Health-Promoting Opportunities of Hemp Hull: The Potential of Bioactive Compounds.

Hemp hull is the outer coat of the hemp seed, derived from the plant Cannabis sativa L., Cannabaceae. While much attention has been paid to hemp seed for its oil, protein and micronutrient content, far less attention has been given to hemp hull, a side stream of hemp processing. Hemp hull is a source of bioactive compounds, dietary fiber, minerals as well as protein, lipids and carbohydrates. Of note, two bioactive compounds, n-trans-caffeoyltyramine and n-trans-feruloyltyramine have been identified in hemp hull as key bioactive compounds that support gut health, liver function and other physiological processes. Both of these compounds were identified as agonists of the transcription factor, hepatic nuclear factor-4 alpha which has been implicated in gene expression that governs gut permeability, factors associated with inflammatory bowel diseases, and hepatic lipid homeostasis. Additionally, the dietary fibers in hemp hull have been demonstrated to be novel prebiotics, which may further amplify hemp hull's effect on gut health and metabolic health. This review article summarizes the nutritional content of hemp hull, explores the physiological effects of bioactive compounds found in hemp hull, and identifies opportunities for further research on hemp hull for human health benefit.

Beyond Insoluble Dietary Fiber: Bioactive Compounds in Plant Foods.

Consumption of plant foods, including whole grains, vegetables, fruits, pulses, nuts, and seeds, is linked to improved health outcomes. Dietary fiber is a nutrient in plant foods that is associated with improved health outcomes, including a lower risk of chronic diseases such as cardiovascular disease, type 2 diabetes, and certain cancers. Different fibers deliver different health benefits based on their physiochemical properties (solubility, viscosity) and physiological effects (fermentability). Additionally, plant foods contain more than dietary fiber and are rich sources of bioactives, which also provide health benefits. The concept of the solubility of fiber was introduced in the 1970s as a method to explain physiological effects, an idea that is no longer accepted. Dividing total dietary fiber (TDF) into insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) is an analytical distinction, and recent work finds that IDF intake is linked to a wide range of health benefits beyond increased stool weight. We have focused on the IDF content of plant foods and linked the concept of IDF to the bioactives in plant foods. Ancestral humans might have consumed as much as 100 g of dietary fiber daily, which also delivered bioactives that may be more important protective compounds in disease prevention. Isolating fibers to add to human diets may be of limited usefulness unless bioactives are included in the isolated fiber supplement.

Protective Effects of Micronutrient Supplements, Phytochemicals and Phytochemical-Rich Beverages and Foods Against DNA Damage in Humans: A Systematic Review of Randomized Controlled Trials and Prospective Studies.

Accumulation of deoxyribonucleic acid (DNA) damage diminishes cellular health, increases risk of developmental and degenerative diseases, and accelerates aging. Optimizing nutrient intake can minimize accrual of DNA damage. The objectives of this review are to: 1) assemble and systematically analyze high-level evidence for the effect of supplementation with micronutrients and phytochemicals on baseline levels of DNA damage in humans, and 2) use this knowledge to identify which of these essential micronutrients or nonessential phytochemicals promote DNA integrity in vivo in humans. We conducted systematic literature searches of the PubMed database to identify interventional, prospective, cross-sectional, or in vitro studies that explored the association between nutrients and established biomarkers of DNA damage associated with developmental and degenerative disease risk. Biomarkers included lymphocyte chromosome aberrations, lymphocyte and buccal cell micronuclei, DNA methylation, lymphocyte/leukocyte DNA strand breaks, DNA oxidation, telomere length, telomerase activity, and mitochondrial DNA mutations. Only randomized, controlled interventions and uncontrolled longitudinal intervention studies conducted in humans were selected for evaluation and data extraction. These studies were ranked for the quality of their study design. In all, 96 of the 124 articles identified reported studies that achieved a quality assessment score ≥ 5 (from a maximum score of 7) and were included in the final review. Based on these studies, nutrients associated with protective effects included vitamin A and its precursor ß-carotene, vitamins C, E, B1, B12, folate, minerals selenium and zinc, and phytochemicals such as curcumin (with piperine), lycopene, and proanthocyanidins. These findings highlight the importance of nutrients involved in (i) DNA metabolism and repair (folate, vitamin B12, and zinc) and (ii) prevention of oxidative stress and inflammation (vitamins A, C, E, lycopene, curcumin, proanthocyanidins, selenium, and zinc). Supplementation with certain micronutrients and their combinations may reduce DNA damage and promote cellular health by improving the maintenance of genome integrity.

