In a recent study published in the Signal Transduction and Targeted Therapy journal, researchers assessed the impact of dietary regulation on human health and disease.
Adequate proportions of nutritional treatment play an essential role in lengthening lifespan as well as delaying the aging process in several species including drosophila, yeast, primate, rodent, and human. Therefore, there is immense potential in the development of precision-nutrition therapeutics against age-related biological mechanisms and several diseases.
Dietary intervention in human health and disease
In the present study, researchers summarized the various forms of dietary regulations prescribed for the improvement of human lifespan and the treatment of different diseases in clinical or pre-clinical.
Since diet-mediated signaling has been detected in the entire human body, the effects of diet interventions are assumed to be incidental in all organs and tissues. Nutrients impact human tissues to different degrees and in several ways, which have been demonstrated to treat diseases while improving the therapeutic effect. The team elaborated on the mechanisms that help dietary interventions aid precision-nutrition therapeutics.
Various studies have shown the impact of overnutrition on the acceleration of disease progression, including type 2 diabetes and obesity. Several diseases such as cardiovascular disease (CVD), cancer, diabetes, and non-alcoholic fatty liver disease (NAFLD) have been positively associated with obesity. A fat-rich diet along with excessive consumption of branched-chain amino acids (BCAAs), methionine, and tryptophan and its metabolites, have resulted in obesity-associated diseases and weight gain. Calorie restriction (CR) has been observed to decrease the concentrations of gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) in healthy adults and improve liver function.
Moreover, alternating prolonged fasting (PF) reduced high-risk factors associated with aging-related diseases and cancer. In comparison to controls, time-restricted feeding (TRF) results in a significant reduction in oxidative stress and insulin resistance while improving the cardiometabolic health of patients suffering from metabolic syndrome. Additionally, an every-other-day fasting (EODF) routine remarkably mitigated NAFLD, obesity, and insulin resistance.
The team noted that the effects of TRF on the reduction of body fat and body weight were not more than that observed with daily CR among obese individuals. Hence, alternating the nutrition components was deemed a feasible mechanism to treat the metabolic syndrome. BCAA restriction was also found to enhance the health of obese and non-obese persons. Overall, the team observed a clear association between metabolic disorders and nutritional interventions, which can be utilized as an adjuvant treatment approach for metabolic syndromes.
High fat or salt diets and diets having high concentrations of BCAAs pose as high-risk factors for cardiovascular diseases (CVDs). Dietary intake of BCAAs has been found to notably facilitate platelet activation, thus increasing the risks associated with CVD and arterial thrombosis. A study has shown the impact of CR in reducing the adverse effects of CVD while enhancing cardiac function along with the decline in cholesterol concentrations. Triglyceride, and low-density lipoproteins (LDLs). A potential mechanism used by CR is the reduction of free leptin by CR into plasma which reverses the process of myocardial hypertrophy and decreases lipid accumulation. The team also noted that CR reduced fibrosis, oxidative stress, myocyte hypertrophy, and cardiac inflammation in mice.
A five-day fasting-mimicking diet (FMD) has been also shown to improve subcutaneous and visceral fat loss and prevent the impairment of cardiac function and vascularity due to obesity. Furthermore, consumption of a high-fiber diet elevates the richness of microbial communities like Bacteroides acidifaciens generated by short-chain fatty acids (SCFAs).
Digestive disorders like Crohn's disease and colitis are regulated using nutritional therapies. For example, long-term consumption of red meat has been correlated to an increased risk of experiencing digestive disorders. The N-glycolylneuraminic acid (Neu5Gc) found in red meat is a potential factor in promoting disorders and carcinomas due to inflammation. In active Crohn’s disease in humans, ω−3 and ω−6 polyunsaturated fatty acids (PUFAs) elicit the expression of chemokines in epithelial cells, leading to the activation of toll-like receptor 2 (TLR2). Dietary restriction has also been found to enhance intestinal barrier function and ensure intestinal homeostasis and alter the intestinal microbiome.
Dietary interventions also influence renal functionality as protein intake has been found to exacerbate the risk factors associated with chronic kidney disease (CKD) among mice models. High intake proteins increased concentrations of uraemic toxins including indole, microbial indoxyl sulfate, and hydrogen sulfide. Excessive dietary intake of salt also potentially worsens symptoms related to renal diseases. Recent research has reported that the restriction of dietary protein reduced the excretion of renal ammonia via alterations in ammonia metabolism.
Overall, the study findings showed that nutritive intervention could be an effective treatment method in maintaining human health and counteracting morbidities.