
By Atli Arnarson
Arsenic is one of the world's most toxic elements. Throughout history, it has been infiltrating the food chain and finding its way into our foods.
However, this problem is now getting worse. Widespread pollution is raising the levels of arsenic in foods, posing a serious health risk.
Recently, studies have detected high levels of arsenic in rice. This is a major concern, since rice is a staple food for a large part of the world's population.
Should you be worried? Let's have a look.
What is Arsenic?
Arsenic is a toxic trace element, denoted by the symbol As.
It is not usually found on its own. Rather, it is bound with other elements in chemical compounds.
These compounds can be divided into two broad categories (1):
- Organic arsenic: mainly found in plant and animal tissues.
- Inorganic arsenic: found in rocks and soil or dissolved in water. This is the more toxic form.
Both forms are naturally present in the environment, but their levels have been increasing due to pollution.
For a number of reasons, rice may accumulate a significant amount of inorganic arsenic (the more toxic form) from the environment.
Bottom Line: Arsenic is a toxic element naturally present in our environment. It is divided into two groups, organic and inorganic arsenic, with inorganic arsenic being more toxic.
Dietary Sources of Arsenic
Arsenic is found in nearly all foods and drinks, but is usually only found in small amounts.
In contrast, relatively high levels are found in:
- Contaminated drinking water: Millions of people around the world are exposed to drinking water that contains high amounts of inorganic arsenic. This is most common in South America and Asia (2, 3).
- Seafood: Fish, shrimp, shellfish and other seafood may contain significant amounts of organic arsenic, the less toxic form. However, mussels and certain types of seaweed may contain inorganic arsenic as well (4, 5, 6).
- Rice and rice-based foods: Rice accumulates more arsenic than other food crops. In fact, it is the single biggest food source of inorganic arsenic, which is the more toxic form (7, 8, 9, 10).
High levels of inorganic arsenic have been detected in many rice-based products, such as:
- Rice milk (11).
- Rice bran (12, 13).
- Rice-based breakfast cereals (13).
- Rice cereal (baby rice) (14, 15).
- Rice crackers (13).
- Brown rice syrup (16).
- Cereal bars containing rice and/or brown rice syrup.
Bottom Line: Seafood contains arsenic, but mostly the organic form. Rice and rice-based products may contain high levels of the inorganic (more toxic) form.
Why is Arsenic Found in Rice?
Arsenic naturally occurs in water, soil and rocks, but its levels may be higher in some areas than others.
It readily enters the food chain and may accumulate in significant amounts in both animals and plants, some of which are eaten by humans.
As a result of human activities, arsenic pollution has been rising.
The main sources of arsenic pollution include certain pesticides and herbicides, wood preservatives, phosphate fertilizers, industrial waste, mining activities, coal burning and smelting (17, 18, 19).
Arsenic often drains into groundwater, which is heavily polluted in certain parts of the world (20, 21).
From groundwater, arsenic finds its way into wells and other water supplies that may be used for crop irrigation and cooking (22).
Paddy rice is particularly susceptible to arsenic contamination, for three reasons:
- It is grown in flooded fields (paddy fields) that require high quantities of irrigation water. In many areas, this irrigation water is contaminated with arsenic (22).
- Arsenic may accumulate in the soil of paddy fields, worsening the problem (23).
- Rice absorbs more arsenic from water and soil compared to other common food crops (8).
Using contaminated water for cooking is another concern, because rice grains easily absorb arsenic from cooking water when they are boiled (24, 25).
Bottom Line: Rice efficiently absorbs arsenic from irrigation water, soil and even cooking water. Some of that arsenic is of natural origin, but pollution is often responsible for higher levels.
Health Effects of Arsenic
High doses of arsenic are acutely toxic, causing various adverse symptoms and even death (26, 27).
Dietary arsenic is generally present in low amounts, and does not cause any immediate symptoms of poisoning.
However, long-term ingestion of inorganic arsenic may cause various health problems and increase the risk of chronic diseases. These include:
- Various types of cancer (28, 29, 30, 31).
- Narrowing or blockage of blood vessels (vascular disease).
- High blood pressure (hypertension) (32).
- Heart disease (33, 34).
