Nutrition and nonmelanoma skin cancers

Trace element zinc and skin disorders

Zinc is a necessary trace element and an important constituent of proteins and other biological molecules. It has many biological functions, including antioxidant, skin and mucous membrane integrity maintenance, and the promotion of various enzymatic and transcriptional responses. The skin contains the third most zinc in the organism. Zinc deficiency can lead to a range of skin diseases. Except for acrodermatitis enteropathic, a rare genetic zinc deficiency, it has also been reported in other diseases. In recent years, zinc supplementation has been widely used for various skin conditions, including infectious diseases (viral warts, genital herpes, cutaneous leishmaniasis, leprosy), inflammatory diseases (hidradenitis suppurativa, acne vulgaris, rosacea, eczematous dermatitis, seborrheic dermatitis, psoriasis, Behcet's disease, oral lichen planus), pigmentary diseases (vitiligo, melasma), tumor-associated diseases (basal cell carcinoma), endocrine and metabolic diseases (necrolytic migratory erythema, necrolytic acral erythema), hair diseases (alopecia), and so on. We reviewed the literature on zinc application in dermatology to provide references for better use.

Dietary antioxidant supplements and risk of keratinocyte cancers in women: a prospective cohort study

PURPOSE

Experimental studies suggested that antioxidants could protect against skin carcinomas. However, epidemiological studies on antioxidant supplement use in relation to basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC) risks yielded inconsistent findings, and few prospective studies have been conducted to date. We aimed to investigate the associations between antioxidant supplement intake and keratinocyte cancer (KC) risk.

METHODS

E3N is an ongoing prospective cohort initiated in 1990 and involving 98,995 French women aged 40-65 years at recruitment. Intakes of dietary antioxidants were estimated via a validated dietary questionnaire in 1993 and self-reported antioxidant supplement use was collected in 1995. We used Cox models to compute hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for age and skin cancer risk factors.

RESULTS

Over 1995-2014, 2426 BCC and 451 SCC cases were diagnosed among 63,063 women. We found positive relationships between vitamin A supplement use and KC risk (HR = 1.37, 95% CI 1.15-1.62), particularly with BCC (HR = 1.40, 95% CI 1.17-1.69); and between vitamin E supplement use and risks of both BCC (HR = 1.21, 95% CI 1.03-1.52) and SCC (HR = 1.43, 95% CI 1.03-1.99). Intake of beta-carotene supplements was associated with an increased SCC risk (HR = 1.59, 95% CI 1.00-2.54). Vitamin C supplement use was not associated with KC risk. We found similar results when considering total antioxidant intake.

CONCLUSIONS

Intakes of vitamin A or E supplements were associated with an increased KC risk in women. Further studies with information on doses and duration of supplement use and the ability to examine their underlying mechanisms are needed.

Dietary components and the risk of non-melanoma skin cancer: A systematic review of epidemiological studies

Non-melanoma skin cancer (NMSC) is the most common cancer among white-skinned people. The main environmental risk factor for all types of skin cancer is ultraviolet (UV) exposure to the sun. However, significant modifiable risk factors, such as diet, have been studied about NMSC risk. Several original studies have been conducted on the link between various dietary components and the risk of NMSC in the past decade, but have not been systematically reviewed. This review focuses on the potential impact of dietary components in the prevention of NMSC and evaluates the findings of epidemiologic evidence for dietary factors. We conducted a systematic search of three databases, including Scopus, ISI Web of Science, and PubMed, to identify relevant epidemiological studies published between 2000 and July 6, 2021. Finally, forty-three articles were included. Because of the inherent limitations of epidemiological studies, no definitive conclusions can be drawn; however, the links between folate, citrus, caffeine, and alcohol with BCC are notable; thus, high dietary folate intake, as well as citrus and alcohol consumption, are associated with an increased risk of basal cell carcinoma (BCC), whereas caffeine is associated with a lower risk. More research is required to reach a definitive conclusion.

