Toward more rigorous and informative nutritional epidemiology: The rational space between dismissal and defense of the status quo.

To date, nutritional epidemiology has relied heavily on relatively weak methods including simple observational designs and substandard measurements. Despite low internal validity and other sources of bias, claims of causality are made commonly in this literature. Nutritional epidemiology investigations can be improved through greater scientific rigor and adherence to scientific reporting commensurate with research methods used. Some commentators advocate jettisoning nutritional epidemiology entirely, perhaps believing improvements are impossible. Still others support only normative refinements. But neither abolition nor minor tweaks are appropriate. Nutritional epidemiology, in its present state, offers utility, yet also needs marked, reformational renovation. Changing the status quo will require ongoing, unflinching scrutiny of research questions, practices, and reporting-and a willingness to admit that "good enough" is no longer good enough. As such, a workshop entitled "Toward more rigorous and informative nutritional epidemiology: the rational space between dismissal and defense of the status quo" was held from July 15 to August 14, 2020. This virtual symposium focused on: (1) Stronger Designs, (2) Stronger Measurement, (3) Stronger Analyses, and (4) Stronger Execution and Reporting. Participants from several leading academic institutions explored existing, evolving, and new better practices, tools, and techniques to collaboratively advance specific recommendations for strengthening nutritional epidemiology.

Optical assessment of skin carotenoid status as a biomarker of vegetable and fruit intake.

Resonance Raman spectroscopy (RRS) and reflection spectroscopy (RS) are optical methods applicable to the non-invasive detection of carotenoids in human skin. RRS is the older, more thoroughly validated method, whereas RS is newer and has several advantages. Since collective skin carotenoid levels serve as a biomarker for vegetable and fruit intake, both methods hold promise as convenient screening tools for assessment of dietary interventions and correlations between skin carotenoids and health and disease outcomes. In this manuscript, we describe the most recent optimized device configurations and compare their use in various clinical and field settings. Both RRS and RS devices yield a wide range of skin carotenoid levels between subjects, which is a critical feature for a biomarker. Repeatability of the methods is 3-15% depending on the subject's skin carotenoid level and the uniformity of its local distribution. For 54 subjects recruited from an ophthalmology clinic, we first checked the validity of the relatively novel RS methodology via biochemical serum carotenoid measurements, the latter carried out with high performance liquid chromatography (HPLC). A high correlation between RS skin and serum HPLC carotenoid levels was established (R = 0.81; p < 0.001). Also, a high correlation was found between RS and RRS skin levels (R = 0.94 p < 0.001). Subsequent comparisons of skin carotenoid measurements in diverse age groups and ethnicities included 569 Japanese adults, 947 children with ages 2-5 screened in 24 day care centers in San Francisco, and 49 predominantly Hispanic adults screened at an outdoor health fair event. Depending on the particular subject group, correlation coefficients between the RRS and RS methods ranged between R ∼0.80 and R ∼0.96. Analysis of the Japanese screening showed that, on average, skin carotenoid levels are higher in women compared to men, skin levels do not depend on age, and tobacco smokers have reduced levels versus non-smokers. For the two most ethnically diverse groups with widely varying melanin levels, we investigated the effect of dermal melanin on RS and RRS skin carotenoid levels. The analysis revealed that large variations in skin carotenoid levels remain detectable independent of the particular melanin index. This behavior is consistent with the absence of melanin effects on the skin carotenoid levels generated with the instrument configurations. The RS method has an advantage over RRS in its relative simplicity. Due to its detection of skin reflection over a wide spectral range from the near UV to the near IR, it has the unique ability to quantify each of the major tissue chromophores and take them into account in the derivation of skin carotenoid levels.

Depletion and repletion of fruit and vegetable intake alters serum bone turnover markers: a 28-week single-arm experimental feeding intervention.