Multivitamin/Multimineral Supplement Use is Associated with Increased Micronutrient Intakes and Biomarkers and Decreased Prevalence of Inadequacies and Deficiencies in Middle-Aged and Older Adults in the United States.

Micronutrient inadequacies are common in older adults and using a multivitamin/multimineral supplement (MVM) may improve their nutritional status. National Health and Nutrition Examination Survey data were analyzed to determine micronutrient intakes based on diet and MVM use in adults aged ≥51 years. Deficiencies were evaluated using nutrient biomarkers. The National Cancer Institute Method was used to estimate usual intakes of 18 micronutrients stratified by age and frequency of MVM use. Compared with food alone, MVM use was associated with higher nutrient intake and lower prevalence of inadequacies of almost all micronutrients examined and improved nutrient biomarker status of folate, iodine, selenium, and vitamins B6, B12, and D. Regular MVM use (≥16 days/month) decreased the odds of clinical deficiency (defined by biomarker status) of vitamins B6 and D but increased the proportion exceeding the tolerable upper intake level of folic acid. Vitamin B6 deficiency in MVM non-users was common and increased with age.

Reformulating cereal bars: high resistant starch reduces in vitro digestibility but not in vivo glucose or insulin response; whey protein reduces glucose but disproportionately increases insulin.

BACKGROUND: Resistant starch (RS) and whey protein are thought to be effective nutrients for reducing glycemic responses. OBJECTIVE: We aimed to determine the effect of varying the sucrose, RS, and whey protein content of cereal bars on glucose and insulin responses. DESIGN: Twelve healthy subjects [mean ± SD age: 36 ± 12 y; mean ± SD body mass index (in kg/m2): 24.9 ± 2.7] consumed 40 g available-carbohydrate (avCHO) portions of 5 whole-grain cereal bars that contained varying amounts of RS and whey protein concentrate [WPC; 70% protein; RS:WPC, %wt:wt: 15:0 (Bar15/0); 15:0, low in sucrose (Bar15/0LS); 15:5 (Bar15/5); 10:5 (Bar10/5); and 10:10 (Bar10/10)] and 2 portion sizes of a control bar low in whole grains, protein, and RS [control 1 contained 40 g avCHO (Control1); control 2 contained total carbohydrate equal to Bar15/0LS (Control2)] on separate days by using a randomized crossover design. Glucose and insulin responses in vivo and carbohydrate digestibility in vitro were measured over 3 h. RESULTS: Incremental area under the curve (iAUC) over 0-3 h for glucose (min × mmol/L) differed significantly between treatments (P < 0.001) [Bar15/0LS (mean ± SEM), 169 ± 14; Control2, 164 ± 20; Bar15/0, 144 ± 15; Control1, 140 ± 17; Bar10/5, 117 ± 12; Bar15/5, 116 ± 9; and Bar10/10, 100 ± 9; Tukey's least significant difference = 42, P < 0.05], but insulin iAUC did not differ significantly. Higher protein content was associated with a lower glucose iAUC (P = 0.028) and a higher insulin-to-glucose iAUC ratio (P = 0.002) All 5 RS-containing bars were digested in vitro ∼30% more slowly than the control bars (P < 0.05); however, in vivo responses were not related to digestibility in vitro. Glucose and insulin responses elicited by high-RS, whey protein-free bars were similar to those elicited from control bars. CONCLUSIONS: The inclusion of RS in cereal bar formulations did not reduce glycemic responses despite slower starch digestion in vitro. Thus, caution is required when extrapolating in vitro starch digestibility to in vivo glycemic response. The inclusion of whey protein in cereal bar formulations to reduce glycemic response requires caution because this may be associated with a disproportionate increase in insulin as judged by an increased insulin-to-glucose iAUC ratio. This trial was registered at clinicaltrials.gov as NCT02537587.

