‘Nutrition transition’ heightens risk of metabolic malfunction: Review

Findings from a Canadian team have outlined the metabolic changes seen at the cellular level resulting from long-term consumption of these foods.

While these mechanisms are initially an adaptive strategy, the researchers believe the changes ultimately lead to metabolic dysfunction.

“Both nutrient deficiency (undernutrition) and nutrient excess (over-nutrition) cause the loss of nutrient/energy homeostasis and thus trigger cellular stress,”​ the review outlined.  

“Stress coping response mechanisms initially promote adaptive strategies to recover homeostasis in the short term but become pathogenic in the long term due to long-term modification of cellular functions.”​

Many metabolic diseases caused by micronutrient deficiencies can be corrected by restoring the missing micronutrients in the diet.

Indeed, the team, based at McGill University in Canada, discuss the effectiveness of single nutrient interventions such as fortification of milk with vitamin D, cereal with iron, and table salt with iodine and its effectiveness in treating the corresponding nutrient deficiencies.

However, the team highlight an inconclusive outcome when this approach is applied to acquired metabolic syndromes such as fatty liver disease and cardiovascular diseases that prevail in modern societies.

Extrinsic factors affecting metabolism​

The team also discuss the impact of extrinsic factors that may contribute, including non-nutrient components of foods such as fibre and certain types of plant polyphenolic compounds.

While dietary fibre, derived from plant-based foods, is not an effective nutrient for humans, it ably serves as a prebiotic for gut microflora.

Such is its influence the team thought the gut microbiota could be capable of altering the susceptibility of its host to metabolic diseases, by transforming these non-nutrient components into useful nutrients for the host.

“Short-chain fatty acids produced from breakdown of dietary fibres can influence the expression of genes involved in proliferation and differentiation of mammalian colonic epithelial cells,”​ the review satted.

Plant polyphenolic compounds or antioxidants also emerged as influencing the composition and metabolic activity of gut microbiota.

However, the team pointed out that not all polyphenolic compounds are beneficial, citing compounds such as caffeic acid and genistein as likely carcinogenic or genotoxic at high dosage.

Rise of the ‘Omics’​

Critical to finding ways of alleviating hunger and improving nutrition and health status is the technologies used in the study of metabolism and nutrition.

The ‘Omics’ technologies (genomics, transcriptomics, proteomics, and metabolomics) have emerged as a rich source of information needed to advance personalised nutrition, providing new insights into nutrient metabolism in humans.

“Fortunately, suites of mature bioinformatics tools and the necessary computing power are now available to decipher these data and infer relationships among genomes, metabolic processes, and cellular functions that are relevant to health and disease,”​ the review outlined.

The team added that a coordinated strategy may prove useful in integrating this mechanistic and descriptive information to generate insights that could go on to formulate recommendations for optimal human nutrition and health.

“Recent advances in high-throughput analyses, creation of animal models of human metabolic diseases and bioinformatic tools hold promise for accelerating the process of formulating more effective nutritional recommendations,”​ the review concluded.

“In the meantime, consumption of foods with low-energy density and high nutrient diversity seems to be a prudent approach for minimizing cellular stress and the promotion of optimal cellular function and health.”​

Source: The Yale Journal of Biology and Medicine​

Published online ahead of print: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6020734/​​

“Importance of Nutrients and Nutrient Metabolism on Human Health.”​

Authors: Yiheng Chen, Marek Michalak, and Luis B. Agellon