Brown rice syrup (BRS) has gained traction as a popular alternative sweetener, often perceived as a healthier choice because it is derived from rice and is free of fructose. This perception has led to its inclusion in many organic, vegan, and gluten-free food products. Consumers must determine if this seemingly wholesome ingredient is truly beneficial or if it carries overlooked risks.
How Brown Rice Syrup is Produced
Brown rice syrup, also known as rice malt syrup, is manufactured through a process called enzymatic hydrolysis. This production begins with cooked brown rice starch, which is steeped with purified bacterial or fungal enzymes. These enzymes break down the complex starches into simpler sugar units. The primary sugar produced is maltose, a disaccharide made up of two linked glucose molecules. The final syrup is typically composed of 45–85% maltose, along with smaller amounts of maltotriose and a small percentage of free glucose. Unlike common table sugar, BRS contains virtually no fructose, giving it a milder flavor and a thick, viscous consistency. The liquid is then strained and boiled down to achieve the desired syrup consistency.
Understanding the High Glycemic Load
Despite its lack of fructose, brown rice syrup presents a significant concern due to its extremely high glycemic load. The syrup is almost entirely glucose and glucose polymers like maltose, meaning it is rapidly digested and absorbed by the body. Maltose quickly breaks down into two glucose molecules, acting essentially as 100% glucose once consumed. This rapid conversion results in a very high Glycemic Index (GI), indicating how quickly a food raises blood sugar levels. Brown rice syrup can have a GI as high as 98, considerably higher than the GI of standard table sugar (sucrose), which is typically around 65. Consuming BRS leads to a sudden spike in blood glucose and insulin levels, often followed by a sharp crash. Frequent consumption of high-GI foods can strain the body’s blood sugar management system, potentially increasing the risk of developing type 2 diabetes.
The Specific Concern of Inorganic Arsenic
A more unique and serious concern for brown rice syrup is the potential for contamination with inorganic arsenic. Rice plants are particularly efficient at absorbing this toxic element from the soil and water, often accumulating higher levels than other food crops. Inorganic arsenic is a known human carcinogen found naturally in the environment. Since BRS is often made from whole brown rice, and arsenic concentrates in the bran layer, the manufacturing process amplifies the contaminant levels in the final sweetener. Inorganic arsenic is the highly toxic form, unlike organic arsenic, which is generally considered harmless. Studies have found elevated levels of inorganic arsenic in commercial products, especially toddler formulas and cereal bars. Some infant formulas sweetened with BRS have been found to contain inorganic arsenic at levels 20 times higher than formulas without the syrup. Chronic, low-level exposure is linked to long-term health risks, including various cancers and developmental issues, particularly in infants and young children. Currently, there are no specific, legally enforceable limits for arsenic in sweeteners in the United States.
Moderation and Label Awareness
Given the metabolic and toxicological concerns, consumers should approach brown rice syrup with caution and prioritize moderation. Identifying this sweetener on food labels is the first step, as it may be listed under names like rice syrup, rice malt, or rice malt syrup. Limiting the overall intake of products containing BRS is particularly important for infants and young children due to their smaller body mass and heightened vulnerability to the neurodevelopmental effects of inorganic arsenic. Consumers may consider alternative sweeteners that do not carry the inherent arsenic risk associated with rice-derived products, such as maple syrup or honey. While BRS lacks fructose, its high glycemic impact and the risk of toxic contamination mean it should not be considered a superior sugar substitute.