So far in this series on additives, I’ve discussed magnesium stearate, soy lecithin, carrageenan, and xanthan gum. These are the most common food additives found in processed foods, especially in processed “health” foods, and many health conscious shoppers have been unnecessarily concerned about avoiding some of the less harmful substances I covered in this series.
In this final installment, I’ll review an assortment of gums that are often found either alongside or replacing xanthan gum and carrageenan in processed foods, acting as thickeners, stabilizers, or emulsifiers.
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I talked briefly about guar gum awhile back in my unexpectedly controversial article on coconut milk, but I’ll give you a bit more detail here. Unlike xanthan gum, which is a product of bacterial fermentation, guar gum is derived from an actual food: the guar bean, or Indian cluster bean, which grows primarily in India and Pakistan. They look similar to green beans, and are a common vegetable dish in the areas in which they grow.
Find out how gums used in processed foods can affect your health.
The physiological effects of guar gum have been extensively studied, first on animals and then on humans. In rats, the only significant effects from guar gum supplementation were reduced body weight and lower blood glucose, even with guar gum making up 15% of the diet (over 100 times the FDA Acceptable Daily Intake). (1) Because guar gum is a soluble fiber, neither of these effects is particularly surprising. Other animal studies conducted to test the safety of guar gum concluded that it is not carcinogenic or teratogenic (harmful to growing fetuses). (2, 3, 4)
Because the animal studies showed no harm even at very high doses, guar gum is now being studied in humans as a therapeutic tool for reducing blood glucose and cholesterol levels. Studies have shown guar gum supplementation to be effective for reducing fasting blood glucose, improving glycemic control, reducing insulin requirements in insulin-dependent diabetics, and reducing LDL cholesterol, although whether these effects could be maintained long-term is uncertain. (5, 6, 7, 8, 9, 10)
Unfortunately, these studies do report gastrointestinal side effects such as increased gas. In one study where subjects were given 21g of guar gum per day for 3 months, two participants dropped out due to excessive gas and abdominal discomfort. (11)
Although 21g per day is far more guar gum than anyone would reasonably encounter in their diet, even small amounts could cause unpleasant symptoms in those with sensitive digestive systems, and I’ve had patients with gut issues improve after removing guar gum from their diet. With that in mind, I think it makes sense to avoid guar gum if you have gut issues, like small intestinal bacterial overgrowth (SIBO) or IBS, unless you’ve removed it and added it back in without noticing any harmful effects.
Locust Bean Gum
Locust bean gum, also known as carob bean gum, is derived from the seeds of the carob tree. During a two-year animal study, rats were given locust bean gum as 5% of their diet, and no carcinogenic or other toxic effects were observed. (12)
Similar to guar gum, locust bean gum has also been studied in humans as a potential cholesterol-lowering compound. (13) Normal subjects and subjects with familial hypercholesterolemia were given between 8 and 30 grams per day of locust bean gum for 8 weeks, resulting in reduced total cholesterol and an improved HDL to LDL ratio. Participants did report increased gas, but it went away after a week or two, and no other harmful effects were reported.
I think the same recommendation I gave for guar gum applies here: if you have gut issues, it would probably be best to avoid locust bean gum. Otherwise, I see no indication that it will cause harm.
Gum arabic is derived from the sap of the acacia tree. Under FDA regulations, gum arabic is given an Acceptable Daily Intake level of ‘not specified,’ which is assigned to additives with little or no observed toxic potential. Animal studies have shown that it is not carcinogenic, mutagenic, or teratogenic, and even at very high doses, the animals did not display any effects of toxicity. (14, 15)
In a small human study, 5 healthy men were given 25g of gum arabic per day for three weeks, and no side effects were reported. (16) In fact, gum arabic had very little effect on the participants, positive or negative, aside from a modest reduction in serum cholesterol and an increase in breath hydrogen.
