Evidence-based nutrition, in plain English — every entry sourced from clinical research.
Every entry in this collection — sourced, checked and written to be read.
The American Journal of Tropical Medicine and Hygiene, 2020 · Systematic review of RCTs Across the randomised trials
Hypertension, 2016 · Meta-analysis of RCTs Across the randomised trials reviewed, magnesium supplementation produced a small reduction in
Cochrane Database of Systematic Reviews, 2013 · Cochrane systematic review Regular vitamin C did not prevent colds in
Across 22 randomised trials, beetroot juice lowered systolic blood pressure by about 3.6 mmHg and diastolic by 1.3 mmHg, more so in trials lasting two weeks or longer. Larger juice doses lowered it more, but juices higher in nitrate did not, suggesting nitrate is not the whole story.
Over a median of about four years, older adults at high cardiovascular risk on a Mediterranean diet with extra olive oil or nuts held their cognitive scores steady or improved slightly, while the control group, advised to cut dietary fat, declined on all three cognitive composites.
Across 28 trials, adding at least 3 g of oat β-glucan a day lowered LDL cholesterol by 0.25 mmol/L and total cholesterol by 0.30 mmol/L, without changing HDL cholesterol or triglycerides. The analysis was funded by DSM Nutritional Products and drew on unpublished trial reports from the oat-fibre company CreaNutrition.
Over ten weeks, a diet high in fermented foods such as yogurt, kefir and kimchi steadily increased gut microbiome diversity and lowered 19 of 93 inflammatory proteins measured in blood. These were secondary results: the trial’s primary immune measure did not change on either diet.
Daily omega-3 supplements (1 g) did not lower major cardiovascular events or invasive cancer compared with placebo over a median of 5.3 years. Among the secondary outcomes, heart attacks were lower (hazard ratio 0.72), but stroke and cardiovascular death were not.
In two large US cohorts of nurses and other health professionals, followed for up to 30 years, people who ate nuts seven or more times a week had a 20% lower death rate than those who ate none, after adjusting for other risk factors. This is an association, not proof of cause, and the study was part-funded by the International Tree Nut Council.
One cup of blueberries a day for six months improved blood-vessel function and arterial stiffness in adults with metabolic syndrome, and raised HDL cholesterol in those not taking statins. Insulin resistance, the main outcome, did not change, and half a cup a day had no effect.
Comparing people who ate the most dietary fibre with those who ate the least, observational studies found 15–30% lower rates of death from all causes and from cardiovascular disease, and of coronary heart disease, stroke, type 2 diabetes and colorectal cancer, with the greatest benefit at 25–29 g a day. Trials showed lower body weight, blood pressure and cholesterol with more fibre.
Over eight weeks, a diet rich in fruit, vegetables and low-fat dairy, with less saturated and total fat, lowered blood pressure by 5.5/3.0 mmHg more than a typical American diet, and by 11.4/5.5 mmHg in people with hypertension. Sodium intake and body weight were held constant.