Why sulphites are bad for you

Remember Me. Forgot username or password? Not a member? Need further assistance? Please call Member Services at Subscribers only Sign in or Subscribe now! You have successfully subscribed to our newsletter. Related Articles. Craving Chinese Food? The Many Health Benefits of Pineapple. Trending Topics. What Parents Need to Know. Most people can safely consume the sulfites found in wine with minimal risk of adverse side effects. For those with asthma who are sensitive to these compounds, consuming them can irritate the respiratory tract 1.

One study in 80 people with a history of wine-induced headaches found that consuming wine with a higher concentration of sulfites was linked to a greater risk of headaches 8.

However, several other compounds in wine, such as alcohol , histamine, tyramine, and flavonoids, may also contribute to symptoms 9. Other potential side effects of sulfites have been reported as well, including hives, swelling, stomach pain, diarrhea, and, in rare cases, anaphylaxis, a severe and potentially fatal allergic reaction 1.

A small percentage of the population is sensitive to sulfites and may experience side effects like headaches, hives, swelling, stomach pain, and diarrhea. In those with asthma, these compounds can also irritate the respiratory tract. If you think that you may have a sensitivity to sulfites, limiting your consumption is key to preventing adverse health effects. Although all wine naturally contains small amounts, many manufacturers have started producing wines without added sulfites. You can also opt for red wine , which has significantly lower concentrations than other varieties, such as white wine or dessert wine 9.

Additionally, be sure to steer clear of other sulfite-containing foods, such as dried apricots, pickles, soft drinks, jams, jellies, and juices 1. Reading food labels can help you determine which foods you should limit in your diet.

Check the label for ingredients like sodium sulfite, sodium bisulfite, sulfur dioxide, potassium bisulfite, and potassium metabisulfite, all of which can indicate that a food product contains added sulfites.

These compounds are required to be labeled in foods and beverages that contain more than 10 parts per million ppm sulfur dioxide If you are sensitive to sulfites, opt for red wine or wine without added sulfites to help reduce your intake.

Check ingredient labels carefully, and avoid other products with high concentrations of these compounds to help limit your intake. These included the triggering of anaphylactic reactions, as well as the elicitation of a wide range of symptoms, including dermatitis, urticaria, flushing, hypotension, abdominal pain and diarrhoea, although the vast majority of reports described the triggering of bronchconstriction in asthmatic patients 7 , 8.

Sulphite-induced asthmatic symptoms range from mild in some individuals, to very severe in others, and in some individuals these reactions can be life threatening 9. For the majority of people, exposure to sulphites occurs as a result of consumption of foods and drinks to which sulphites have been added, primarily for the purpose of preservation Table 1.

In addition to their preservative activity, sulphites are used to prevent the browning of foods, as bleaching agents, as dough conditioning agents, to prevent excess alkalinity of foods, as food processing aids, colour stabilizers and antioxidants 2 , 3. Thus, in addition to being cheap and convenient, the sulphites are extremely versatile, and their addition to many foods serves more than one purpose.

Foods containing sulphites include dried fruits, dried vegetables, pickled onions and bottled soft drinks and cordials 8 , The addition of sulphite additives to beer and wine is permitted in most countries, and although the use of sulphites in fresh salads, fruit salads, mincemeat or sausage meat, is illegal in many countries, it may occur illegally.

In addition to food, exposure to sulphites can occur through the use of cosmetics and medicines Table 2. Cosmetics containing sulphites include hair colours and bleaches, creams, and perfumes Medicines containing sulphites include eye drops, topical medications, and parenteral medications such as adrenaline, phenylephrine, corticosteroids and local anaesthetics 4 , The sulphites also have a number of industrial uses, including in the photographic and textile industries, and consequently, occupational exposures to these additives may also occur 13 , Whilst most non-asthmatic individuals can tolerate up to 5 ppm SO 2 , there is evidence that a large number of asthmatics are hypersensitive to this gas 16 , In contrast to hyperresponsiveness to SO 2 gas, sulphite sensitivity predominantly refers to the triggering of adverse symptoms following ingestion, or parenteral or topical exposure to these additives.

While sensitivity to the sulphites can present in a number of ways, it is the triggering of adverse respiratory symptoms predominantly amongst asthmatics that seems to occur most frequently.

One of the earliest reports suggesting that ingestion of sulphites could cause irritation of the respiratory tract was published in 5. Since then numerous case reports and reviews have been published on the phenomenon of respiratory hypersensitivity to ingested sulphites.

The first case of anaphylaxis following ingestion of sodium metabisulphite in a restaurant salad was reported in 6 , and the following year SO 2 in orange drinks was reported to induce asthma In the early s there were numerous reports suggesting that ingestion of sulphites by susceptible individuals was the cause of severe adverse reactions. Although many of these were asthmatic responses 19 — 21 , urticaria and angioedema 22 , abdominal pain and diarrhoea 23 , as well as anaphylaxis 24 , 25 were reported.

In , Yang and Purchase 26 reported that there had been more than cases of sulphite-related adverse reactions, including six deaths, in the United States, while in Canada, 10 sulphite-related adverse reactions and one death, thought to be sulphite related, had been reported. As a consequence of these reported adverse reactions, the US Food and Drug Administration FDA acted in to prohibit the use of sulphites on fruits and vegetables that were to be served raw or presented as fresh to the public.