- Type 2 diabetes (35).
In addition, arsenic is toxic to nerve cells and may affect brain function (36, 37). In children and teenagers, arsenic exposure has been associated with:
- Impaired concentration, learning and memory (38, 39).
- Reduced intelligence and social competence (40, 41, 42).
Some of these impairments may have taken place before birth. Several studies indicate that high arsenic intake among pregnant women has adverse effects on the fetus, increasing the risk of birth defects and hindering development (43).
Bottom Line: The toxic symptoms of dietary arsenic usually take a long time to develop. Long-term ingestion may increase the risk of various health problems, including cancer, heart disease, type 2 diabetes and decreased intelligence.
Is Arsenic in Rice a Concern?
Yes. There is no doubt about it, arsenic in rice is a problem.
This may pose a health risk to those who eat rice every day in considerable amounts.
This mainly applies to people in Asia or people with Asian-based diets.
Other groups who may eat a lot of rice products include young children and those on a milk-free or gluten-free diet. Rice-based infant formulas, rice crackers, pudding and rice milk sometimes make up a large portion of these diets.
Young children are especially vulnerable because of their small body size. Therefore, feeding them rice cereals every day may not be such a good idea (14, 15).
Of additional concern is brown rice syrup, a rice-derived sweetener that may be high in arsenic. It is often used in baby formulas (16, 44).
Of course, not all rice contains high arsenic levels, but determining the arsenic content of a particular rice product may be difficult (or impossible) without actually measuring it in a lab.
Bottom Line: Arsenic contamination is a serious concern for the millions of people who rely on rice as their staple food. Young children are also at risk if rice-based products make up a large part of their diet.
How to Reduce Arsenic in Rice
The arsenic content of rice can be reduced by washing and cooking the rice with clean water that is low in arsenic.
This is effective for both white and brown rice, potentially reducing the arsenic content by up to 57 percent (45, 46, 47).
However, if the cooking water is high in arsenic, it may have the opposite effect and raise the arsenic content significantly (24, 45, 48).
The following tips should help reduce the arsenic content of your rice:
- Avoid using small amounts of water when cooking.
- Wash the rice before cooking. This method may remove 10–28 percent of the arsenic (45, 47).
- Brown rice contains higher amounts of arsenic than white rice. If you eat large amounts of rice, the white variety may be a better choice (12, 49, 50).
- Choose aromatic rice, such as basmati or jasmine (51).
- Choose rice from the Himalayan region, including North India, North Pakistan and Nepal (7).
- If possible, avoid rice that is grown during the dry season. The use of arsenic-contaminated water is more common during that time (7, 23).
The last and most important piece of advice concerns your diet as a whole. Make sure to diversify your diet by eating many different foods. Your diet should never be dominated by one type of food.
Not only does this ensure that you are getting all the nutrients you need, it also prevents you from getting too much of one thing.
Bottom Line: You can follow a few simple cooking methods tips to reduce the arsenic content of rice. Also keep in mind that some types of rice, such as basmati and jasmine, are lower in arsenic.
Take Home Message
Arsenic in rice is a serious concern for many people.
A huge percentage of the world's population relies on rice as a main food source, and millions of people may be at risk of developing arsenic-related health problems.
That being said, if you eat rice in moderation as a part of a varied diet, you should be totally fine.
However, if rice happens to be a large part of your diet, make sure that it was grown in a non-polluted area.
This article was reposted from our media associate Authority Nutrition.
YOU MIGHT ALSO LIKE
Will Arsenic Finally be Removed From Poultry Production?
Does Greek Yogurt Live Up to All its Hype?
10 Foods Banned in Other Parts of the World, But Not in America
In 2010, world leaders agreed to 20 targets to protect Earth's biodiversity over the next decade. By 2020, none of them had been met. Now, the question is whether the world can do any better once new targets are set during the meeting of the UN Convention on Biodiversity in Kunming, China later this year.
