Sodium-rich COndiments Unifying Health and Taste

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

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