Nutrition and nonmelanoma skin cancers

Nonmelanoma skin cancer (NMSC), the most widely diagnosed cancer in the United States, is rising in incidence despite public health and educational campaigns that highlight the importance of sun avoidance. It is,therefore, important to establish other modifiable risk factors that may be contributing to this increase. There is a growing body of evidence in the literature suggesting certain nutrients may have protective or harmful effects on NMSC. We review the current literature on nutrition and its effect on NMSC with a focus on dietary fat, vitamin A, nicotinamide, folate, vitamin C, vitamin D, vitamin E, polyphenols, and selenium.

Mediterranean diet, Dietary Approaches to Stop Hypertension, and Pro-vegetarian dietary pattern in relation to the risk of basal cell carcinoma: a nested case-control study within the Seguimiento Universidad de Navarra (SUN) cohort

BACKGROUND

The association of dietary pattern with the risk of basal cell carcinoma (BCC) is little understood and has scarcely been investigated.

OBJECTIVES

We assessed the association of several complete dietary patterns [Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Pro-vegetarian dietary pattern] with the risk of BCC, conducting a nested case-control study (4 controls for each case).

METHODS

Cases and controls were selected from the SUN (Seguimiento Universidad de Navarra) cohort using risk set sampling. Cases were identified among subjects free of skin cancer at baseline but who later reported a physician-made BCC diagnosis during the follow-up period. In the cohort we identified 101 incident cases of BCC.

RESULTS

In multivariable-adjusted conditional logistic regression analyses, better adherence to the Mediterranean diet (highest compared with lowest quintile) was associated with a 72% relative reduction in the odds of BCC (OR: 0.28; 95% CI: 0.10, 0.77; Ptrend = 0.014); the DASH diet was associated with a 68% RR reduction (OR: 0.32; 95% CI: 0.14, 0.76; Ptrend = 0.013) for the comparison between extreme quintiles. No association was found between a Pro-vegetarian dietary pattern and BCC. Higher fruit consumption (highest compared with lowest quintile, OR: 0.27; 95% CI: 0.11, 0.64; Ptrend < 0.001) and low-fat dairy products (OR: 0.39; 95% CI: 0.16, 0.92; Ptrend = 0.014) were associated with a lower BCC risk.

CONCLUSIONS

Our results suggest that Mediterranean and DASH dietary patterns may be associated with a lower risk of BCC, but confirmatory studies are required.

Holistic dermatology: An evidence-based review of modifiable lifestyle factor associations with dermatologic disorders

BACKGROUND

Holistic dermatology focuses on treating the human body as a whole and implementing lifestyle changes to enhance the treatment and prognosis of skin disease. Understanding the interplay between modifiable lifestyle factors and patients' dermatologic health will help physicians better inform patients on self-care methods to mitigate the burden of their skin disease(s).

OBJECTIVE

To review the current scientific literature on the relationship between modifiable lifestyle factors and the dermatologic outcome of skin disorders.

METHODS

A systematic literature search on PubMed, Cochrane, and Web of Science was conducted to identify research articles examining the relationship between dermatology and 6 major categories of modifiable lifestyle factors: diet, sleep, exercise, stress, alcohol, and smoking.

RESULTS

A substantial amount of evidence supports the relationship between modifiable lifestyle factors and dermatologic outcomes. There were the most studies on diet, stress, alcohol, and smoking, but all lifestyle factors were supported by some degree of scientific evidence.

CONCLUSION

All modifiable lifestyle factors explored in this review play a critical role in modulating the onset and progression of skin disease. We anticipate more research studies in the future and an increasing integration of holistic dermatology into patient care.

Mediterranean dietary pattern and skin cancer risk: A prospective cohort study in French women

BACKGROUND

The Mediterranean diet (MD) has been reported to be associated with lower cancer risk. However, while previous studies explored major single components of the MD, only 1 previous study has investigated adherence to the MD in relation to melanoma risk.