Effect of serving size and addition of sugar on the glycemic response elicited by oatmeal: A randomized, cross-over study.

BACKGROUND & AIMS: We aimed to determine the impact of serving size and addition of sucrose on the glycemic response elicited by oatmeal. METHODS: We studied 38 healthy subjects (mean ± SD age 40 ± 12 yr, BMI 26.4 ± 3.6 kg/m2) on 8 separate days using a randomized, cross-over design. Capillary blood-glucose responses over 2hr after consuming 30, 40 and 60 g Classic Quaker Quick Oats (18, 24 and 36 g available-carbohydrate [avCHO], respectively) and 30 g Oats plus 9 g sucrose (27 g avCHO) were compared with those after avCHO-matched servings of Cream of Rice cereal (Control) (22, 29, 44 and 33 g cereal, respectively). Blood-glucose incremental area under the curve (iAUC), peak-rise, rate-of-decline, time-to-peak and time-to-baseline were calculated. RESULTS: As serving size increased, iAUC, peak-rise, rate-of-decline and time-to-baseline increased significantly for both cereals, but the rate of increase was significantly greater for Control than for Oats. Time-to-peak increased significantly with serving size only for Oats. Compared to avCHO-matched servings of Control, mean (95%CI) iAUC, peak-rise and rate-of-decline, respectively were 22 (16, 27)%, 22 (19, 26)% and 23 (18, 27)% lower after consuming Oats without sucrose and 26 (18, 34)%, 14 (9, 20)% and 16 (9, 24)% lower after consuming Oats plus sucrose. CONCLUSIONS: Oatmeal elicited a significantly lower glycemic response than avCHO-matched servings of Cream of Rice, even when sucrose was added to the oatmeal. Measures of glycemic response tended to increase with increased serving size; although the pattern of change varied between cereal types. These results suggest that oatmeal may be a good choice for minimizing postprandial glycemia. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov (NCT02506972).

Instant Oatmeal Increases Satiety and Reduces Energy Intake Compared to a Ready-to-Eat Oat-Based Breakfast Cereal: A Randomized Crossover Trial.

BACKGROUND: Foods that enhance satiety can help consumers to resist environmental cues to eat and help adherence to calorie restriction. The objective of this study was to compare the effect of 2 oat-based breakfast cereals on appetite, satiety, and food intake. METHODS: Forty-eight healthy individuals, 18 years of age or older, were enrolled in a randomized, crossover trial. Subjects consumed isocaloric servings of either oatmeal or an oat-based ready-to-eat breakfast cereal (RTEC) in random order at least a week apart. Visual analogue scales measuring appetite and satiety were completed before breakfast and throughout the morning. Lunch was served 4 hours after breakfast. The physicochemical properties of oat soluble fiber (ß-glucan) were determined. Appetite and satiety responses were analyzed by area under the curve. Food intake and ß-glucan properties were analyzed using t tests. RESULTS: Oatmeal increased fullness (p = 0.001) and reduced hunger (p = 0.005), desire to eat (p = 0.001), and prospective intake (p = 0.006) more than the RTEC. Energy intake at lunch was lower after eating oatmeal compared to the RTEC (p = 0.012). Oatmeal had higher viscosity (p = 0.03), ß-glucan content, molecular weight (p < 0.001), and radius of gyration (p < 0.001) than the RTEC. CONCLUSIONS: Oatmeal suppresses appetite, increases satiety, and reduces energy intake compared to the RTEC. The physicochemical properties of ß-glucan and sufficient hydration of oats are important factors affecting satiety and subsequent energy intake.

Toward a more standardised and accurate evaluation of glycemic response to foods: recommendations for portion size calculation.

This study aimed at evaluating the adequacy of calculation methods for portions to be provided to subjects in clinical trials evaluating glycemic response to foods. Portion sizes were calculated for 140 food samples, based on Nutrition Facts labels (current practice) and actual available carbohydrate content (current recommendation), and compared against the amount of monosaccharides yielded by the digestive breakdown of their actual available carbohydrate content (basis for glycemic response to food). The current practice can result in significant under- or over-feeding of carbohydrates in 10% of tested cases, as compared to the targeted reference dosage. The method currently recommended can result in significantly inadequate yields of monosaccharides in 24% of tested cases. The current and recommended calculation methods do not seem adequate for a standardised evaluation of glycemic response to foods. It is thus recommended to account for the amount of absorbable monosaccharides of foods for portion size calculation.

