In early 2024, a study reported that some people who were given human growth hormone (HGH) treatments from human cadavers (dead bodies) decades ago later showed signs of Alzheimer’s disease. This raised new questions about how Alzheimer’s disease might spread and whether it may be connected to growth hormone.

In this article, we’ll look more closely at the study, explain what growth hormone is, and help you understand what the findings could mean for people today.

What Is Growth Hormone?

Human growth hormone (HGH) is a natural substance made by the pituitary gland. The pituitary gland is a small organ at the base of the brain. HGH helps our bodies grow and stay healthy. In children, it helps them grow taller. In adults, it can help lower body fat and build muscle.

Growth Hormone and the Brain

Growth hormone doesn’t just help with height and muscles. Some studies show it also helps the brain. It may support brain development and function and help brain cells grow and repair. It may even help protect the brain from damage as we get older.

Medical Uses of Human Growth Hormone

Doctors sometimes use HGH to treat certain health problems. For example, children with growth hormone deficiency, or GHD — a condition where the body doesn’t make enough HGH — may get HGH injections to help them grow. Adults with certain medical conditions may also receive HGH to help with muscle loss or other issues.

Before scientists could make synthetic growth hormone in a lab, doctors used HGH from the pituitary glands of people who had died. This was sometimes referred to as pituitary-derived growth hormone or cadaver-derived growth hormone (c-hGH). This technique was used from the late 1950s until the mid-1980s, when it was replaced by safer, lab-made versions.

What Did the Study Discover?

The 2024 study, published in Nature Medicine, looked at people who had received cadaver-derived HGH as children to treat short stature. Years later, some of these people showed signs of environmentally acquired Alzheimer’s disease, even though they were still relatively young.

Researchers found that the HGH they were given may have come from contaminated brain tissue that had tiny clumps of amyloid-beta protein. These clumps are known to build up in the brains of people with Alzheimer’s and are believed to play a role in causing the disease. The study suggests that these harmful proteins might have been passed from the donor brains to the individuals through the growth hormone treatment.

This idea is similar to how another brain disease, Creutzfeldt-Jakob disease (CJD), was once spread through cadaver-derived HGH. Because of this risk, doctors stopped using HGH treatment from human donors in the 1980s.

Should You Be Worried?

The short answer is no. The type of HGH treatment that may have caused this problem hasn’t been used in almost 40 years. Today, HGH is made safely in labs. There’s no evidence that modern HGH treatments carry any risk of Alzheimer’s or similar brain diseases.

So, if you or someone you know is getting HGH treatment today, there’s no reason to be concerned about this issue.

Is the Link Between HGH and Alzheimer’s Proven?

Not yet. The 2024 study raised some important questions and public health concerns, but it didn’t prove that cadaver-derived HGH caused Alzheimer’s. Another study published later that year showed that the evidence wasn’t strong enough to say for sure. That’s partly because the number of people in the study was small. Other factors may have played a role too.

This shows that more research is needed. Scientists are still learning how Alzheimer’s develops and whether it can be passed from person to person in rare cases of Alzheimer’s like this.

Has HGH Ever Been Studied as a Treatment for Alzheimer’s?

Yes. Over the years, some studies have looked into whether HGH could help prevent or treat Alzheimer’s disease. Since some believe HGH may help the brain grow and repair — a process called neuroplasticity — some scientists have wondered whether HGH could protect the brain from damage.

But the results of these studies have been mixed. Some studies showed benefits, while others didn’t. Most of the research was done on animals or small groups of people, so we don’t have clear answers yet. One study from 2018 found that HGH helped improve brain function in areas responsible for memory, learning, and behavior. However, this study only involved one older adult who had mild cognitive impairment. The person did not have Alzheimer’s but did have a family history of the disease.

While the idea is interesting, research is still very limited. We still don’t know if HGH could be a helpful treatment for Alzheimer’s.

What Do We Know About HGH and Alzheimer’s?

Alzheimer’s disease is a serious and complex brain condition that affects millions of people around the world. Scientists are still trying to understand what causes it and how to prevent or treat it.

The link between HGH and Alzheimer’s is complicated. Some recent findings are important, but they don’t mean people should worry about HGH treatments. Instead, these studies remind us why it’s important to keep learning about the brain and studying how it works. Ongoing research has led to new clinical trials and other possible treatments, such as stem cell therapy.

If you have questions about HGH or Alzheimer’s, talk to your doctor or neurologist. And if you want to support Alzheimer’s research, many organizations are working hard to find answers and help people living with the disease.

Talk With Others Who Understand

On myALZteam, the social network for people with Alzheimer’s disease and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with Alzheimer’s.

Have you learned anything new about growth hormone and Alzheimer’s disease? Do you follow the latest Alzheimer’s research? Share your thoughts in the comments below, or start a conversation by posting on your Activities page.