Influence of observational study design on the interpretation of cancer risk reduction by carotenoids.

Recently published literature has been reviewed to determine whether lycopene, beta-carotene, alpha-carotene, and beta-cryptoxanthin are associated with reductions in cancer risk and whether study findings differ by study design. A total of 57 publications meeting pre-defined inclusion and exclusion criteria were identified, with the majority (55) being observational studies. None of the intervention studies supported a significant reduction in cancer risk with carotenoid (beta-carotene) supplementation.

Carotenoid bioavailability is higher from salads ingested with full-fat than with fat-reduced salad dressings as measured with electrochemical detection.

Background: The amount of dietary fat required for optimal bioavailability of carotenoids in plant matrices is not clearly defined.

Objective: The objective was to quantify the appearance of carotenoids in plasma chylomicrons after subjects ingested fresh vegetable salads with fat-free, reduced-fat, or full-fat salad dressings.

Design: The subjects (n = 7) each consumed 3 salads consisting of equivalent amounts of spinach, romaine lettuce, cherry tomatoes, and carrots with salad dressings containing 0, 6, or 28 g canola oil.

Molecular factor analysis applied to collections of NMR spectra.

It is often useful to identify and quantify mixture components by analyzing collections of NMR spectra. Such collections arise in metabonomics and many other applications. Many mixtures studied by NMR can contain hundreds of compounds, and it is challenging to analyze the resulting complex spectra.

Fat, carbohydrate, and calories in the development of diabetes and obesity in the C57BL/6J mouse.

We have previously shown that the C57BL/6J (B6) mouse will develop obesity and diabetes if raised on a high-fat diet. Because high fat feeding is associated with hyperphagia, the present study was designed to separate the effects of fat from those of excess caloric consumption in this animal model. B6 mice were fed a low-fat diet (LF group) diet, high-fat diet (HF group) diet, or high-fat-restricted diet (HFR group), in which intake animals were pair-fed a high-fat diet to caloric level consumed by LF for 11 weeks.

Carotenoids in health and disease: recent scientific evaluations, research recommendations and the consumer.

In addition to his many research achievements, James Allen Olson made important contributions to evaluations of the role of dietary carotenoids in prevention of chronic diseases such as cancer, heart disease and age-related macular degeneration in well-nourished populations. This paper reviews recent scientific evaluations of the role of carotenoids in disease, recommendations for future research, and consumer-related trends of relevance to carotenoids. Authoritative scientific evaluations by key leading thinkers have not been able to ascribe a disease prevention function to carotenoids because of the absence of definitive evidence.

Diet and lifestyle correlates of lutein in the blood and diet.

Observational studies have suggested an inverse relationship between dietary or serum lutein and risk for age-related macular degeneration and cataracts. This evidence has stimulated interest in the biological and other characteristics of lutein, and also zeaxanthin, a structurally similar carotenoid; together, they comprise the macular pigment. Accurate interpretation of data linking dietary intake or serum concentrations of lutein and zeaxanthin and risk for eye disease in epidemiologic and clinical studies requires knowledge of biological and nondietary factors influencing these intake data or concentrations.