Antioxidants: A Premature Scientific Hypothesis that Reshuffled the Traditional Food Pyramid

Abstract

The curious story of dietary antioxidants, i.e., reducing agents found in considerable amounts in edible plants and often not necessarily understood fully in the context of redox chemistry, can be traced back to the famous statistical analysis of carcinogenic risk factors by Doll and Peto (1981). Their work revealed among others the positive correlation between cancer incidence and meat consumption. In particular, the statistical strength of meat's impact on human health created a kind of a shock that such an obvious component of the human diet may be as carcinogenic as cigarette smoke; unfortunately subsequent epidemiological studies were repeatedly confirming this worrisome association (WCRF/AICR 1997). The emerging results of consecutive statistical analyses derived from ever larger human studies, however, uncovered another, more optimistic association, i.e., a decreased risk of cancer (and also of other chronic diseases) in populations whose diets were rich in plant-based foods, especially in all types of colorful fruits and vegetables, and thus rich in (redox active) secondary metabolites (for sources see Explanatory Box 1).A. Bartoszek (*) Department of Food Chemistry, Technology and Biotechnology, Gdańsk University of Technology, Narutowicza Street 11/12, Gdańsk, Poland e-mail: agnieszka.bartoszek@pg.gda.pl Explanatory Box 1: Sources of Secondary MetabolitesSecondary metabolites are organic compounds that are not directly involved in the normal growth, development, or reproduction of the organism they originate from. They are found extensively in nature, especially, but not exclusively in plants, where they serve numerous and often diverse purposes,

More than Just Antioxidants: Redox-Active Components and Mechanisms Shaping Redox Signalling Network

“…At that time, the latter were gaining popularity at a pace. The number and variety of antioxidant products marketed after 2005 began to grow much faster [ 12 ] than the number of scientific articles published in the PubMed database with the term “antioxidant” among the keywords ( Figure 1 ). As a consequence, the commercial success of antioxidants preceded research on understanding their real effects on the body’s redox homeostasis.…”

“… The number of scientific articles published in the PubMed database in 1990–2019 with the term “antioxidant” and “functional food containing antioxidants” among the keywords compared to the number of products bearing information about the presence of antioxidants that were introduced to the market in 2005–2011 (on the basis of [ 12 ]). …”