Effect of Flax in Yogurt on Blood Cyanide Levels

Participants will receive yogurt containing the following flaxseed products in a random order:

• 40 g ground flaxseed, untreated;
• 40 g ground flaxseed, roasted before grinding;
• 40 g intact whole flaxseed;
• 28 g flaxseed hulls;
• 0 g flaxseed.

Venous blood will be collected at the following time points: 0 (before consumption of test product), 15, 30, 45, 60, 75, 90, 120, 150, 180 min.

Urine will be collected prior to consumption of test product and 180 min.

Primary endpoints: 1) Peak blood level of cyanide and incremental area under the curve (iAUC) for cyanide in blood over a 3h postprandial period. Secondary endpoint: 1) cyanogenic glycoside and thiocyanate concentrations in plasma and urine over a 3h postprandial period.

Tertiary endpoints: 1) metabolic profile in plasma and urine over 3 h postprandial period.

Inclusion criteria

• Generally healthy adult, 18 years or older;
• Willing to provide informed consent;
• Willing/able to comply with the requirements of the study.

Exclusion criteria

• Pregnant or lactating;
• Medical history of disease that is currently under treatment;
• Active treatment for any type of cancer within 1 year prior to study start;
• Presence of a gastrointestinal disorder, daily use of any stomach acid-lowering medications or laxatives (including fibre supplements) within the past month or antibiotic use within the past 6 weeks;
• Plasma concentration of vitamin B12 < 148 pmol/L;
• Complete blood count outside normal range;
• Medical history of liver disease or liver dysfunction (defined as plasma AST or ALT ≥3 times the upper limit of normal (ULN));
• Fasting blood glucose ≥6.1 mmol/L and/or HbA1c ≥6.0%;
• Fasting plasma total cholesterol >7.8 mmol/L;
• Fasting plasma HDL <0.9 mmol/L;
• Fasting plasma LDL >5.0 mmol/L;
• Fasting plasma triglycerides >2.3 mmol/L;
• Systolic blood pressure >140 mmHg or diastolic blood pressure >90 mmHg;
• Major surgery within the last 3 months;
• Smoking, use of tobacco, vape or cannabis (within the last week);
• Allergies to flaxseed or yogurt;
• Aversion or unwillingness to eat study foods;
• Participation in another clinical trial, current or in the past 4 weeks