A large gap still exists in our knowledge of the effects of dietary supplements on lung cancer risk/mortality in asthmatic smokers and nonsmokers. There is a lack of reliable studies for detecting such an effect says a researcher in the journal Nutrients . The researcher undertook a comprehensive review of studies on the topic, and is now calling for trials and studies of these supplements to detect their benefits and harms. The best way to reduce lung cancer risk is to get those at greatest risk of lung cancer (active and passive smokers, particularly those with asthma) to stop smoking or reduce exposure to tobacco smoke. In industrial societies, airborne environmental pollutants are also risk factors.
 Alsharairi, N. The effects of dietary supplements on Asthma and Lung Cancer risk in smokers and non-smokers: A review of the literature. Nutrients, 2019, 11, 725.
It has been estimated that around 7 million of global deaths per year were caused by smoking . Reviews of published systematic reviews and meta-analysis have confirmed that the risk of lung cancer and asthma has increased in current and former smokers . In fact, tobacco smoke is the largest contributor to the most common histological types of lung cancer such as adenocarcinoma and small-cell and squamous cell carcinoma, with over 76% of lung cancer deaths in men and 37-42% of lung cancer deaths in women aged ≥50 years are attributable to tobacco use . Tobacco smoke provokes asthma exacerbations and causes other allergy symptoms to worsen in adults. There is also unequivocal evidence that secondhand smoke exposure is the main contributor to asthma and lung cancer risk in nonsmokers, disproportionately affecting women . The researcher claims that "people with asthma are generally at higher risk of lung cancer than the general population, whether they smoke or are exposed to tobacco smoke".
There is controversy over the role of dietary supplements in reducing or treating lung cancer in smokers and nonsmokers. There is also much uncertainty about its effectiveness and the consequences in asthmatic smokers and nonsmokers, and our understanding of whether dietary supplements can reduce lung cancer risk in asthmatic smokers and nonsmokers remains unclear in the absence of clinical trials . The researcher claims that "in order to evaluate the safety and effectiveness of dietary supplement use by asthmatic smokers and nonsmokers before, during, and after lung cancer treatment, we need realistic and reliable studies worldwide".
2. Data, Applications and Influences
Dietary supplements use has increased globally , and have become of particular interest to consumer and the pharmaceutical companies , in addition to be significant part of complementary medicines to maintain or improve health . The most common dietary supplements used by cancer and asthmatic patients were multivitamins and antioxidants .
There is strong belief that taking dietary supplements prevents occurrence of cancers . To the contrary, these supplements are not safe for cancer patients and have increased risk of mortality in Westernized adult populations . Indeed, studies have been contradictory regarding the effects of dietary supplements on lung cancer risk and mortality in smokers and nonsmokers . However, there is now scientific evidence that urged caution in recommending long-term, high-dose supplements that contain β-carotene, retinyl palmitate, B vitamins and vitamin E for lung cancer patients, particularly current and former smokers .
Given that long-term supplements use can have adverse effects, why do companies still claim of anticancer benefits for marketing of these supplements? Pharmaceutical companies have not adequately complied with dietary supplement manufacturing standards. These supplements contain harmful ingredients which continue to be sold to cancer patients for economic reasons . Sales of dietary supplements could represent harm, rather than health benefits, if national standards and regulations do not rigorously apply. Despite the efforts of the Western countries to improve supplements safety and quality in the marketplace, many challenges still exist. These include inadequate assurance of safety/efficacy, inaccuracy of product labeling, misleading health claims and lack of conceptual clarity concerning a regulatory framework for marketing and assessing the quality of supplements .
RCTs revealed that dietary supplements including methyl donor nutrients and antioxidant vitamins were found not to improve pulmonary function in patients with asthma . Pharmaceutical companies are involved in manufacturing supplements purported for use in asthma such as Quercetin and Pycnogenol . A need remains for more efforts to provide regulatory guidelines about using dietary supplements to reduce asthma risk. Few RCTs to date have sought to examine the effects of dietary supplements on asthma risk in smokers. Although vitamin D supplementation alone has proven beneficial in reducing asthma risk in current/former smokers, the intake of vitamin D supplements together with calcium/other supplements may not be advocated . Further RCTs to examine the efficacy of dietary supplements in improving asthma symptoms are needed . More studies are also needed to clarify the effects of dietary supplements on asthma risk in both smokers and nonsmokers.
Dietary supplements use in lung cancer prevention elicits considerable controversy. Long-term use of specific dietary supplements appears to increase lung cancer risk. The naturopathy sector makes millions of dollars by making claims about cancer-fighting supplements- this should be backed up with empirical research, and if it's false, those companies should not be profiting from misleading people. Dietary supplements might actually reduce other cancers risk because some studies have made very grand claims. Given active and passive smoking are the main risk factors for asthma and lung cancer, the researcher is therefore suggesting future trials and prospective studies of these supplements to detect their benefits and harms for lung cancer prevention in asthmatic smokers and non-smokers.
The entry is from 10.3390/nu11040725
- Schane, R.E.; Ling, P.M.; Glantz, S.A. Health effects of light and intermittent smoking: A review. Circulation 2010, 121, 1518-1522.
- West, R. Tobacco smoking: Health impact, prevalence, correlates and interventions. Health. 2017, 32, 1018-1036.
- GBD 2015 Tobacco Collaborators. Smoking prevalence and attributable disease burden in 195 countries and territories, 1990-2015: A systematic analysis from the Global Burden of Disease Study 2015. Lancet 2017, 389, 1885-1906.