- Ocean Scientists Create Global Network to Help Save Biodiversity ... ›
- 5 Reasons Why Biodiversity Matters - EcoWatch ›
- 26 Organizations Working to Conserve Seed Biodiversity - EcoWatch ›
- The Top 10 Ocean Biodiversity Hotspots to Protect - EcoWatch ›
- New Platform Shows How to Protect Biodiversity and Save Planet ... ›
- These Scientists Are Listening to the Borneo Rainforest to Protect ... ›
EcoWatch Daily Newsletter
By Andrew Rosenberg
The first 24 hours of the administration of President Joe Biden were filled not only with ceremony, but also with real action. Executive orders and other directives were quickly signed. More actions have followed. All consequential. Many provide a basis for not just undoing actions of the previous administration, but also making real advances in public policy to protect public health, safety, and the environment.
- Here Are Biden's Day One Actions on Climate and Environment ... ›
- UCS Offers Science Advice for Biden Administration - EcoWatch ›
Trending
A first-of-its-kind study has examined the satellite record to see how the climate crisis is impacting all of the planet's ice.
- 'Ghost Forests' Are an Eerie Sign of Sea-Level Rise - EcoWatch ›
- Sea-Level Rise Takes Business Toll in North Carolina's Outer Banks ... ›
- Sea Level Rise Is Locked in Even If We Meet Paris Agreement ... ›
A Healthy Microbiome Builds a Strong Immune System That Could Help Defeat COVID-19
By Ana Maldonado-Contreras
Takeaways
- Your gut is home to trillions of bacteria that are vital for keeping you healthy.
- Some of these microbes help to regulate the immune system.
- New research, which has not yet been peer-reviewed, shows the presence of certain bacteria in the gut may reveal which people are more vulnerable to a more severe case of COVID-19.
You may not know it, but you have an army of microbes living inside of you that are essential for fighting off threats, including the virus that causes COVID-19.
How Do Resident Bacteria Keep You Healthy?
<p>Our immune defense is part of a complex biological response against harmful pathogens, such as viruses or bacteria. However, because our bodies are inhabited by trillions of mostly beneficial bacteria, virus and fungi, activation of our immune response is tightly regulated to distinguish between harmful and helpful microbes.</p><p>Our bacteria are spectacular companions diligently helping prime our immune system defenses to combat infections. A seminal study found that mice treated with antibiotics that eliminate bacteria in the gut exhibited an impaired immune response. These animals had low counts of virus-fighting white blood cells, weak antibody responses and poor production of a protein that is vital for <a href="https://doi.org/10.1073/pnas.1019378108" target="_blank">combating viral infection and modulating the immune response</a>.</p><p><a href="https://doi.org/10.1371/journal.pone.0184976" target="_blank" rel="noopener noreferrer">In another study</a>, mice were fed <em>Lactobacillus</em> bacteria, commonly used as probiotic in fermented food. These microbes reduced the severity of influenza infection. The <em>Lactobacillus</em>-treated mice did not lose weight and had only mild lung damage compared with untreated mice. Similarly, others have found that treatment of mice with <em>Lactobacillus</em> protects against different <a href="https://doi.org/10.1038/srep04638" target="_blank" rel="noopener noreferrer">subtypes of</a> <a href="https://doi.org/10.1038/s41598-017-17487-8" target="_blank" rel="noopener noreferrer">influenza</a> <a href="https://doi.org/10.1371/journal.ppat.1008072" target="_blank" rel="noopener noreferrer">virus</a> and human respiratory syncytial virus – the <a href="https://doi.org/10.1038/s41598-019-39602-7" target="_blank" rel="noopener noreferrer">major cause of viral bronchiolitis and pneumonia in children</a>.</p>Chronic Disease and Microbes
