There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Summary Some of the most exciting research in the last decade has been the discovery of a group of nutrients, which have protective eAects against cell oxidation. These naturally occurring compounds impart bright colour to fruits and vegetables and act as antioxidants in the body by scavenging harmful free radicals, which are implicated in most degenerative diseases. Epidemiological studies have established a positive correlation between the intake of fruits and vegetables and prevention of diseases like atheroscelerosis, cancer, diabetes, arthritis and also ageing. So pronounced has been their eAect on ageing that they have been called ‘fountains of youth’. Fruits and vegetables have thus had conferred on them the status of ‘functional foods’, capable of promoting good health and preventing or alleviating diseases. Phenolic flavonoids, lycopene, carotenoids and glucosinolates are among the most thoroughly studied antioxidants. The present review highlights the potential of fruits and vegetables rich in antioxidants, their health benefits and the eAect of processing on the bioavailability of these nutrients. The paper also reviews some of the important methods used to determine the antioxidant activity.

Antioxidants in fruits and vegetables – the millennium’s health

Phytosterols, phytostanols, and their conjugates in foods: structural diversity, quantitative analysis, and health-promoting uses

Phytochemicals, as plant components with discrete bio-activities towards animal biochemistry and metabolism are being widely examined for their ability to provide health benefits. It is important to establish the scientific rationale to defend their use in foods, as potential nutritionally active ingredients. Phytochemicals could provide health benefits as: (1) substrates for biochemical reactions; (2) cofactors of enzymatic reactions; (3) inhibitors of enzymatic reactions; (4) absorbents/sequestrants that bind to and eliminate undesirable constituents in the intestine; (5) ligands that agonize or antagonize cell surface or intracellular receptors; (6) scavengers of reactive or toxic chemicals; (7) compounds that enhance the absorption and or stability of essential nutrients; (8) selective growth factors for beneficial gastrointestinal bacteria; (9) fermentation substrates for beneficial oral, gastric or intestinal bacteria; and (10) selective inhibitors of deleterious intestinal bacteria. Such phytochemicals include terpenoids, phenolics, alkaloids and fiber. Research supporting beneficial roles for phytochemicals against cancers, coronary heart disease, diabetes, high blood pressure, inflammation, microbial, viral and parasitic infections, psychotic diseases, spasmodic conditions, ulcers, etc is based on chemical mechanisms using in vitro and cell culture systems, various disease states in animals and epidemiology of humans. However, it must be emphasized that a distinction needs to be drawn between the types of information that can be obtained from studies in vitro, in animals and in humans. Mechanisms of action must certainly be established in vitro; however, the efficacy of these same ingredients with their mechanisms of action, must also be demonstrated in vivo. The rapid growth in the use of phytochemicals in nutraceutical and functional foods requires that the food and pharmaceutical industries face new challenges: in addressing worldwide public concern over the efficacy and safety of supplements and foods claimed to be health-promoting; in government regulations related to safety, labeling and health claims for products that contain phytochemicals; in the manufacturing of foods with different qualities and stabilities; and in marketing issues, particularly as they relate to consumers' recognizing added value.

© 2000 Society of Chemical Industry

Phytochemicals: nutraceuticals and human health.

A healthful eating pattern, regular physical activity, and often pharmacotherapy are key components of diabetes management. For many individuals with diabetes, the most challenging part of the treatment plan is determining what to eat. It is the position of the American Diabetes Association (ADA) that there is not a “one-size-fits-all” eating pattern for individuals with diabetes. The ADA also recognizes the integral role of nutrition therapy in overall diabetes management and has historically recommended that each person with diabetes be actively engaged in self-management, education, and treatment planning with his or her health care provider, which includes the collaborative development of an individualized eating plan (1,2). Therefore, it is important that all members of the health care team be knowledgeable about diabetes nutrition therapy and support its implementation.

This position statement on nutrition therapy for individuals living with diabetes replaces previous position statements, the last of which was published in 2008 (3). Unless otherwise noted, research reviewed was limited to those studies conducted in adults diagnosed with type 1 or type 2 diabetes. Nutrition therapy for the prevention of type 2 diabetes and for the management of diabetes complications and gestational diabetes mellitus is not addressed in this review.