- Jayes, L.; Haslam, P.L.; Gratziou, C.G.; Powell, P.; Britton, J.; Vardavas, C.; Jimenez-Ruiz, C.; Leonardi-Bee, J.; Tobacco Control Committee of the European Respiratory Society. SmokeHaz: Systematic reviews and meta-analyses of the effects of smoking on respiratory health. Chest 2016, 150, 164-179.
- Skaaby, T.; Taylor, A.E.; Jacobsen, R.K.; Paternoster, L.; Thuesen, B.H.; Ahluwalia, T.S.; Larsen, S.C.; Zhou, A.; Wong, A.; Gabrielsen, M.E.; et al. Investigating the causal effect of smoking on hay fever and asthma: A Mendelian randomization meta-analysis in the CARTA consortium. Rep. 2017, 7, 2224.
- Santillan, A.A.; Camargo, C.A., Jr.; Colditz, G.A. A meta-analysis of asthma and risk of lung cancer (United States). Cancer Causes Control 2003, 14, 327-334.
- Rosenberger, A.; Bickeböller, H.; McCormack, V.; Brenner, D.R.; Duell, E.J.; Tjønneland, A.; Friis, S.; Muscat, J.E.; Yang, P.; Wichmann, H.E.; et al. Asthma and Lung Cancer risk: A systematic investigation by the International Lung Cancer Consortium. Carcinogenesis 2012, 33, 587-597.
- Qu, Y.L.; Liu, J.; Zhang, L.X.; Wu, C.M.; Chu, A.J.; Wen, B.L.; Ma, C.; Yan, X.Y.; Zhang, X.; Wang, D.M.; et al. Asthma and the risk of lung cancer: A meta-analysis. Oncotarget 2017, 8, 48525.
- Institute for Health Metrics and Evaluation. Global Burden of Disease 2017. 2017. Available online: http://vizhub.healthdata.org/gbd-compare/# (accessed on 24 December 2018).
- Binns, C.W.; Lee, M.K.; Lee, A.H. Problems and prospects: Public health regulation of dietary supplements. Ann Rev Public Health. 2018, 39, 403-420.
- Dzeparoski M.; Trajkovic-Jolevska, S. Analysis of marketing strategy for food supplements and over-the-counter medicines. Open Access Maced J Med Sci. 2016, 4, 499-503.
- Kamiński, M.; Kręgielska-Narożna, M.; Bogdański, P. Determination of the popularity of dietary supplements using Google search rankings. Nutrients. 2020, 12, 908.
- Barnes, J. Quality, efficacy and safety of complementary medicines: fashions, facts and the future. Part I. Regulation and quality. Br J Clin Pharmacol. 2003,55, 226-233.
- Ventola, C.L. Current issues regarding complementary and alternative medicine (CAM) in the United States: Part 2: Regulatory and safety concerns and proposed governmental policy changes with respect to dietary supplements. P T. 2010, 35, 514-522.
- Miller, P.E.; Vasey, J.J.; Short, P.F.; Hartman, T.J.Description of dietary supplement use in adult cancer survivors. Oncol Nurs Forum. 2009, 36, 61-68.
- Moreno-Macias, H.; Romieu, I. Effects of antioxidant supplements and nutrients on patients with asthma and allergies. J Allergy Clin Immunol. 2014, 133, 1237-1244.
- Song, S.; Youn, J.; Lee, Y.J.; Kang, M.; et al. Dietary supplement use among cancer survivors and the general population: a nation-wide cross-sectional study. BMC Cancer. 2017, 17, 891.
- Martínez, M.E.; Jacobs, E.T.; Baron, J.A.; Marshall, J.R.; Byers, T. Dietary supplements and cancer prevention: Balancing potential benefits against proven harms. J Natl Cancer Inst. 2012, 104, 732-739.
- Marik, P.E.; Flemmer, M. Do dietary supplements have beneficial health effects in industrialized nations: what is the evidence? JPEN J Parenter Enteral Nutr. 2012, 36, 159-168.
- Brasky, T.M.; White, E.; Chen, C. Long-term, supplemental, one-carbon metabolism-related vitamin B use in relation to lung cancer risk in the vitamins and lifestyle (VITAL) cohort. J Clin Oncol. 2017, 35, 3440-3448.
- Lammersfeld, C.A.; Levin, M.D.; Reilly, P.; Coyne, J.W,; Birdsall, T.C.; Markman, M. Assuring quality of dietary supplements for cancer patients: An integrative formulary systems approach. Integr Med (Encinitas). 2017,16, 38-44.
- Starr, R.R. Too little, too late: Ineffective regulation of dietary supplements in the United States. Am J public health. 2015, 105, 478-485.
- Amagase, H. US Dietary supplement labeling rules and the possibility of medical cost reduction. J Nutr Sci Vitaminol (Tokyo). 2015, 61, S136-S138.
- Dwyer, J.T.; Coates, P.M.; Smith, M.J. Dietary supplements: Regulatory challenges and research resources. Nutrients. 2018, 10, 41.
- Bailey, R.L. Current regulatory guidelines and resources to support research of dietary supplements in the United States. Crit Rev Food Sci Nutr. 2020, 60, 298-309.
- Han, Y.; Blatter, J.; Brehm, J.M.; Forno, E.; Litonjua, A.A.; Celedón, J.C. Diet and asthma: Vitamins and methyl donors. Lancet Respir. 2013, 1, 813-822.
- Yeh, G.Y.; Horwitz, R. Integrative medicine for respiratory conditions: Asthma and COPD. Med Clin North Am. 2017, 101, 925-941.
- Alsharairi, N.A. Diet and food allergy as risk factors for asthma in the Arabian Gulf Region: Current evidence and future research needs. Int J Environ Res Public Health. 2019, 16, 3852.