We know from previous studies that vitamin D and marine-based omega-3 fatty acids have a beneficial effect on inflammation and immunity.
According to the results of a new survey of approximately 26,000 Americans (ages 50 and older), taking daily vitamin D supplements, or a combination of vitamin D and omega-3s, appears to reduce the risk of developing an autoimmune disease, especially after two years of supplementation.
Currently, autoimmune diseases, which are conditions particularly prevalent in the elderly, do not have effective treatments. They are characterized by a dysfunction of the body’s immune system: it attacks the healthy tissues of the individual in question.
Among the approximately 80 diseases that fall into this category, we find multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus or psoriasis.
What studies have to say about the benefits of these supplements
For this reason, researchers conducted an analysis as part of a large study on vitamin D and omega-3.
This is a randomized (double-blind) placebo-controlled research study conducted among 25,871 Americans (51% women; mean age 67 years, with a minimum age of 50) for approximately five years. Their original goal was to find out if taking vitamin D3 or omega-3 supplements daily could reduce the risk of developing cancer, heart disease or stroke.
As part of an underlying study, the researchers also decided to examine the influence of these dietary supplements on the development of autoimmune diseases. For this, participants received doses of vitamin D (2000 IU/day) with an omega-3 fatty acid supplement (1 g/day), or vitamin D with placebo, or an omega-3 fatty acid with placebo, or placebo only.
They then reported a possible diagnosed autoimmune disease. Some cases were confirmed through medical records, while those that were not documented enough to be proven were classified as “probable” cases.
Supplements capable of reducing the appearance of autoimmune diseases by 30%
In the group supplemented with vitamin D, autoimmune disease was diagnosed in 123 participants, compared with 155 in the placebo group (22% reduction, considered significant).
In the omega-3 fatty acid supplements group, 130 cases were diagnosed versus 148 in the placebo group (a 15% decrease). But this result was not statistically significant. In contrast, when ‘probable’ cases in the omega-3 fatty acid group (with or without placebo) were included, this decrease reached 18% and there was a significant impact over time.
Taking these supplements long-term seems to have better results and further widen the gap between the supplemented group and the placebo group. In the end, vitamin D and omega-3 fatty acid supplementation reduced the risk of developing autoimmune diseases by about 30% compared to placebo.
Although the sample of participants was large and diverse, young people were not included. Therefore, the results may not generalize to autoimmune diseases that appear in the young.