In this portion of the investigation, a team of military researchers surveyed 5,778 service members on two occasions a little over a year apart with identical questionnaires, disproving their hypothesis that adverse effects would curb both supplement use and reporting.
“These results indicate that even when service members believe they are experiencing adverse effects from specific classes of dietary supplements, they continue to use them,” the researchers wrote in the journal Food and Chemical Toxicology. “Focus group studies designed to explore service members’ continued use of dietary supplements despite awareness of their adverse effects provide insight into this seemingly counterproductive, unhealthy behavior.”
The research was supported by the Department of Defense's Center Alliance for Nutrition and Dietary Supplement Research initiative of the Defense Medical Research and Development Program at the U.S. Army Medical Research and Development Command (USAMRDC).
Determining adverse effects
According to previous findings from The Military Dietary Supplement Use Study, over 70% of U.S. service members regularly use dietary supplements and about 18% have reported adverse effects associated with use. They are also more likely than the general population to use combination products promoted for bodybuilding, performance enhancement or weight loss—the three categories most often flagged for safety concerns.
“Adverse effects could result from specific compounds in the dietary supplements, interactions with prescribed medications, excessive intake, allergic reactions to ingredients, contamination due to poor quality control, and/or the inclusion of unlisted or illegal compounds,” the study noted.
The questionnaire included 96 generic dietary supplements (e.g., multivitamins/multiminerals [MVMs], individual vitamins and minerals, proteins/amino acids, herbals, joint health products, fish oils) and 91 brand name products previously used in armed forces studies and updated based on dietary supplements available in and around base.
Respondents also reported frequency of use and selected from potential adverse effects listed next each supplement related to cardiovascular, gastrointestinal, muscular, sleep disturbance and neurological symptoms. Specific symptoms listed included palpitations/racing heart, abdominal pain, nausea/vomiting, diarrhea, muscle cramps/pain/weakness, sleep disturbances/insomnia, dizzy/confusion/lightheaded, tingling/numb in extremities, seizures/convulsions/tremors and other.
Continued use despite reporting
Among service members who consumed dietary supplements at least once a week, 15% reported at least one associated adverse effect at follow up compared to 19% at baseline for most categories. Only for combination products did those reporting adverse effects at baseline have “an increased risk of use at follow up,” the researchers noted.
In descending order, adverse effects in the baseline phase were most often reported for combination products, prohormones, protein/amino acids, individual vitamins/minerals, MVM, herbals, other dietary supplements, fish oils and joint health products. The order was similar in the follow-up phase, but adverse effects for individual vitamins/minerals were slightly more prevalent than for proteins/amino acids.
In addition, service members who used any dietary supplement and reported adverse effects at baseline were more likely to use dietary supplements at follow up while continuing to report adverse events.
“Surprisingly, having experienced an adverse effect from a supplement had little effect on whether service members continued to take them,” said Harris Lieberman, PhD, research psychologist at the U.S. Army Research Institute of Environmental Medicine (USARIEM) and senior researcher on the study. “This may occur because when service members experience certain adverse effects, it may be interpreted by them as indicating that their supplement is working.”
Other reasons cited for continued use: blaming individual misuse or an unknown medical condition rather than the product and the perception of the risk of dietary supplement use as minimal compared to serving in a combat arms profession.
Protecting the troops, considering causation
The research is part of a wider effort to protect the troops from not only unwanted side effects but to ensure readiness for combat through appropriate nutritional strategies that do not comprise health or careers. The main program charged with this effort is the Department of Defense’s Operation Supplement Safety (OPSS), whose mandated mission is to educate the military community about dietary supplements and their conditions of use.
Andrea Lindsey, senior nutrition scientist and director of OPSS, co-authored an opinion piece with Steve Mister, president and CEO of the Council for Responsible Nutrition (CRN), published this week in the Military Times, to continue to raise awareness about the differences between safe and legal dietary supplements and fraudulently marketed products.
“One goal of the Military Times piece was to help educate this class of consumers on how and where to avoid purchasing adulterated or illegal products especially since many of these consumers do so via the internet,” Mister said. “Illegal ingredients have no place in health and wellness regimes, and we are united in our goal to clean up the market.”
Stefan M. Pasiakos, PhD, director of the Office of Dietary Supplements (ODS) at the National Institutes of Health and former USARIEM researcher, highlighted the importance of the ongoing research led by Dr. Lieberman for capturing dietary supplement use by active-duty service members, reasons for use and the potential for health and performance benefits or harm.
While he noted that the data from dietary supplement surveillance does not infer causation (something which the study authors also acknowledged), he said that concerns raised by the U.S. Military Dietary Supplement Use Study are not surprising and provide the impetus for continued research, education and surveillance in this population.
These efforts continue to inform resources like the ODS and OPSS websites to raise awareness about which supplements are considered safe for service members and their careers.
“Risking military readiness and the health and welfare of the nation’s service members due to possible unsafe dietary supplement use is not an option,” Dr. Pasiakos said. “We in the dietary supplement research community must continue to do our part to ensure that the military community has the most accurate and up to date information necessary to inform the safe and effective use of dietary supplements.”
In terms of what’s next in this line of research, Dr. Lieberman shared that future studies will examine the occurrence of serious medical conditions from the use of dietary supplements in continuing users based on the service members’ medical records.
“If such associations are present, this would be much more of an issue than the self-reported adverse events observed in the studies discussed above,” he said.
Source: Food and Chemical Toxicology
doi: 10.1016/j.fct.2024.114635
“Longitudinal changes in adverse effects reporting in multiple dietary supplement classifications: The US military dietary supplement use study”
Authors: Knapik et al.
