Loading…
Story
synergy · 1
The idea that older people should eat less protein is a mistaken belief, and it harms two things at once: the bone framework and muscle. Bone density and muscle mass already decline together, and they jointly set the risk of falling, so they should be managed together.
cofactor · 4
Older muscle responds less to protein (anabolic resistance): the same meal of protein produces less muscle building. Morton 2018 cites per-meal amounts at which muscle protein synthesis nears its plateau of about 0.24 g per kilogram of body weight in younger adults and about 0.40 g in older adults. The PROT-AGE 2013 consensus for adults over 65: 1.0–1.2 g/kg a day if healthy, at least 1.2 g/kg if exercising regularly, and 1.2–1.5 g/kg with acute or chronic illness, together with strength training. These figures do not apply to people with severe kidney disease who are not on dialysis; their protein intake is for the doctor to set.
Older muscle builds less protein from the same meal (anabolic resistance). Morton 2018 cites per-meal amounts at which muscle protein synthesis nears its plateau of about 0.24 g per kilogram of body weight in younger adults and about 0.40 g in older adults. So the answer for older adults is enough high-quality protein at each meal plus strength training, not an ever-lighter diet.
Creatine is one of the best-value supplements for sarcopenia: combined with strength training it has a fairly consistent effect on both muscle mass and strength, and it is cheap. Taken without training it does much less; it helps you train harder, and it cannot replace the training.
Vitamin D's effect on sarcopenia shows up mainly in people who are deficient: once they are corrected, strength may improve and falls may decrease. For people who already have enough, taking more does not add strength, which matches the conclusion for bone.
antagonism · 1
Narrowing your eating window also cuts the number of times you can spread out protein, and muscle building has to be triggered meal by meal; older adults need about 0.4 g of protein per kilogram of body weight at a meal to trigger it. The conflict is sharpest when older people try time-restricted eating.
depletes · 1
Inflammation and muscle loss may form a vicious circle: rising inflammation speeds up muscle breakdown; with less muscle, activity drops, abdominal fat increases, and inflammation climbs again. This is one reason keeping muscle matters so much for health in old age.
regulates · 9
Sarcopenia means muscle mass, strength and physical performance declining together. Part of it can be trained back: in Fiatarone 1994, very old, frail nursing-home residents who did progressive strength training gained a great deal of strength while those who did not train barely changed, and their walking speed and stair climbing improved; the difference in thigh-muscle cross-sectional area was not statistically significant, and a nutritional supplement without training did not improve the main outcomes. Frailty is not destiny.
Muscle is the largest destination for blood sugar after a meal; with less muscle, the body handles glucose less well, and insulin resistance and blood sugar can both worsen. In turn, the nerve damage and chronic inflammation of diabetes speed up muscle loss. People losing weight on GLP-1 drugs especially need enough protein and steady strength training to hold on to their muscle.
After menopause, muscle responds less to training and protein, and muscle loss speeds up. Regular strength training is the best-supported countermeasure; for protein, the PROT-AGE 2013 consensus advises at least 1.2 g per kilogram a day for adults over 65 who exercise regularly.
Eating the same and moving the same, yet heavier with a thicker waist: part of that really does come from hormonal change, not just willpower. Muscle mass is also declining with age at the same time, and the two add up, which is why strength training matters so much in this period.
Muscle is not lost at a steady rate: the loss speeds up year by year after midlife and becomes more marked after 70, and strength falls faster than muscle size. In women, the curve may steepen further once estrogen falls at menopause.
The Liu 2009 Cochrane review pooled 121 randomized trials in older adults: progressive strength training clearly increased strength (standardized mean difference 0.84, a large effect) and improved walking speed, rising from a chair and stair climbing. No drug is approved specifically to treat sarcopenia; strength training plus enough protein is the main answer.
Older people's appetite shrinks and they eat less, while their muscle responds less to the protein in a meal, which is called anabolic resistance: in pooled data, older men needed about 0.40 g of protein per kilogram of body weight in a meal for muscle building to peak, against about 0.24 g in young men. So older people need enough protein, spread across every meal.
Men have no cliff like menopause, only a gentle slope: testosterone falls slowly with age and muscle slowly follows. What men should really watch is keeping up strength training and enough protein over the long term, not any single testosterone test result.
→HMB
HMB is a breakdown product of leucine, usually taken at 3 g a day. It mainly reduces muscle breakdown rather than driving muscle building, so it fits situations dominated by breakdown: in a small trial of 19 older adults on 10 days of bed rest, the group taking HMB lost almost no lean mass. For people who simply train, the extra benefit is small.