High dietary antioxidant intakes are associated with decreased chromosome translocation frequency in airline pilots

Healthy Nutrition, Physical Activity, and Sleep Hygiene to Promote Cardiometabolic Health of Airline Pilots: A Narrative Review

Background

Airline pilots experience unique occupational demands that may contribute to adverse physical and psychological health outcomes. Epidemiological reports have shown a substantial prevalence of cardiometabolic health risk factors including excessive body weight, elevated blood pressure, poor lifestyle behaviors, and psychological fatigue. Achieving health guidelines for lifestyle behavior nutrition, physical activity, and sleep are protective factors against the development of noncommunicable diseases and may mitigate the unfavorable occupational demands of airline pilots. This narrative review examines occupational characteristics for sleep, nutrition, and physical activity and outlines evidence-based strategies to inform health behavior interventions to mitigate cardiometabolic health risk factors among airline pilots.

Methods

Literature sources published between 1990 and 2022 were identified through electronic searches in PubMed, MEDLINE (via OvidSP), PsychINFO, Web of Science, and Google Scholar databases, and a review of official reports and documents from regulatory authorities pertaining to aviation medicine and public health was conducted. The literature search strategy comprised key search terms relating to airline pilots, health behaviors, and cardiometabolic health. The inclusion criteria for literature sources were peer-reviewed human studies, meta-analyses, systematic reviews, and reports or documents published by regulatory bodies.

Results

The results of the review show occupational factors influencing nutrition, sleep, and physical activity behaviors and delineate evident occupational disruptions to these lifestyle behaviors. Evidence from clinical trials demonstrates the efficacy of nutrition, sleep, and physical activity interventions for enhancing the cardiometabolic health of airline pilots.

Conclusion

This narrative review suggests that implementing evidence-based interventions focused on nutrition, physical activity, and sleep could help mitigate cardiometabolic health risk factors among airline pilots, who are particularly susceptible to adverse health outcomes due to unique occupational demands.

Protective Role of Natural Compounds under Radiation-Induced Injury

In recent years, evidence has shown the potential therapeutic effects of different natural compounds for the prevention and treatment of radiotherapy-induced mucositis (RIOM). RIOM represents one of the most frequent side effects associated with anti-neoplastic treatments affecting patients' quality of life and treatment response due to radiation therapy discontinuation. The innate radio-protective ability of natural products obtained from plants is in part due to the numerous antioxidants possessed as a part of their normal secondary metabolic processes. However, oxygen presence is a key point for radiation efficacy on cancer cells. The aim of this review is to describe the most recent evidence on radiation-induced injury and the emerging protective role of natural compounds in preventing and treating this specific damage without compromising treatment efficacy.

The role of nutrition in space exploration: Implications for sensorimotor, cognition, behavior and the cerebral changes due to the exposure to radiation, altered gravity, and isolation/confinement hazards of spaceflight

Multi-year crewed space exploration missions are now on the horizon; therefore, it is important that we understand and mitigate the physiological effects of spaceflight. The spaceflight hazards-radiation, isolation, confinement, and altered gravity-have the potential to contribute to neuroinflammation and produce long-term cognitive and behavioral effects-while the fifth hazard, distance from earth, limits capabilities to mitigate these risks. Accumulated evidence suggests that nutrition has an important role in optimizing cognition and reducing the risk of neurodegenerative diseases caused by neuroinflammation. Here we review the nutritional perspective of how these spaceflight hazards affect the astronaut's brain, behavior, performance, and sensorimotor function. We also assess potential nutrient/nutritional countermeasures that could prevent or mitigate spaceflight risks and ensure that crewmembers remain healthy and perform well during their missions. Just as history has taught us the importance of nutrition in terrestrial exploration, we must understand the role of nutrition in the development and mitigation of spaceflight risks before humans can successfully explore beyond low-Earth orbit.

