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.

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 β-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.

Background: Dietary fiber is a key component of a health-promoting diet, and it is acknowledged as a short-fall nutrient in most Western diets. Some sources of dietary fiber, such as hemp hull fiber, also include inherent small molecule bioactives that further promote health and well-being. While dietary fiber is a key component that supports digestive health, it also can cause digestive discomfort. Digestive symptoms such as gas, bloating, belly pain, and the resulting decrease in digestive quality of life are common among adults. The aim of this study was to evaluate changes in digestive comfort, in individuals who currently experience digestive discomfort, after consuming either a proprietary dietary fiber supplement from hemp hull, a dietary fiber supplement made from inulin, or a digestible control (maltodextrin). Methods: This study was a completely virtual, double-blind, placebo-controlled, randomized clinical trial of healthy adults. The parallel arm study tested two fiber supplements at a practical dose yielding a “Good Source of Fiber” based on United States Dietary Reference Intakes (2.8 grams of fiber per day) for six weeks. Results Five hundred seventy nine randomized participants provided follow-up outcomes data. Digestion-associated quality of life questionnaire, belly pain, and gas and bloating scores were assessed and found to be superior after hemp hull fiber intake compared to inulin intake at multiple time points in a post-hoc analysis (p<0.05). Conclusion This study demonstrated that a practical dose of bioactive-rich fiber from hemp hull is well-tolerated, provides superior digestive comfort relative to both placebo and inulin fiber, and can aid in reaching total fiber intake goals.