This study was designed to evaluate the effects of elevated fruit and vegetable intake on bone turnover markers. In all, twenty-nine subjects (nine male and twenty female, with a mean age of 32·1 (sem 2·5) years) participated in a 28-week single-arm experimental feeding intervention trial and consumed a prescribed low-fruit and vegetable diet for 6 weeks (depletion-1), a provided high-fruit and vegetable diet for 8 weeks (fruit: 360-560 g; vegetables: 450-705 g), another prescribed low-fruit and vegetable diet for 6 weeks (depletion-2) and then their usual diets for 8 weeks (repletion). Serum bone-related biomarkers were analysed with commercial ELISA kits. Plasma carotenoid levels decreased as a result of the depletion phase and increased with the high-fruit and vegetable diet. Compared with the baseline, depletion-1 resulted in higher serum bone resorption marker C-terminal telopeptide of type 1 collagen (CTX) and lower bone formation marker alkaline phosphatase (BAP) (CTX, 0·68 (sem 0·05) v. 0·97 (sem 0·08) ng/ml and BAP, 10·7 (sem 0·7) v. 9·5 (sem 0·8) µg/l for the baseline and the depletion-1, respectively, P<0·05). High intake of fruit and vegetables decreased serum CTX (P<0·05) to 0·60 (sem 0·04) ng/ml and increased serum BAP to 11·3 (sem 0·7) µg/l (P<0·05), compared with the depletion-1 phase. Serum concentrations of CTX were inversely correlated and those of BAP were positively correlated with blood lycopene. These data show that increased fruit and vegetable consumption at or above federal dietary guidance may be beneficial to bone health.

Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial.

The purpose of this work was to determine the effects of varying levels of dietary protein on body composition and muscle protein synthesis during energy deficit (ED). A randomized controlled trial of 39 adults assigned the subjects diets providing protein at 0.8 (recommended dietary allowance; RDA), 1.6 (2×-RDA), and 2.4 (3×-RDA) g kg(-1) d(-1) for 31 d. A 10-d weight-maintenance (WM) period was followed by a 21 d, 40% ED. Body composition and postabsorptive and postprandial muscle protein synthesis were assessed during WM (d 9-10) and ED (d 30-31). Volunteers lost (P<0.05) 3.2 ± 0.2 kg body weight during ED regardless of dietary protein. The proportion of weight loss due to reductions in fat-free mass was lower (P<0.05) and the loss of fat mass was higher (P<0.05) in those receiving 2×-RDA and 3×-RDA compared to RDA. The anabolic muscle response to a protein-rich meal during ED was not different (P>0.05) from WM for 2×-RDA and 3×-RDA, but was lower during ED than WM for those consuming RDA levels of protein (energy × protein interaction, P<0.05). To assess muscle protein metabolic responses to varied protein intakes during ED, RDA served as the study control. In summary, we determined that consuming dietary protein at levels exceeding the RDA may protect fat-free mass during short-term weight loss.

Foods advertised in US weekly supermarket sales circulars over one year: a content analysis.

BACKGROUND: The nutritional content of Americans' shopping carts is suboptimal despite federal dietary guidance, in this case, the MyPlate consumer icon which displays desired proportions of vegetables, fruits, dairy, grains and protein foods for consumption. Consumers mention print advertising-such as weekly sales circulars-frequently as influencing their grocery shopping decisions. METHODS: To examine and describe the relative proportions of advertised foods aggregated into the MyPlate food grouping system, a content analysis of 9 209 foods advertised in 52 weekly supermarket newspaper sales inserts in 2009 from a local grocery chain was conducted in a Midwestern community. RESULTS: Overall, the protein foods group was most often represented in sales circulars (25% of total items), followed by grains (18%); dairy (10%); vegetables (8%) and fruits (7%). Less than 3% of sales advertisements were for dark green and red & orange vegetables. Over twice as much whole fruit versus 100% fruit juice was advertised (70% vs. 30%, respectively; P < 0.001). Significantly fewer protein foods and more grains than expected were advertised in the fall, and slightly more dark green vegetables were advertised in winter and spring than in summer and fall (P = 0.05). CONCLUSIONS: The average American diet, including underconsumption of fruits and vegetables but overconsumption of protein foods, was reflected in the relative frequency of food groups advertised in weekly sales circulars. Modifying sales circulars to represent healthier food groups may preserve retail profits (considering these groups' higher profit margin) while promoting adherence to federal dietary guidance.

Association of Social Vulnerability and COVID-19 Mortality Rates in Texas between 15 March 2020, and 21 July 2022: An Ecological Analysis.

