Developing an autoimmune disease isn’t usually a top concern among women. Most of us are more worried about our present health and how we can prevent our risk of certain cancers as we grow older. However, autoimmune diseases are more prevalent than we may think, and the need to find solutions and preventive medicine is growing. Thankfully, new research from The Boston Medical Journal (BMJ) suggests that taking vitamin D (or a combination of vitamin D and omega-3 fatty acids) may reduce our risk of autoimmune disease.
Autoimmune diseases affect a large portion of the US population: More than 24 million Americans suffer from them, according to The National Institute of Health (NIH). An additional 8 million people have autoantibodies, or blood molecules that indicate a person’s risk of developing an autoimmune disease. As a result, studies like this one from the BMJ are even more important.
What is an autoimmune disease?
As noted by the NIH, an autoimmune disease is a condition where your immune system attacks the healthy cells of your organs and tissues. Ordinarily, the immune system would attack only foreign germs, viruses, and bacteria.
Researchers aren’t quite sure what causes autoimmune diseases, though they do know that many of these illnesses have a genetic cause. Viruses, certain chemicals, and other environmental factors may also trigger flare ups if a person has the genes for a particular condition.
There are over 80 types of autoimmune diseases. According to the Autoimmune Registry, some of the most common in the U.S. include:
- Celiac disease
- Crohn’s disease
- Pernicious anemia (ie. deadly anemia)
- Ulcerative colitis
- Autoimmune thyroiditis
- Type 1 diabetes
The Autoimmune Registry also listed long COVID-19, or long-haul COVID, as the most common autoimmune disease. While the scientific community is still debating whether long COVID is an autoimmune disease, research suggests that it should be classified as such. (For the purposes of BMJ study, however, the study authors did not include long-haul COVID in their definition of autoimmune diseases.)
Understanding the Study
To better understand whether certain supplements reduce autoimmune disease risk, researchers associated with the Harvard T.H. Chan School of Public Health, Brigham and Women’s Hospital, and Harvard Medical School in Boston, Massachusetts designed a nationwide study. They recruited 25,871 participants, all of whom were aged 50 or older. The team did not include any volunteers who had a serious illness (such as renal failure, cancer, or cardiovascular disease) at the beginning of the study.
The researchers decided to test two different supplements: vitamin D-3 gels and omega-3 fatty acids (in the form of fish oil capsules). Some of the participants received vitamin D, some received omega-3s, and others received both vitamin D and omega-3s. In addition, two placebo groups received either a fake vitamin D pill or a fake omega-3 pill. (The fake pills were filled with soybean oil.) Neither the study authors nor the participants knew who received the placebo and who received a real supplement.
Over the course of five years, the participants had to take the supplements (or placebo pills) daily. Each year, they also completed questionnaires about their lifestyle, fish and dairy intake, and whether they were diligent about taking their supplements. About 81 percent of the participants stuck to protocol and regularly took their pills. In addition, the researchers routinely took blood samples and kept track of how many participants developed an autoimmune disease. (To be considered a person with an autoimmune disease, the participants needed a doctor’s diagnosis.)
Which supplements had benefits?
When the researchers zeroed in on the last three years of the five-year study, they noticed that the vitamin D group had 39 percent fewer cases of autoimmune disease than the corresponding placebo group. In effect, those who took vitamin D alone were less likely to develop an autoimmune disease.
Taking omega-3 fatty acids alone didn’t seem to make a difference. However, when the researchers altered their calculations to include participants who likely had an autoimmune disease (but didn’t have a diagnosis), they found that omega-3s reduced the rate of autoimmune diseases by 18 percent. In addition, taking both vitamin D and omega-3s reduced the prevalence of the diseases by about 30 percent.
Why might vitamin D lower the risk of autoimmune illness? The researchers state that vitamin D-3 boosts the function of immune system cells and regulates inflammation in the body. As a result, it may help reduce levels of inflammatory molecules that could contribute to the development of autoimmune dysfunction.
As for omega-3 fatty acids, the research is somewhat less clear. This study suggests that they reduce inflammation as well, but more research is needed to confirm the positive effects of omega-3s on autoimmune diseases.
Still, the data on both supplements are promising. If you’re looking to boost your intake of vitamin D and omega-3 fatty acids, be sure to speak with your primary care doctor first. If you get the go-ahead, we recommend Nature Made Vitamin D-3, 2,000 IU (Buy from iHerb, $8.33) and KORI Pure Antarctic Krill Oil for omega-3s (Buy from Walmart, $19.97). Boosting your daily intake of both nutrients — in accordance with the recommended daily allotment — may improve your health in more ways than one.
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