The increased breath hydrogen indicates metabolism by intestinal bacteria, which has been confirmed by more recent studies on the prebiotic properties of gum arabic. A study using healthy human volunteers found that gum arabic acts as a powerful prebiotic, selectively stimulating the growth of bifidobacteria and lactobacilli. (17) The study authors concluded that gum arabic is at least as effective a prebiotic as inulin, if not more so. Many of you are probably aware that inulin is sold as a prebiotic supplement, so that’s pretty significant!
Based on the available research, gum arabic seems pretty benign, even for those with gut issues. I certainly wouldn’t be concerned about consuming small amounts of it, although as always, be aware of your individual tolerance.
Like guar gum and locust bean gum, tara gum is derived from the endosperm of a legume. Tara gum is a relatively new food additive so there’s less data on it, but it has been thoroughly studied for toxic effects in animals. Researchers conducted multiple 90-day trials in rats, mice, and beagles with tara gum as 5% of the diet, and found no adverse effects other than decreased body weight in the experimental groups. (18) Three-generation reproductive rat studies and genotoxicity studies found no harmful effects of tara gum. (19) In 2-year trials, the experimental groups had more tumors than the control groups, but due to the “high spontaneous incidence” of this particular tumor and the fact that nearly all of the control mice developed the tumor as well, researchers concluded that this was not a result of the tara gum supplementation. (20)
I’m slightly more skeptical of tara gum compared with the other gums because the toxicity results are less conclusive. Also, while all of the other gums have been tested on humans, tara gum has not. That doesn’t mean it’s not safe, because the available evidence indicates it is; it just means we don’t have as much to go on, and it’s always good to be cautious of new food additives.
Gellan gum is similar to xanthan gum in that it is an exopolysaccharide produced by bacterial fermentation. Unfortunately, the routine animal toxicity studies conducted for new food additives aren’t available online, but we do have a human study to look at. To test the safety of gellan gum, the diets of ten volunteers were supplemented with gellan gum at approximately 30 times the level of normal dietary exposure for 23 days. (21) Gellan gum acted as a bulking agent similar to xanthan gum, but no adverse effects were reported. However, a rat study with gellan gum supplemented at 5% of the diet for 4 weeks resulted in abnormalities in intestinal microvilli, which is concerning. (22)
This rat study, as well as the lack of data overall, makes me cautious, and I think those with sensitive guts should avoid it just to be on the safe side. For everyone else, I doubt the small amounts found in food will cause a problem, but it might be best to avoid it if possible.
As a general rule, gums can be problematic for those with digestive issues simply because they’re mostly indigestible, but it’s very unlikely any of them will actually cause harm. Of course it’s ideal to avoid food additives altogether, but I know it’s not realistic for everyone to prepare all food from scratch, and unless you have digestive issues or a sensitivity to certain gums, I don’t think it’s necessary.
Because I’ve covered a lot of different additives with similar applications (primarily thickening or emulsifying), I’ll try to rank them for you. Let’s say you’re buying some almond milk, and there are a bunch of different brands that use different additives. First, do your best to avoid carrageenan. As I mentioned in the article, the concerns have been largely overblown, but it definitely shows the highest potential for harm among the additives we’ve discussed, and with all of the choices available to us, it should be pretty easy to find a brand that doesn’t use it.
Next, I would avoid tara and gellan gums, not because they appear to be harmful, but because we have less information on them.
I’d probably rank guar gum above xanthan gum because it’s derived from a food instead of a bacterial exopolysaccharide, and it isn’t produced using common food allergens. Locust bean gum is probably on about the same level as guar gum, although based on the available studies, the gut symptoms associated with locust bean gum appear to be less severe.
Gum arabic seems the least likely to create digestive symptoms, and it even stimulates the growth of beneficial bacteria, so out of all the gums, it appears to be the least problematic.
Finally, just remember that the overall quality of your diet is far more important than how well you avoid these additives. Luckily, the two correlate pretty well!