BACKGROUND: Despite the key role of social vulnerability such as economic disadvantage in health outcomes, research is limited on the impact of social vulnerabilities on COVID-19-related deaths, especially at the state and county level in the USA. METHODS: We conducted a cross-sectional ecologic analysis of COVID-19 mortality by the county-level Minority Health Social Vulnerability Index (MH SVI) and each of its components in Texas. Negative binomial regression (NBR) analyses were used to estimate the association between the composite MH SVI (and its components) and COVID-19 mortality. RESULTS: A 0.1-unit increase in the overall MH SVI (IRR, 1.27; 95% CI, 1.04-1.55; p = 0.017) was associated with a 27% increase in the COVID-19 mortality rate. Among the MH SVI component measures, only low socioeconomic status (IRR, 1.55; 95% CI, 1.28-1.89; p = 0.001) and higher household composition (e.g., proportion of older population per county) and disability scores (IRR, 1.47; 95% CI, 1.29-1.68; p < 0.001) were positively associated with COVID-19 mortality rates. CONCLUSIONS: This study provides further evidence of disparities in COVID-19 mortality by social vulnerability and can inform decisions on the allocation of social resources and services as a strategy for reducing COVID-19 mortality rates and similar pandemics in the future.

Discretizing continuous variables in nutrition and obesity research: a practice that needs to be cut short.

BACKGROUND/OBJECTIVES: Nutrition and obesity researchers often dichotomize or discretize continuous independent variables to conduct an analysis of variance to examine group differences. We describe consequences associated with dichotomizing and discretizing continuous variables using two cross-sectional studies related to nutrition. SUBJECTS/METHODS: Study 1 investigated the effects of health literacy and nutrition knowledge on nutrition label accuracy (n = 612). Study 2 investigated the effects of cognitive restraint and BMI on fruit and vegetable (F/V) intake (n = 586). We compare analytic approaches where continuous independent variables were either discretized/dichotomized or analyzed as continuous variables. RESULTS: In Study 1, dichotomization of health literacy and nutrition knowledge for 2 × 2 ANOVA revealed health literacy had an effect on nutrition label accuracy. Nutrition knowledge has an effect on nutrition label accuracy, but the health literacy by nutrition knowledge interaction was not significant. When analyzed using regression, the nutrition knowledge effect was significant. The simple effect of health literacy was also significant when health literacy equals zero. Finally, the quadratic effect of health literacy was negative and significant. In Study 2, dichotomization and discretization of cognitive restraint and BMI were used for three ANOVAs, which discretized BMI in three ways. For all ANOVAs, the BMI main effect for predicting fruit and vegetable intake was significant, the interaction between BMI and cognitive restraint was non-significant, and cognitive restraint was only significant when both variables were dichotomized. When analyzed using regression, the continuous mean-centered variables, and their interaction each significantly predicted F/V intake. CONCLUSIONS: Dichotomizing continuous independent variables resulted in distortions of effect sizes across studies, an inability to assess the quadratic effect of health literacy, and an inability to detect the moderating effect of BMI. We discourage researchers from dichotomizing and discretizing continuous independent variables and instead use multiple regression to examine relationships between continuous independent and dependent variables.

Nutrition and Health Programming and Outreach in Grocery Retail Settings: A Community Coalition in Action.

Grocery stores can provide a conducive environment for interventions targeting healthy eating and access to health services, particularly in low-income communities. A wide array of organizations deliver nutrition and related programs in community settings, but rarely in a coordinated fashion. Collaboration of local health promotion organizations with grocery stores could increase consumers' access to and selection of healthy foods and related services. This evaluation of the In-Store Programming and Outreach Coalition (IPOC) uses thematic analysis of first-person accounts from coalition members. To our knowledge, this is the first study of such a coalition. We present perspectives from six stakeholders about the IPOC strengths, challenges, and recommendations for strengthening the delivery of in-store interventions. Themes identified include partnership, increased client reach and cross-referrals, conflicting work schedules, leadership, and recommendations to identify coalition leaders and expand services to other grocery stores. We conclude that grocery stores can offer a suitable setting for programming and community outreach through coalitions.

Examining the impacts of public transit on healthy aging through a natural experiment: study protocols and lessons learned from the Active El Paso project.

