For how we live.
Diets, supplements, and food claims tested against the evidence.
Higher whole-grain intake is consistently linked to lower rates of heart disease, cancer and early death, with benefit rising up to about seven servings a day. Refined grains show no such signal.
The fear that soy fuels breast cancer is not supported by the human data; if anything, soy food intake tracks with lower recurrence and death after diagnosis. Its other health claims are weaker.
Cohorts link both to modestly higher rates of heart disease and early death, on low-certainty evidence. A 2019 guideline then told people to keep eating them — and split the field over how to weigh nutrition science.
Large randomised trials mostly find no cardiovascular benefit from ordinary fish-oil capsules. One high-dose prescription drug is the striking exception, and the case for brain protection is weak.
People who eat nuts have lower rates of heart disease and early death in large cohorts, and a Mediterranean diet with nuts cut cardiovascular events in one trial. Most of the evidence is observational.
The official figure is 0.8 grams per kilogram of bodyweight a day — but that number is a floor to prevent deficiency, not a target for optimal health, and that distinction drives most of the argument.
Whole fruit is linked to lower type 2 diabetes risk, sugary drinks to clearly higher risk, and fruit juice sits closer to the drinks than to the fruit it comes from.
For heart disease and death, dairy looks roughly neutral to modestly favourable in large cohorts, and the long-standing warning against whole-fat dairy is not well supported by outcome data.
Across nearly 1.1 million people, each extra daily cup tracks with lower diabetes risk in a clear dose-response. It is consistent and large — and still only observational.
Health authorities converge on a ceiling — under 10% of daily calories, and lower is better still. Large cohorts single out sugary drinks as the form most clearly tied to dying earlier.
A randomised trial found the Portfolio diet cut LDL cholesterol by about 13%, and a large cohort study links closer adherence to lower cardiovascular risk. Its authors' industry funding belongs in the record.
A twins trial found a vegan diet lowered LDL cholesterol, insulin and weight in eight weeks. The same pattern comes with real gaps — vitamin B12 must be supplemented, and iron stores tend to run lower.
Head-to-head randomised trials find low-carbohydrate and low-fat diets produce similar weight loss over a year or two. The differences that survive are in blood lipids and glycemic control, not the scale.
Two controlled-feeding trials found a diet rich in fruit, vegetables and low-fat dairy lowered blood pressure, most in people who already had hypertension, and more still when sodium was cut.
Spain's PREDIMED trial is the strongest randomised evidence that a dietary pattern lowers cardiovascular events. In 2018 its authors withdrew it over flawed randomisation and reissued corrected results.