HMB, Magnesium, Omega 3, and Vitamin D Supplements for Age-Related Muscle Loss

Previously, I’ve covered the evidence surrounding supplementation for older adults with protein or amino acids like leucine. What about a metabolite of leucine known as β‑hydroxy β‑methylbutyrate, known as HMB? Adding HMB to an exercise regimen fails across the board to improve muscle mass, muscle strength, or physical performance among older individuals, and since everyone should be exercising that pretty much takes HMB off the table. But there are circumstances when you’re laid up, for example recuperating from a broken hip.

Researchers in Spain randomized about 100 men and women over the age of 65 in rehab recovering from a hip fracture to a nutritional supplement with about 3 grams of HMB. They suffered less loss of fat-free mass loss compared to the control group who didn’t get the supplement. Unfortunately, the supplement provided other components, so it’s impossible to tease out the HMB effects, but regardless, there was no significant change in muscle strength or muscle function. This was roughly consistent with a 10-day bedrest study of straight HMB versus placebo in which the HMB group similarly lost less lean mass—but only when an outlier was excluded, which isn’t really kosher—and there was no apparent improvement in strength or function.

This is what meta-analyses of all such studies have found—an improvement in fat-free mass in older sedentary adults with no change in strength or function and no benefits for any muscle parameters when combined with physical activity. Since we all should be exercising, and there’s a questionable benefit of lean mass for lean mass’s sake, combined with the fact that HMB activates the engine-of-aging enzyme mTOR, I see little reason to recommend supplementing with HMB.

What about magnesium? Higher blood levels correlate with muscle performance. One cohort study of older adults found that those with higher magnesium intake had greater lean mass over time, though the dietary intake of magnesium appeared to be similar between those with and without sarcopenia, excessive age-related muscle loss. There was one randomized controlled trial of magnesium supplements that found that those taking about the RDA for 12 weeks had no effect on lean mass or upper or lower body strength, but it did appear to improve walking speed and chair stand times. Unfortunately, it wasn’t a randomized placebo-controlled trial, so that may all have just been the placebo effect.

What about omega-3 fatty acid supplements? Some population studies suggest that fish consumption is associated with greater muscle strength. In others, seafood consumption was associated with a greater loss of muscle strength over time, maybe because of its mercury content. When put to the test in placebo-controlled trials, fish oil and other omega-3 supplements showed no effect on lean mass, muscle strength, or clinically significant effects on functional performance.

What about vitamin D? Osteomalacia and rickets, softened bone diseases resulting from severe vitamin D deficiency, are often accompanied by muscle weakness. Mice genetically engineered without vitamin D receptors suffer muscle atrophy, and vitamin D-depleted rats show impaired muscle function. In a petri dish vitamin D increased muscle fiber growth. Human observational studies show correlations between lower vitamin D blood levels and lower muscle mass, lower muscle strength, performance such as walking speed, and higher odds of prefrailty or frailty. Of course, rather than low vitamin D levels leading to frailty, frailty may be leading to low levels of the sunshine vitamin, because frail individuals may not be out walking around as much. You don’t know until you put it to the test.

Multiple meta-analyses of randomized controlled trials found that giving vitamin D supplements to people with low vitamin D levels significantly improved their muscle strength and/or performance—that is, until multiple studies were retracted for fabricated data. It turns out, if you exclude the fraudulent studies, the benefit evaporates. If anything, there may be small adverse effects to vitamin D supplementation on muscle health. The 180o turn demonstrates that the “publication of fake data can have major health implications.”