Cyanide Toxicity of Freshly Prepared Smoothies and Juices Frequently Consumed

Introduction: Humans are exposed to low levels of CN- on a daily basis due to vehicle exhaust, water sources, foods, and even cigarettes smoke. Many of these raw and natural foods such as seeds and nuts have become a large part of human nutrition with the “eat raw and natural” push over the past decade with a reported 40% of adults consuming raw seeds and nuts daily. Most forms of CN- in health foods originate from amygdalin contained in apple seeds and almonds or, linamarin contained in flax seeds. Many of these items are used in the health food industry (e.g., fresh smoothies and juices) as a selling point for improving one’s fitness, vigor, and strength as they are a good source of omega-3 fatty acids, lignans, and fiber.

Aims: This study evaluated popular fruit and vegetable smoothies and juices marketed as raw and natural. Data showed that some items contained the presence of cyanide at various levels.

Study Design: There were eleven (11) popular varieties of drinks analyzed for total cyanide (TCN). These drinks contained juiced raw vegetables and fruits, flax seeds, whole apples with seeds, raw almond milk, and pasteurized almond milk as ingredients.

Place and Study Duration: Sampling was conducted in Las Vegas, Nevada where items were collected from health food eateries during the summer of 2017.

Methodology: Brief, fifty milliliters (mL) of a homogenized smoothie and juice drink and 1 gram of flax seeds were subjected to the above-referenced methods for sample preparation per USEPA Methods 9012B (digestion) followed by USEPA method 9014 (colorimetry).

Results: Data indicated the highest TCN was identified in drinks containing raw flax seeds, followed by unpasteurized raw almond milk, then fresh whole apple juice. It was found that no TCN was present in drinks containing none of the above mentioned ingredients (e.g. flax seed, raw almond milk) or pasteurized ingredients.

Conclusion: Research establish that TCN is present in smoothies and juices containing, highest to lowest, raw flax seeds, fresh whole apples, and/or unpasteurized almond milk. Concentrations were detected as high as 341 μg L-1 in commercially available smoothies containing vegetables, raw flax seeds, and almond milk and fruits. Smoothies containing raw vegetables, fruits, unpasteurized almond milk, and no flax seeds contained 41 ug L-1 TCN, while similar smoothies with pasteurized almond milk contained negligible to 9.6 ug L-1 CN. Unpasteurized almond milk and raw flax seeds were the major sources of TCN in drinks. With the increased demand for raw and natural foods, there is a potential sublethal exposure of TCN by consumers. Findings have also shown that TCN is present in smoothies and juices containing raw flax seeds, fresh whole apples, and/or unpasteurized almond milk.  Potentially any fruit or vegetable containing cyanogenic glycosides, linamarin and amygdalin, may be contributing to TCN content in health food drinks such as smoothies. Cyanide from linamarin has been linked to a variety of health issues such as diabetes mellitus, neurological deficits, sensory or memory impairments, and weight gain through damage to the adrenal gland function. Moreover, thiocyanate, a metabolic by-product of CN, has been tied to goiter growth and hypothyroidism. The presence of CN- in these drinks do not pose an acute threat of poisoning; however, this study suggests that a diet consisting of regular raw flax seeds, fresh whole apples, and/or unpasteurized almond milk, smoothie intake may result in chronic sublethal exposure to TCN. The average adult can mitigate CN- toxins consumed in their daily diets. Women who may become pregnant, currently pregnant and people with developing or, compromised immune systems should monitor or restrict their intake of drinks containing raw flax seeds and almonds or unpasteurized almond milk. Finally, additional research is required to fully understand the possible health effects that exist in unprocessed fresh foods.

Read full article: