Our most recent column drew comments challenging our interpretation of the proposed effects of carnitine in beef on cardiovascular disease. Certainly, challenges move scientists to strive for correctness and truth rather than trying to be “right” in their beliefs. In this context, we thought our readers should know who we are scientifically and how we decide on topics to write about and positions to take in our column for the Star-Advertiser.
Question: Who are you scientifically?
Answer: Both of us were trained in nutritional sciences at the University of California at Davis, earning doctoral degrees in nutrition. Our academic minors focused on physiology and metabolism. Our overall focus over the years has been on understanding nutrient functions and the effects of nutrient deficiencies on human physical and mental performance.
We are not journalists by training. However, as faculty in the field of nutrition at the University of Hawaii at Manoa, part of our work involves translating nutrition science for public consumption. To do this, we focus primarily on “cause and effect” types of scientific research and place less emphasis on studies that show statistical associations between nutrients and diseases that may or may not be linked by cause and effect. In contrast to our columns, much of the health journalism in popular media is based on correlational studies rather than research showing cause-and-effect relationships.
Q: Why is there so much confusion about nutrition?
A: We all have beliefs that are based on our life experience, and we like to think those beliefs represent “the truth.” We all eat food and have personal beliefs about what is good, bad or indifferent. Ultimately, we each need to be our own expert about what should go into our mouths. Consequently, what is accepted as popular nutrition “truth” comes largely from a consensus of popular beliefs.
In science, truth is based on facts and reality as much as possible and on the best information available. However, it is human nature to have biases that lead us to seek support for what we already believe. Unfortunately, this can lead to the phenomenon of “truth by consensus.” Just like a snowball rolling downhill, misinformation that takes on a growing mantle of “truth” can be harmful to the progression of science, the health of individuals and society at large.
Q: Are there examples of popular misinterpretations of nutrition science?
A: A common misconception is that dietary cholesterol is a primary cause of heart disease. Although blood cholesterol is correlated with heart disease risk, reputable scientific research spanning more than 50 years shows that dietary cholesterol raises blood cholesterol only slightly. The relative risk of heart disease due to the cholesterol in foods is inconsequential to the majority of people. Smoking, excess body fat, inactivity and stress play significantly greater roles in increasing blood cholesterol and the risk of heart disease.
Q: How do we decide on what positions we take?
A: We do our best to base our writing on what we consider to be the soundest science. When we first started writing this column in 1997, we had both consumed a vegetarian diet for more than a couple of decades. Despite our personal choice of eating style at that time, we never used this column to promote our belief in vegetarianism because we perceived a lack of critical scientific support. As we continue to write this column as omnivores, we continue to strive to base our content on scientific objectivity as much as possible.
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Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dobbs also works with University Health Services.
