The Association Between Core Temperature and Health

Study to Explore How Core Temperature Reduction Influence Health

The goal of this clinical trial is to learn if cold water drinking could promote body composition and further extend healthy lifespan in Chinese older adults. The main questions it aims to answer are:

1. Does cold water drinking lower the body fat percentage?
2. Will cold water drinking positively extend lifespan in a long-term Researchers will compare cold water intervention group to a control group (drinking 37℃ water instead) to see if cold water drinking works to promote health and slow down ageing process.

Participants will:

1. Drink 4℃ or 37℃ water 4 times (9a.m., 12p.m., 15p.m., 18p.m.) every day for 6 months.
2. Visit the institute and health checkup department for tests and checkup at baseline, the end of the 3rd month, and the end of 6th month.

According to pilot study, we found 4℃ water could significantly reduce core body temperature. Thus, we aim to explore whether 4℃ water drinking could promote body composition and further help to extend lifespan.

Participants will be randomly divided into intervention (drinking 4℃ water at 9a.m., 12p.m., 15p.m., 18p.m.) and control group (drinking 37℃ water at 9a.m., 12p.m., 15p.m., 18p.m.) for 6-month intervention. Tests will be conducted in Shenzhen Institute of Advanced Technology, while checkup will be tested at Health Checkup Department of Shenzhen University General Hospital. Body composition will be tested by Magnetic Resonance Imaging (MRI), Dual-Energy X-Ray Absorptiometry (DEXA), and TANITA (bioelectrical method). In addition, we will test participants' waist and hip circumferences using 3D scanning. Besides, we will test core body temperature and brown adipose tissue.

Apart from above main outcomes, we will also test their physical activity, food intake, metabolic rate, glucose, IL-6, TNF-alpha, HDL, LDL, insulin level. Meanwhile, ageing biomarkers, namely Phenotypic Age, eye fundus image, facial changes, bone density, gut microbiota, GlycanAge, will also be measured.

The whole intervention period will last for 6 months. All the tests and checkup will be tested at baseline, the end of the third month and the endpoint of the study.

Inclusion Criteria:

• Aged between 50 and 65 years old (including 50 and 65)
• No surgery in the past 6 months
• Healthy (No metabolic diseases, cardiovascular diseases, lung diseases (COPD, asthma, et al.), endocrine diseases and gastrointestinal diseases)
• Based in Shenzhen during the whole study period
• No significant change on body weight in the past 3 months

Exclusion Criteria:

• Those who need to take medication for a long term (including diet pills)
• On a diet
• Disabled
• Females who are trying to get pregnant, pregnant, or breastfeeding
• Presence of a metal implant in the body (e.g. pacemaker)
• Those with claustrophobia
• Those with blood phobia, pathological hypotension or hypertension
• Those who are in other intervention studies