Folic Acid Lowers Blood Pressure and Prevents Blood Clots

April 19, 2005

While folic acid lowers blood pressure, the dose must be large enough to have this effect. Diet alone will not provide a significantly large enough dose, so it is essential to take folic acid as a supplement. The vitamin also simultaneously protects the heart and brain against blood clots.

It has long been documented that the B vitamin, folic acid, prevents the birth defect Spina bifida. For eight years, Canada has fortified all flour with folic acid and has thus prevented 80% of these sad cases. Enrichment is also required in the United States, but in Denmark, expectant mothers must manage on their own. It’s their own problem to find out to take a supplement – before they get pregnant!

The main source of folic acid is green vegetables (“folium” means “leaf”). Many people do not like them, and a lack of folic acid is therefore the most common vitamin deficiency. Unfortunately, this not only harms the unborn, but also adults, where it increases mortality from both blood clots in the heart and from apoplexy (blood clot in the brain). Not only that: the deficiency probably also increases the tendency to high blood pressure.

The previously unknown connection with blood pressure was discovered when 156,000 American nurses were observed for eight years. 1) Their risk of developing high blood pressure as a young adult (27-44 years old) was only half as high when they received one mg of folic acid per day as when they received only 0.2 mg. The latter amount is a very common dietary intake in both the United States and Denmark (average 0.25 mg per day). On the other hand, it is almost impossible to get 1 mg, five times as much, without supplementation.

With regard to stroke and blood clots in the heart, very interesting knowledge has emerged in recent years:

In the USA, where flour fortification was introduced in 1996, mortality from stroke has since fallen very dramatically, in all population groups and for both men and women, i.e. quite independently of lifestyle.

Before 1996, the annual decline in mortality from stroke was just over one percent and could be attributed to better treatment and prevention. But in the following three years, mortality fell 3-4 times as much, a total of 10-15%! This has only been statistically explained by the fact that the typical American now has twice as much folic acid in their blood as before. 2)

Stroke is also particularly harmful if you lack folic acid. This was recently demonstrated in mice. They were artificially induced to have a stroke by simply clamping an artery to the brain. It turned out that the brain damage was only half as extensive when the mice had received enough folic acid as when they suffered from a deficiency. 3)

But apparently folic acid also protects the heart. This was most recently revealed when Italian doctors examined approximately 900 patients who were hospitalized with and without a blood clot in the heart.

They divided all the hospitalized patients according to how much folic acid they received daily, and of the third who received the least folic acid, the researchers found that most were admitted to the cardiac ward. This third had a risk that was twice as high as those who received the most folic acid. When taking into account the intake of vitamin B6 – B6 works together with folic acid – those who received the most had a relative risk of only 29%. 4)

It is not folic acid itself that protects the heart and brain. However, folic acid lowers the blood’s level of the harmful amino acid homocysteine, which attacks blood vessels.

Approximately 10% of the population has, without knowing it, a hereditary increase in homocysteine (and therefore needs more folic acid). Recently, it has been shown that these 10% suffer from stroke significantly more often than others. 5, 6). It was already known that exactly the same is true for blood clots in the heart. 7)

No one has yet conducted blinded trials where supplementation has effectively lowered blood levels of homocysteine. This is now encouraged. 8) However, with the existing knowledge, it seems wise to take a supplement.
The ideal is perhaps 0.8 mg (800 micrograms) per day.

By: Vitality Council

References:
1. Forman JP, Rimm EB, Stampfer MJ, Curhan GC. Folate intake and the risk of incident hypertension among US women. JAMA. 2005 Jan 19;293(3):320-9.
2. American Heart Association’s 44th annual Conference on Cardiovascular Disease Epidemiology and Prevention. carole.bullock@heart.org
3. Endres M, Ahmadi M, Kruman I, Biniszkiewicz D, Meisel A, Gertz K. Folate deficiency increases postischemic brain injury. Stroke. 2005 Feb;36(2):321-5. Epub 2004 Dec 29.
4. Taivani A et al. Folate and vitamin B6 intake and risk of acute myocardial infarct in Italy. Eur J Clin Nutr 2004;58:1266-72.
5. Al-Delaimy WK, Rexrode KM, Hu FB, Albert CM, Stampfer MJ, Willett WC, Manson JE. Folate intake and risk of stroke among women. Stroke. 2004 Jun;35(6):1259-63.
6. Casas JP et al. Homocysteine and stroke: Evidence on a causal link from mendelian randomisation. The Lancet 2005;365: 224-32.
7. Klerk M, Verhoef P, Clarke R, Blom HJ, Kok FJ, Schouten EG; MTHFR Studies Collaboration Group. MTHFR 677C– T polymorphism and risk of coronary heart disease: a meta-analysis. JAMA. 2002 Oct 23-30;288(16):2023-31.
8. S Schwammenthal et al. Homocysteine, B-vitamin supplementation, and stroke prevention. From observational to interventional trials. Lancet Neurol. 2004;3(8):493.

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