Long-Term Vitamin D Supplementation and the Effects on Recurrence and Metabolic Status of Cervical Intraepithelial Neoplasia Grade 2 or 3: A Randomized, Double-Blind, Placebo-Controlled Trial

Natural Health Products for Anti-Cancer Treatment: Evidence and Controversy

Natural Health Products (NHPs) have long been considered a valuable therapeutic approach for the prevention and treatment of various diseases, including cancer. However, research on this topic has led to inconclusive and often controversial results. This review aims to provide a comprehensive update of the effects and mechanisms related to the use of NHPs, to describe the results of randomized clinical trials (RCTs) on their effects in cancer patients, and to critically discuss factors influencing clinical outcomes. RCTs available in the literature, even those studying the same NHP, are very heterogeneous in terms of indications, doses, route and timing of administration, and outcomes evaluated. Silymarin, ginsenoside, and vitamin E appear to be useful in attenuating adverse events related to radiotherapy or chemotherapy, and curcumin and lycopene might provide some benefit in patients with prostate cancer. Most RCTs have not clarified whether NHP supplementation provides any real benefit, while harmful effects have been shown in some cases. Overall, the available data suggest that although there is some evidence to support the benefits of NHPs in the management of cancer patients, further clinical trials with the same design are needed before their introduction into clinical practice can be considered.

The effects of dietary supplements in patients with cervical cancer: a comprehensive systematic review

Background

Recent studies reported that complementary therapy including dietary supplements may has a beneficial role in cervical cancer. However, the results are inconsistent. This study aimed to investigate the association between cervical cancer and dietary supplements.

Methods

A systematic literature review was conducted to summarize and quantify the most recent findings on dietary supplement and cervical cancer. Several databases were checked for relevant publications published in English up to March 2023. Of the 32 articles identified, only 20 met the inclusion criteria and were included.

Results

Women with cervical intraepithelial neoplasia may benefit from folate supplementation against oxidative stress and inflammation. Vitamin D may reduce oxidative stress and may have a therapeutic effect. Zinc promotes the clearance of the human papilloma virus and reduces the chance of viral infection. The use of probiotic supplements may improve the complications associated with chemotherapy in patients with cervical cancer, such as diarrhea and abdominal pain. Radiotherapy and chemotherapy complications may also be reduced by omega-3 fatty acids.

Conclusion

Some dietary supplements including folate, vitamin D, zinc, probiotics, and omega-3 fatty acids may have beneficial effects in patients with cervical cancer. Further studies are warranted to confirm these results.

Effects of vitamin D supplementation on inflammatory response in patients with cancer and precancerous lesions: Systematic review and meta-analysis of randomized trials

BACKGROUND & AIMS

Inflammation plays a key role in tumor development and progression. Vitamin D has potential tumor suppressing effects through modulation of inflammatory processes. The aim of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to summarize and evaluate the effects of vitamin D3 supplementation (VID3S) on serum inflammatory biomarkers among patients with cancer or pre-cancerous lesions.

METHODS

We searched PubMed, Web of Science and Cochrane databases until November 2022. The effects of VID3S were estimated from pooled standardized mean differences (SMDs) with their 95% confidence intervals (CIs) for inflammatory biomarker follow-up levels between intervention and control groups.

RESULTS

Meta-analysis of eight RCTs (total of 592 patients with cancer or pre-cancerous conditions) showed that VID3S significantly lowered levels of serum tumor necrosis factor (TNF)-α (SMD [95%CI]: -1.65 [-3.07; -0.24]). VID3S also resulted in statistically non-significantly lower serum levels of interleukin (IL)-6 (SMD [95%CI]: -0.83, [-1.78; 0.13]) and C-reactive protein (CRP) (SMD [95%CI]: -0.09, [-0.35; 0.16]), whereas IL-10 levels were unaltered (SMD [95%CI]: -0.00, [-0.50; 0.49]).

CONCLUSION

Our study shows evidence of a significant reduction of TNF-α levels by VID3S for patients with cancer or precancerous lesions. Patients with cancer or precancerous lesions may benefit from personalized VID3S in suppressing tumour-promoting inflammatory response.

PROSPERO REGISTRATION NUMBER

CRD42022295694.

