While there may not be a single set of dietary guidelines that are right for all fibromyalgia patients, there are certain foods, or food groups, that appear to make a difference for a significant number of people. But remember, avoiding these foods is not a guarantee that your symptoms will change. Also, avoiding one group may offer benefit while another may make no difference at all. Nevertheless, the experts WebMD talked to agree that eliminating at least some of these foods is worth a try.
1. Aspartame (NutraSweet). All the experts WebMD talked to agree that for a large majority of people with fibromyalgia, foods sweetened with aspartame could exacerbate fibromyalgia symptoms.
"There is a pain receptor in the nervous system known as NMDA," says McNett. "When pain turns from acute to chronic, it involves opening the NMDA pain receptor. Aspartame, which is classified as an excitotoxin, helps to stimulate this event." He also says people with fibromyalgia appear to already have overly active NMDA pain receptors, making them more susceptible to the stimulation.
In one study published in the Journal of Rheumatology in 2006, experts found patients with fibromyalgia did have an increased expression of NMDA receptors in their skin. This indicated a general increase in activity of peripheral nerves.
Holtorf says aspartame may play a role in stimulating those nerve pathways. Then he adds that for some people, "cutting it out of their diet can have a dramatic impact on pain."
That appeared to be the case for patients in one small study published in the Annals of Pharmacotherapy in 2001. Researchers found that, when patients with fibromyalgia avoided aspartame as well as the flavor enhancer MSG, they felt better overall.
Other artificial sweeteners such as Splenda, saccharin, and stevia do not appear to have the same effect as aspartame.
2. Food additives including MSG (monosodium glutamine) and nitrates. MSG is an additive or flavor enhancer that's found in many processed and frozen foods and in some Asian cuisines. Experts say it can intensify pain symptoms in many individuals. Like aspartame, MSG is classified as an excitotoxin and has the same potential for affecting NMDA receptors.
The same is true, says McNett, for foods containing preservatives such as nitrates, commonly found in lunchmeats like ham or bologna or in bacon.
"A lot of people who don't have fibromyalgia can't tolerate nitrates or MSG very well. But one of the hallmarks of this condition is that it amplifies unpleasant reactions," McNett says. "So a stimulus that some people would find mildly unpleasant becomes very unpleasant in those who have fibromyalgia." Cutting these ingredients out of the diet, he adds, usually helps.
3. Sugar, fructose, and simple carbohydrates. There is no clear evidence that cutting out simple carbohydrates -- like sugar, cake, or white bread -- will have an impact on fibromyalgia. What it can do, though, is reduce symptoms of chronic yeast infection -- a fungus that thrives on sugars and may be a secondary condition contributing to the pain of fibromyalgia. This theory, however, is still being debated by experts.
"Cutting out sugary foods, particularly high fructose corn syrup, can make a difference in these patients," says Holtorf. "And that's independent of any weight loss that might occur when they stop eating these foods."
Shikhman adds that cutting out carbonated beverages sweetened with fructose may yield even more noticeable results. That's because the carbonation, he says, causes a metabolic reaction. This reaction results in much more sugar pouring into the blood much more quickly.
"It's this quick rise in blood sugar," Shikhman says, "followed by the subsequent fall that exacerbates the fatigue element of fibromyalgia. That, in turn, creates more cravings for sugar, followed by still more fatigue -- allowing a vicious cycle to develop." Cutting out the sugar, he says, particularly soda, can result in better, more even control of blood sugar. Better control will help reduce fatigue and at least some of the related pain.
4. Caffeine -- including coffee, tea, colas, and chocolate. Because it is considered a stimulant, many fibromyalgia patients turn to caffeine-rich beverages as a source of energy. But McNett says the boost you get is false -- and can quickly exacerbate fatigue.
"The problem with caffeine is that the 'up' is relatively brief and transient," he says. "And it's followed by substantially longer and deeper sedative effect."
Because people with fibromyalgia are already tired, McNett cautions, those sedative effects can be much more powerful. "They are starting off from a point of fatigue, so the sedative qualities are amplified -- leading to a much deeper and long lasting sense of fatigue."
The good news is that cutting out caffeine can make a difference within less than a week. "Most patients begin to see a difference in their fatigue level almost right away," he says.
5. Yeast and gluten. Although these are two separate food substances, they frequently appear together -- particularly in baked goods like cake, donuts, and bread. For this reason, cutting out one, usually means you are cutting out both. That can actually yield two separate benefits for people with fibromyalgia.
In the case of yeast, some doctors say it fosters the overgrowth of the yeast fungus in the body. This overgrowth may cause or exacerbate much of the joint and muscle pain experienced by people with fibromyalgia. Research, though, has yet to confirm this link.
Gluten can exacerbate a condition known as gluten intolerance. Gluten intolerance, Shikhman says, frequently results in a variety of stomach ailments and other digestive problems. It also is associated with fatigue in patients with fibromyalgia.
"I have seen people with and without fibromyalgia experience enormous positive changes in their health by simply cutting out gluten products," Shikhman says.
6. Dairy. Be they low fat or high fat, some experts say, dairy products -- particularly, milk -- have been known to drive the symptoms of fibromyalgia. Avoiding these products may help some people turn their health around.
On the other hand, if you feel as if milk is doing your body some good, keep chugging a glass or two of skim milk a day. It's got calcium to build bones and protein to build muscle, and it's fat free.
7. Nightshade Plants: Tomatoes, chili and bell peppers, potatoes, and eggplant. There are over 2,000 species of plants that that can be listed under the category of "nightshade." Those which are edible comprise a group that some say can trigger flares of various types of arthritis, including fibromyalgia.
"I have seen patients who do much better when they cut these foods out of their diet," says Holtorf. We're not sure why, but it seems to work in a significant percentage of fibromyalgia patients." At the same time, these vegetables are among the most nutritious. So if they don't trigger your fibro pain, don't ban them from your fridge.
A final word - Nutrients and the power of a healthy diet
Avoiding certain foods may help individual patients better cope with their disease. Nutritionist Samantha Heller, MS, RD, says, however, that most can also benefit from an overall heart-healthy approach to good eating.
Kent Holtorf, MD, Medical Director, Holtorf Medical Group Center for Endocrine, Neurological and Infection Related Illness, Torrance, Calif.