Imbalances in trace metal levels usually result in toxicity and disease (Mehri, 2020; Marieb and Hoehn, 2018). However, research suggests that the proper balance of these trace metals may play a role in the effective management of some chronic diseases, including osteoporosis and diabetes mellitus (Minich, 2021; Gupta, 2018.). Furthermore, certain essential metals may also work to control the uptake of toxic metals (Minich, 2021). Selenium is one of the trace metals that can attenuate the adverse effects of free radical damage which is caused by aluminum toxicity (Igbokwe, et al., 2019). Healthy levels of zinc help protect against cadmium accumulation and the subsequent cadmium-induced toxicity (Pan, et al., 2017). As outlined in Table 1, the major route of introducing these essential metals into the body is through diet (NIH, 2016; National Center for Complementary and Integrative Health, 2018; Marieb and Hoehn, 2018).Some essential nutrients, including some essential metals, are better absorbed at the intraluminal level of the gut when they occur in certain
forms (Montoro-Huguet Miguel A., et al., 2021; NIH, 2016; Camaschella, 2017). For example, iron is classified as either heme iron, meaning it is available in animal products, or as nonheme iron, meaning it is available in plant products and supplements (Ems, et al., 2021; NIH, 2016).. Although the body can absorb both forms of iron, several studies have shown that in humans heme iron has greater bioavailability than nonheme iron (Jackson, Williams, McEvoy, Macdonald-Wicks, & Patterson, 2016; Ems, et. al., 2021) Drug-metal interactions and certain chronic diseases can play a part in how the body absorbs certain essential metals (Johnson, 2021; Livon Labs, 2019). For example, antacids can decrease the body’s ability to absorb iron (Iron Disorders Institute, 2020) and ACE inhibitors can potentially reduce a person’s zinc levels (Suliburska, et al., 2018). Furthermore, patients with chronic inflammatory diseases, such as liver disease, are less able to absorb trace elements, specifically iron (Marieb and Hoehn, 2018; Gkamprela, et al., 2017).
METALS HARMFUL TO HEALTH
Many toxic metals, such as lead, mercury, aluminum, cadmium, nickel, and arsenic, are present in the environment and can be introduced into the body via air, water, and food (United States Food and Drug Administration, 2021; United States Environmental Protection Agency, 2021). Overexposure to these metals can lead to a multitude of pathological effects (Witkowska, et al., 2021; Garza-Lombo, et al., 2018). The World Health Organization (WHO) has listed arsenic as one of WHO’s 10 chemicals of major public health concern as it is found in the earth’s crust, and has a side distribution in air, water and land (WHO, 2018). Arsenic is primarily found in and absorbed through food and water sources (Centers for Disease Control and Prevention, 2017; WHO, 2018). Arsenic may also be found in commercial pesticides, certain alcoholic products, seafood, kelp, and wood treated with preservatives (Centers for Disease Control and Prevention 2017). It is a known carcinogen and has been linked to cases of skin, scrotal, liver, bladder, lung, and lymphatic system cancers (Bulka, Jones, Turyk, Stayner, & Argos, 2016;; WHO, 2018;Centers for Disease Control and Prevention, 2017). Arsenic poisoning primarily affects the lungs, skin, and liver (Bulka et al., 2016; Mohammed, et al., 2020; Tidy, 2021). Lead can be found in a variety of substances, including paint, ceramic glazes, soldering, car batteries, and water from lead pipes (EPA, 2016; WHO, 2021). It may also be found in soil contaminated as a result of dumped leaded gasoline, lead- based paint, industrial sources and battery acid, which can then affect plants as well (EPA, 2016; Centers for Disease Control and Prevention, 2021). Lead accumulates in the body, and toxic amounts can damage the kidneys, liver, heart, and nervous system (EPA, 2016; Florida Health, 2021). Lead poisoning can lead to paralysis of the extremities, blindness, mental disturbances, loss of memory, convulsions, brain edema, and coma (Baranowska-Bosiacka et al., 2016; EPA, 2016; Agency for Toxic Substances and Disease Registry (ATSDR), 2019). Some studies have shown that zinc, iron, and calcium may exert a protective effect against lead poisoning (Zak, 2017; Talpur, et al., 2018; Kordas, 2017). Mercury also occurs naturally in the environment and is present in certain seafood, thermometers, paints, and amalgam restorations (National Association of Rare Disorders (NORD), 2021; World Health Organization [WHO], 2016). Mercury can be distributed in the air and soil in regions close to incinerators and coal-fired power stations because of the combustion of mercury- containing items (Jackson, 2018; Dias et al., 2016). Mercury is retained within the brain and in the central nervous system,
making its effects cumulative (Jackson, 2018; Ralston, Ralston, & Raymond, 2016). Significant amounts cause insomnia, dizziness, fatigue, weakness, depression, memory loss, dermatitis, and hair loss (Dias et al., 2016;; Ye et al., 2016). Studies show that selenium may reduce toxic levels of mercury in the body (Spiller, 2018; Ralston et al., 2016). Aluminum, the third most abundant element found in in the earth’s crust, is used in some foods, medicines, cosmetic products, and vaccinations (Klotz, et. al. 2017; Igbokwe, et al., 2019). It is also present in air, water, and soil, and therefore it can enter through the food supply (Klotz, et al., 2017; Igbokwe, e. al., 2019). Increased aluminum absorption leads to aluminum salt accumulation in the brain, an effect that has been implicated in seizures, and reduced mental faculties (Exley and Mold, 2020; Igbokwe, et al., 2019). Some studies also suggest that increased levels of aluminum may contribute to Alzheimer’s disease; however, there is not yet conclusive evidence supporting this hypothesis (Klotz, et. al., 2017; Hara, 2018; Alzheimer’s Society, 2022). Cadmium is found in tobacco, drinking water, fertilizer, and fungicides and is a by-product of pollution (Genchi, et al., 2020; Louisiana Department of Health, 2017). It is also used in the production of nickel-cadmium batteries and as a corrosion- protective coating on the metal chassis of electronic and similar devices (Louisiana Department of Health, 2017; Koons, 2021). Cadmium accumulates in the body and replaces the body’s store of zinc in the liver and kidneys, and it can lead to kidney disease and liver damage (Genchi, et al., 2020; Koons, 2021). Elevated levels may result in hypertension, anemia, joint soreness, hair loss, and loss of appetite (World Health Organization, 2019). Zinc and calcium may exert a protective effect for the body against cadmium (Minich 2021; Neltner and Maffini, 2020). Nickel is an essential trace element that may be useful in small amounts in the body, but it can be harmful in large amounts (Al- Fartusie and Mohssan, 2017; National Institute for Occupational Safety and Health [NIOSH], 2016). It is an important component of stainless steel and electroplated items and is found in cooking utensils, refined and processed foods, tobacco smoke, and jewelry (Buxton, et al., 2019).. Nickel is also known to cause contact dermatitis (Buxton, et al. 2019). . It is important in DNA and RNA stabilization, and it helps activate trypsin, arginase, and carboxylase (Kumar and Trivedi, 2016; Kim and Benner, 2021). Excessive amounts generally cause allergic dermatitis and respiratory problems and may also be carcinogenic (NIOSH, 2016; Al-Fartusie and Mohssan, 2017).
Page 26
EliteLearning.com/Dental
Powered by FlippingBook