OBJECTIVE

The aim of this study was to explore the relations between adherence to the MD and the risk of skin cancer, including melanomas, basal cell carcinomas (BCCs), and squamous cell carcinomas (SCCs).

DESIGN

Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale (E3N) is a prospective cohort of 98,995 French women aged 40-65 y in 1990. Dietary data were collected via a validated food questionnaire in 1993. Adherence to the MD was assessed using a 9-unit dietary score that incorporates intakes of fruit, vegetables, legumes, cereal products, olive oil, fish, dairy products, meat products, and alcohol. We used Cox proportional hazards regression models to compute HRs and 95% CIs adjusted for age and main known skin cancer risk factors.

RESULTS

From 1993 to 2008, a total of 2003 skin cancer cases were ascertained among 67,332 women, including 404 melanomas, 1367 BCCs, and 232 SCCs. Score of adherence to the MD was associated with lower risk of skin cancer (HR: 0.83; 95% CI: 0.73, 0.93 for high compared with low score, Ptrend = 0.001). MD score was also inversely and linearly associated with risks of melanoma (HR: 0.72; 95% CI: 0.54, 0.96; Ptrend = 0.02) and BCC (HR: 0.77; 95% CI: 0.66, 0.90; Ptrend = 0.0006) but not SCC (HR: 1.08; 95% CI: 0.75, 1.55; Ptrend = 0.68), although with no heterogeneity across skin cancer types (Pheterogeneity = 0.23).

CONCLUSION

These findings suggest that adherence to the MD is associated with a lower skin cancer risk in women, particularly melanoma and BCC. If confirmed in future research, these findings may have important implications in skin cancer prevention.

Exposure to Trace Elements and Risk of Skin Cancer: A Systematic Review of Epidemiologic Studies

Exposure to environmental trace elements has been studied in relation to many cancers. However, an association between exposure to trace elements and skin cancer remains less understood. Therefore, we conducted a systematic review of published epidemiologic literature examining the association between exposure to trace elements, and risk of melanoma and keratinocyte carcinoma in humans. We identified epidemiologic studies investigating exposure to arsenic, cadmium, chromium, copper, iron, selenium, and zinc and risk of skin cancer in humans. Among the minerals, arsenic, selenium, and zinc had more than five studies available. Exposure to arsenic was associated with increased risk of keratinocyte carcinoma, while too few studies existed on melanoma to draw conclusions. Exposure to selenium was associated with possible increased risk of keratinocyte carcinoma. Studies of zinc and skin cancer were case-control in design and were found to have inconsistent associations. The data on the association between cadmium, chromium, copper, and iron and risk of skin cancer remain too sparse to draw any conclusions. In summary, epidemiologic studies on exposure to trace elements and cutaneous malignancies are limited. Studies with larger sample sizes and prospective designs are warranted to improve our knowledge of trace elements and skin cancer.

Diet and Skin Cancer: The Potential Role of Dietary Antioxidants in Nonmelanoma Skin Cancer Prevention

Nonmelanoma skin cancer (NMSC) is the most common cancer among Americans. Ultraviolet (UV) radiation exposure is the major risk factor for the development of NMSC. Dietary AOs may prevent free radical-mediated DNA damage and tumorigenesis secondary to UV radiation. Numerous laboratory studies have found that certain dietary AOs show significant promise in skin cancer prevention. These results have been substantiated by animal studies. In human studies, researchers have evaluated both oral AO supplements and dietary intake of AOs via whole foods. In this review, we provide an overview of the role of AOs in preventing tumorigenesis and outline four targeted dietary AOs. We review the results of research evaluating oral AOs supplements as compared to dietary AOs intake via whole foods. While these specific supplements have not shown efficacy, intake of AOs via consumption of whole foods has shown some promise. Lessons learned from the field of hypertension research may provide important guidance in future study design. Further research on the role of dietary AOs in the prevention of NMSC is warranted and should focus on intake via whole food consumption.

