Lentis/Conflicts of Interest in US Nutrition Research

Conflicts of Interest in US Nutrition Research

Introduction

Nutrition research is a multidisciplinary field that studies the complex relationship between diet, nutrients, and health outcomes. By examining how food influences both physical and mental well-being, this research provides a crucial foundation for public health recommendations, dietary guidelines, and individual dietary choices. The process of conducting nutrition research and implementing its findings involves a variety of participants who play critical roles in shaping public health and advancing the knowledge of nutrition.

Participants in nutrition research include researchers, government entities, private sectors, and non-profit organizations, each contributing in distinct ways. Researchers form the backbone of the field through their studies and published findings, driving advancements in understanding nutrition. Government entities fund, regulate, and translate research into policies and state regulations that impact public health on a larger scale. Private sectors, such as food industries, develop new products and often fund research, sometimes focusing on their own products and interests. Lastly, non-profit organizations and advocacy groups raise awareness, provide funding, and work to advance public health initiatives. However, the involvement of these diverse participants can sometimes lead to conflicts of interest. Financial or personal relationships may influence research outcomes or interpretations, raising significant concerns about potential bias and the credibility of nutritional science.

The complex issue of conflicts of interest in U.S nutrition research is further investigated through an exploration of its historical context, supported by specific examples that highlight the influence of financial and personal relationships on research outcomes. A discussion of actionable recommendations for future work is also included to continue the discussion in promoting unbiased research.

History

Conflicts of interest are present throughout nutritional research, particularly within influential institutions, like the US Department of Agriculture (USDA), industry-funded research initiatives, and the Academy of Nutrition and Dietetics (AND).

The USDA and the Dietary Guidelines for Americans

One example of how the USDA influences dietary health is through a published document called the Dietary Guidelines Advisory (DGA). The DGA was introduced in 1980 and is around a one hundred fifty page document that is revised every 5 years to provide dietary advice to meet nutrient needs, promote health and prevent disease . The DGA forms the foundation for all nutrition programs in the US and provides dietary recommendations for states and local governments along with healthcare professionals and community groups. For the development of the 2020–2025 DGA, the USDA and Health and Human Services (HHS) first identified nutrition topics to be reviewed, then appointed an external Dietary Guidelines Advisory Committee (DGAC), composed of twenty experts from the fields of nutrition and medicine. They then wrote the DGA based largely on the DGAC’s scientific report. As the DGAC plays a large influential role in the content of the DGA, a study has been conducted to review conflicts of interest present within the members. This study found that 95% of the members in this committee had some form of a conflict of interest (COI) with the food and/or pharmaceutical industries and that particular actors had connections with multiple members . These actors included large industries like Kraft and Kellogg. The main COI found was that these actors funded the research performed at some point within the member’s participation in the DGAC. This could lead to potential bias in the nutritional research findings that are published in the DGA. Bias would cause incorrect nutrient information to be implemented into the lives of US citizens, negatively impacting their health.

Industry-Funded Research

Food and drink companies have also been influencing the public opinion on healthy foods by directly funding research. This often goes unnoticed, but some nutrition experts and advocates are attempting to expose industry-funded research and draw attention to the bias it introduces.

One expert who has gained popularity is Marion Nestle, a molecular biologist and nutritionist who teaches at NYU. On top of faculty positions at several universities, she has a background in policy from her position as senior policy advisor for the HHS. She regularly posts on her blog “Food Politics” to share how current events may affect the politics surrounding nutrition and food. Nearly once a week, Nestle gathers a piece of industry-funded research that is typically sent in by a reader or nutrition advocate. Of the first 168 studies that she reviewed, the results of 156 favored the funder. Reflective of these numbers, she claims that "funding exerts influence, whether recognized by researchers or not." Her goal in writing these posts is not to contradict or disprove the research, but to prompt her readers to question the importance of the results and validity of the source of similar nutrition news.

Nestle calls readers to “be skeptical about the importance of studies like this,” referring to a study showing the benefits of eating grapes while failing to mention other fruits that have similar benefits. Many industry-funded studies seem to follow this pattern: prove an amazing benefit of consuming a certain food or drink, which happens to be sold by a funder of the study, and fail to compare to any other foods that contain the same nutrients. A study done on the benefit of Concord grape juice provides a good example of this pattern. The study is funded by Welch Foods Inc, a major American grape juice brand, and claims that regular consumption of the juice can improve cognitive function and performance on complex daily tasks like driving. The study attributes these benefits to Concord grapes being flavonoid-rich. Although all studies that specifically mention Concord grapes and these benefits are in part funded by Welch’s, the idea that flavonoids contribute to cognitive functions seems to be widely accepted and supported by studies that are not industry-funded. However, these studies list numerous flavonoid-rich foods such as strawberries, oranges, celery, and peppers rather than emphasizing grapes as the Welch’s study did. Although the results of Welch's study may be reliable, it should be noted that it was funded by a group that would profit from increased grape juice sales and has motivation to overplay the importance of the study.

By presenting their product as the key to a healthy diet, companies like Welch’s are able to profit off Americans’ desire to live healthy lives. This is not necessarily a danger to the health of U.S. citizens, but it does raise doubts about the groups that are shaping Americans' nutrition views and what their agendas may be.

The Academy of Nutrition and Dietetics

Conflicts of interest in nutritional research involving the AND stem from its close financial ties with corporate sponsors, including major food, beverage and pharmaceutical companies. The AND is the largest organization of food and nutrition professionals in the world, representing over 100,000 registered dietitian nutritionists, researchers, and educators. Their mission is to advance public health and nutrition through research, education, and advocacy by providing evidence-based guidance on diet and health. However, its ties with sponsors have led to concerns that corporate funding may compromise the integrity of its research and public health recommendations. In 2013, Michele Simon critically examined the AND’s corporate sponsorship programing, highlighting how partnerships with companies such as Coca-Cola, PepsiCo, and McDonald’s may influence the organization’s educational content and public positions which could align the AND with corporate interests rather than public health priorities. Similarly, in 2022 a published study containing documents obtained through Freedom of Information Act (FOI) requests revealed practices such as accepting an undisclosed millions of dollars from food, pharmaceutical, and agribusiness companies and has invested in ultra-processed food company stocks. These financial ties raise concerns about conflicts of interest that may compromise the objectivity of the AND’s education materials and certification programs. In response to these allegations, the AND states that its procedures and agreements with external organizations are designed to prevent corporate influence, emphasizing that its programs, decisions, policies, and positions remain independent of sponsors . Overall, such practices highlight a potential compromise in the organization's objectivity and ultimately undermine public trust in its nutritional recommendations.

Conclusion and Recommendations

Conflicts of interest in U.S. nutrition research pose a significant challenge to the credibility and effectiveness of public health recommendations. The involvement of diverse stakeholders is essential for advancing the field but the potential for financial or personal relationships to influence research outcomes raises concerns about bias. The historical examples provided highlight the pressing need for greater transparency and accountability in nutritional science.

Future work could address several key areas. Expanding the discussion to explore the long-term impacts of conflicts of interest on public health outcomes would provide deeper insight into their significance. Incorporating a global perspective by comparing conflicts of interest in the U.S. with practices in other countries could offer valuable lessons from alternative approaches and their effectiveness. Additionally, integrating interviews or perspectives from a diverse range of stakeholders, including researchers, policymakers, industry representatives, and advocacy groups, could add depth and nuance to the discussion, creating a more comprehensive understanding of the issue and potential solutions.