The hidden toxin in a staple food

Why rice absorbs more arsenic than almost any other crop, what that means for your health, and practical ways to reduce your exposure

Rice absorbs arsenic from soil and water more readily than almost any other grain, and inorganic arsenic — the form found in rice — is a Group 1 carcinogen linked to cancers of the bladder, lung, and skin, as well as cardiovascular disease and developmental harm in children. For most people who eat rice regularly, it is their single largest dietary source of inorganic arsenic [1]. This does not mean rice is a food to eliminate. It means understanding where the risk is highest, choosing varieties wisely, and using simple cooking techniques that can cut arsenic content by 40–74% [4].

Why rice accumulates arsenic

Arsenic is a naturally occurring element found in soil and groundwater worldwide. It also accumulates from decades of pesticide use — lead arsenate was widely applied to agricultural land in the US until the 1980s — and from industrial runoff. Rice paddies are flooded with water, which creates anaerobic (low-oxygen) soil conditions that release bound arsenic into the water. Rice plants then absorb this dissolved arsenic through the same channels they use to take up silica, a nutrient they need in large amounts. The result is that rice accumulates arsenic at concentrations far higher than most other crops [1].

Inorganic arsenic is the dangerous form — roughly 100 times more toxic than organic arsenic species, which are less readily absorbed by the body. Inorganic arsenic comprises 50–90% of total arsenic in most white rice and a higher proportion in brown rice [2].

Brown rice vs. white rice: the arsenic trade-off

Brown rice contains more fiber, magnesium, B vitamins, and phytonutrients than white rice. It also contains more arsenic — typically 30–50% more — because arsenic concentrates in the bran layers that are polished away to make white rice [2]. This creates a genuine trade-off that is worth acknowledging honestly rather than glossing over. For people who eat rice daily in large quantities, the arsenic load from brown rice adds up over time. For moderate consumers — one to two servings per day — the nutritional benefits of brown rice likely outweigh the marginal increase in arsenic exposure. Context matters: if you eat rice two or three times a week, variety matters less than if it is a dietary staple eaten at every meal.

Which rice varieties are lower in arsenic

Arsenic content varies substantially by origin and variety [3]:

Basmati rice from India, Pakistan, and California consistently tests lower in arsenic than long-grain American rice
Jasmine rice from Thailand is also relatively lower
American-grown long-grain rice, particularly from Arkansas, Louisiana, and Missouri, tends to have higher arsenic concentrations — largely due to legacy pesticide use in those agricultural soils
Rice grown in California generally has lower arsenic levels than rice from the southern US

This means origin matters as much as type. A bag of brown basmati from California is meaningfully different from brown long-grain rice grown in the Arkansas delta region.

How to reduce arsenic through cooking

The most effective interventions happen in the kitchen. Arsenic is water-soluble, which means the right cooking approach can flush a substantial portion out of the grain [4]:

Rinse before cooking. Rinsing removes surface starch and can reduce arsenic by 10–20%, though rinsing alone is not sufficient by itself. Note that for enriched (fortified) white rice, rinsing also removes some added B vitamins.

Cook in excess water, then drain. Cooking rice in a large ratio of water (6:1 water to rice or more) and draining the excess — rather than the absorption method where all the water is cooked in — removes approximately 35–45% of inorganic arsenic in long-grain and basmati rice [4].

The parboiling absorption method (PBA). A more effective technique involves parboiling the rice in pre-boiled water for five minutes, then draining and replacing with fresh water, and finishing with the absorption method on low heat. Research shows this approach can reduce arsenic by over 50% in brown rice and up to 74% in white rice while preserving mineral content better than excess-water cooking alone [3].

Avoid rice cookers for high-exposure households. Standard rice cookers use the full-absorption method in which all cooking water remains in the rice, so no arsenic is removed. For daily rice eaters, stovetop cooking with excess water is preferable.