Systematic review of studies investigating the association between dietary habits and cutaneous malignant melanoma

OBJECTIVE

Several papers have dealt with diet as a risk factor for cutaneous malignant melanoma (CMM). This study aimed to synthesize available data on the topic.

STUDY DESIGN

A systematic review of observational studies assessing the association between dietary habits and CMM was performed.

METHODS

Electronic databases were used to identify eligible articles. Quality was assessed through the Newcastle-Ottawa scale. Case-control and cohort studies evaluating the intake of food/nutrients through the assessment of dietary habits and the occurrence of CMM were considered eligible. Data comparing the highest and lowest levels of consumption were collected from single studies and described qualitatively as data combination was not possible. Results were reported as percentages on the basis of relative risks and odds ratios.

RESULTS

Eighteen studies reported in 21 articles were selected. Cohort studies showed better quality than case-control studies. Most articles did not detect any significant association between food/nutrient intake and CMM, except for limited evidence of a protective role associated with fish, vegetables and fruit. Risk reduction was shown to be 35-37%, 40-57% and 34-46%, respectively, in studies reporting significant results. Similarly, few articles showed protective roles of beta-carotene and vitamins A, C, D and E, with risk reduction of 64%, 37-43%, 41%, 15-39% and 50-66%, respectively.

CONCLUSION

A trend towards reduced risk of CMM associated with higher intake of fish, vegetables and fruit, as well as beta-carotene and vitamins A, C, D and E, has been shown but further research is needed to provide decisive data.

Prospective association between dietary folate intake and skin cancer risk: results from the Supplémentation en Vitamines et Minéraux Antioxydants cohort

BACKGROUND

The role of folate in skin carcinogenesis is unclear, with experimental data suggesting potentially protective but also deleterious effects.

OBJECTIVE

Our main objective was to investigate the prospective association between dietary folate intake and risks of skin cancer (overall), nonmelanoma skin cancer (NMSC), and basal cell carcinoma (BCC). As an exploratory analysis, we also investigated the prospective association between erythrocyte folate concentration and skin cancer risk.

DESIGN

In this study, we included 5880 participants in the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort (follow-up: 1994-2007) who completed at least six 24-h dietary records during the first 2 y of the study. Associations between sex-specific tertiles of dietary and erythrocyte folate and skin cancer risk were assessed by using multivariate Cox proportional hazards models.

RESULTS

After a median follow-up of 12.6 y, 144 incident skin cancers were diagnosed. Dietary folate intake was associated with increased risk of overall skin cancer [HR for tertile 3 compared with tertile 1 (HR(T3vs.T1)): 1.79; 95% CI: 1.07, 2.99; P-trend = 0.03], NMSC (HR(T3vs.T1): 1.85; 95% CI: 1.06, 3.23; P-trend = 0.03), and BCC (HR(T3vs.T1): 1.78; 0.98, 3.24; P-trend = 0.05). This association was observed in women (corresponding P-trend = 0.007, 0.009, and 0.009, respectively) but not in men (P-trend = 0.8, 0.8, and 0.9, respectively). P-interaction values between tertiles of dietary folate intake and sex were 0.04, 0.02, and 0.02 for overall skin cancer, NMSC, and BCC, respectively. Erythrocyte folate concentration was directly associated with increased risk of overall skin cancer (HR(T3vs.T1): 2.54; 95% CI: 0.95, 6.81; P-trend = 0.03), NMSC (HR(T3vs.T1): 3.49; 95% CI: 1.11, 11.0; P-trend = 0.01), and BCC (HR(T3vs.T1): 7.44; 95% CI: 1.57, 35.3; P-trend = 0.004) (men and women combined).

CONCLUSIONS

This prospective study suggests an association between dietary folate intake and erythrocyte folate concentration and increased risk of overall skin cancer, NMSC, and BCC. Although several mechanistic hypotheses and 2 previous large prospective studies on BCC are in line with these results, epidemiologic literature is limited, and future research is needed to better elucidate the potential role of folate in the cause of skin cancers.

