Our website could not exist without the hundreds of scientific studies we review each month in the area of food, nutrition, and health. We depend on the latest research information for everything we tell you about the World's Healthiest Foods and their relationship to a healthy lifestyle. We work exclusively from scientific studies when we post information for you about nutrition and the unique health benefits that are provided by the World's Healthiest Foods and The Healthiest Way of Eating. When reporting information from these scientific studies, there are four aspects that we consider especially important: (1) understanding different types of research; (2) differentiating between studies on animals versus humans; (3) setting clear publication standards; and (4) maintaining a focus on food.
When it comes to scientific studies on food, nutrition, and health, one size does not fit all! Scientific studies are conducted in many different ways. The conclusions that we can draw from a scientific study depends not only on the quality of the study, since a study can be conducted with the utmost integrity and quality and still not be helpful in providing certain kinds of information. Our conclusions from a scientific study depend entirely upon the type of research that was conducted. For this reason, it's important to understand the basic types of research that are available for review and the kinds of conclusions that can and cannot be drawn from these different types of research that we review on our website. Epidemiologic research looks at the way things affect an entire population of people. In this type of study, researchers simply observe "what's going on." For example, "what's going on" could involve a disease and how often that disease was occurring. Researchers don't actively try out any particular approach to health when they conduct an epidemiologic study. Clinical trials are a type of research design that does involve trying out a particular approach to health. Clinical trials look at specialized groups of people rather than whole populations, and they seek to determine whether a particular approach to health might have benefits for a particular group of people. For example, researchers conducting a clinical trial might want to evaluate the possible benefits of high-fiber snacks for digestion and overall health in a group of teenage girls, or a group of adult males at risk for colon cancer. In vitro studies encompass other basic approaches to research that do not involve people at all. Instead, various aspects of food, nutrition, and health can be studied at a tissue or organ level, or even at the level of individual cellular activity. Particularly when a researcher is trying to understand a biochemical process inside the body, which is very important in the study of food and nutrition, it can be almost impossible to develop a precise understanding unless a large number of factors can be carefully isolated and controlled. Real, living people with trillions of cells and thousands of biochemical reactions taking place inside each cell are simply too complicated to analyze to draw insights into very specialized events occurring with the body's biochemistry. For this reason, in vitro studies can play a key role in the information about the connection between food, nutrients, metabolism, and health that we provide at the World's Healthiest Foods.
For anyone trying to interpret the results of a high-quality research study, the trick is matching the type of research with the type of conclusions that can and cannot be drawn from that type of research. From our perspective at the World's Healthiest Foods, it is impossible to draw general conclusions about a food and its health benefits from biochemical or cellular research alone. These types of research studies just don't lend themselves to practical conclusions about everyday health, foods, and meal plans. In order to draw practical conclusions in this area, we believe it is important to have research evidence from very broad epidemiologic studies on whole populations of real, everyday people. Controlled clinical trials can also be a great way of gaining information about specific foods and nutrients and their relationship to specific kinds of health problems. On the other hand, when we want to understand the underlying mechanisms that connect food and nutrients to our health, information from cellular and biochemical studies is usually essential.
Not only in the study of food, but also in the study of most every health-related lifestyle factor, the issue of animal versus human research has been one of ongoing controversy. The next section describes our approach at the World's Healthiest Foods to this "animals versus humans" research study issue.
Hundreds of important scientific studies become available each month offering diet-related research on both animals and humans. Animal studies typically involve rats or mice. Human studies typically involve individuals who share common health problems like diabetes or heart disease. We believe it's important for you to have information about any study that focuses on the World's Healthiest Foods and their potential health benefits. For this reason, you'll find information about both animal and human studies in sections of our website like our Breakthrough News feature. However, when it comes to the core informational components of our website—like our food and nutrient profiles—we never make general statements about the health benefits of a food based on animal studies alone. Similarly, in these core informational sections of our website, we never make general statements about a food's value based on a human study that has yet to be corroborated by one or more follow-up studies. In these core informational sections, we only present information that is backed by larger scale human studies. We believe that these larger scale human studies are needed to make food recommendations that apply to a wide variety of individuals.
In the world of research, there are many different types of studies available for review. For example, some studies have never been published in a professional journal. Although we may occasionally make exceptions for very high-quality unpublished studies, virtually all of the research presented on our website has been published in a scholarly journal. Even among published studies, however, there can sometimes be a vast difference in research quality. For this reason, and with some exceptions, we limit our review to studies that fall into a category called "indexed journal studies." The word "indexed" simply means that a research journal applied for inclusion in a special research collection with special scientific standards and was accepted to become a part of that research collection (or "index"). Indexed journal studies are typically peer-reviewed by scholars in the relevant subject area. The index we use most is the MEDLINE index established by the U.S. National Library of Medicine. Approximately 5,000 research journals are currently indexed in MEDLINE.
In addition to the issue of indexed journal standards in the publication of scientific research, a common issue in the publication of scholarly studies is the role of commercial funding. Within the United States, approximately 65% of all scientific studies in the area of health are currently funded in full or in part by companies or corporations; only 35% are funded exclusively through public funds. While organizations as well-informed as the National Academy of Sciences have publicly questioned this balance of public and private funding in the pursuit of health science research, the fact remains that approximately two-thirds of all health science information has been gathered with the help of private money. This body of knowledge is far too valuable for anyone interested in health science to ignore, and we make extensive use of privately-funded studies at the World's Healthiest Foods. At the same time, however, we receive no funding of any kind from any private company or corporation, and we are absolutely independent in our ability to evaluate the scientific research, discard studies that appear compromised to us by conflict of interest, and only present information to you that meets high standards of research credibility. Many privately-funded studies meet these very high standards, even when for-profit motives have been involved in the initial funding.
Many studies in the area of nutrition and health are studies that do not involve food. Sometimes food extracts are prepared by companies that conduct research on dietary supplements. Sometimes processed food components are used to enrich animal feeds. Since we do not believe that research practices of this kind can be counted on to provide helpful information about the routine eating of whole, natural foods, we do not use them as the basis for our recommendations to you about the World's Healthiest Foods. We might, however, use research information of this kind to keep you up to date on current trends in food-related research and to pinpoint areas of special interest that may pay special dividends in the future with respect to the World's Healthiest Foods and their amazing health benefits.
National Academies Press. (2007). Rising Above the Gathering Storm: Energizing and Employing America for a Brighter Economic Future. Committee on Prospering in the Global Economy of the 21st Century: An Agenda for American Science and Technology, National Academy of Sciences, National Academy of Engineering, Institute of Medicine, Washington, D.C. Available online at: http://www.nap.edu/catalog.php?record_id=11463