Oats, more than just a whole grain: an introduction.

In May 2012, an oats workshop was held in New York to convene a group of international experts to discuss the implications and applications of oats relative to human health. These diverse experts represented disciplines including, but not limited to, epidemiology, food regulation, nutrition and food science, grain breeding and plant genetics, food processing, medicine and public-health policy. This ensuing series addresses three important aspects pertinent to oats: a brief overview of the dynamics of oats; the spectrum of established and emerging research in agriculture and health; and the options and opportunities for future applications of oats that extend beyond dietary fibre. Oats have many unique chemical properties, potential health benefits, agricultural challenges and nutrition-policy opportunities ­ but global production of oats appears to be falling. This is occurring despite contemporary research in the development of drought and infestation resistance and climate-adaptive cultivars and assessments of oats' unique components (such as dietary fibre, lipids, ß-glucan and avenanthramides) that may contribute to health benefits. This suggests that oats represent a promising grain in the whole-grains landscape. New insights have been created into benefits beyond cardiovascular health. Modern milling and processing technologies have been developed to retain the nutritive value and functional properties of oats and to assure a consistent foundation for global health policies.

The future of oats in the food and health continuum.

A large body of clinical evidence suggests that the consumption of 3 g or more per d of ß-glucan from oats or barley, as part of a diet low in saturated fat and cholesterol, may reduce the risk of CHD. The unique chemical and physical properties of oats and physiological responses to oat consumption contribute to their demonstrated health benefits; other health attributes are still under evaluation. Many of these benefits, such as those associated with a reduced risk of CVD, are codified in health claims by several regulatory agencies, such as the Food and Drug Administration in the USA and the European Food Safety Authority in Europe. Despite these oat-health relationships, an apparent decline in agricultural production, the presence of an array of plant pathogens, and dynamics of climatic conditions may preclude the availability and subsequent consumption of this commodity worldwide. Therefore, it is incumbent on scientists from multiple disciplines to advance research in a spectrum of arenas, including physico-chemical properties of oats, the impact of oats on an array of non-communicable diseases and human microbiome, agricultural practices and environments, and processing technologies that contribute to global food policies.

Acute effect of oatmeal on subjective measures of appetite and satiety compared to a ready-to-eat breakfast cereal: a randomized crossover trial.

OBJECTIVE: The physicochemical properties of soluble oat fiber (ß-glucan) affect viscosity-dependent mechanisms that influence satiety. The objective of this study was to compare the satiety impact of oatmeal with the most widely sold ready-to-eat breakfast cereal (RTEC) when either was consumed as a breakfast meal. METHODS: Forty-eight healthy individuals ≥18 years of age were enrolled in a randomized crossover trial. Following an overnight fast, subjects consumed either oatmeal or RTEC in random order at least a week apart. The breakfasts were isocaloric and contained 363 kcal (250 kcal cereal, 113 kcal milk). Visual analogue scales measuring appetite and satiety were completed before breakfast and throughout the morning. The content and physicochemical properties of oat ß-glucan were determined. Appetite and satiety responses were analyzed by area under the curve (AUC). Physicochemical properties were analyzed using t tests. RESULTS: Oatmeal, higher in fiber and protein but lower in sugar than the RTEC, resulted in greater increase in fullness (AUC: p = 0.005 [120 minute: p = 0.0408, 180 minute: p = 0.0061, 240 minute: p = 0.0102]) and greater reduction in hunger (AUC: p = 0.0009 [120 minute: p = 0.0197, 180 minute: p = 0.0003, 240 minute: p = 0.0036]), desire to eat (AUC: p = 0.0002 [120 minute: p = 0.0168, 180 minute: p < 0.0001, 240 minute: p = 0.0022]), and prospective intake (AUC: p = 0.0012 [120 minute: p = 0.0058, 180 minute: p = 0.006, 240 minute: p = 0.0047]) compared to the RTEC. Oatmeal had higher ß-glucan content, higher molecular weight (p < 0.0001), higher viscosity (p = 0.025), and larger hydration spheres (p = 0.0012) than the RTEC. CONCLUSION: Oatmeal improves appetite control and increases satiety. The effects may be attributed to the viscosity and hydration properties of its ß-glucan content.