A grading system, developed by the ADA and modeled after existing methods, was utilized to clarify and codify the evidence that forms the basis for the recommendations (1) (Table 1). The level of evidence that supports each recommendation is listed after the recommendation using the letters A, B, C, or E. A table linking recommendations to evidence can be reviewed at http://professional.diabetes.org/nutrition. Members of the Nutrition Recommendations Writing Group Committee disclosed all potential financial conflicts of interest with industry. These disclosures were discussed at the onset of the position statement development process. Members of this committee, their employers, …

https://care.diabetesjournals.org/content/diacare/37/Supplement_1/S120.full.pdf

Nutrition Therapy Recommendations for the Management of Adults With Diabetes

Modulation of plasma lipid levels and cholesterol kinetics by phytosterol versus phytostanol esters

Phytosterols (plant sterols), abundant in fat-soluble fractions of plants, are consumed at levels of 200-400 mg/day in Western diets. Chemically resembling cholesterol, phytosterols inhibit the absorption of cholesterol. Phytosterol consumption in human subjects under a wide range of study conditions has been shown to reduce plasma total and low density lipoprotein (LDL) cholesterol levels; however, the response varies widely. Greater cholesterol-lowering efficacy occurs with consumption of the saturated phytosterol sitostanol versus sitosterol or campesterol. Most studies report no effect of phytosterol administration in high density lipoprotein (HDL) cholesterol or triglyceride levels, although certain evidence exists for an HDL cholesterol raising effect of sitostanol. Phytosterol absorption is limited, although serum phytosterol levels have proven to be important indicators of both cholesterol absorption and synthesis. Serum phytosterols correlate with HDL cholesterol level. In addition, higher phytosterol/cholesterol ratios appear in HDL versus LDL particles, suggesting the existence of an intrinsic phytosterol action, in addition to the extrinsic effect on cholesterol absorption. In conclusion, addition to diet of the phytosterol sitostanol represents an effective means of improving circulating lipid profiles to reduce risk of coronary heart disease.

Dietary phytosterols as cholesterol-lowering agents in humans.

Cholesterol-lowering efficacy of a sitostanol-containing phytosterol mixture with a prudent diet in hyperlipidemic men

Unesterified plant sterols and stanols lower LDL-cholesterol concentrations equivalently in hypercholesterolemic persons

Importance Vitamin D supplementation in infancy is required to support healthy bone mineral accretion. A supplement of 400 IU of vitamin D per day is thought to support plasma 25-hydroxyvitamin D (25[OH]D) concentrations between 40 and 50 nmol/L; some advocate 75 to 150 nmol/L for bone health. Objective To investigate the efficacy of different dosages of vitamin D in supporting 25(OH)D concentrations in infants. Design, Setting, and Participants Double-blind randomized clinical trial conducted among 132 one-month-old healthy, term, breastfed infants from Montreal, Quebec, Canada, between March 2007 and August 2010. Infants were followed up for 11 months ending August 2011 (74% completed study). Intervention Participants were randomly assigned to receive oral cholecalciferol (vitamin D 3 ) supplements of 400 IU/d (n=39), 800 IU/d (n=39), 1200 IU/d (n=38), or 1600 IU/d (n=16). Main Outcomes and Measures The primary outcome was a plasma 25(OH)D concentration of 75 nmol/L or greater in 97.5% of infants at 3 months. Secondary outcomes included 25(OH)D concentrations of 75 nmol/L or greater in 97.5% of infants at 6, 9, and 12 months; 25(OH)D concentrations of 50 nmol/L or greater across all times; growth; and whole body and regional bone mineral content. Data were analyzed by intention to treat using available data, logistic regression, and mixed-model analysis of variance. Results By 3 months, 55% (95% CI, 38%-72%) of infants in the 400-IU/d group achieved a 25(OH)D concentration of 75 nmol/L or greater vs 81%(95% CI, 65%-91%) in the 800-IU/d group, 92% (95% CI, 77%-98%) in the 1200-IU/d group, and 100% in the 1600-IU/d group. This concentration was not sustained in 97.5% of infants at 12 months in any of the groups. The 1600-IU/d dosage was discontinued prematurely because of elevated plasma 25(OH)D concentrations. All dosages established 25(OH)D concentrations of 50 nmol/L or greater in 97% (95% CI, 94%-100%) of infants at 3 months and sustained this in 98% (95% CI, 94%-100%) to 12 months. Growth and bone mineral content did not differ by dosage. Conclusions and Relevance Among healthy, term, breastfed infants, only a vitamin D supplement dosage of 1600 IU/d (but not dosages of 400, 800, or 1200 IU/d) increased plasma 25(OH)D concentration to 75 nmol/L or greater in 97.5% of infants at 3 months. However, this dosage increased 25(OH)D concentrations to levels that have been associated with hypercalcemia. Trial Registration clinicaltrials.gov Identifier: NCT00381914

https://jamanetwork.com/journals/jama/articlepdf/1682941/joc130038_1785_1792.pdf

Catherine A. Vanstone

Papers

Modulation of plasma lipid levels and cholesterol kinetics by phytosterol versus phytostanol esters

Dietary phytosterols as cholesterol-lowering agents in humans.

Cholesterol-lowering efficacy of a sitostanol-containing phytosterol mixture with a prudent diet in hyperlipidemic men

Unesterified plant sterols and stanols lower LDL-cholesterol concentrations equivalently in hypercholesterolemic persons

Effect of Different Dosages of Oral Vitamin D Supplementation on Vitamin D Status in Healthy, Breastfed Infants: A Randomized Trial