Science shorts: Latest research findings on caffeine, selenium, probiotic

Caffeine kick: Intake improves time to exhaustion in runners – meta-analysis​ ​

The intake of caffeine has been shown to improve running performance, especially at long-distances, according to the findings of a meta-analysis.

The time to complete endurance running was also shorter in participants who took caffeine as compared to the placebo.

Researchers from Beijing Sport University and Rey Juan Carlos University studied 21 randomised placebo-controlled trials involving 254 participants for this particular meta-analysis.

Selenium supplementation may lower insulin resistance in cardio-metabolic disease patients: Chinese meta-analysis​ 

Selenium supplementation may be effective in reducing insulin resistance in those with cardio-metabolic diseases (CMDs), according to a systematic review and meta-analysis by researchers in China.

The analysis looked at 10 RCTs involving 526 participants, with insulin levels, insulin resistance, fasting plasma glucose and glycosylated haemoglobin A1C (HbA1c) as the primary outcome markers, while lipid markers are the secondary outcome markers.

In a sub-group analysis, the review found that selenium supplementation actually increased HDL cholesterol levels more significantly in cardiovascular disease patients, followed by diabetes patients.

Prebiotic supplementation reduces blood pressure among people with hypertension – Australian trial​​

A high-fibre supplement helped reduce blood pressure among people with hypertension by changing their gut bacteria, a three-week trial from Australia has reported.

In the study, the intervention group was given food that either comes with the resistant starch acetylated and butyrylated high-amylose maize starch (HAMSAB) or the placebo.

The group who ate the diet with the resistant starch had a clinically significant drop in their systolic blood pressure. There were also changes in their gut bacteria, which are likely to be a contributing factor to their decrease in blood pressure.

Probiotics mitigate disruptions to gut microbiota during bacteria-eradication treatment – China RCT​ ​

Probiotics supplementation could reduce gastrointestinal side effects and restore alterations to the gut microbiota caused by Helicobacter pylori (H. pylori)-eradication therapy, a new study reveals.

Nearly 250 patients were randomised to receive a 14-day quadruple therapy (bismuth potassium citrate, esomeprazole, amoxicillin, furazolidone), combined with probiotics supplementation (Bifidobacterium tetravaccine tablets) for 28 days or the therapy with placebo.

Notably, patients supplemented with probiotics had smaller fluctuations of gut microbiota compared to those who received placebo. Also, the microbiota was restored to baseline as soon as two weeks after the therapy.

Folic acid and iodine supplementation speeds up conception rate – new study​

Dietary supplementation of folic acid and iodine could boost fertility rate, while evening primrose oil is associated with a longer time to pregnancy (TTP), say Singapore researchers.

It was found that women who consumed any type of supplement had higher fecundability – the probability of achieving pregnancy within one menstrual cycle – compared to those who did not.

Specifically, folic acid and iodine users had significantly greater fecundability than non-users.