The Role of Micronutrients in Human Papillomavirus Infection, Cervical Dysplasia, and Neoplasm

There is evidence that diet and nutrition are modifiable risk factors for several cancers. In recent years, attention paid to micronutrients in gynecology has increased, especially regarding Human papillomavirus (HPV) infection. We performed a review of the literature up until December 2022, aiming to clarify the effects of micronutrients, minerals, and vitamins on the history of HPV infection and the development of cervical cancer. We included studies having as their primary objective the evaluation of dietary supplements, in particular calcium; zinc; iron; selenium; carotenoids; and vitamins A, B12, C, D, E, and K. Different oligo-elements and micronutrients demonstrated a potential protective role against cervical cancer by intervening in different stages of the natural history of HPV infection, development of cervical dysplasia, and invasive disease. Healthcare providers should be aware of and incorporate the literature evidence in counseling, although the low quality of evidence provided by available studies recommends further well-designed investigations to give clear indications for clinical practice.

The Preventive Role of the Vitamin D Endocrine System in Cervical Cancer

Vitamin D along with its active metabolite calcitriol and its metabolic and signaling system, known as the vitamin D endocrine system, have been widely recognized as a pivotal regulator of calcium homeostasis in addition to non-calcemic antitumoral effects in a variety of human cancers, including cervical cancer. Several studies have found an inverse relationship between the incidence of cervical neoplasia and vitamin D levels. This narrative review updates the current evidence supporting the notion that the vitamin D endocrine system has a preventive role on cervical cancer, mainly in the early phases of the disease, acting at the level of suppressing cell proliferation, promoting apoptosis, modulating inflammatory responses, and probably favoring the clearance of human papillomavirus-dependent cervical lesions. Although an optimal vitamin D status helps in the prevention and regression of low-grade squamous intraepithelial lesions of the cervix, it appears that vitamin D alone or combined with chemotherapeutic agents has little effectivity once advanced cervical cancer is established. These observations suggest that an optimal vitamin D status might exert beneficial actions in the early phases of cervical cancer by preventing its onset and progression.

Effect of Alpha-Lipoic Acid Supplementation on Low-Grade Squamous Intraepithelial Lesions-Double-Blind, Randomized, Placebo-Controlled Trial

Low-grade squamous intraepithelial lesion (SIL) is a cytologic diagnosis etiologically related to human papilloma virus (HPV) infection that leads to the release of inflammation mediators, the formation of reactive oxygen species (ROS) and decreased levels of antioxidants in tissues, which is why antioxidants might be considered effective against SIL progression. This randomized double-blind placebo-controlled study aimed to investigate the effectiveness of alpha-lipoic acid (ALA) supplementation (600 mg/day) on the regression of low-grade SIL in 100 patients. Low-grade SIL was determined after the cytological screening, colposcopic examination and targeted biopsy and histological confirmation of cytological−colposcopic diagnosis. Inflammation parameters and the presence of HPV were determined by standard laboratory methods. Dietary and lifestyle habits were investigated using a standardized and validated semi-quantitative food questionnaire (FFQ). ALA supplementation significantly reduced the proportion of patients with low-grade cytological abnormalities, in comparison to placebo. Given the obtained level of significance (p < 0.001), the presented results indicate that short-term ALA supplementation shows a clinically significant effect on cervical cytology. Future studies should focus on the use of innovative formulations of ALA that might induce bioavailability and therapeutic efficiency against HPV infection and the investigation of synergistic effects of concurrent dietary/lifestyle modification and ALA supplementation in both low-grade and high-grade SIL.

The Preventive Effect of Dietary Antioxidants on Cervical Cancer Development

Cervical cancer results from a continuous process, starting from a normal cervical epithelium after human papillomavirus (HPV) infection and progressing to cervical intraepithelial neoplasia (CIN), before finally developing into invasive squamous carcinoma (ISC). In recent decades, dietary antioxidants, such as vitamins, have received much attention in relation to cancer prevention. We reviewed the relevant literature to investigate the dietary and nutrient intake on cervical cancer. The intake of vitamins A and D and carotenoids may inhibit early cervical cancer development. The intake of folate may prevent or inhibit HPV infection rom progressing to various grades of CIN. The intake of vitamins C and E may widely inhibit the process of cervical cancer development. Polyphenols are often used in cases of cervical cancer in combination chemotherapy and radiation therapy. Regarding nutrients, different antioxidants may have differing abilities to intervene in the natural history of cervical diseases associated with HPV infection. Regarding foods, the intake of both vegetables and fruits containing multiple vitamins may widely suppress cervical cancer development. Most previous papers have described epidemiological studies. Thus, further research using in vitro and in vivo approaches will be needed to clarify the effects of the dietary and nutrient intake in detail.