Effect of fortification with multiple micronutrients and n-3 fatty acids on growth and cognitive performance in Indian schoolchildren: the CHAMPION (Children's Health and Mental Performance Influenced by Optimal Nutrition) Study.

BACKGROUND: Fortification with multiple micronutrients has been shown to improve growth and cognitive performance among children in developing countries, but it is unknown whether higher concentrations are more effective than lower concentrations. OBJECTIVE: We compared the effect of 2 different concentrations of a combination of micronutrients and n-3 (omega-3) fatty acids on indicators of growth and cognitive performance in low-income, marginally nourished schoolchildren in Bangalore, India. DESIGN: In a 2-by-2 factorial, double-blind, randomized controlled trial, 598 children aged 6-10 y were individually allocated to 1 of 4 intervention groups to receive foods fortified with either 100% or 15% of the Recommended Dietary Allowance of micronutrients in combination with either 900 mg alpha-linolenic acid plus 100 mg docosahexaenoic acid or 140 mg alpha-linolenic acid for 12 mo. Anthropometric and biochemical assessments were performed at baseline and 12 mo. Cognitive performance was measured at baseline and at 6 and 12 mo. RESULTS: The high micronutrient treatment significantly improved linear growth at 12 mo (0.19 cm; 0.01, 0.36) and short-term memory at 6 mo (0.11 SD; 0.01, 0.20) and was less beneficial on fluid reasoning at 6 (-0.10 SD; -0.17, -0.03) and 12 (-0.12 SD; -0.20, -0.04) mo than was the low micronutrient treatment, whereas no differences were observed on weight, retrieval ability, cognitive speediness, and overall cognitive performance. No significant differences were found between the n-3 treatments. CONCLUSIONS: The high micronutrient treatment was more beneficial for linear growth than was the low micronutrient treatment. However, with some small differential effects, higher micronutrient concentrations were as effective as lower concentrations on cognitive performance. This trial was registered at clinicaltrials.gov as NCT00467909.

Effect of a 12-mo micronutrient intervention on learning and memory in well-nourished and marginally nourished school-aged children: 2 parallel, randomized, placebo-controlled studies in Australia and Indonesia.

BACKGROUND: Little is known about the combined effect of micronutrients and essential fatty acids on cognitive function in school-aged children. OBJECTIVE: We assessed the effect of micronutrients, long-chain n-3 fatty acids, or both on indicators of cognitive performance in well-nourished and marginally nourished school-aged children. DESIGN: Two 2-by-2 factorial randomized controlled double-blind trials were performed home-based in Adelaide, South Australia, and at 6 primary schools in Jakarta, Indonesia. A total of 396 children (aged 6-10 y) in Australia and 384 children in Indonesia were randomly allocated to receive a drink with a micronutrient mix (iron, zinc, folate, and vitamins A, B-6, B-12, and C), with docosahexanoic acid (DHA, 88 mg/d) and eicosapentaenoic acid (EPA, 22 mg/d), or with both or placebo 6 d/wk for 12 mo. Biochemical indicators were determined at baseline and 12 mo. Cognitive performance was measured at baseline, 6 mo, and 12 mo. RESULTS: The micronutrient treatment significantly improved plasma micronutrient concentrations in Australian and Indonesian children. DHA+EPA treatment increased plasma DHA and total plasma n-3 fatty acids in both countries. The micronutrient treatment resulted in significant increases in scores on tests representing verbal learning and memory in Australia (estimated effect size: 0.23; 95% CI: 0.01, 0.46). A similar effect was observed among Indonesian girls (estimated effect size: 0.32; 95% CI: -0.01, 0.64). No effects were found on tests measuring general intelligence or attention. No effects of DHA+EPA on the factors of cognitive tests were observed. CONCLUSION: In well-nourished school-aged children, fortification with multiple micronutrients can result in improvements in verbal learning and memory.