Who should be most attentive

Infants and young children are the highest priority group. Because they eat far more relative to body weight than adults, their arsenic exposure from infant rice cereals and rice-based baby foods is proportionally much higher. The FDA established an action level of 100 micrograms per kilogram (ppb) for inorganic arsenic in infant rice cereals in 2020 [5]. Parents may want to diversify infant cereals rather than relying exclusively on rice-based products.

People who eat rice as a daily staple — particularly at multiple meals per day — have cumulative exposure that meaningfully differs from occasional rice consumers. For these individuals, variety selection and cooking method make a practical difference.

Pregnant women. Inorganic arsenic crosses the placenta and is associated with adverse pregnancy outcomes and neurodevelopmental effects in children. Reducing dietary arsenic during pregnancy is a reasonable precaution.

Keeping this in perspective

Rice has been a dietary staple for billions of people for thousands of years. The arsenic concern is real but proportionate: moderate rice consumption is not a meaningful health risk for most adults who eat a varied diet. The practical message is targeted: diversify your grains, use lower-arsenic varieties when possible, rinse and cook with extra water, and pay special attention to infant and daily-consumption scenarios where exposure is highest.

See our microplastics page and water filtration guide for related coverage of environmental contaminants in food and water.

Evidence Review

Arsenic accumulation and global exposure (Zhu et al., 2008)

Zhu, Williams, and Meharg published one of the foundational reviews establishing rice as the dominant dietary exposure pathway to inorganic arsenic for populations in rice-eating regions [1]. The paper reviewed the geochemistry of arsenic in paddy soils and its uptake by rice plants, noting that the flooding conditions of paddy agriculture uniquely favor arsenic mobilization from soil into irrigation water and subsequently into grain.

Key findings from the synthesis: inorganic arsenic comprises approximately 50–90% of total arsenic in white rice, and typical concentrations in rice consumed in Asia (where rice may provide 50–80% of daily calories) resulted in estimated inorganic arsenic exposures approaching or exceeding established health-based guidance values for chronic cancer risk. The authors identified rice as "the major global contributor" to dietary inorganic arsenic exposure, particularly for Asian populations, and flagged it as a globally significant public health concern that had received insufficient regulatory attention relative to drinking water arsenic.

Comparative exposure across demographic groups (González et al., 2020)

This Spanish study by González et al. measured total and inorganic arsenic in 116 rice and rice-based product samples and used probabilistic dietary exposure modeling to estimate risk across population groups including infants, toddlers, children, adolescents, and adults [2]. Results showed:

Brown rice arsenic: mean 189 µg/kg total arsenic, vs. 132 µg/kg for white rice — a 43% differential attributable to arsenic concentration in the bran
Toddlers and infants showed the highest absolute daily exposure (4.08 and 3.99 µg/day, respectively), but their exposure was predominantly organic arsenic from rice products specifically formulated for young children
Adult exposure was dominated by inorganic arsenic from standard rice, making adults the group most exposed to the carcinogenic form
Baby cereals and breakfast cereals were identified as the most significant contributors for infant inorganic arsenic exposure, underscoring the FDA's regulatory focus on this category

The authors recommended substituting white rice varieties and pre-cooked (parboiled) rice where possible, and universal pre-cooking rinsing practices.

Mitigation options review (Kumarathilaka et al., 2019)

Kumarathilaka et al. reviewed evidence on arsenic content in cooked rice and evaluated cooking and post-harvest interventions systematically [3]. The review covered:

Variety and origin effects: Basmati and jasmine rice consistently had lower inorganic arsenic concentrations than long-grain American varieties. Among American rice, California-grown rice had lower arsenic than rice from the southern US. The review attributed geographic differences largely to legacy pesticide soil contamination rather than natural geology.

Cooking method efficacy:

Standard absorption method (no water drain): no arsenic reduction beyond soaking
6:1 water to rice excess water cooking with drain: 35–45% reduction in inorganic arsenic
Parboiling absorption (PBA) method: 50–74% reduction, with better mineral retention than excess-water methods
Percolating cooking water (continuous flow through rice during cooking): 40–85% reduction, though impractical for most home kitchens

Limitations: The review noted that all cooking methods that remove arsenic also risk removing water-soluble B vitamins, particularly in enriched polished rice. Brown rice, which is not enriched, loses less in nutritional value from these methods.

