Researchers tested whether taking folic acid supplements could help people with a specific type of brain blood vessel damage that affects thinking and memory. In a carefully controlled study with 220 participants in China, people who took folic acid pills for six months showed better scores on thinking and memory tests compared to those who took fake pills. The supplement also lowered harmful substances in the blood that can damage brain blood vessels. While these results are promising, more research is needed to confirm whether this benefit applies to people in other parts of the world and different age groups.

The Quick Take

  • What they studied: Can taking folic acid pills help improve memory and thinking skills in people whose brain blood vessels are damaged and causing cognitive problems?
  • Who participated: 220 adults with cerebral small vessel disease-related cognitive impairment (a condition where tiny blood vessels in the brain are damaged, affecting thinking and memory) from hospitals in Shanxi, China
  • Key finding: People who took folic acid supplements (0.8 mg daily) for six months showed meaningful improvements in memory and thinking tests compared to those taking placebo pills. The supplement also reduced harmful blood chemicals linked to brain vessel damage.
  • What it means for you: If you have brain blood vessel damage affecting your memory, folic acid supplements may help slow or improve cognitive decline. However, talk to your doctor before starting any supplement, as this study was conducted in China and results may vary for different populations.

The Research Details

This was a randomized controlled trial, which is considered the gold standard for testing whether a treatment actually works. Researchers divided 220 patients into two groups: one received folic acid tablets (0.8 mg per day) and the other received identical-looking placebo pills with no active ingredient. Neither the participants nor the researchers knew who was getting the real supplement until the study ended—this is called “double-blinding” and helps prevent bias. The study lasted six months, with researchers measuring thinking and memory abilities at the beginning and end using standard medical tests.

This study design is important because it allows researchers to determine whether folic acid actually causes the improvement, rather than just observing that people who take it happen to do better. The double-blind approach ensures that expectations don’t influence the results. By comparing folic acid to placebo in a controlled way, scientists can be more confident that any differences are due to the supplement itself.

This study has several strengths: it used a randomized design (random assignment to groups), included a control group taking placebo, was double-blinded, and measured multiple outcomes. The study was published in a peer-reviewed journal focused on Alzheimer’s prevention. However, the study was conducted only in China, so results may not apply equally to all populations. The sample size of 220 is reasonable but moderate-sized.

What the Results Show

People taking folic acid showed significantly better scores on two standard memory and thinking tests (Montreal Cognitive Assessment and Mini-Mental State Examination) compared to the placebo group after six months. These improvements were statistically significant, meaning they’re unlikely to have happened by chance. The folic acid group also showed improvements in balance and mobility tests, suggesting broader benefits beyond just memory. Additionally, people taking folic acid had higher levels of folate in their blood (the active form of folic acid) and lower levels of homocysteine, a harmful substance linked to brain blood vessel damage.

The study measured several other important outcomes. Balance and walking ability improved more in the folic acid group compared to placebo. Quality of life measures also showed improvements in the folic acid group. Importantly, researchers found that a protein called MMP-9, which damages blood vessel walls, decreased significantly in the folic acid group. This suggests folic acid may protect brain blood vessels through multiple mechanisms.

This is the first randomized controlled trial specifically testing folic acid in people with small vessel disease-related cognitive impairment. Previous research suggested folic acid might help with vascular cognitive problems, but this study provides stronger evidence. The findings align with earlier research showing that homocysteine (which folic acid lowers) is linked to brain blood vessel damage. However, most previous studies were observational rather than controlled experiments.

The study was conducted only in China, so results may not apply equally to people of different ethnic backgrounds or in different healthcare settings. The study lasted only six months, so we don’t know if benefits continue longer or if they’re permanent. The study didn’t compare folic acid to other treatments that might help cognitive decline. Some participants may have dropped out or not taken their pills as directed, which could affect results. The study didn’t measure whether folic acid helps prevent future cognitive decline in people without current problems.

The Bottom Line

If you have been diagnosed with small vessel disease affecting your thinking and memory, discuss folic acid supplementation with your neurologist or primary care doctor. The evidence suggests it may help improve cognitive function, but it should be part of a comprehensive approach that includes managing blood pressure, blood sugar, and other vascular risk factors. Standard supplementation in this study was 0.8 mg daily (two 0.4 mg tablets). Do not start supplements without medical guidance, as they can interact with medications.

This research is most relevant to people diagnosed with cerebral small vessel disease who are experiencing memory or thinking problems. It may also be relevant to people at high risk for vascular cognitive decline. People without cognitive symptoms or those with cognitive decline from other causes (like Alzheimer’s disease) should consult their doctor about whether these findings apply to them. Pregnant women should consult their doctor before taking folic acid supplements.

In this study, meaningful improvements in thinking and memory tests appeared after six months of daily supplementation. You should not expect immediate results. It typically takes several weeks to months to see benefits from folic acid supplementation. Consistency in taking the supplement daily is important.

Want to Apply This Research?

  • If your doctor recommends folic acid supplementation, use the app to track daily supplement adherence (did you take your pills today?) and monthly cognitive self-checks using simple memory or attention tasks. Note any changes in memory, focus, or mental clarity in a journal feature.
  • Set a daily reminder to take your folic acid supplement at the same time each day (such as with breakfast). Create a simple checklist to mark off each day you take it. If you miss doses, the supplement won’t work as well. Consider pairing supplement-taking with an existing daily habit like brushing your teeth.
  • Track your supplement adherence weekly and note any changes in memory, concentration, or mental fatigue monthly. If possible, work with your doctor to repeat cognitive testing every 3-6 months to objectively measure any improvements. Keep a log of any side effects or concerns to discuss with your healthcare provider.

This research summary is for educational purposes only and should not replace professional medical advice. The study was conducted in a specific population in China and results may not apply equally to all groups. Folic acid supplementation should only be started under the guidance of a qualified healthcare provider, as supplements can interact with medications and may not be appropriate for everyone. If you have cognitive concerns or have been diagnosed with small vessel disease, consult your doctor or neurologist before beginning any supplement regimen. This summary does not constitute medical advice or a recommendation to use folic acid supplements.