This paper describes protocols and experiences from a seven-year natural-experiment study in El Paso, Texas, a border city of predominantly Latino/Hispanic population. The study focuses on how Bus Rapid Transit (BRT) impacts physical activity and thus plays a role in alleviating obesity and related chronic diseases that impact healthy aging. Our protocols describe a longitudinal and case-comparison study, which compared residents exposed to new BRT stations with those who were not. This paper also introduces lessons and experiences to overcome the following challenges: delays in the BRT opening (the main intervention), the COVID-19 pandemic, methodological challenges, participant recruitment and retention, and predatory survey takers. Our transdisciplinary approach was pivotal in addressing these challenges. We also proposed and tested multi-level intervention strategies to reduce modifiable barriers to transit use. Our most important takeaway for researchers, practitioners, and policy makers is the importance of being flexible and ready to adapt to new circumstances. Future natural-experiment researchers need to become more versatile in an increasingly volatile and uncertain world.

The Commit to Be Fit framework: a community case study of a multi-level, holistic school-based wellness initiative in rural Virginia.

Background: Public health interventions that target children's physical, mental, and emotional health will enhance their ability to learn and grow. Although more complex, school initiatives that address multiple ecological levels and take a holistic view may be more effective and likely to lead to lasting change. Aims: This article presents the framework of Commit to Be Fit (C2BF) as an example of how schools can integrate multi-level and holistic approaches for health. This innovative school-based intervention includes activities addressing individual, home, school, and community to create a culture of wellness. We describe the implementation of C2BF and its basis in ecological models and give examples of activities across three components: cafeteria, classroom, and community. We discuss challenges and note that leadership engagement and alignment were critical elements for C2BF's success thus far. Discussion: C2BF uses a school-based multi-level approach to creating a culture of wellness and holistic health for students, teachers, and community members. C2BF is unique compared to other school-based programming and includes activities that address all eight domains posited for program sustainability within public health. Built to be flexible and adaptive, C2BF was able to successfully pivot during the COVID pandemic and also follow new science. Conclusion: C2BF and other multi-level holistic approaches are more likely to achieve long-term change by utilizing strategies across the multiple levels of the ecological model to improve health and wellbeing.

Eat Well El Paso!: Lessons Learned From a Community-Level Restaurant Initiative to Increase Availability of Healthy Options While Celebrating Local Cuisine.

PURPOSE: Restaurants have the potential to improve nutrition and positively shape social norms. We describe lessons learned and recommended strategies from Eat Well El Paso! (EWEP), a local restaurant initiative. DESIGN: Descriptive case study. SETTING: EWEP partnered with local restaurants from 2012-2017 in El Paso, Texas, along the US/Mexico border. SAMPLE: Our sampling frame included EWEP staff and managers/owners at participating restaurants, of which the majority participated (80% and 85%, respectively). INTERVENTION: EWEP was a local restaurant initiative led by the city public health department. EWEP contracted registered dietitians to assist locally-owned restaurants to increase availability of healthy menu options. MEASURES: Observation, key informant interviews, and document review assessed participation, barriers, and facilitators to restaurant participation and program sustainability. ANALYSIS: Thematic and descriptive analyses. RESULTS: 57% of restaurants completed the full on-boarding process, but long-term retention was low (24% of completers). Restaurant managers/owners perceived value in marketing, nutritional analysis, and menu design. Barriers included scheduling, complexity of restaurant culture, fear of food inspections, restaurant turnover, competing responsibilities, and lack of dedicated funding. CONCLUSION: Although local context and sample size may limit generalizability, lessons learned and recommended strategies are relevant and informative for communities working to increase restaurants' healthy menu options.

Comparison of obstetrician-gynecologists and family physicians regarding weight-related attitudes, communication, and bias.

OBJECTIVES: To assess physician perceptions regarding weight-related communication, quality of care, and bias in obstetrics-gynecology (OBGYN) and family physician (FP) practices. METHODS: A cross-sectional survey study based on a convenient sampling of OBGYN and FP was conducted. Physicians completed a 40-question survey assessing perceived obesity management and weight bias in caring for female patients with body mass index ≥25kg/m2. RESULTS: Reponses from 51 physicians (25 OBGYN and 26 FP) were received. There was no difference between specialties in satisfaction with care or level of confidence in treating patients with obesity. However, OBGYNs reported more negative perceptions of patients with obesity (mean score 19.2±3.3 vs. 15.0±4.0, p<0.001) and greater weight bias (11.8±2.0 vs. 9.7±2.5, p<0.01) compared to FPs. OBGYNs were also more likely to expect less favorable treatment outcomes (13.3±2.5 vs. 15.5±2.8. p<0.01). Physicians between 31-50 years old displayed a significantly higher perception of weight bias in their profession when compared to the reference 21-30year olds, and for each unit increase in self-reported BMI there was a 0.18 average increase in the composite score for perceived weight bias. CONCLUSIONS: OBGYN physicians reported significantly higher levels of weight bias than FP physicians, indicating a need for improved education in OBGYN training. CLINICAL TRIAL REGISTRATION: N/A.

