A common bodybuilding supplement, HMB, might do more than help with those gains. In a collaborative study between Nevada’s Simmaron Research Institute and Rush University in Illinois, researchers found that beta-hydroxy beta-methylbutyrate slows cognitive decline in mice. If the same benefit extends to humans, the supplement could help aging adults stave off dementia.
In a paper published in the journal Cell Reports, a team of neurologists writes that HMB—typically used by athletes to boost performance and muscle growth—binds with PPAR-alpha, a nuclear hormone receptor in the brain's hippocampus region. Responsible for energy homeostasis, PPAR-alpha regulates how fats are metabolized. This process is vital to its newly-discovered role in slowing cognitive decline.
People with Alzheimer’s disease and other cognitive losses have shown low levels of brain-derived neurotrophic factors (BDNFs), a protein essential to the hippocampus’s function. Because the hippocampus is responsible for memory formation and retrieval, a relative lack of BDNFs is believed to impact a person’s ability to recall long-term memories, keep track of their belongings, or perform other cognitive tasks many take for granted. But HMB appears to help replenish the BDNF supplies that people with Alzheimer’s lack.
To see whether HMB could help restore BDNFs, the neurologists orally administered HMB to mice “with Alzheimer’s-like pathology,” as described by corresponding study author Dr. Kalipada Pahan in a Rush University release. Thanks to its interactions with PPAR-alpha, HMB was found to stimulate the brain to produce more BDNFs. Not only do the researchers believe this helps keep the hippocampus healthy, but they also found that HMB reduces plaque buildup in the brain. (Despite some challenges to the theory, plaques between neurons are commonly thought to cause or exacerbate Alzheimer’s.)
It’s too early to know whether HMB will have a similar impact on the human brain, but if so, it could become a simple way to reduce cognitive decline in older adults. “This may be one of the safest and the easiest approaches to halt disease progression and protect memory in Alzheimer’s disease patients,” Pahan said, referring to HMB's relative lack of adverse side effects.
While HMB has a somewhat accidental effect on neurological health, other researchers are working on formulations that specifically target the neurological phenomena behind Alzheimer’s. A new Eli Lilly drug called donanemab is said to slow cognitive decline by 22% to 84%, depending on the patient’s age and severity of symptoms. Depending on how future HMB and donanemab studies go, an Alzheimer’s diagnosis could soon mean something different than it historically has.
