Hydroxytyrosol Dietary Supplement and Prevention of Age-Related Diseases

The primary objective of this study is to ascertain the effects of chronic consumption of a hydroxytyrosol-rich extract from olive in a population at high risk of developing age-related pathologies such as type 2 diabetes and cardiovascular diseases. The markers measured will be associated with oxidative stress, inflammation, and homeostasis glucose and lipid profiles. Improvements in these parameters could potentially prevent the onset of pathologies associated with aging.

Fifty subjects 40-75 years old overweight (BMI between 24-29,9 kg/m2) and prediabetes (fasting blood sugar between 100-126 mg/dl and/or glycated hemoglobin between 5,7-6,4%) will be recruited. Detailed inclusion and exclusion criteria are provided below.

Participants will be randomly divided into two groups, one to consume the Hytolive® capsule and the other a placebo. The intervention study has been designed for daily consumption before breakfast of one capsule for 16 weeks. The study includes a two-week washout period during which subjects will not be allowed to consume olives or virgin olive oil.

At the beginning and end of the study, upon arrival at the ICTAN-CSIC Human Nutrition Unit, volunteers will provide a urine sample corresponding to the first morning void, and a nurse will draw a fasting blood sample (20 mL distributed in tubes with various anticoagulants for measurements). Additionally, their blood pressure will be measured, and a complete anthropometric and body composition study will be conducted. Furthermore, volunteers will provide a stool sample from the preceding days (these samples will not be used in this study but will be stored at -80°C for potential future determination of the intestinal microbiota metagenomic profile). Subsequently, dietary controls will be conducted, physical activity and emotional well-being tests will be administered, and fatigue will be evaluated. Additionally, there will be an interim visit aimed at verifying adherence to supplementation. For this purpose, volunteers will provide a urine sample corresponding to the first morning void on an empty stomach, in which levels of hydroxytyrosol and its derivatives will be determined. Likewise, dietary and physical activity controls will be conducted to confirm that volunteers are not altering their habits.

Eligibility Criteria:
Inclusion Criteria:

* Prediabetes (defined as fasting glucose levels according to the American Diabetes Association guideline, with fasting blood glucose ≥100 and \<126 mg/dL, or hemoglobin A1c levels ranging from 5.7% to 6.4%)
* Overweight (body mass index BMI 24-29.9 kg/m2)

Exclusion Criteria:

* Any prior diagnosis of diabetes, hypertension, hyperlipidemia, other cardiovascular diseases, thyroid gland disorders, asthma, arthritis, or inflammatory conditions, cirrhosis, or other liver diseases
* Weight loss \> 2.5 kg in the last 6 months
* Being on pharmacological treatment of any kind
* Taking dietary supplements containing antioxidants other than vitamins
* Being a smoker or habitual alcohol consumer; being HIV positive
* Being pregnant or breastfeeding
* Blood pressure ≥ 140 mmHg (systolic) and ≥ 90 mmHg (diastolic)
* Total cholesterol ≥ 240 mg/dL, LDL cholesterol ≥ 160 mg/dL, or TG ≥ 200 mg/dl