
St. John's wort: herbal supplement with potential side-effects
This article is prompted by some research I did after visiting my doctor the other day and getting a higher-than-normal blood pressure reading. Now first I should say, my blood pressure is normally quite low (110/70) and so the "high" reading of 132/79 is not cause for alarm. The doctor said I might be nervous about the tests being done for a recent complaint, and not to worry about it. I have a full physical in February in any case.
But I got thinking: if my blood pressure is suddenly higher than it's been in ten years by a significant margin, what is the cause? There was one definite difference in my lifestyle that was a red flag: I recently started taking St. John's wort in capsule form, to address some moodiness and irritability that may be the result of peri-menopause (or perhaps just a natural reaction to the stressful economic meltdown and its attendant problems). St. John's wort (known as hypericum) is a plant that contains hypericin, a substance that can act similarly to an MAOI in alleviating depression. It has been touted as wonderful natural alternative to MAOI drugs with none of the side effects.
High blood pressure concerns
The last time I used St. John's wort (SJW), I had to get emergency surgery, and due to concerns that it might spike my blood pressure in combination with general anaesthesia, I was given a spinal anaesthetic. So this made me wonder if the St. John's wort might be to blame for the recent high BP reading.
Disclaimer: I am not a doctor, folks. And I caution anyone against tying their symptoms into a search engine because it's an exercise in paranoia and futility. For all I know the SJW has nothing to do with the recent spike in my blood pressure, But in looking into I found out something I had not known; that a chemical found in many common foods, if eaten in combination with a daily regimen of St. John's wort, may cause a dangerous rise in blood pressure, among other symptoms.
Tyramine is a naturally-occurring substance in a number of foods, including beer, red wine, coffee, aged cheese, yogurt, sour cream, smoked meats such as salami and pepperoni, eggplant, Italian broad beans, soy sauce, yeasted baked goods like home-made bread, and salted dried fish, among others. For those of us contemplating a holiday season filled with rich foods such as these, this may be disheartening news. Some research studies suggest that only people with high blood pressure need to be cautious in eating these foods in combination with St. John's wort. But the Mayo Clinic says anyone taking MAOIs needs to avoid these foods.
St. John's wort and salami: a no no?
Taking drugs in combination with certain foods may cause dangerous side effects, so it is important to be informed about what is safe in combination. This site gives some basic information on food/drug interaction that is useful. This one specifically looks at foods that shouldn't be eaten with MAOIs. Research also says that taking SJW in combination with amino acid supplements, cold medications or diet drugs like Dexatrim could also cause a serous reaction.
If you are taking St. John's wort or a prescription MAOI, talk to your doctor about your concerns. Most MDS will have mentioned, or given you literature about, the need to avoid tyramine. But St. John's wort is available as a food supplement, and most of the time no cautionary information about tyramine appears on labels.
And go easy on the tyramine-containing foods in general; even in healthy people who are not taking MAOIs, some of these foods have been linked with migraines, food allergies, increased rates of certain cancers, and, of course, obesity. Have a healthy holiday season!