The authors concluded that combination approaches — choosing lower-arsenic origin varieties plus PBA or excess-water cooking — represent the most practical risk reduction strategy achievable at the household level.

Excess water cooking quantification (Gray et al., 2016)

Gray et al. conducted a controlled laboratory study measuring arsenic and enriched vitamin content in US rice types cooked by three methods: standard absorption, excess water with drain, and pre-wash plus excess water [4]. Arsenic reduction by rice type using the excess water method:

Long-grain polished white rice: 40% inorganic arsenic reduction
Parboiled white rice: 60% reduction
Brown rice: 50% reduction

The trade-off with vitamins was documented clearly: rinsing before cooking removed 10–15% of surface arsenic but also washed away substantial amounts of enriched iron, folate, thiamin, and niacin from polished and parboiled rice — not from brown rice, which is not artificially enriched. The study provided the quantitative basis for recommending that consumers who depend on enriched white rice for micronutrient intake consider other sources of B vitamins if adopting arsenic-reduction cooking practices.

FDA regulatory action on infant exposure (FDA, 2020)

The FDA established an action level of 100 ppb (µg/kg) for inorganic arsenic in infant rice cereals based on a risk assessment concluding that inorganic arsenic exposure during infancy and early childhood may contribute to neurodevelopmental effects and increase lifetime cancer risk [5]. Sampling data showed 76% of infant rice cereal samples were at or below 100 ppb by 2018, compared to only 36% in 2011–2013, indicating that the regulatory signal drove meaningful industry reformulation.

The FDA noted that rice intake for infants is approximately three times greater per unit of body weight than for adults, making infant rice cereal the highest per-body-weight arsenic exposure food in the diet. The guidance reinforced recommendations to diversify infant cereals and reduce reliance on rice-based products during the first year of life.

Overall evidence assessment

The evidence base for arsenic in rice as a meaningful health concern is strong and consistent across multiple study designs, countries, and population groups. The carcinogenicity of inorganic arsenic is established beyond doubt — it is IARC Group 1 and EPA Class A. The primary scientific uncertainty is around the precise dose-response relationship at the moderate exposures typical of regular rice consumption in Western diets, where rice is not the caloric staple it is in many Asian countries.

For everyday US consumers eating rice several times per week, the absolute cancer risk increment is small. For populations where rice provides the majority of calories — or for infants fed rice cereal exclusively — the risk is more significant and the mitigation evidence is actionable. The practical hierarchy of interventions is well-supported: choose basmati or jasmine over southern US long-grain, use the parboil-drain-absorb cooking method, diversify grains, and avoid rice-only infant feeding regimens.

References

Exposure to inorganic arsenic from rice: a global health issue?Zhu YG, Williams PN, Meharg AA. Environmental Pollution, 2008. PubMed 18448219 →
Dietary exposure to total and inorganic arsenic via rice and rice-based products consumptionGonzález N, Calderón J, Ramos AJ, Sanchis V, Marín S, Domingo JL, Hernández-Jerez AF. Food and Chemical Toxicology, 2020. PubMed 32413457 →
Arsenic in cooked rice foods: Assessing health risks and mitigation optionsKumarathilaka P, Seneweera S, Ok YS, Meharg A, Bundschuh J. Environment International, 2019. PubMed 30986740 →
Cooking rice in excess water reduces both arsenic and enriched vitamins in the cooked grainGray PJ, Conklin SD, Todorov TI, Kasko SM. Food Additives and Contaminants: Part A, 2016. PubMed 26515534 →
FDA Issues Final Guidance for Industry on Action Level for Inorganic Arsenic in Infant Rice CerealsU.S. Food and Drug Administration. U.S. FDA, 2020. Source →