Reading the label: sweeteners, glutamate and gluten

Some words on labels raise more doubt than they should: sweetener, flavor enhancer, gluten. This guide shows how each one appears on the package, what trials in people showed and what to bring to your appointment when symptoms worry you. It does not tell you to remove or add any food.

Sweeteners: label names and the aspartame math

The World Health Organization review lists acesulfame K, aspartame, advantame, cyclamate, neotame, saccharin, sucralose and stevia as non-sugar sweeteners [1]. On imported products, they may appear by code: aspartame is E951, acesulfame K is E950 and sucralose is E955. Sorbitol, xylitol and others ending in "-ol" are a different category, with calories.

The FAO and WHO expert committee kept the daily limit of 40 mg of aspartame per kilogram of body weight in 2023. In the WHO example, a can contains 200 to 300 mg, and a 70 kg adult would need more than 9 to 14 cans a day to reach the limit. That same year, the WHO cancer agency classified aspartame as possibly carcinogenic, with limited evidence; that classification measures the strength of evidence, not the risk at a given amount [2].

The most useful question is: instead of what? Swapping sugary soda or juice for a sweetened version led to about 1 kg less in trials [3][4], analyses whose authors declare ties to industry. Instead of water, sweeteners did not change weight, and if you already drink water there is no reason to sweeten it. Trials are short; long-term studies link use to more diabetes and cardiovascular disease [5], without knowing whether sweeteners cause it or whether people already at higher risk started using them [1].

Glutamate on the label and on the plate

Glutamate gives the taste called umami, the flavor of broth and meat. In Brazil, it appears as a flavor enhancer, monosodium or sodium glutamate, or as INS 621 [13]. It also comes from ingredients such as hydrolyzed vegetable protein, autolyzed yeast, yeast extract, soy extracts, soy sauce, tomatoes and cheese [10][11].

The scare began with a 1968 letter that mentioned salt, wine and glutamate as possible causes of feeling unwell after Chinese dishes [6], and with glutamate injections in newborn mice, which are not the same as eating seasoning [7]. In 130 people who said they reacted, 38.5% had symptoms only with 5 g of glutamate without food and 13.1% only with the drink without it, and the response did not repeat consistently [8]. With food, only 1 of 6 studies found a difference in headache [9].

Mild, short-lived symptoms have been described in sensitive people at 3 g or more, without food [10]. The European limit is disputed by a review that argues glutamate should first be assessed as a nutrient [12]. Also check the sodium on the nutrition table: monosodium glutamate has 12.28 g of sodium per 100 g, versus 39.34 g in table salt.

Before cutting gluten: a 14-day diary

Celiac disease is a permanent immune response to gluten from wheat, barley and rye, diagnosed with a blood test and, in most cases, an intestinal biopsy [14]; about 0.7% of people worldwide have a confirmed diagnosis [15]. Doctors do not recommend starting a gluten-free diet before testing, because it can change the results [19].

About 10% of adults report sensitivity to gluten or wheat, and in blinded tests 16% to 30% of them have symptoms caused specifically by gluten, with no test to confirm it [16]. In 10 trials, 38 of 231 people with suspected sensitivity had gluten-specific symptoms [17], and in 59 adults symptoms were greater with fructan, a carbohydrate in wheat, than with gluten [18].

For 14 days, without changing what you eat, write one line per meal. Example:

• Based on my symptoms, should I be tested for celiac disease?
• How should I eat until the tests?
• I already cut gluten for a while. Does that change what we should do?
• Are there other causes to look into, such as wheat allergy or irritable bowel?
• If the tests are normal, what do we do about the symptoms I logged?
• Would it help to work with a dietitian to adjust my diet?

How CatLena uses it

When you log a meal, each item shows calories, protein, carbohydrate, fat and fiber, and the Sources of values link shows where each number comes from. In the example below, a snack of 1 apple and 15 g of Brazil nuts added up to 170 kcal. The day’s log also works as a diary to bring to your appointment.

When to see a professional