Beetroot Extract and Quality of Life in Adults Aged 75 and Over

Keywords

• beetroot extract
• dietary nitrate
• cardiovascular health
• functional health
• quality of life
• cognitive function

Study arms

• Placebo comparator
  Placebo Control Group

  Participants receive a placebo (nitrate-depleted beetroot juice) and continue with their usual daily activities without any additional intervention.

  Dietary Supplement: Placebo group: nitrate-depleted beetroot juice

• Experimental
  Beetroot Extract Supplementation

  Participants receive daily supplementation with beetroot extract juice and continue with their usual daily activities.

  Dietary Supplement: Beetroot Extract Supplementation

• Experimental
  Beetroot Extract Plus Multicomponent Exercise

  Participants engage in a multicomponent physical exercise program, supervised during the first 6 weeks and then prescribed but not supervised for the following 6 weeks, combined with daily supplementation of beetroot extract juice.

  Dietary Supplement: Beetroot Extract Supplementation

• Active comparator
  Placebo Plus Multicomponent Exercise

  Participants engage in a multicomponent physical exercise program, supervised during the first 6 weeks and then prescribed but not supervised for the following 6 weeks, combined with placebo supplementation (nitrate-depleted beetroot juice).

  Dietary Supplement: Placebo group: nitrate-depleted beetroot juice

Interventions

• Dietary supplementBeetroot Extract Supplementation

  Participants receive daily supplementation with beetroot extract juice, with or without participation in a multicomponent physical exercise program, depending on group allocation. When applicable, the exercise program targets strength, balance, mobility, and aerobic capacity, and is supervised by trained professionals during the first 6 weeks and subsequently prescribed but not supervised for the following 6 weeks. This intervention aims to evaluate the independent and combined effects of beetroot extract supplementation and physical exercise on cardiovascular, functional, and cognitive outcomes in adults aged 75 years and older.

• Dietary supplementPlacebo group: nitrate-depleted beetroot juice

  Participants receive daily supplementation with nitrate-depleted beetroot juice, with or without participation in a multicomponent physical exercise program, according to group allocation. The placebo juice is derived from beetroot but has had its nitrate content removed, maintaining similar appearance, taste, and texture to the active supplement. When applicable, the exercise program targets strength, balance, mobility, and aerobic capacity and is supervised by trained professionals during the first 6 weeks, followed by a prescribed but unsupervised phase for the subsequent 6 weeks. This placebo-controlled intervention is designed to isolate the effects of dietary nitrate from beetroot extract and to evaluate the independent and combined effects of physical exercise on cardiovascular, functional, and cognitive outcomes in adults aged 75 years and older.

Primary outcomes

1. Blood Pressure

   Blood pressure (systolic and diastolic) will be measured three times in a row, and the average of the three readings will be calculated.

   Time frame: At baseline - 6 weeks - 12 weeks

2. Heart rate

   Heart rate will be measured at rest, after the 6-minute walk test, and then 3 minutes after the test has finished.

   Time frame: [Time Frame: Baseline - 6 weeks and 12 weeks]

3. Stroop Test

   This test measures cognitive control and attention by asking individuals to name the color of a word rather than the word itself. It evaluates the ability to manage interference between conflicting information.

   Time frame: At baseline - 6 weeks - 12 weeks

4. Symbol Digit Modalities Test (SDMT)

   This test assesses processing speed, attention, and working memory by requiring individuals to match symbols with corresponding numbers under time pressure. Faster and more accurate performance indicates better cognitive functioning.

   Time frame: At Baseline - 6 weeks - 12 weeks

5. Trail Making Test - A (TMT-A)

   This test evaluates visual attention and task switching by asking individuals to connect a sequence of numbers (Part A). It measures cognitive flexibility, speed, and executive function.

   Time frame: At baseline - 6 weeks - 12 weeks

6. 6 minute walk test (6MWT)

   This test measures functional exercise capacity by assessing how far a person can walk in six minutes on a flat surface. It reflects endurance and helps evaluate cardiovascular, respiratory, and musculoskeletal function.