Zeaxanthin and Lutein: Photoprotectors, Anti-Inflammatories, and Brain Food

This review compares and contrasts the role of carotenoids across the taxa of life—with a focus on the xanthophyll zeaxanthin (and its structural isomer lutein) in plants and humans. Xanthophylls’ multiple protective roles are summarized, with attention to the similarities and differences in the roles of zeaxanthin and lutein in plants versus animals, as well as the role of meso-zeaxanthin in humans. Detail is provided on the unique control of zeaxanthin function in photosynthesis, that results in its limited availability in leafy vegetables and the human diet. The question of an optimal dietary antioxidant supply is evaluated in the context of the dual roles of both oxidants and antioxidants, in all vital functions of living organisms, and the profound impact of individual and environmental context.

Growth and Essential Carotenoid Micronutrients in Lemna gibba as a Function of Growth Light Intensity

Duckweed is a promising food crop with multiple benefits for space applications. Fresh duckweed could deliver synergistically acting essential antioxidant nutrients to a crew - but only if growth conditions provide the plant with the right cues to trigger antioxidant formation. We grew Lemna gibba under continuous growth light ranging from low to very high intensities (photosynthetic photon flux densities = PPFDs) in order to investigate the effect on plant growth, photosynthesis, and level of carotenoid antioxidants that are essential human micronutrients. Lemna gibba achieved remarkably high growth rates under modest growth PPFD by virtue of superior light absorption resulting from minimal self-shading and high chlorophyll levels. Conversely, L. gibba's growth rate remained high even under very high growth PPFDs. This notable ability of L. gibba to avoid inactivation of photosynthesis and diminished growth under very high growth PPFDs resulted from a combination of downregulation of chlorophyll synthesis and increased biochemical photoprotection that limited a build-up of excessive excitation energy. This biochemical photoprotection included accumulation of zeaxanthin (an essential human micronutrient) and high levels of zeaxanthin-catalyzed thermal energy dissipation of excess excitation. Compared to the light levels needed to saturate L. gibba photosynthesis and growth, higher light levels were thus required for strong induction of the essential antioxidant zeaxanthin. These results indicate a need for design of light protocols that achieve simultaneous optimization of plant yield, nutritional quality, and light-use efficiency to circumvent the fact that the light requirement to saturate plant growth is lower than that for production of high zeaxanthin levels. How this trade-off between light-use efficiency of growth and nutritional quality might be minimized or circumvented to co-optimize all desired features is discussed.

Effects of ionizing radiation on bio-active plant extracts useful for preventing oxidative damages

Humans are exposed to ionizing radiations in medical radiodiagnosis and radiotherapy that cause oxidative damages and degenerative diseases. Airplane pilots, and even more astronauts, are exposed to a variety of potentially harmful factors, including cosmic radiations. Among the phytochemicals, phenols are particularly efficient in countering the oxidative stress. In the present study, different extracts obtained from plant food, plant by-products and dietary supplements, have been compared for their antioxidant properties before and after irradiation of 140 cGy, a dose absorbed during a hypothetical stay of three years in the space. All the dry extracts, characterized in terms of vitamin C and phenolic content, remained chemically unaltered and maintained their antioxidant capability after irradiation. Our results suggest the potential use of these extracts as nutraceuticals to protect humans from oxidative damages, even when these extracts must be stored in an environment exposed to cosmic radiations as in a space station.

Antioxidants Taken Orally prior to Diagnostic Radiation Exposure Can Prevent DNA Injury

PURPOSE

To evaluate efficacy of oral antioxidant treatment given to patients before radiologic procedures in reducing x-ray-induced DNA damage.

MATERIALS AND METHODS

In a single-center prospective controlled trial, antioxidant treatment with 2 g ascorbate, 1.2 g N-acetylcysteine, 600 mg lipoic acid, and 30 mg beta carotene was given to 5 consecutive participants before undergoing clinically indicated technetium-99m methylene diphosphonate (^99mTc MDP) bone scans for cancer staging. These participants were compared with 5 participants without antioxidant treatment. DNA damage was visualized in peripheral blood mononuclear cells (PBMCs) before and after bone scans using three-dimensional microscopy and fluorescently labeled gamma-H2AX protein. Wilcoxon rank sum test was used to determine whether there was a statistically significant difference in the radiation received between the control and antioxidant groups, the number of foci/cell before and after bone scan within groups, and foci/cell after bone scan between groups.

RESULTS

There was a significantly higher number of gamma-H2AX foci/cell after ionization radiation in the control group compared with the antioxidant group (P = .009). There was no statistically significant difference in number of gamma-H2AX foci/cell before or after exposure in the antioxidant group; the number of gamma-H2AX foci/cell was statistically significantly higher (P = .009) in the control group after exposure to ^99mTc MDP.

CONCLUSIONS

In patients undergoing ^99mTc MDP bone scans, treatment with oral antioxidants before scanning significantly prevented DNA damage in PBMCs. Antioxidants may provide an effective means to protect patients and health care professionals from radiation-induced DNA damage during imaging studies.

Influence of nutrition on the decline of ovarian reserve and subsequent onset of natural menopause

The early loss of ovarian reserve and subsequent menopause has a major impact on fertility potential and increases the risk of cardiovascular disease, osteoporosis, cognitive decline and mortality later in life. While many studies have reported that lifestyle factors such as diet can influence the age of onset of natural menopause, their results are often contradictory. Therefore, the aim of this study was to examine the influence of diet on the onset of natural menopause using a self-reported food frequency questionnaire in a cohort of 1146 pre-menopausal women followed up for an average of 12.5 years. The primary finding was that the age of natural menopause was positively correlated with dietary intake of the micronutrient β-cryptoxanthin (r(2 )=( )0.105, p < 0.001) and fruit (r(2 )=( )0.07, p = 0.01), with these relationships remaining significant even after adjustment for other known co-variants for onset of menopause (parity, BMI, physical activity level, education, smoking, energy and alcohol intake). Kaplan-Meier survival analysis confirmed that both β-cryptoxanthin and fruit intake was associated with a significant delay in the onset of natural menopause. While still acknowledging that further research is required, in the interim we would advocate that a diet containing ∼400 mcg of β-cryptoxanthin per day from fruits (mandarins, oranges and peaches) has significant potential to delay ovarian senescence by 1.3 years.

Increased levels of chromosomal aberrations and DNA damage in a group of workers exposed to formaldehyde

Formaldehyde (FA) is a commonly used chemical in anatomy and pathology laboratories as a tissue preservative and fixative. Because of its sensitising properties, irritating effects and cancer implication, FA accounts probably for the most important chemical-exposure hazard concerning this professional group. Evidence for genotoxic effects and carcinogenic properties in humans is insufficient and conflicting, particularly in regard to the ability of inhaled FA to induce toxicity on other cells besides first contact tissues, such as buccal and nasal cells. To evaluate the effects of exposure to FA in human peripheral blood lymphocytes, a group of 84 anatomy pathology laboratory workers exposed occupationally to FA and 87 control subjects were tested for chromosomal aberrations (CAs) and DNA damage (comet assay). The level of exposure to FA in the workplace air was evaluated. The association between genotoxicity biomarkers and polymorphic genes of xenobiotic-metabolising and DNA repair enzymes were also assessed. The estimated mean level of FA exposure was 0.38±0.03 ppm. All cytogenetic endpoints assessed by CAs test and comet assay % tail DNA (%TDNA) were significantly higher in FA-exposed workers compared with controls. Regarding the effect of susceptibility biomarkers, results suggest that polymorphisms in CYP2E1 and GSTP1 metabolic genes, as well as, XRCC1 and PARP1 polymorphic genes involved in DNA repair pathways are associated with higher genetic damage in FA-exposed subjects. Data obtained in this study show a potential health risk situation of anatomy pathology laboratory workers exposed to FA (0.38 ppm). Implementation of security and hygiene measures may be crucial to decrease risk. The obtained information may also provide new important data to be used by health care programs and by governmental agencies responsible for occupational health and safety.

