The applicability of hydroxytyrosol

As a natural polyphenolic compound, the applicability of hydroxytyrosol in pregnant women and children requires comprehensive evaluation based on pharmacokinetic characteristics and safety data. Although relevant research is less comprehensive than that in the general population, existing evidence has provided preliminary references for its safety, which is analyzed separately for the two groups as follows:

I. Applicability in Pregnant Women: Pharmacokinetic and Pregnancy Safety Evidence

1. Pharmacokinetic Characteristics: Placental Permeability and In Vivo Distribution

Limited placental transport capacity: Animal experiments (e.g., rats) show that hydroxytyrosol can be absorbed into the bloodstream after oral administration, but the amount passing through the placental barrier is small. Its polar structure (containing phenolic hydroxyl groups) may limit transplacental transport efficiency, so the fetal exposure to maternal hydroxytyrosol intake is relatively low.

Maternal metabolism and excretion: The metabolic pathway of hydroxytyrosol in pregnant women is similar to that in ordinary adults, mainly inactivated through glucuronidation or sulfation conjugation reactions and excreted in urine, with no specific metabolic disorders during pregnancy observed.

2. Safety Data: Animal Experiments and Limited Clinical Evidence

Animal teratogenicity test results: In teratogenicity tests on rats and rabbits, when the dosage of hydroxytyrosol was as high as 200 mg/kg bw/day, no fetal structural abnormalities, growth retardation, or adverse pregnancy outcomes (such as increased abortion or stillbirth rates) were observed. Converting this dosage to human body weight (calculated based on a 60 kg adult) is approximately 20 mg/day, which is far higher than the dosage possibly ingested in daily diets (e.g., about 1-50 mg/day through olive oil).

Clinical observation data: At present, large-scale clinical trials for pregnant women are lacking, but in small-scale cohort studies, intake of olive oil rich in hydroxytyrosol during pregnancy did not increase the risk of pregnancy complications (such as gestational diabetes and hypertension), and had no significant association with neonatal birth weight, Apgar score, and other indicators. It should be noted that such studies are mostly observational data, making it difficult to completely exclude the influence of confounding factors.

3. Potential Risks and Recommendations

Although existing data support safety, pregnant women, as a special population, still need to be cautious about high-dose supplements. Due to the lack of human data on long-term exposure to high doses, it is not recommended to deliberately take hydroxytyrosol supplements during pregnancy, and intake through daily diets (such as appropriate olive oil) is more 稳妥.

II. Applicability in Children: Pharmacokinetic Differences and Safety Studies

1. Pharmacokinetics: Metabolic Differences Between Children and Adults

Possibly higher absorption efficiency: The gastrointestinal tract of children is not fully developed, and the intestinal mucosa permeability is high, so the oral bioavailability of hydroxytyrosol may be slightly higher than that in adults. However, studies have shown that the activity of phenolic acid metabolizing enzymes (such as UGT enzymes) in children is close to that in adults, so there is no significant difference in the metabolic rate.

Distribution and excretion characteristics: The tissue distribution of hydroxytyrosol in children is similar to that in adults, mainly accumulating in organs such as the liver and kidney, but due to the higher body fluid proportion in children, the apparent volume of distribution may increase slightly, and the final excretion rate in urine is similar to that in adults.

2. Safety Evidence: Animal Experiments and Studies in Children

Toxicity tests on animal pups: Administering hydroxytyrosol (50-100 mg/kg bw/day) to lactating rat pups (from birth to weaning) did not show adverse effects on growth and development (body weight, organ index), hematological indicators (such as red blood cell and white blood cell counts), and there was no difference in behavioral tests (such as learning and memory ability) after weaning compared with the control group.

Clinical studies in children: In intervention studies for children with iron-deficiency anemia, the combined use of hydroxytyrosol and iron supplements (dosage about 10 mg/day) can improve iron absorption rate, and no adverse reactions such as vomiting and diarrhea occurred. In addition, when olive oil rich in hydroxytyrosol is used as a component of children's complementary foods, long-term intake (more than 6 months) does not cause allergies or digestive dysfunction.

3. Dosage Recommendations and Precautions

The safe intake of hydroxytyrosol in children's daily diets has not been clearly defined, but based on the safety coefficient from animal experiments (NOAEL=200 mg/kg bw/day, converted to children's body weight is about 1-2 mg/kg bw/day), combined with dietary exposure, intake through natural foods generally does not need to worry about toxicity. It should be noted to avoid giving children high-purity hydroxytyrosol supplements to prevent overdose.

III. Summary: Existing Evidence and Limitations

Hydroxytyrosol shows good safety in pregnant women and children. Pharmacokinetic characteristics do not suggest special risks, and animal and limited clinical data support the safety of routine dietary intake. However, it should be noted that:

Studies on pregnant women lack high-dose randomized controlled trials, and data on long-term high-dose exposure in children are insufficient;

The safety of hydroxytyrosol in natural foods may differ from that in supplements, and supplements are not recommended as a daily source.

At present, authoritative institutions (such as EFSA) have not put forward special restrictions on the intake of hydroxytyrosol by pregnant women and children, and maintaining natural intake in diets is still a more secure choice.