<p>Patients with chronic illnesses including Type 2 diabetes, obesity and cardiovascular disease exhibit a hyperactive immune system that fails to recognize a harmless stimulus and is linked to an altered gut microbiome.</p><p>In these chronic diseases, the gut microbiome lacks bacteria that activate <a href="https://doi.org/10.1126/science.1198469" target="_blank" rel="noopener noreferrer">immune cells</a> that block the response against harmless bacteria in our guts. Such alteration of the gut microbiome is also observed in <a href="https://doi.org/10.1073/pnas.1002601107" target="_blank" rel="noopener noreferrer">babies delivered by cesarean section</a>, individuals consuming a poor <a href="https://doi.org/10.1038/nature12820" target="_blank" rel="noopener noreferrer">diet</a> and the <a href="https://doi.org/10.1038/nature11053" target="_blank" rel="noopener noreferrer">elderly</a>.</p><p>In the U.S., 117 million individuals – about half the adult population – <a href="https://health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/" target="_blank" rel="noopener noreferrer">suffer from Type 2 diabetes, obesity, cardiovascular disease or a combination of them</a>. That suggests that half of American adults carry a faulty microbiome army.</p><p>Research in my laboratory focuses on identifying gut bacteria that are critical for creating a balanced immune system, which fights life-threatening bacterial and viral infections, while tolerating the beneficial bacteria in and on us.</p><p>Given that diet affects the diversity of bacteria in the gut, <a href="https://www.umassmed.edu/nutrition/melody-trial-info/" target="_blank" rel="noopener noreferrer">my lab studies show how diet can be used</a> as a therapy for chronic diseases. Using different foods, people can shift their gut microbiome to one that boosts a healthy immune response.</p><p>A fraction of patients infected with SARS-CoV-2, the virus that causes COVID-19 disease, develop severe complications that require hospitalization in intensive care units. What do many of those patients have in common? <a href="https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e2.htm" target="_blank" rel="noopener noreferrer">Old age</a> and chronic diet-related diseases like obesity, Type 2 diabetes and cardiovascular disease.</p><p><a href="http://doi.org/10.1016/j.jada.2008.12.019" target="_blank" rel="noopener noreferrer">Black and Latinx people are disproportionately affected by obesity, Type 2 diabetes and cardiovascular disease</a>, all of which are linked to poor nutrition. Thus, it is not a coincidence that <a href="https://www.cdc.gov/mmwr/volumes/69/wr/mm6933e1.htm" target="_blank" rel="noopener noreferrer">these groups have suffered more deaths from COVID-19</a> compared with whites. This is the case not only in the U.S. but also <a href="https://www.washingtonpost.com/world/europe/blacks-in-britain-are-four-times-as-likely-to-die-of-coronavirus-as-whites-data-show/2020/05/07/2dc76710-9067-11ea-9322-a29e75effc93_story.html" target="_blank" rel="noopener noreferrer">in Britain</a>.</p>Discovering Microbes That Predict COVID-19 Severity
<p>The COVID-19 pandemic has inspired me to shift my research and explore the role of the gut microbiome in the overly aggressive immune response against SARS-CoV-2 infection.</p><p>My colleagues and I have hypothesized that critically ill SARS-CoV-2 patients with conditions like obesity, Type 2 diabetes and cardiovascular disease exhibit an altered gut microbiome that aggravates <a href="https://theconversation.com/exercise-may-help-reduce-risk-of-deadly-covid-19-complication-ards-136922" target="_blank" rel="noopener noreferrer">acute respiratory distress syndrome</a>.</p><p>Acute respiratory distress syndrome, a life-threatening lung injury, in SARS-CoV-2 patients is thought to develop from a <a href="http://doi.org/10.1016/j.cytogfr.2020.05.003" target="_blank" rel="noopener noreferrer">fatal overreaction of the immune response</a> called a <a href="https://theconversation.com/blocking-the-deadly-cytokine-storm-is-a-vital-weapon-for-treating-covid-19-137690" target="_blank" rel="noopener noreferrer">cytokine storm</a> <a href="http://doi.org/10.1016/S2213-2600(20)30216-2" target="_blank" rel="noopener noreferrer">that causes an uncontrolled flood</a> <a href="http://doi.org/10.1016/S2213-2600(20)30216-2" target="_blank" rel="noopener noreferrer">of immune cells into the lungs</a>. In these patients, their own uncontrolled inflammatory immune response, rather than the virus itself, causes the <a href="http://doi.org/10.1007/s00134-020-05991-x" target="_blank" rel="noopener noreferrer">severe lung injury and multiorgan failures</a> that lead to death.</p><p>Several studies <a href="https://doi.org/10.1016/j.trsl.2020.08.004" target="_blank" rel="noopener noreferrer">described in one recent review</a> have identified an altered gut microbiome in patients with COVID-19. However, identification of specific bacteria within the microbiome that could predict COVID-19 severity is lacking.