Acceptance-based therapy: the potential to augment behavioral interventions in the treatment of type 2 diabetes.

Diabetes is a complex and multifactorial disease affecting more than 415 million people worldwide. Excess adiposity and modifiable lifestyle factors, such as unhealthy dietary patterns and physical inactivity, can play a significant role in the development of type 2 diabetes. Interventions that implement changes to lifestyle behaviors, in addition to pharmacological treatment, may attenuate the development and worsening of diabetes. This narrative review delineates how standard behavioral interventions (SBTs), based in "first wave" behavioral therapies and "second wave" cognitive behavioral therapies, serve as the foundation of diabetes treatment by supporting effective lifestyle changes, including improving adherence to healthful behaviors, medication, and self-monitoring regimens. Moreover, "third wave" "acceptance-based therapies" (ABTs), which integrate techniques from acceptance and commitment therapy, are proposed as a potential novel treatment option for diabetes management. Further research and long-term, randomized controlled trials will clarify the feasibility, acceptability, and effectiveness of ABT for improving glucose control via enhancing medication adherence and promoting effective lifestyle changes in people with diabetes.

Strategies to increase vegetable or reduce energy and fat intake induce weight loss in adults.

For obese individuals seeking to optimize health and well-being, healthy dietary strategies are important. Vegetables and fruits contribute to a healthy diet, and increased consumption may cause weight reduction by displacing foods high in energy and fat. The objective of this study was to determine if advising high vegetable (8 servings) and moderate fruit (2-3 servings) consumption would result in weight reduction in obese individuals. We compared this to advising a more traditional strategy of reducing daily energy intake by 500 kcal (2.1 MJ)/d and limiting energy from fat to

Using the 13C/12C carbon isotope ratio to characterise the emission sources of airborne particulate matter: a review of literature.

Particulate matter (PM) from atmospheric aerosols contains carbons that are harmful for living organisms and the environment. PM can originate from vehicle emissions, wearing of vehicle components, and dust. Size and composition determine PM transport and penetration depth into the respiratory system. Understanding PM emission characteristics is essential for developing strategies to improve air quality. The number of studies on carbon isotope composition (13C/12C) of PM samples to characterise emission factors has increased. The goal of this review is to integrate and interpret the findings from 13C/12C carbon isotope ratio (δ13C, ‰) analyses for the most common types of emission sources. The review integrates data from 25 studies in 13 countries. The range of δ13C of PM from vehicle emissions was from -28.3 to -24.5 ‰ and for non-vehicle anthropogenic emissions from -27.4 to -23.3 ‰. In contrast, PM ranges for δ13C from biomass burning sources differed markedly. For C3 plants, δ13C ranged from -34.7 to -25.4 ‰ and for C4 plants from -22.2 to -13.0 ‰. The 13C/12C isotope analysis of PM is valuable for understanding the sources of pollutants and distinguishing vehicle emissions from biomass burning. However, additional markers are needed to further distinguish other anthropogenic sources.

A diet high in carotenoid-rich vegetables and fruits favorably impacts inflammation status by increasing plasma concentrations of IFN-α2 and decreasing MIP-1ß and TNF-α in healthy individuals during a controlled feeding trial.

The health benefits of vegetable and fruit (VF) intake include benefits for diseases that have an inflammatory component, although the relationship between VF intake and systemic inflammatory status is unclear due to the lack of comprehensive analysis of inflammatory markers in most studies. Therefore, our hypothesis was that the consumption of carotenoid-rich vegetables and fruits in the diet would have a beneficial effect on systemic inflammation status. In this study, we determined the association between varying doses of carotenoid-rich VF intake, plasma carotenoids, and a broad array of markers including 26 cytokines and high-sensitivity C-reactive protein. Data were derived from a single-arm controlled clinical feeding trial in which healthy, nonobese individuals received a low-carotenoid prescription for 6 weeks and then consumed a provided high-VF diet for 8 weeks. Proinflammatory cytokines and plasma carotenoids were measured at baseline, at 6 weeks, and at the end of the 8-week feeding period. Maximum likelihood estimation was used to calculate overall correlations between total plasma carotenoid concentrations and the cytokines. Plasma carotenoids decreased during the low-carotenoid treatment and increased during the feeding treatment. Of the inflammatory markers measured, we found increased plasma concentrations of interferon α-2 (P = .003) and decreased macrophage inflammatory protein-1ß (P = .027) and tumor necrosis factor-α (P = .012) after consumption of the carotenoid-rich diet. These results indicate that consumption of VF may be important in the maintenance of beneficial inflammatory homeostasis.

Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans.

BACKGROUND: Conjugated linoleic acid (CLA) has been shown to be an effective supplement for reducing fat mass in animals, whereas results in humans have been inconsistent. OBJECTIVE: This is a meta-analysis of human studies in which CLA was provided as a dietary supplement to test its efficacy in reducing fat mass. DESIGN: We searched the PubMed database (National Library of Medicine, Bethesda, MD) and references from the resulting search to identify studies in which CLA was provided to humans in randomized, double-blinded, placebo-controlled trials and in which body composition was assessed by using a validated technique. RESULTS: We identified 18 eligible studies. Of these, 3 were single-isomer studies, and results comparing CLA isomers were inconclusive. We compared the length of treatment by using studies in which a mixture of purified isomers were used and those in which purified trans-10,cis-12 isomers were used. This comparison indicated that the effect of CLA was linear for up to 6 mo and then slowly approached an asymptote at 2 y. An analysis of the dose effect indicated that fat loss compared with placebo was -0.024 kg x g CLA(-1) x wk(-1) (P=0.03). After adjustment to the median dose of 3.2 g CLA/d, CLA was effective and produced a reduction in fat mass for the CLA group alone (0.05 +/- 0.05 kg/wk; P<0.001) and for the CLA group compared with placebo (0.09 +/- 0.08 kg/wk; P<0.001) CONCLUSION: Given at a dose of 3.2 g/d, CLA produces a modest loss in body fat in humans.

Diet Quality of Items Advertised in Supermarket Sales Circulars Compared to Diets of the US Population, as Assessed by the Healthy Eating Index-2010.

BACKGROUND: Supermarkets use sales circulars to highlight specific foods, usually at reduced prices. Resulting purchases help form the set of available foods within households from which individuals and families make choices about what to eat. OBJECTIVE: The purposes of this study were to determine how closely foods featured in weekly supermarket sales circulars conform to dietary guidance and how diet quality compares with that of the US population's intakes. DESIGN: Food and beverage items (n=9,149) in 52 weekly sales circulars from a small Midwestern grocery chain in 2009 were coded to obtain food group and nutrient and energy content. Healthy Eating Index-2010 (HEI-2010) total and component scores were calculated using algorithms developed by the National Cancer Institute. HEI-2010 scores for the US population aged 2+ years were estimated using data from the 2009-2010 National Health and Nutrition Examination Survey. HEI-2010 scores of circulars and population intakes were compared using Student's t tests. RESULTS: Mean total (42.8 of 100) HEI-2010 scores of circulars were lower than that of the US population (55.4; P<0.001). Among individual components, Total Protein Foods was the only one for which 100% of the maximum score was met by both circulars and the population. The scores were also similar between the circulars and population for Whole Grains (22%; P=0.81) and Seafood and Plant Proteins (70% to 74%; P=0.33). Circular scores were lower than those of the population for Total and Whole Fruits, Total Vegetables and Greens and Beans, Dairy, Sodium, and Empty Calories (P<0.001); they were higher only for Fatty Acids (P=0.006) and Refined Grains (P<0.001). CONCLUSIONS: HEI-2010 total scores for these sales circulars were even lower than US population scores, which have been shown repeatedly to reflect low diet quality. Supermarkets could support improvements in consumer diets by weekly featuring foods that are more in concordance with food and nutrient recommendations.

Optical detection of carotenoids in living tissue as a measure of fruit and vegetable intake.

Circulating blood carotenoids have long been accepted as the most accurate biomarker of total fruit and vegetable intake. Recent technological developments have led to a novel optical detection method of carotenoids in living human tissue, allowing for a non-invasive and rapid method to assess fruit and vegetable intake. Future technological advances to increase sensitivity and molecular specificity, reduce cost, and detect other biomedically important compounds would expand use of this methodology.