Folic acid supplements lower your risk of stroke caused by elevated blood pressure

Hypertension is a growing problem. Worldwide, it causes more premature deaths than any other risk factor. Chinese researchers have now found that supplementation with a combination of folic acid and anti-hypertensive medicine lowers the risk of stroke by nearly 75 percent. It is important to underline that many people have elevated blood pressure without knowing about it, and many things can cause a folic acid deficiency or poor utilization of the vitamin.

Folic acid supplements are normally recommended in connection with anemia or pregnancy, but they may also be important for the circulatory system, the heart, and the brain. It is already known that elevated blood levels of the amino acid, homocysteine, contribute to the formation of blood clots. It is also established that folic acid lowers levels of homocysteine, and that levels of homocysteine increase if there too little folic acid. Slow metabolism (hypothyroidism), kidney diseases, psoriasis, and the use of different kinds of medicine may also result in elevated homocysteine levels

Why hypertension increases your risk of stroke

In the United States, stroke (apoplexy) is the fifth leading cause of death. It is caused by cerebral hemorrhage or a blood clot in the brain. Cerebral hemorrhages are mainly a result of permanently elevated and poorly managed blood pressure and blood-thinning medication. Blood clots in the brain are mainly caused by atherosclerosis and circulating blood clots that may become lodged in the blood vessels of the brain.

The study

The Chinese researchers were interested in seeing whether folic acid supplementation could lower the risk of stroke, so they studied 10,789 older Chinese people in the ages 45-75 years. All patients had elevated blood pressure but had never suffered a stroke or a heart attack.
All study participants received anti-hypertensive medication. In addition, half of the patients got folic acid supplements, while the other half got matching placebo. The participants were examined after four years of following this regimen.
Among those who had taken folic acid, 1.8% had suffered a stroke, compared with 5.6% in the placebo group. A 75% difference, in other words. The researchers assumed that patients had a higher risk of stroke if they had higher blood levels of homocysteine combined with a lower blood platelet count. According to the scientists, the reduction of blood platelets was a result of the increased number of blood platelets used to repair the vessel damage caused by the elevated homocysteine levels. Their assumption is somewhat unusual, however, and it actually turned out that folic acid supplementation did not make much of a difference in terms of homocysteine levels and blood platelet count. So, even if there was a large difference between the stroke risk in the two groups, it is too early to conclude that folic acid supplements can prevent stroke by lowering homocysteine levels in the blood. Nonetheless, it is plausible that folic acid can lower the risk of stroke by means of other mechanisms than homocysteine regulation.
The researchers behind the Chinese study also refer to the fact that folic acid supplementation may be less relevant in countries where folic acid is added to food. They also point to other risk-reducing factors such as eating a healthy diet, exercising regularly, abstaining from smoking and avoiding altogether or limiting your intake of alcohol. Their study is published in the Journal of the American College of Cardiology
This study supports an earlier Chinese study.

Did you know that folic acid (together with vitamin B6 and vitamin B12) regulates levels of homocysteine?

Folic acid may save millions of human lives globally

Dr. Yong Huo and his team of researchers from Beijing University Hospital studied the effect of folic acid on 20,000 adult patients, who already took anti-hypertensive medicine and had not yet suffered a stroke. As part of the study, half of the patients took folic acid together with their blood pressure medicine, while the other half only took their medicine. After four and half years, the scientists observed a 21 percent lower risk of stroke among those who had taken folic acid compared with those who only took their medicine. The study is published in the Journal of the American Medical Association in 2016.
As 800,000 Americans die of stroke every year, this study suggests that folic acid supplementation, at least in theory, could save 200,000 American lives a year.

Deficiency and poor utilization of folic acid may be a result of

• Overconsumption of alcohol
• Unhealthy diets
• Smoking and substance abuse
• Poor intestinal microflora
• Pregnancy
• Old age (especially in combination with unhealthy eating habits)
• Birth control pills
• Methotrexate (medication against rheumatism and cancer)

References

Kong X et al. Platelet Count Affects Efficacy of Folic Acid in Preventing First stroke. Journal of the American College of Cardiology. Published online May 7, 2018
http://www.onlinejacc.org/content/71/19/2136

https://www.nhs.uk/news/neurology/folic-acid-may-help-reduce-stroke-risk-people-high-blood-pressure/

http://www.dailymail.co.uk/health/article-5699861/The-power-folic-acid-Supplements-slash-stroke-75.html

http://jama.jamanetwork.com/article.aspx?articleid=2205876

http://www.medicinenet.com/script/main/art.asp?articlekey=187452

http://www.healio.com/cardiology/stroke/news/online/%7Beb28b746-2cf7-4ac6-b598-21e7d9938e7b%7D/folic-acid-supplementation-reduces-stroke-risk

https://www.sundhed.dk/borger/sygdomme-a-aa/hjerte-og-blodkar/sygdomme/diverse/homocystein/