I started Paleo in Feb, and one of the many reasons I started looking for alternate ways of eating was that I had a metallic taste in the mucous membranes of my mouth, especially around my gums and lips. It has the effect of almost leeching the taste out of food. Also, although the gums look OK, my lips tend to peel - it feels like I'm dehydrated, regardless of how much water I'm drinking. It's not an every day experience since Paleo, but it happens often enough to be a pain in the proverbial.
It's not gum disease, I checked with a dentist.
It doesn't seem to be associated with any particular foods. I had thought at one point that it might be related to ketosis, but I'm fairly high carb a la Perfect Health Diet
I don't take allopathic meds
I take fish oil (4 caps a day), vitamin B, and l-glutamine. These supplements haven't been constant, and are more recent than the taste, which goes back about a year now
I have IBS, but the taste doesn't seem to correlate with IBS flares
I'm confused and annoyed by this. Any ideas, Paleohackers?? I wondered if it fits the symptoms of some kind of vitamin, mineral or trace nutrient deficiency, but I don't even know how to check for it! It's quite unpleasant.
Have you any amalgam (mercury) fillings in your teeth? They can leech or offgas and will give a metallic taste. Have you possibly been or are being exposed to any fungicides, pesticides, or insecticides? I had acute fungicide poisoning once and one of the biggest symptoms was metallic taste in my mouth for several weeks.
Assuming you don't have "pine mouth" (see Simibee's post) or "ketosis breath", I would recommend that you get yourself checked for mineral deficiencies/imbalances.
When I switched from a Loren Cordain version of Paleo (High fruit & veg, lean meat, etc.) to a lower carb "Primal" type of diet I noticed a metallic taste in my mouth on and off for several weeks.
I began supplementing with ConcenTrace Ionic Zinc (also has trace minerals) and Natural Calm Magnesium Citrate and haven't experienced it since.
The alterations in the sense of taste, usually a metallic taste, and sometimes smell are the only symptoms.
Do you regularly consume pine nuts?
How many g of carbs are you eating? I seem to stay in ketosis even at 50-150g, so you may not be able to rule out ketosis entirely if you're in the low-end of the carb range for your diet. Maybe add some additional starches and see if that helps alleviate it? Are you eating more dietary fat?
Are you constantly thirsty? Maybe you have an electrolyte imbalance (coconut water/juice will help) and you should check yourself out for diabetes while you're at it (because of the excessive thirst). Diseases and disorders can cause it (the metallic taste), but so can the common cold.