Association between Phytate Intake and C-Reactive Protein Concentration among People with Overweight or Obesity: A Cross-Sectional Study Using NHANES 2009/2010

Perspective: Plant-based Whole-Grain Foods for Chronic Kidney Disease: The Phytate-Phosphorus Conundrum

Restriction of dietary phosphorus intake is an important component of good clinical practice in kidney failure patients, particularly after dialysis initiation. Greater consumption of predominantly plant-based diets, including phytate-rich foods, is increasingly recommended for health maintenance/disease prevention in this population, with the implicit assumption that phytate-phosphorus in whole-grain cereals, legumes, pulses, and nuts is poorly absorbed. Review of human interventions with diets high in phytate-phosphorus indeed suggests an absorption of at least 50%, still less than animal protein-bound phosphorus, but higher than the generally believed 10-30%. Factors largely ignored up to now, but of potential influence on phytate-phosphorus bioavailability, include effect of food processing in releasing phosphorus, action of colonic bacteria that are able to release inorganic phosphorus, and capacity of the colon to absorb phosphorus. These issues may become increasingly important as new plant-based alternatives to meats, all containing phytate, are being rapidly introduced in the market.

Estimated Phytate Intake Is Associated with Improved Cognitive Function in the Elderly, NHANES 2013-2014

Phytate, an antioxidant, may improve cognition by inhibiting iron catalyzed hydroxyl radical formation. Particularly in the elderly, this provides a potential dietary approach for mitigating age-related brain neuronal dysfunction and loss. In this study, we investigated the relationship between phytate intake and cognitive function in the elderly. We used data from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) and the corresponding Food Patterns Equivalents Database (FPED). Phytate content of food groups from published data were merged with the appropriate FPED data to estimate the total phytate intake for each subject. Principal component analysis was used to develop a composite score from four cognitive function scores in NHANES data, and regression analysis was used to determine the relationship between this score and phytate intake. Median phytate intake was 0.65 (0.61, 0.71) g/day. It was low among females, non-Hispanic blacks, and people with history of at least one chronic disease (p < 0.05). In regression analysis adjusted for confounders, phytate intake was positively associated with cognitive function (β (95% CI) = 1.90 (0.73-3.07); p = 0.015). These results suggest that phytate may be associated with improved cognition, hence the need to consider including phytate-rich foods in the diet among the elderly.

Salivary cystatin SN is a factor predicting iron bioavailability after phytic acid rich meals in female participants

Phytic acid is an inhibitor of iron bioavailability, but it has been suggested that individuals may adapt to phytic acid over time, and that the salivary protein, cystatin SN, may be involved. This study evaluated the relationship between human cystatin SN levels and iron bioavailability after a phytic acid rich meal. Three groups of ten women consumed meals with: (1) 500 mg phytate sprinkles, (2) 500 mg phytate capsules, or (3) no phytic acid. Iron bioavailability was measured by the mealtime percentage of maximum iron recovery; cystatin SN was measured pre-and post-meal by enzyme-linked immunosorbent assay. Pre-to-post meal cystatin SN was positively correlated with improved iron bioavailability in group 1. Pre-to-post meal cystatin SN was correlated with improved iron absorption in groups 1 and 2. Cystatin SN recovery after phytic acid rich meals may be a physiological factor predicting iron bioavailability.

Chemoprotective effects of inositol hexaphosphate against cyclophosphamide-induced testicular damage in rats

Cyclophosphamide (CP) is commonly used as an anticancer agent but has been associated with high toxicity in several animal organs, including the testes. Inositol hexaphosphate (IP6) is a polyphosphorylated carbohydrate that is present in foods with high fibre contents and has a wide range of essential physiological and pathological activities. Thus, we estimated the defensive effects of IP6 against CP-related testicular toxicity in rats. Sperm counts, motilities, viabilities and abnormalities and levels of testosterone, luteinising hormone and follicle-stimulating hormone were evaluated. Testicle specimens were also processed for histological and biochemical analyses, including determinations of malondialdehyde, nitric oxide, total antioxidant capacity, alkaline phosphatase, acid phosphatase, gamma glutamyl transferase, ß-glucuronidase, c-reactive protein, monocyte chemoattractant protein and leukotriene-4 and in comet assays. CP treatments were associated with deleterious histopathological, biochemical and genetic changes in rat testicles, and these were ameliorated by IP6 supplements in drinking water.