What does the science actually say?
Evidence-graded summaries of what peer-reviewed studies say about supplements, vitamins, foods and lifestyle habits, with every claim linked to its PubMed sources.
Latest
- Does honey help a cough? What the trials found — In children, honey slightly eases a cold cough in small trials; a good adult trial found no benefit. Never give honey to babies under 12 months.
- Does cutting salt lower blood pressure? — Pooled data from 133 trials show cutting sodium lowers systolic blood pressure by about 4 mm Hg, and salt substitutes also cut strokes and deaths.
- How many steps a day do you really need for a longer life? — Large reviews link more daily steps to longer life and fewer depressive symptoms, with most of the benefit arriving well below 10,000 steps a day.
- Aromatherapy for sleep, anxiety and low mood: what 27 trials found — A 2025 review of 2,072 adults found inhaled essential oils improved sleep, anxiety and depression scores, but trials were small and most were unblinded.
- Eye health supplements: 60-trial review ranks lutein combinations highest — A 2024 review of 60 eye-supplement trials: lutein with zeaxanthin, often plus omega-3, raised the eye's protective pigment most. Vision gains were smaller.
- Does cranberry juice help with UTIs? What the trials show — Cranberry juice and capsules cut repeat UTIs by about a quarter to a third in women, and by about half in children, pooled trials found.
- Does swimming lower blood pressure? — Swimming and water exercise lower blood pressure by about 4 to 9 mmHg in trials, with the biggest drops in people who already have high blood pressure.
- Does St John's wort help with depression? — Trials find St John's wort works better than placebo and about as well as standard antidepressants for mild to moderate depression, with fewer side effects.
- Does red yeast rice lower cholesterol? — Trials show red yeast rice lowers LDL cholesterol by roughly 20 to 40 mg/dL. It contains a statin-like compound, so side effects and product quality matter.
Recently updated
- Honey — Small trials suggest honey eases acute cough in children a little better than no treatment or placebo, with most of the benefit in the first three days.
- Salt — Cutting salt lowers blood pressure - by about 4 mm Hg systolic in pooled trials, and more when blood pressure starts higher.
- Aromatherapy — Inhaling essential oils may modestly improve sleep, anxiety and low mood, and sleep is the most consistent finding.
- Blueberries — Blueberries may help memory in older adults with mild memory decline: a meta-analysis of nine trials found better episodic memory (memory for everyday events)…
- Fish Oil — Fish oil rich in EPA eases symptoms of depression in adults, a modest benefit supported by low-certainty evidence.
- Lutein and Zeaxanthin — Lutein and zeaxanthin supplements raise the eye's protective pigment, and at 20 mg a day or more the rise is clear in pooled trials.
- Zinc — Zinc lozenges taken at the start of a cold shorten the illness by roughly two to three days in randomised trials.
- Cranberry — Cranberry products - juice, capsules or tablets - help prevent repeat urinary tract infections: pooled trials found about a quarter to a third fewer infections…
- Swimming — Swimming and other water exercise lower blood pressure in trials — systolic pressure falls by roughly 4 to 9 mmHg, with the biggest drops in people who already…
- St John's Wort — St John's wort extracts ease mild to moderate depression: in pooled trials they worked better than placebo and about as well as standard antidepressants, with…
- Red Yeast Rice — Red yeast rice lowers LDL ('bad') cholesterol in trials, by roughly 20 to 40 mg/dL, because it naturally contains monacolin K — the same compound as the prescr…
- Music — Listening to music at bedtime improves how well people with sleep problems rate their sleep, and music also eases stress and anxiety in many trials.
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