What is blackcurrant seed oil?

Blackcurrant seed oil is a nutritional supplement. It’s rich in both omega-3 and omega-6 fatty acids that are important for maintaining joints’ cell structure and function, and can fight joint inflammation. Blackcurrant oil is thought to be relatively well-tolerated, but the little available evidence suggests that it may not be effective in treating rheumatoid arthritis.

  • Family: Nutritional supplement from the Saxifragaceae family
  • Scientific name: Ribes nigrum
  • Other names: Quinsy berries, squinancy berries, cassis, red currant, European blackcurrant, mustaherukka, grosellero negro, siyah frenkuzumu

The blackcurrant plant is native to northern parts of Europe and Asia. Its berries are a very dark purple and contain seeds. The berries and leaves are used for maintaining health and treating several diseases. You can buy capsules and bottled oil over the counter or over the internet from UK-based suppliers.

How does it work?

Oil produced from blackcurrant seeds contains 13% omega-3 alpha-linolenic acid (ALA) and 17% omega-6 gamma-linolenic acid (GLA). GLA is an essential fatty acid that’s important for maintaining a joint’s cell structure and function. Your body converts it into hormone-like substances called prostaglandins, which regulate your immune system and fight joint inflammation. GLA might also suppress inflammatory responses by directly acting on some inflammatory cells.

Is it safe?

No studies appear to have been done to assess the safety of blackcurrant seed oil in people with musculoskeletal conditions, but studies on other GLA-rich oils suggest that they’re relatively well tolerated with no serious side-effects. How it might affect other drugs hasn’t been well studied and no trials have been done to find the best dosage of blackcurrant seed oil for musculoskeletal conditions, although trials have used doses of 3 g a day and 10.5 g a day.

Trials for rheumatoid arthritis

Trial 1

In the first RCT, two groups of participants were randomly selected to receive one of the following treatments daily for 24 weeks:

  • One group (14 participants) was given 10.5 g blackcurrant seed oil.
  • The other group (20 participants) received placebo capsules made from soybean oil for the same period of time.

All participants were asked to continue their usual diets and medications.

  • Only 50% of participants in the blackcurrant seed oil capsules completed the trial. The two main reasons for stopping the medication were:

1. the large amount (15 capsules) and size of the capsules
2. participants believing the treatment wasn’t effective.

Compared to the placebo group, members of the blackcurrant seed oil group who completed the trial had:

  • a significant but moderate reduction in joint tenderness
  • only mild and non-significant reduction in pain, morning stiffness and overall disease severity.

The minor side-effects of blackcurrant seed oil didn’t contribute to participants withdrawing from the trial. The nature of the side-effects wasn’t reported.

Trial 2

In the second RCT, participants were randomly selected to receive one of the following treatments daily for six weeks:

  • One group (20 participants) were given 3 g blackcurrant seed oil (six capsules)
  • The other group (10 participants) received placebo capsules made of sunflower seed oil.

The effects on morning stiffness, grip strength, pain and physical function were measured at the end of the trial and again six weeks after treatment.

Compared to the placebo group, who showed no improvement at both assessment points, participants on blackcurrant seed oil had significant reduction in morning stiffness at the end of the treatment; however, this beneficial effect wasn’t observed six weeks after the trial had ended.

Compared with the placebo, blackcurrant seed oil had no significant effect on improving the following at either at assessment point:

  • pain
  • grip strength
  • physical function.