Is there less arsenic in parboiled rice?

November 25, 2025 •

3 min read

According to a 2021 study, the 'parboiling with absorption method' can remove over 50% of inorganic arsenic from brown rice and over 70% from white rice. This confirms that there is less arsenic in parboiled rice than in raw or traditionally cooked rice. The process involves a pre-boiling stage that effectively flushes out a large portion of the toxic element before final cooking.

Quick Summary

Studies show that parboiling rice significantly reduces its inorganic arsenic content compared to un-parboiled rice. This processing method, which partially cooks the grain while still in its husk, helps remove the water-soluble heavy metal. The technique is a practical way for consumers to lower their arsenic exposure from rice, a major dietary source in many regions.

Key Points

Parboiling Significantly Reduces Arsenic: Studies show that parboiling can remove over 50% of inorganic arsenic from rice, with some methods removing over 70% from white rice.
Arsenic is Water-Soluble: The process of parboiling works by using water to leach out the water-soluble inorganic arsenic from the rice grain.
Parboiled Retains Nutrients: Unlike simple washing or milling, the parboiling process also helps retain essential vitamins and minerals within the rice grain.
Brown Rice Still Has More Arsenic: Despite the benefits of parboiling, brown rice naturally contains higher arsenic levels than white rice because arsenic concentrates in the bran.
Best Practices Lower Arsenic Further: To minimize arsenic, combine parboiled rice with cooking methods that use excess water, such as the 6-to-1 method, and use filtered water.
Arsenic Levels Vary by Region: The amount of arsenic in rice depends heavily on where it is grown, as contamination comes from the soil and water.

The Science Behind Arsenic in Rice

Arsenic is a naturally occurring element found in the earth's crust, which can contaminate soil and water. Rice is uniquely susceptible to accumulating arsenic, especially the more toxic inorganic form, because it is grown in flooded paddy fields. The arsenic is absorbed from the soil and water, and it concentrates primarily in the outer bran layer of the rice grain. This is why brown rice, which retains its bran, generally contains higher levels of arsenic than white rice, where the bran is removed during milling. Long-term exposure to high levels of inorganic arsenic has been linked to various health issues, including certain cancers and cardiovascular problems.

How Parboiling Works to Reduce Arsenic

Parboiling is a process where the rice is partially boiled in its husk. It typically involves three main steps: soaking, steaming, and drying. The initial soak and boil in water draw out a significant portion of the water-soluble inorganic arsenic. Research has specifically investigated the 'parboiling with absorption method' (PBA), which was developed to maximize arsenic removal while preserving nutrients. This method is particularly effective for several reasons:

Leaching: The initial boiling step actively leaches the water-soluble arsenic from the rice.
Pressure: The steaming under pressure helps mobilize minerals and nutrients from the bran into the starchy endosperm, preventing them from being lost later.
Draining: The final stage involves draining and replacing the water, which flushes away the extracted arsenic.

Arsenic Levels: Parboiled vs. Raw and White Rice

Multiple studies have quantified the reduction in inorganic arsenic achieved through parboiling. One 2021 study demonstrated that the PBA method removed 54% of inorganic arsenic from brown rice and 73% from white rice. This contrasts with cooking rice in excess water (like pasta), which typically removes about half the arsenic, and simple rinsing, which is less effective.

Parboiling also changes the way arsenic is distributed in the grain. A 2021 study in ScienceDirect found that while polishing removes arsenic from the outer layers, high-pressure parboiling can redistribute the element, making a comparison to simple polished white rice complex. However, when comparing a parboiled and re-polished white rice to a standard polished white rice, the parboiled version may contain more arsenic because the process drives elements inward. The key is the cooking method used afterward. If cooked with a drain-and-refresh method, a significant reduction still occurs.

Cooking Practices to Further Minimize Arsenic Exposure

Beyond choosing parboiled rice, other cooking methods can further lower arsenic levels:

The 6-to-1 Method: This involves using a large volume of water (six parts water to one part rice), boiling the rice until cooked, and then draining the excess water, similar to cooking pasta. This can significantly reduce the arsenic content, often by more than 50%.
Rinsing and Soaking: While less effective than parboiling, thoroughly rinsing rice with clean water before cooking helps remove some surface arsenic. Pre-soaking is also beneficial.
Low-Arsenic Water: Since rice absorbs water during cooking, using filtered water with a low arsenic concentration is crucial. This prevents reintroducing the toxin during the final cooking stage.
Diversifying Grains: Limiting overall rice consumption and including other grains like quinoa, bulgur, or farro can help manage arsenic exposure from your diet.

Comparison Table: Arsenic Levels in Rice Varieties and Cooking Methods


Rice Type	Inherent Arsenic Level	Parboiling Effect	Impact of Cooking Method (approx.)
Brown Rice	Higher (concentrated in bran)	Reduces inorganic arsenic by >50% (PBA method)	Excess water cooking removes about 50%
Standard White Rice	Lower (bran removed)	Reduces inorganic arsenic by >70% (PBA method)	Excess water cooking removes about 40%
Parboiled White Rice	Lower, but process can redistribute	Not applicable; already parboiled	Cooking with drain-and-refresh still lowers final content

Conclusion: Making Informed Choices

Yes, there is less arsenic in parboiled rice when processed and cooked correctly, making it a safer option for those concerned about this toxin. While parboiling doesn't eliminate all arsenic, it is a highly effective pre-treatment step. The effectiveness depends on the specific parboiling technique and subsequent cooking method. Consumers should look for parboiled rice varieties and consider using the 'parboiling with absorption' method or cooking with excess water to minimize inorganic arsenic exposure. Furthermore, varying grain intake and using filtered water are excellent complementary strategies to reduce health risks associated with long-term arsenic intake. By understanding these nuances, individuals can make more informed dietary decisions and enjoy rice safely as part of a balanced diet.

World Health Organization Fact Sheet on Arsenic

Frequently Asked Questions

While regular white rice has less arsenic than brown rice, studies show that parboiling can significantly reduce the inorganic arsenic content of both white and brown rice. Parboiled rice, when cooked with a draining method, can therefore be considered a safer option for minimizing exposure.

No, parboiling does not remove all arsenic from rice. It is a highly effective method for reducing the levels of inorganic arsenic, but some residual amount remains.

The parboiling process helps to retain more nutrients, such as B vitamins, compared to regular milling. The nutrients from the bran are driven into the endosperm, resulting in a more nutritious product than standard white rice.

To maximize arsenic removal, use the 'parboiling with absorption' (PBA) method. You can also use the 6-to-1 method, which involves boiling the rice in a large volume of water and then draining the excess.

Rice primarily contains inorganic arsenic, which is the more toxic form. Parboiling methods are specifically effective at removing this water-soluble inorganic form.

No, buying organic rice does not guarantee lower arsenic levels. Arsenic is naturally present in soil and water, so organic growing methods do not prevent absorption. In fact, some studies have found higher arsenic levels in organic rice.

Arsenic concentrates in the outer bran layer of the rice grain. Brown rice, which retains its bran, therefore contains higher levels of arsenic than white rice, which has its bran layer removed during the milling process.