Fact Check: Reports Link GLP-1 Medication Users to Rare Disease Historically Associated with Pirates

WASHINGTON — Popular GLP-1 weight-loss medications have helped millions of people shed pounds, but new research from Australia suggests doctors and patients may need to pay closer attention to what users are actually eating while taking them.

A systematic review from the Hunter Medical Research Institute (HMRI) found that while the medications are effective for weight loss, many clinical trials fail to track changes in diet or whether patients are still getting enough essential nutrients. According to researchers, that gap could increase the risk of malnutrition over time.

“Very little is known about the exact changes these medications have on what people actually eat, whether vitamin and mineral intakes are adequate, and whether weight-loss achieved through medication also supports optimal nutrition-related health and wellbeing in the long-term,” stated researchers from HMRI.

One concern highlighted in the review is the potential for vitamin deficiencies — including rare cases of scurvy, a disease caused by a lack of vitamin C. Historically known as “pirate’s disease,” scurvy develops when the body doesn’t receive enough fruits and vegetables to maintain healthy tissue repair and immune function.

Symptoms of scurvy can include anemia, loose teeth, bruising, bleeding under the skin, swollen or bleeding gums, and wounds that don’t heal. These symptoms can significantly impact quality of life and overall health if left unaddressed.

The rising popularity of GLP-1 medications, including brands like Ozempic, Wegovy, and Mounjaro, has transformed the weight loss landscape. Originally developed for type 2 diabetes, these drugs work by mimicking hormones that regulate appetite and blood sugar. Their effectiveness has led to widespread use, with some patients reporting significant weight loss of 15% or more of their total body weight.

However, the rapid reduction in food intake that accompanies these medications may have unintended consequences. Beyond vitamin C, researchers say other deficiencies could also pose risks. Iron deficiency can lead to anemia, while low levels of certain B vitamins may contribute to serious neurological conditions such as Wernicke’s encephalopathy — though experts note these complications remain rare.

Dr. Jessica Bartfield, an obesity medicine specialist not involved in the research, explained in a recent interview that “these medications work primarily by slowing gastric emptying and increasing feelings of fullness. This means patients naturally eat less, but it also means they need to be more intentional about food quality.”

Another challenge, researchers say, is that symptoms of nutrient deficiency — including fatigue, nausea, and irritability — can overlap with the common side effects of GLP-1 medications, making problems harder to spot early. This overlap can lead to delays in identifying and addressing nutritional issues.

Experts stress that these cases appear uncommon and that the findings are not a call for people to stop taking GLP-1 medications. Instead, the results point to a major blind spot in current research that needs to be addressed through more comprehensive clinical studies.

Doctors are now being urged to monitor patients’ diets more closely and ensure that even smaller meals remain nutritionally dense. The review also calls for future clinical trials to include detailed dietary assessments to better understand long-term health effects.

The global market for GLP-1 medications is expected to reach $100 billion by 2030, according to industry analysts. This explosive growth underscores the importance of understanding the full impact of these drugs on patients’ nutritional health.

For patients concerned about their nutritional status, experts recommend working with a registered dietitian and considering screening for deficiencies before starting treatment. Simple blood tests can identify potential vitamin and mineral deficiencies, allowing for early intervention.

“The key is not to avoid these medications, which have proven benefits for many patients with obesity, but to use them as part of a comprehensive approach to health that includes nutritional awareness,” said nutritionist Sarah Hallberg, who specializes in medical weight management.

The bottom line from researchers: GLP-1 medications can be highly effective for weight loss, but long-term success depends not just on appetite suppression — it also requires careful nutrition management to avoid potentially serious deficiencies.