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Randomised trial · Nutrients · 2019Conflicts declared

Saffron and central retinal function in Stargardt disease

Piccardi M, Fadda A, Martelli F, et al · Free full text

What it found

In 31 people with ABCA4-related Stargardt disease, six months of saffron supplements left the retina's electrical response unchanged, while placebo tended to reduce it.

Saffron was well tolerated.

What they found

Studies in people

Retina response after saffron

After six months of saffron, the electrical response of the central retina did not change. In the group that started on saffron, there was only a minimal, non-significant reduction.

Retina response after placebo

After six months of placebo, the retina's electrical response tended to drop from the starting level, with an average fall of 0.18 log units. This drop was significant.

Switching treatments

When the placebo group switched to saffron, their retina response stayed stable. When the saffron group switched to placebo, the response also tended to fall slightly but not significantly.

Visual acuity

Visual acuity did not change significantly throughout the study in either group.

Tolerance and side effects

All patients tolerated the supplement well, with no major or minor side effects reported. More than 99% of pills were taken.

Longer follow-up

Outside the trial, 22 patients continued saffron for another 36 months. Fifteen kept the visual acuity they had at enrollment, and seven lost 2 lines. No side effects were recorded.

What the authors conclude

“short-term saffron supplementation was well tolerated and had no detrimental effects on the electroretinographic responses of the central retina and visual acuity.”
Piccardi M, Fadda A, Martelli F, et al, 2019

Also in their conclusions

  • They conclude that short-term saffron supplementation was well tolerated and had no detrimental effects on the electroretinographic responses of the central retina and visual acuity.
  • They state that the current findings warrant further long-term clinical trials to assess the efficacy of saffron supplementation in slowing down the progression of central retinal dysfunction in ABCA4-related STG/FF.
  • They advise that future trials should evaluate major clinical parameters like visual acuity, central perimetric sensitivity, and fundus autofluorescence as the main outcome measures.

How it was done

The authors wanted to see whether saffron's carotenoid components, which have shown antioxidant and cell-protecting effects, could help central retinal function in people with this inherited macular dystrophy.

They randomly assigned 31 patients with ABCA4-related Stargardt disease and visual acuity above 0.25 to take 20 mg of oral saffron or a placebo daily for six months, then switched the groups for another six months. They measured the retina's focal electrical response and visual acuity at the start and after each six-month period.

What it can’t tell you

  • This was a short six-month study, so it cannot show whether saffron slows the disease over years.
  • The long-term follow-up was not part of the original trial and had no placebo control, so it cannot prove cause and effect.
  • The study measured retinal electrical response and visual acuity, but not other aspects like retinal autofluorescence or dark adaptation.

The paper

Title
Antioxidant Saffron and Central Retinal Function in ABCA4-Related Stargardt Macular Dystrophy
Type
Randomised controlled trial
Evidence
Studies in people
Summarised from
Full text
Cite
Piccardi M, Fadda A, Martelli F, et al (2019). Antioxidant Saffron and Central Retinal Function in ABCA4-Related Stargardt Macular Dystrophy. Nutrients. doi:10.3390/nu11102461Free full textPubMed 31618812DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error