Tea, coffee, and caffeine and early-onset basal cell carcinoma in a case-control study

Tea and coffee are hypothesized to play a protective role in skin carcinogenesis through bioactive components, such as caffeine, yet the epidemiologic evidence is mixed. Existing data support an inverse association with basal cell carcinoma (BCC), more so than for melanoma or squamous cell carcinoma. To understand whether tea, coffee, and caffeine are related to early-onset BCC, we evaluated data from 767 non-Hispanic Whites under age 40 in a case-control study in Connecticut. BCC cases (n=377) were identified through Yale's Dermatopathology database. Controls (n=390) were randomly sampled from individuals in the same database with benign skin diagnoses and frequency matched to cases on age, sex, and biopsy site. Participants completed an in-person interview including assessment of caffeinated coffee and hot tea. We calculated multivariate odds ratios (ORs) and 95% confidence intervals (CIs) with unconditional logistic regression for regular consumption and frequency and duration measures. Combined regular consumption of caffeinated coffee plus hot tea was inversely associated with early-onset BCC (OR=0.60, 95% CI=0.38-0.96). Those in the highest category of caffeine from these sources had a 43% reduced risk of BCC compared with nonconsumers (OR=0.57, 95% CI=0.34-0.95, P-trend=0.037). Our findings suggest a modest protective effect for caffeinated coffee plus tea in relation to early-onset BCC that may, in part, be due to caffeine. This study adds to the growing body of literature suggesting potential health benefits from these beverages.

Diet in dermatology: Part I. Atopic dermatitis, acne, and nonmelanoma skin cancer

Patients commonly inquire about dietary modifications as a means to prevent or manage skin disease. Answering these questions is often challenging, given the vast and conflicting evidence that exists on this topic. This 2-part continuing medical education article summarizes the evidence to date to enable physicians to answer patients' questions in an evidence-based manner. Part I includes atopic dermatitis, acne, and nonmelanoma skin cancer. The role of dietary supplementation, dietary exclusion, food allergy, maternal diet, and breastfeeding in the development and/or prevention of atopic dermatitis is summarized. The dermatoendocrinologic mechanism for the effects of glycemic index/glycemic load and milk on acne is described, as well as related clinical evidence for dietary modifications. Finally, evidence and recommendations for restriction or supplementation of dietary factors in the prevention of nonmelanoma skin cancer, including fat, vitamins A, C, D, and E, and selenium, are reported.

Review of natural compounds for potential skin cancer treatment

Most anti-cancer drugs are derived from natural resources such as marine, microbial and botanical sources. Cutaneous malignant melanoma is the most aggressive form of skin cancer, with a high mortality rate. Various treatments for malignant melanoma are available, but due to the development of multi-drug resistance, current or emerging chemotherapies have a relatively low success rates. This emphasizes the importance of discovering new compounds that are both safe and effective against melanoma. In vitro testing of melanoma cell lines and murine melanoma models offers the opportunity for identifying mechanisms of action of plant derived compounds and extracts. Common anti-melanoma effects of natural compounds include potentiating apoptosis, inhibiting cell proliferation and inhibiting metastasis. There are different mechanisms and pathways responsible for anti-melanoma actions of medicinal compounds such as promotion of caspase activity, inhibition of angiogenesis and inhibition of the effects of tumor promoting proteins such as PI3-K, Bcl-2, STAT3 and MMPs. This review thus aims at providing an overview of anti-cancer compounds, derived from natural sources, that are currently used in cancer chemotherapies, or that have been reported to show anti-melanoma, or anti-skin cancer activities. Phytochemicals that are discussed in this review include flavonoids, carotenoids, terpenoids, vitamins, sulforaphane, some polyphenols and crude plant extracts.

