An Interview with Dr. Javier Ottaviani on the importance of biomarkers when undertaking and interpreting nutrition research
Today we are talking to Dr. Javier Ottaviani, Director of the Mars Edge Core Laboratory, about the latest paper in collaboration with the team of Prof. Gunter Kuhnle, Professor of Nutrition and Food Science at the University of Reading, U.K.
The paper, “Reliance on self-reports and estimated food composition data in nutrition research introduces significant bias that can only be addressed with biomarkers,” was published in eLife recently.
Dr. Ottaviani’s research focuses on understanding the nutritional relevance of bioactive compounds and their impact on disease prevention and health, as well as the development, evaluation and application of nutritional biomarkers.
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Welcome, Dr. Ottaviani. I understand your new paper explores different methodologies in nutrition research and their impact on outcomes. Can you tell us more?
Nutrition research is critical for understanding the links between diet and health, and significant advancements have been made in the last decades to enable and shape dietary guidance in support of public health. Key to this progress were methods that allowed researchers to estimate people’s consumption of foods and specific nutrients, and to study if and how diet may be associated with health and disease. Traditional methods pose challenges because they depend on subjective, self-reported data on food consumption, as well as on complex, but limited, food composition databases. Because of this, traditional approaches carry inherent limitations on the reliability and strength of the insights generated. While this has been known for some time, the degree by which these limitations potentially impact the outcomes of nutrition research remains largely unknown and has not previously been studied or quantified at scale.
That sounds interesting. What did this study look at?
We compared two different methods to measure nutrient intake in more than 18,000 study participants: the traditional method of combining self-reported diet data with food composition databases, and a newly developed approach based on the use of nutritional biomarkers. Nutritional biomarkers are based on compounds produced by the body after food has been absorbed and metabolized. Therefore, they can provide a more accurate and objective measurement of nutrient consumption.
To compare the two methods, we looked at three different food compounds: flavanols and epicatechin, which are found in foods such as tea, apples and berries; and nitrate, which is found in foods such as beetroot. It had previously been demonstrated that the intake of these compounds in clinical dietary intervention trials is linked to lower blood pressure, and we investigated if we could confirm these findings using large-scale data sets from observational studies on peoples’ diets.
What did the findings show?
The results from our study showed very little agreement between the traditional method and objectively measured nutrient intake based on biomarkers. When using nutritional biomarkers, we found a strong link between intake and lower blood pressure — but this finding was absent when using self-reported diet and food composition data from the same group of people.
What are the implications of these findings?
Current tools used to assess nutrient intake in nutrition science have limitations and can pose challenges in accuracy related to self-reported data. In addition, food content databases cannot accurately account for nutrient variability in food.
These findings show that nutritional biomarkers help solve this challenge, because biomarkers can provide unbiased data on nutrient intake, which will allow for improved accuracy and objectivity of nutrition and health insights. This will have a great impact on future research and dietary recommendations.
One last question: Why were you interested in researching biomarkers in the first place?
At Mars, we have been researching the impact of flavanols on health for over twenty years. Critical to this understanding has been a long-term collaboration with scientists at the University of Reading to analyze and assess how flavanols are absorbed and metabolized in the human body. Through this research, we have identified and validated several human metabolites that could be used as nutritional biomarkers objectively measuring flavanol consumption without the limitations of traditional approaches.
Our collaboration with Brigham and Women’s Hospital on the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) offers a unique opportunity to apply the biomarker approach to a long term, randomized, controlled dietary intervention trial. COSMOS-Web, an ancillary trial under COSMOS, used the biomarkers we developed for biomarker-based assessment of habitual flavanol consumption in the context of cognitive aging. This was critical to enabling our collaborators at Columbia University, who led COSMOS-Web, to determine that flavanols work to support memory and cognition during normal cognitive aging.