   Time frame: At baseline - 6 weeks - 12 weeks

7. Short Physical Performance Battery (SPPB)

   Physical Function: Assessed using the Short Physical Performance Battery (SPPB), which combines balance, gait velocity, and leg strength as a single score on a 0 (worst) to 12 (best scale)

   Time frame: At baseline - 6 weeks - 12 weeks

8. Strength

   Handgrip strength and maximal concentric strength (leg press, chest press, knee extension, seated row machine). Changes in "1RM", defined as the maximum resistance/load a person can move in one repetition of an exercise will be assessed. These values are mesured in Kilograms and results are individualized.

   Time frame: At baseline - 6 weeks - 12 weeks

9. Quality of life (QoL)

   Measurment of quality of life using EQ5D-3L, the patients indicate their health state by choosing one level for each of the five dimensions, creating a 5-digit code representing 243 possible health states. EQ VAS, includes a vertical Visual Analogue Scale (0-100) where patients rate their self-rated health, with 100 being the "best imaginable health state". Utility. The responses can be converted into a single index value (utility score) using country-specific valuation sets, where 1 represents full health and 0 represents death.

   Time frame: At baseline - 12 weeks

10. Medication Use (Polypharmacy and Psychotropic Drugs)

    Number and type of medications will be recorded. Polypharmacy will be defined as the use of ≥5 medications. Psychotropic drug use and medications related to comorbid or intercurrent conditions (e.g., antibiotics) will also be documented

    Time frame: At baseline - 12 weeks

11. Sleep Health Index (SATED)

    SATED : This questionnaire assesses sleep health across five dimensions: Satisfaction, Alertness, Timing, Efficiency, and Duration. It provides a brief evaluation of overall sleep quality and habits.

    Time frame: At baseline - 12 weeks

12. Nutritional Status

    Mini Nutritional Assessment (MNA) ranges from normal nutritional status (24-30points), risk of malnutrition (17-23.5points), or malnourished(\<17points).

    Time frame: At baseline

13. Barthel Index

    Barthel Index of independence during activities of dailyliving (ADLs) ranges from 0 (severe functional dependence) to 100 (functional independence).

    Time frame: At baseline

14. International Physical Activity Questionnaire (IPAQ)

    This questionnaire measures physical activity levels by asking about the frequency and duration of different intensities of activity. It is used to estimate total physical activity and categorize individuals into activity levels.

    Time frame: At baseline

15. Mini-Mental State Examination (MMSE)

    This test is a brief screening tool used to assess cognitive function, including orientation, memory, attention, language, and visuospatial skills. It helps identify cognitive impairment and monitor changes over time.

    Time frame: At baseline

Secondary outcomes

1. Continuous Glucose Monitoring

   Continuous Glucose Monitoring (FreeStyle Libre 2): This system measures glucose levels continuously through a small sensor placed on the skin, providing real-time data without frequent finger pricks. It helps track glucose trends and fluctuations, supporting better diabetes management and treatment decisions.

   Time frame: During the first 15 days

2. Laboratory Parameters: Blood Nitrate and Nitric Oxide Assessment

   Blood Nitrate and Nitric Oxide Assessment: This measurement evaluates nitric oxide (NO) bioavailability by analyzing changes in blood nitrate levels, a stable indirect marker of NO production, typically expressed in µmol/L. . Blood samples (10-20 mL) will be collected alongside routine clinical testing using Vacutainer tubes (EDTA, citrate, or serum tubes as appropriate). Samples will be left upright for 10 minutes and centrifuged at 3000 rpm for 15 minutes to obtain serum and plasma for analysis. Aliquots will be stored at -80°C for future specialised analyses, including flow cytometry.

   Time frame: At baseline - 6 weeks - 12 weeks

3. Body Composition by Bioimpedance

   Body Composition by Bioimpedance (BIA 101 BIVA® PRO): This method assesses body composition by measuring electrical impedance through a two-electrode system, providing estimates of body water, fat mass, and fat-free mass. It also uses bioelectrical impedance vector analysis (BIVA) to evaluate hydration status and cellular health, offering insights into nutritional and physiological condition.

   Time frame: At baseline - 6 weeks - 12 weeks