Modulation of DNA-induced damage and repair capacity in humans after dietary intervention with lutein-enriched fermented milk

Dietary factors provide protection against several forms of DNA damage. Additionally, consumer demand for natural products favours the development of bioactive food ingredients with health benefits. Lutein is a promising biologically active component in the food industry. The EFSA Panel on Dietetic Products, Nutrition and Allergies considers that protection from oxidative damage may be a beneficial physiological effect but that a cause and effect relationship has not been established. Thus, our aim was to evaluate the safety and potential functional effect of a lutein-enriched milk product using the Comet Assay in order to analyze the baseline, the induced DNA-damage and the repair capacity in the lymphocytes of 10 healthy donors before and after the intake of the mentioned product. Our data suggest that the regular consumption of lutein-enriched fermented milk results in a significant increase in serum lutein levels and this change is associated with an improvement in the resistance of DNA to damage and the capacity of DNA repair in lymphocytes. Our results also support the lack of a genotoxic effect at the doses supplied as well as the absence of interactions and side effects on other nutritional and biochemicals markers.

Preventive or potential therapeutic value of nutraceuticals against ionizing radiation-induced oxidative stress in exposed subjects and frequent fliers

Humans are constantly exposed to ionizing radiation deriving from outer space sources or activities related to medical care. Absorption of ionizing radiation doses over a prolonged period of time can result in oxidative damage and cellular dysfunction inducing several diseases, especially in ageing subjects. In this report, we analyze the effects of ionizing radiation, particularly at low doses, in relation to a variety of human pathologies, including cancer, and cardiovascular and retinal diseases. We discuss scientific data in support of protection strategies by safe antioxidant formulations that can provide preventive or potential therapeutic value in response to long-term diseases that may develop following exposure.

Hass avocado composition and potential health effects

Hass avocados, the most common commercial avocado cultivars in the world, contain a variety of essential nutrients and important phytochemicals. Although the official avocado serving is one-fifth of a fruit (30 g), according to NHANES analysis the average consumption is one-half an avocado (68 g), which provides a nutrient and phytochemical dense food consisting of the following: dietary fiber (4.6 g), total sugar (0.2 g), potassium (345 mg), sodium (5.5 mg), magnesium (19.5 mg), vitamin A (43 μg), vitamin C (6.0 mg), vitamin E (1.3 mg), vitamin K1 (14 μg), folate (60 mg), vitamin B-6 (0.2 mg), niacin (1.3 mg), pantothenic acid (1.0 mg), riboflavin (0.1 mg), choline (10 mg), lutein/zeaxanthin (185 μg), phytosterols (57 mg), and high-monounsaturated fatty acids (6.7 g) and 114 kcals or 1.7 kcal/g. The avocado oil consists of 71% monounsaturated fatty acids (MUFA), 13% polyunsaturated fatty acids (PUFA), and 16% saturated fatty acids (SFA), which helps to promote healthy blood lipid profiles and enhance the bioavailability of fat soluble vitamins and phytochemicals from the avocado or other fruits and vegetables, naturally low in fat, which are consumed with avocados. There are eight preliminary clinical studies showing that avocado consumption helps support cardiovascular health. Exploratory studies suggest that avocados may support weight management and healthy aging.

Vitamin C for DNA damage prevention

The ability of vitamin C to affect genetic damage was reviewed in human studies that used molecular epidemiology methods, including analysis of DNA adducts, DNA strand breakage (using the Comet assay), oxidative damage measured as levels of 8-oxo-7,8-dihydroxy-2'-deoxyguanosine (8-oxodG), cytogenetic analysis of chromosomal aberrations and micronuclei, and the induction of DNA repair proteins. The protective effect of vitamin C was observed at plasma levels>50μmol/l. Vitamin C supplementation decreased the frequency of chromosomal aberrations in groups with insufficient dietary intake who were occupationally exposed to mutagens, and also decreased the sensitivity to mutagens as assessed using the bleomycin assay. High vitamin C levels in plasma decreased the frequency of genomic translocations in groups exposed to ionizing radiation or c-PAHs in polluted air. The frequency of micronuclei was decreased by vitamin C supplementation in smokers challenged with γ-irradiation, and higher vitamin C levels in plasma counteracted the damage induced by air pollution. The prevalence of DNA adducts inversely correlated with vitamin C levels in groups environmentally exposed to high concentrations of c-PAHs. Increased vitamin C levels decreased DNA strand breakage induced by air pollution. Oxidative damage (8-oxodG levels) was decreased by vitamin C supplementation in groups with plasma levels>50μmol/l exposed to PM2.5 and c-PAHs. Modulation of DNA repair by vitamin C supplementation was observed both in poorly nourished subjects and in groups with vitamin C plasma levels>50μmol/l exposed to higher concentrations of c-PAHs. It is possible that the impact of vitamin C on DNA damage depends both on background values of vitamin C in the individual as well as on the level of exposure to xenobiotics or oxidative stress.

