Researchers concluded that nattokinase is “of low toxicological concern” for oral consumption, based on both animal and human studies.
A new safety assessment of nattokinase, an enzyme found in fermented soybean food natto, suggests that NSK-SD brand nattokinase from Japan Bio Science Laboratory (JBSL; Walnut Creek, CA) is of “low toxicological concern” for oral consumption. The findings are based on previous human and animal studies, as well as in vitro assays.
In 28-day and 90-day subchronic toxicity studies conducted in Sprague-Dawley rats, no adverse effects were observed for NSK-SD doses up to 167 mg/kg per day and 1000 mg/kg per day, respectively. An in vitro study also found nattokinase to be non-mutagenic and non-clastogenic.
Additionally, mice that were inoculated with 7.55 x 108 CFU of the nattokinase-producing bacterial strain B. subtilis var. natto “showed no signs of toxicity or residual tissue concentrations of viable bacteria.” And a 4-week, open clinical trial of eleven healthy human volunteers aged 20–64 also found that 10 mg/kg per day of nattokinase was well tolerated in humans.
“We take great pride in this assessment, as it demonstrates further validated, clinical evidence for the safety of NSK-SD nattokinase under the conditions evaluated in the assessment,” says Vincent Hackel, president of JBSL-USA. “This safety assessment, in combination with our ever-growing wealth of additional studies, supports JBSL as a valued leader for NSK-SD nattokinase across the globe.”
The newly published safety assessment includes information from eight studies, dated 2003–2006.
“Publishing robust safety assessments in a reputable, peer-reviewed journal like Food Chemical and Toxicology provides tremendous value to public health,” says Robert Donofrio, PhD, director of the applied research center, NSF International (Ann Arbor, MI). “It ushers important safety information into the public domain and provides scientific assurance to regulatory agencies as well as companies interested in bringing the latest food and dietary ingredients like NSK-SD into their products safely.”
Nutritional Outlook Magazine
Lampe BJ et al., “Toxicological assessment of nattokinase derived from Vacillus subtilis var. natto,” Food and Chemical Toxicology,” vol. 88 (February 2016): 87–99