Despite the introduction of these regulations, there continued to be sporadic reports of serious adverse effects following unintended ingestion of sulphites. The potentially severe nature of sulphite sensitivities is highlighted by a number of reports of life-threatening reactions to these additives 28 — One report highlighted the case of a patient who was hypersensitive to metabisulphite and developed anaphylaxis following ingestion of metabisulphite-treated food This patient had a prolonged clinical course, requiring two visits to the emergency department and three weeks of corticosteroid therapy, suggesting that the relapse and delayed recovery may have been related to continued exposure to sulphites during treatment.

Some older, rarely used bronchodilator solutions such as isoproterenol and isoetharine contain sulphites at concentrations sufficient to cause bronchoconstriction in most asthmatic patients, even in the absence of a history of sulphite sensitivity The presence of sulphites in some other pharmaceutical products is also reason for concern.

There are published reports of anaphylactic or asthmatic reactions associated with the use of sulphite-containing local anaesthetics, as well as gentamicin, metoclopramide, doxycycline and vitamin B complex The generic form of the anaesthetic agent, propofol, contains sodium metabisulphite and has the potential to cause adverse effects, particularly in the paediatric population Treatment of anaphylaxis in patients who are sensitive to sulphite also poses a conundrum in that administration of adrenaline is regarded as the primary treatment for anaphylaxis, and yet all commercially available preparations of adrenaline contain metabisulphite However, even in patients with serious sulphite sensitivity, the benefit from adrenaline is considered to outweigh the risk of sulphite exposure associated with use of adrenaline in an emergency Asthmatic responses have also been reported following exposure to sulphites in occupational settings.

Valero et al. Metabisulphite-induced occupational asthma has also been reported in a photographic technician 14 and a radiographer Occupational asthma has been reported in a worker who sprinkled dry metabisulphite powder onto potatoes 41 and three cases of occupational asthma related to metabisulphite exposure were reported in France The use of sodium metabisulphite in the fish and prawn-processing industry, with associated exposures to high concentrations of SO 2 , has been identified as an under-recognised cause of occupational airways disease An increased incidence of asthma and increased asthma-related mortality have also been reported in sulphite pulp mill workers, probably as a consequence of repeated exposures to peak concentrations of SO 2 44 , Over the past three decades a number of challenge studies have been performed in an attempt to confirm sulphite sensitivity and estimate its prevalence in subjects with suggestive histories.

The interpretation of these studies is difficult, as the criteria for the selection of subjects have varied and may have been biased towards those with a history of sensitivity or more severe asthma. In addition, the dose and physical form of sulphite used in challenge protocols has varied widely, as have the criteria considered indicative of a positive response 1 , 7 , 46 — Steroid-dependent asthmatics and those with marked airway hyperresponsiveness appear to be at greater risk of adverse reactions to sulphite-containing foods 8.

There are some indications that respiratory sensitivity to sulphites may be more common amongst women 7 , 51 and children 52 — Reports in the literature describe adverse dermatological responses following exposure to cosmetics, such as facial cosmetic creams 58 , hair dyes 59 and false tanning lotion In addition, topical medications, such as antifungal 55 and haemorrhoid creams 60 and eye drops 61 have been associated with the elicitation of skin symptoms.

Similarly, a wide range of occupational exposures have also been linked with adverse skin reactions to the sulphites 13 , 14 , 62 — Given the wide variations in symptoms, in the severity of reactions, and in the sensitivities of individuals to different forms of sulphite, it is unlikely that any single mechanism can explain all reactions to the sulphite additives.

A number of potential mechanisms that might explain asthmatic reactions to the sulphites have been postulated, although the mode of exposure is a confounding factor 7 , 8.

Nebulized bisulphite solutions, acidified metabisulphite solutions, encapsulated metabisulphite and sulphite containing food or drinks may or may not provoke reactions in the same individual, and the types of reactions and concentrations of sulphite that provoke reactions may vary widely with different forms of exposure.

Inhalation of SO 2 , generated from ingested sulphites in the warm acidic environments of the mouth and stomach, may cause respiratory symptoms. Although nebulized metabisulphite was also thought to cause bronchoconstriction through generation of SO 2 in the airways 48 , airway responsiveness to acidic metabisulphite solutions and SO 2 were not significantly related Some studies have suggested that sulphites may stimulate the parasympathetic system, with bronchoconstriction being mediated by a cholinergic pathway 7.

The enzyme sulphite oxidase oxidizes sulphite to sulphate, and it was suggested that inadequate activity of this enzyme may result in excessive accumulation of sulphite, resulting in cholinergic mediated bronchoconstriction in some individuals The release of histamine and other mediators as a consequence of mast cell degranulation through IgE or non-IgE mediated mechanisms has also been suggested as a possible mechanism in some individuals There is some evidence supporting a role for prostaglandins in sulphite induced asthma 70 , and the inhibition of bronchoconstriction by leukotriene receptor antagonists, in asthmatic subjects exposed to SO 2 , suggests a possible role for leukotrienes 71 , Many individuals are sensitive to sulphite additives and may experience a range of symptoms, including dermatological, gastrointestinal and respiratory symptoms.

Nevertheless, reactions manifesting in the respiratory tract account for the majority of cases of sulphite sensitivity.