High dietary niacin intake is associated with decreased chromosome translocation frequency in airline pilots

Experimental studies suggest that B vitamins such as niacin, folate, riboflavin, vitamin B6 and vitamin B12 may protect against DNA damage induced by ionising radiation (IR). However, to date, data from IR-exposed human populations are not available. We examined the intakes of these B vitamins and their food sources in relation to the frequency of chromosome translocations as a biomarker of cumulative DNA damage, in eighty-two male airline pilots. Dietary intakes were estimated by using a self-administered semi-quantitative FFQ. Translocations in peripheral blood lymphocytes were scored by using fluorescence in situ hybridisation whole-chromosome painting. Negative binomial regression was used to estimate rate ratios and 95 % CI, adjusted for age and occupational and lifestyle factors. We observed a significant inverse association between translocation frequency and dietary intake of niacin (P = 0·02): adjusted rate ratio for subjects in the highest tertile compared with the lowest tertile was 0·58 (95 % CI 0·40, 0·83). Translocation frequency was not associated with total niacin intake from food and supplements as well as dietary or total intake of folate, riboflavin or vitamin B6 or B12. However, the adjusted rate ratios were significant for subjects with ≥ median compared with < median intake of whole grains (P = 0·03) and red and processed meat (P = 0·01): 0·69 (95 % CI 0·50, 0·96) and 1·56 (95 % CI 1·13, 2·16), respectively. Our data suggest that a high intake of niacin from food or a diet high in whole grains but low in red and processed meat may protect against cumulative DNA damage in IR-exposed persons.

Citrus consumption and cancer incidence: the Ohsaki cohort study

Basic research and case-control studies have suggested that citrus consumption may protect against cancer. However, the protective effect has been observed from few prospective studies. This study investigated the association of citrus consumption with cancer incidence among 42,470 Japanese adults in the Ohsaki National Health Insurance Cohort, which covered an age range of 40-79 years, and was followed up from 1995 to 2003 for all-cancer and individual cancer incidence. Citrus consumption was assessed using a self-administered questionnaire. The Cox proportional hazard model was applied to estimate relative risks (RRs) and 95% CIs. During the 323,204 person-years of follow-up, 3,398 cases were identified totally. Citrus consumption, especially daily consumption, was correlated with reduced all-cancer incidence, the RRs were 0.89 (95% CI = 0.80-0.98) for total participants, 0.86 (0.76-0.98) for males and 0.93 (0.79-1.09) for females, as well as multiple cancers at individual sites, especially pancreatic (RR = 0.62, 95% CI = 0.38-1.00) and prostate cancer (RR = 0.63, 95% CI = 0.41-0.97). Joint effect analysis showed a reduced risk of overall cancer existed only for subjects who consumed >or=1 cup green tea/day (RR = 0.83, 95% CI = 0.73-0.93) as well as for males (RR = 0.83, 95% CI = 0.71-0.97) or females (RR = 0.82, 95% CI = 0.68-0.99). These findings suggest that citrus consumption is associated with reduced all-cancer incidence, especially for subjects having simultaneously high green tea consumption. Further work on the specific citrus constituents is warranted, and clinical trials are ultimately necessary to confirm the protective effect.