Greens, glutathione and the mucosal barrier

'Eat your greens' is a phrase most of us will have heard on several occasions when growing up. I have to admit to being a bit of a 'goody two-shoes' in this respect, having had a lasting affection for things like Brussels sprouts and broccoli. Indeed, sprouts still tend to be on my menu several times a week (boiled with a drop of Greek olive oil).

I say all this because an interesting article published a few years back has caught my eye recently. The paper by Hoensch and colleagues* (open-access) looked at the various factors potentially affecting the functioning of the gastrointestinal glutathione system with some interesting observations.

I will admit that glutathione (GSH) is something which I am becoming very interested in at the moment. Over on my autism research blog, I recently discussed the pretty remarkable findings emerging in some cases of autism with regards to plasma GSH which might (might!) eventually have some diagnostic usefulness in combination with other factors. The Hoensch paper talks about GSH levels in the upper gastrointestinal mucosa and how factors such as diet, some medications and even gender seemed to affect levels of GSH and accompanying enzyme activity (glutathione S-transferase, GST).

The particulars:

• Biopsy pinches taken from two sites (antral and duodenal mucosa) for 202 adults (104 males: 98 female) undergoing endoscopy were analysed for GSH and GST activities. Various background information was also taken from participants including details of family history, medication and current dietary habits via a food frequency questionnaire.
• The findings: different biopsy sites reflected different levels of GSH and enzyme activity. Female participants showed higher levels of GSH and GST activity in their antral mucosa samples than males. High intake of vegetables (more than 3 days a week) seemed to enhance aspects of GST activity.
• A subsequent author reply to a suggestion that Helicobacter pylori infection might also have had an effect suggested that indeed, one aspect of GST activity was negatively affected by H.pylori infection.

Bearing in mind that GSH and its related sub-systems represent an important part of our defences against those dastardly free radicals among other things, making sure that the system is in tip-top condition is probably quite important. I don't want to make sweeping gender generalisations but the fact that females seemed to be in a slightly more advantageous position compared with male participants leads me back to some interesting work on the fragile male. Having said that, let's not be too defeatist here; greater vegetable consumption seemed to have an enhancing effect as per other results so one could argue, guys in particular, eat more greens - especially more brassica vegetables to support your mucosal antioxidant defence system.

* Hoensch H. et al. Influence of clinical factors, diet, and drugs on the human upper gastrointestinal glutathione system. Gut. 2002; 50: 235-240.