</p><p>To address this question, my colleagues and I recruited COVID-19 hospitalized patients with severe and moderate symptoms. We collected stool and saliva samples to determine whether bacteria within the gut and oral microbiome could predict COVID-19 severity. The identification of microbiome markers that can predict the clinical outcomes of COVID-19 disease is key to help prioritize patients needing urgent treatment.</p><p><a href="https://doi.org/10.1101/2021.01.05.20249061" target="_blank" rel="noopener noreferrer">We demonstrated</a>, in a paper which has not yet been peer reviewed, that the composition of the gut microbiome is the strongest predictor of COVID-19 severity compared to patient's clinical characteristics commonly used to do so. Specifically, we identified that the presence of a bacterium in the stool – called <em>Enterococcus faecalis</em>– was a robust predictor of COVID-19 severity. Not surprisingly, <em>Enterococcus faecalis</em> has been associated with <a href="https://doi.org/10.1053/j.gastro.2011.05.035" target="_blank" rel="noopener noreferrer">chronic</a> <a href="https://doi.org/10.1016/S0002-9440(10)61172-8" target="_blank" rel="noopener noreferrer">inflammation</a>.</p><p><em>Enterococcus faecalis</em> collected from feces can be grown outside of the body in clinical laboratories. Thus, an <em>E. faecalis</em> test might be a cost-effective, rapid and relatively easy way to identify patients who are likely to require more supportive care and therapeutic interventions to improve their chances of survival.</p><p>But it is not yet clear from our research what is the contribution of the altered microbiome in the immune response to SARS-CoV-2 infection. A recent study has shown that <a href="https://doi.org/10.1101/2020.12.11.416180" target="_blank" rel="noopener noreferrer">SARS-CoV-2 infection triggers an imbalance in immune cells</a> called <a href="https://doi.org/10.1111/imr.12170" target="_blank" rel="noopener noreferrer">T regulatory cells that are critical to immune balance</a>.</p><p>Bacteria from the gut microbiome are responsible for the <a href="https://doi.org/10.7554/eLife.30916.001" target="_blank" rel="noopener noreferrer">proper activation</a> <a href="https://doi.org/10.1126/science.1198469" target="_blank" rel="noopener noreferrer">of those T-regulatory</a> <a href="https://doi.org/10.1038/nri.2016.36" target="_blank" rel="noopener noreferrer">cells</a>. Thus, researchers like me need to take repeated patient stool, saliva and blood samples over a longer time frame to learn how the altered microbiome observed in COVID-19 patients can modulate COVID-19 disease severity, perhaps by altering the development of the T-regulatory cells.</p><p>As a Latina scientist investigating interactions between diet, microbiome and immunity, I must stress the importance of better policies to improve access to healthy foods, which lead to a healthier microbiome. It is also important to design culturally sensitive dietary interventions for Black and Latinx communities. While a good-quality diet might not prevent SARS-CoV-2 infection, it can treat the underlying conditions related to its severity.</p><p><em><a href="https://theconversation.com/profiles/ana-maldonado-contreras-1152969" target="_blank">Ana Maldonado-Contreras</a> is an assistant professor of Microbiology and Physiological Systems at the University of Massachusetts Medical School.</em></p><p><em>Disclosure statement: Ana Maldonado-Contreras receives funding from The Helmsley Charitable Trust and her work has been supported by the American Gastroenterological Association. She received The Charles A. King Trust Postdoctoral Research Fellowship. She is also member of the Diversity Committee of the American Gastroenterological Association.</em></p><p><em style="">Reposted with permission from <a href="https://theconversation.com/a-healthy-microbiome-builds-a-strong-immune-system-that-could-help-defeat-covid-19-145668" target="_blank" rel="noopener noreferrer" style="">The Conversation</a>. </em></p>By Jeff Masters, Ph.D.
The New Climate War: the fight to take back our planet is the latest must-read book by leading climate change scientist and communicator Michael Mann of Penn State University.
- 12 New Books Explore Fresh Approaches to Act on Climate Change ... ›
- Dr. Michael Mann on Climate Denial: 'It's Impaired Our Ability to ... ›