Anti(angiogenic) food components: can be a major source of bias in the investigation of angiogenesis inhibitors

Abstract

Background Natural and diet-derived angiogenesis inhibitors/promotors are widely found in diets. These compounds can in several ways impact the results of oncological research of angiogenesis inhibitors. Methods We very briefly overview some of the most important examples to show how these compounds can create a bias in current research of cancer. Implications of this expert opinion cover similar angiogenesis-related diseases. Results Significant intra-individual differences in terms of dietary intake and differential effect of food processing techniques result in differential bioactivity and bioavailability of these compounds. There are only a handful of validated dietary questionnaire to quantify natural angiogenesis inhibitors/promotors. A corollary consequence is that participants in non-randomized clinical trials will have different baseline levels of serum/plasma/tissue/organ diet-derived angiogenesis inhibitors/promotors. This will lead to creation of clinical uncertainty and a hidden bias and consequently creation of translational efficiency bias, sampling efficiency, and waste of resources. We call for developing and validating a semi-quantitative food frequency questionnaire (FFQ) to gather data on these agents, specifically designed for oncological research because there is a clear gap in the literature of oncology. Conclusions This might facilitate the discovery of better prognostic, diagnostic, preventive measures, and therapeutic agents for the management of different cancers. Implications of this paper cover similar settings like ophthalmologic research.

Effect of nano-curcumin supplementation on angina status, and traditional and novel cardiovascular risk factors in overweight or obese patients with coronary slow flow phenomenon: a randomized double-blind placebo-controlled clinical trial

“…These differences in the results might be partly due to the higher efficacy of nano-curcumin, like many other treatments, to change cardiometabolic risk factors when the baseline values are impaired. Moreover, Rastmanesh et al recently showed that the intra-individual differences in terms of dietary intake and food processing techniques result in differential bioactivity and bioavailability of many antioxidants including curcumin and curcuminoids [ 62 ]. They also added that even randomization protocols or using cross-over or parallel designs cannot eliminate this source of bias [ 62 ].To our knowledge, dietary intakes of curcumin and curcuminoids have not been assessed in previous studies as well as the current trial.…”

“…Moreover, Rastmanesh et al recently showed that the intra-individual differences in terms of dietary intake and food processing techniques result in differential bioactivity and bioavailability of many antioxidants including curcumin and curcuminoids [ 62 ]. They also added that even randomization protocols or using cross-over or parallel designs cannot eliminate this source of bias [ 62 ].To our knowledge, dietary intakes of curcumin and curcuminoids have not been assessed in previous studies as well as the current trial. Serum concentrations of these compounds have not been evaluated, either; while the effects of these compounds are greatly influenced by their concentrations.…”