Sodium-rich COndiments Unifying Health and Taste

Overview

This research aims to develop an evidence-based classification for sodium-rich condiments (natremic index) based on their CVD-related risks. It is hypothesised that the acute cardiovascular and physiological response (effectively extrapolated to long-term CVD risks) to meals prepared with various sodium-rich condiments can be leveraged upon for the development of such an index that will systematically classify sodium-rich condiments based on the risk they present to cardiovascular health.

Detailed description

Hypertension is the leading risk factor for cardiovascular diseases (CVDs) in older adults. While absolute dietary sodium reductions remain vital for prevention, effective long-term management must take stock of sensorial efficacy and acceptance, alongside the corresponding impacts on health. In Asia, this phenomenon is distinct due to a genetic predisposition of the population to salt sensitivity (increased risk), and a distinct food culture characterised by regional condiments (e.g. soy sauce, fermented bean paste).

The aim of this research is to develop an evidence-based classification for sodium-rich condiments (natremic index) based on their CVD-related risks. Perceived saltiness intensity is influenced by factors beyond the total amount of sodium consumed (e.g. flavour enhancers like MSG, tastes synergism etc.).

Similarly, while hypertension is predisposed by excessive sodium intake, growing evidence also suggests the potential role of bioactive compounds and ingredients (including some identified from Asian-style condiments e.g. spices, soya-derived flavonoids) that may elicit cardiovascular protective properties.

Contrary to generic recommendations that focused solely on absolute sodium reduction, sustainable solutions must simultaneously address concerns surrounding long-term health and consumer acceptance.

Much like the well-established glycemic index, it is hypothesised that the development of a natremic index, designed to evaluate and classify sodium-rich condiments according to their risks to cardiovascular health will serve as a vital, first of its kind strategy that can reliably guide public health recommendations, and spearhead next-generation innovations in the food and nutrition industry. The proposed research is split into two main parts that will investigate in detail three sodium-rich condiments commonly used in Asia cuisines: light soy sauce (condiment 1), fermented bean paste (condiment 2), and table salt (control), from sensory and health perspectives

Interventions

• Other Control porridge with no condiments
  To examine acute cardiovascular health response to plain porridge.
• Other Porridge with light soya sauce
  To examine acute cardiovascular health response to plain porridge with saltiness-matched light soya sauce
• Other Porridge with fermented bean paste
  To examine acute cardiovascular health response to plain porridge with saltiness-matched fermented bean paste
• Other Porridge with table salt
  To examine acute cardiovascular health response to plain porridge with saltiness-matched table salt.

Primary outcome measures

• Endopat assessment [Time frame: EndoPAT assessments which will serve as the primary outcome of interest will be measured at postprandial intervals (up to 3 measurements) over 4 hours.]

Secondary outcome measures (7)

• Ambulatory blood pressure [Time frame: 24 hour period consisting of: Postprandially 15 minutes intervals (over 4 hours), 30 minutes interval (after 4 hours)]
• Palatability questionnaire rated on a visual analogue scale "Good" to "Bad" [Time frame: Test meal is consumed for 15 minutes. At the end of 15 minutes, palatibility questionnaire is completed.]
• Serum and Plasma sodium and potassium [Time frame: Blood will be sampled at timepoints, t = 0 minute (Baseline) and at t = 30, 45, 60, 120, 180, 240 minute for each session]
• Subjective appetite questionnaire [Time frame: t=0 minute (Baseline), and t= 30, 45, 60, 120, 180, 240 minute for each session.]
• Taste acuity test [Time frame: Test administered once at each session (5 sessions). Each test takes 20 minutes.]
• Ultrasound scan of carotid intima-media thickness [Time frame: At baseline only]
• Evaluation [Time frame: Administered during session4, 5 and 6. Each evaluation takes1 hour.There is a 1-minute inter-stimulus break between each sample for palate cleansing.]

Eligibility criteria

Inclusion criteria

• ≥ 50, < 75 years old
• Male or postmenopausal female (self-reported)
• ≥ 50 kg body weight
• Systolic blood pressure (≥ 130, < 160 mmHg) or diastolic blood pressure (≥ 85, < 100 mmHg)
• Willing and able to follow intervention protocol
• Ability to identify basic tastes (determined by taste discrimination test)
• English speaking

Exclusion criteria

• Prescribed and taking medication which may affect study outcomes (i.e. for blood pressure management, blood thinning etc.) in consultation with study physician (Prof Melvin Leow) and PI(Dr Darel Toh)
• Type 1 or type 2 diabetes mellitus (i.e. fasting blood glucose ≥ 7.0 mmol/L or HbA1c ≥ 6.5 %)
• Taking dietary supplements which may affect study outcomes one month prior to their first visit in consultation with study physician, PI and study team
• Obesity (BMI ≥ 27.5 kg/m2)
• History or known present diagnosis of hematological (G6PD and coagulation disorders), hepatic (hepatitis B and C), renal, gastrointestional or other relevant disease / disorders which may affect the outcomes of interest in consultation with study physician, PI and study team
• History of arteriovenous shunt or mastectomy
• Women who are pregnant, lactating or planning pregnancy
• History or present diagnosis of HIV and/or tuberculosis
• History of severe vasovagal syncope (blackouts or near faints) following blood draw
• Drug abuse within last 5 years
• Excessive alcoholic beverage consumption > 2 servings per day (1 serving defined as 360 mL beer, 150 mL wine or 45 mL distilled spirits)
• Smoking (cigarette, e-cigarette, cigar, pipe, vape)
• Engaging in habitual vigorous physical activity (as defined by physical activity questionnaire-PAR)
• Allergic or intolerance to intervention foods.
• Dislike or unwilling to consume intervention foods
• Photophobic (sensitivity to intense lights and colours), particularly to intense red lights
• Has sinus problems problems that affect taste and smell
• Involvement in other clinical studies that may influence the outcome of the study
• An ASTAR Staff.
• A study team member or their immediate family member

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Double blind

Primary purpose

Other

Study locations

Singapore · 1 center

• Clinical Nutrition Research Centre — Singapore

Identifiers

NCT: NCT07397754 · 2025-063

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