: -19.93% vs. -1.61%, p?0.01). Oxidative stress was lowered as seen by the reduction of malondialdehyde (-14.03% vs. 2.76%) and the increase in superoxide dismutase and glutathione (17.38% vs. 2.19% and 4.63% vs. -2.36%, respectively, p?0.01). No adverse effects were observed. Kidney, liver, and lipid panels remained unchanged. These results indicated that Sinetrol-XPur supplementation is a viable option for reducing abdominal fat, waist and hip circumference, and body weight and for improving inflammatory, glycemic, and oxidative status in healthy overweight individuals.
PMID: 23554029 [PubMed – indexed for MEDLINE]