Cognition is slow to change and hard to measure, so this is one of the weakest evidence areas in nutrition despite being one of the most marketed. Expect a lot of orange.
Memory, attention, cognitive ageing and neurological markers.
10 foods, grouped by the strongest rating any of its claims in this area reaches. Ratings describe the research, not the food. How ratings are decided.
Several human studies point the same way, with real caveats.
Early human work, or mostly lab and animal research.
Not enough human research to say anything useful yet.
Rubus fruticosus
Dark aggregate fruit of bramble canes, distinguished from raspberries by keeping the central core when picked. Sold fresh in…
Cognitive function: Blackberries are often grouped with blueberries in claims about memory, but the human research that exists is almost entirely on other berries. There is not enough dependable evidence on blackberries themselves to say anything useful.
Cocos nucifera
Fat extracted from coconut flesh, solid below about 24 degrees Celsius and dominated by saturated fatty acids, principally lauric…
Cognitive function: Claims that coconut oil supports memory in dementia have no dependable human research behind them. The ketone rationale comes from studies of purified medium-chain triglycerides, and even there the findings are preliminary and contested.
Gallus gallus domesticus
A complete package of protein, fat and micronutrients built to grow a chick, split between a protein-and-water white and a…
Cognitive function: Evidence is limited for eggs improving cognition. The claim rests on choline, which is genuinely required for acetylcholine synthesis, but no controlled trial has shown that eating eggs changes cognitive performance in people who are not deficient.
Vitis vinifera
The fruit of the common grapevine, eaten fresh, dried as raisins or fermented into wine. Red and black varieties carry…
Cognitive function: Grapes and grape-derived resveratrol are widely promoted for memory and brain ageing. The human trials are few, small, mostly use extracts, and do not add up to a dependable finding.
Salvia rosmarinus
A woody Mediterranean shrub whose needle-like leaves are used fresh or dried. Rosemary extract is also used industrially as a…
Cognitive function: Rosemary aroma and rosemary extract have been tested in a handful of small cognition studies with mixed results, inconsistent endpoints and no dependable replication. The marketing of rosemary as a memory herb runs far ahead of what has been shown.
Salvia officinalis
The grey-green leaf of Salvia officinalis, used fresh or dried and traditionally paired with fatty meats. The USDA entry is per…
Cognitive function: A few small acute trials of sage extracts report short-term improvements in memory and attention tasks in healthy adults. The trials are small, use concentrated extracts rather than the herb, measure effects lasting hours, and have not been dependably replicated.
Juglans regia
The wrinkled kernel of the walnut tree, unusual among common nuts for being dominated by polyunsaturated rather than…
Cognitive ageing: The idea that walnuts support the ageing brain is heavily marketed and poorly supported. The largest and longest trial designed to test it did not find a benefit on its primary cognitive outcome, and the observational associations are confounded by overall diet quality.
Salmo salar
An anadromous fish that feeds at sea and returns to fresh water to spawn. Its pink flesh comes from astaxanthin accumulated…
Cognitive ageing: Observational data links higher fish intake with slower cognitive decline in older adults, but intervention trials of omega-3s have largely failed to reproduce a benefit. Confounding by overall diet quality is a serious problem in this literature.