Do goji berries help against ageing?
Goji has shown interesting properties in experiments with cells and in animal studies. In people, its effect on ageing has barely been studied.
One study in 50 people aged 55 to 72 found that drinking goji juice every day for 30 days improved the body's antioxidant activity in the blood by 8 to 10 percent and reduced oxidative damage by around 9 percent. That is a statistically measurable, but modest, effect.
Experiments with cells and animal studies show a broader picture: an active substance in goji berries (a polysaccharide, a type of complex sugar) reduces substances that drive inflammation, restores the functioning of the energy factories of the cell and slows the build-up of damaged cells. Flavonoids from goji leaves even extend the lifespan of roundworms in the laboratory. But what works in a test tube or in a worm does not automatically work in people.
Whether goji protects against specific age-related diseases such as heart and vascular disease, dementia or diabetes has not yet been demonstrated in people. Large, well-designed studies on this question are lacking. In addition, the composition of goji products varies considerably depending on their origin and preparation method, which makes it difficult to compare studies with one another.
Goji is generally safe, but two cases have been reported in which people who were taking the blood thinner warfarin experienced an interaction. If you take blood thinners, have a quick word with your doctor before making goji a regular part of your diet.
The evidence rests on one small study in people, supplemented by several reviews that summarise almost exclusively experiments with cells and animal studies. The researchers themselves emphasise that large studies in people are largely absent and that variation in product composition makes comparisons between studies difficult. The evidence base for effects in people is therefore thin.