Role of vitamin D metabolism in cutaneous tumour formation and progression

OBJECTIVES

Very limited information is available on the role of vitamin D in skin carcinogenesis. For most individuals, skin cancer can be readily managed with surgery; however, some patients may face life-threatening neoplasia. Sun exposure, specifically UV radiation, is a causative agent for development of skin cancer, though, somewhat ironically, sunlight through the production of vitamin D may have protective effect against some skin cancers. This review focuses on the development and progression of cutaneous carcinogenesis and the role of vitamin D in the prevention of the initiation and progression of lethal skin cancers.

KEY FINDINGS

Vitamin D is involved in regulation of multiple signalling pathways that have implications in carcinogenesis. Skin cancer metastasis depends on the tumour microenvironment, where vitamin D metabolites play a key role in prevention of certain molecular events involved in tumour progression. The vitamin D receptor (VDR) is a well-known potent regulator of cellular growth and differentiation.

SUMMARY

The VDR's possible involvement in cell death, tumour microenvironment and angiogenesis makes it a candidate agent for cancer regulation.

Photoprotection by dietary carotenoids: concept, mechanisms, evidence and future development

Carotenoids are micronutrients present mainly in fruits and vegetables, and they are ingested from these sources with the diet. They exhibit specific antioxidant activity but also influence signaling and gene expression at the cellular level. β-Carotene and lycopene, the colorants of carrots and tomatoes, respectively, are among the most prominent members of this group of lipids, and they are usually the dominating carotenoids in human blood and tissues. Both compounds modulate skin properties when ingested as supplements or as dietary products. There is evidence that they protect the skin against sunburn (solar erythema) by increasing the basal defense against UV light-mediated damage. Their photoprotective efficacy, however, is not comparable to the use of a sunscreen. In vitro data show that also other carotenoids are efficient photoprotectors. Among them are lutein and structurally unusual phenolic polyenes like 3,3'-dihydroxyisorenieratene.

In vitro and in vivo percutaneous absorption of seleno-L-methionine, an antioxidant agent, and other selenium species

AIM

To investigate the in vitro and in vivo percutaneous absorption of seleno-L-methionine (Se-L-M), an ultraviolet (UV)-protecting agent, from aqueous solutions.

METHODS

Aqueous solutions of Se-L-M were prepared in pH 4, 8, and 10.8 buffers. The pH 8 buffer contained 30% glycerol, propylene glycol (PG) and polyethylene glycol (PEG) 400. The in vitro skin permeation of Se-L-M via porcine skin and nude mouse skin was measured and compared using Franz diffusion cells. The in vivo skin tolerance study was performed, which examined transepidermal water loss (TEWL), skin pH and erythema.

RESULTS

In the excised porcine skin, the flux was 0.1, 11.4 and 8.2 μg·cm(-2)·h(-1) for the pH 4, 8, and 10.8 buffers, respectively. A linear correlation between the flux and skin deposition was determined. According to permeation across skin with different treatments (stripping, delipidation, and ethanol treatments), it was determined that the intracellular route comprised the predominant pathway for Se-L-M permeation from pH 8 buffer. Aqueous solutions of seleno-DL-methionine (Se-DL-M), selenium sulfide and selenium-containing quantum dot nanoparticles were also used as donor systems. The DL form showed a lower flux (7.0 vs 11.4 μg·cm(-2)·h(-1)) and skin uptake (23.4 vs 47.3 μg/g) as compared to the L form, indicating stereoselective permeation of this compound. There was no or only negligible permeation of selenium sulfide and quantum dots into and across the skin. With in vivo topical application for 4 and 8 h, the skin deposition of Se-L-M was about 7 μg/g, and values were comparable to each other. The topical application of Se-L-M for up to 5 d did not caused apparent skin irritation. However, slight inflammation of the dermis was noted according to the histopathological examination.

CONCLUSION

Se-L-M was readily absorbed by the skin in both the in vitro and in vivo experiments. The established profiles of Se-L-M skin absorption will be helpful in developing topical products of this compound.