Food Poisoning: Causes and Natural Solutions

Food poisoning refers to the onset of symptoms following the consumption of contaminated food or drink. This contamination may be caused by bacteria, viruses, parasites, toxins produced by certain micro-organisms or, more rarely, by chemical substances.

The term ‘foodborne infection’ is used when symptoms are linked to the ingestion of food contaminated by a microorganism or by a toxin produced by it. When at least two people develop similar symptoms after consuming the same meal or food, this is referred to as a foodborne outbreak, often abbreviated to TIAC.

Most commonly, the symptoms affect the digestive system: vomiting, diarrhoea, abdominal cramps, nausea. Some cases are brief and mild. Others require special attention, particularly in vulnerable individuals.

Contamination can occur at various stages: production, transport, storage, preparation or consumption. A break in the cold chain, undercooking, poor hand hygiene or cross-contamination between raw and ready-to-eat foods can increase the risk.

Food poisoning can therefore cause symptoms of gastroenteritis. The two concepts may overlap, but they do not refer to exactly the same thing.

Bacteria

Certain bacteria can contaminate food and cause digestive symptoms. Bacteria frequently implicated include Salmonella, Campylobacter, certain strains of Escherichia coli, Listeria monocytogenes and Yersinia.

Contamination can be caused by undercooking, improper storage or cross-contamination between raw and ready-to-eat foods. Cross-contamination refers to the transfer of microorganisms from one food to another, for example via a chopping board, a knife or poorly washed hands.

Viruses

Certain viruses can be transmitted through food or water. Norovirus is one of the most common causes of foodborne infections. It can cause nausea, vomiting, watery diarrhoea and abdominal pain.

Transmission can occur via contaminated food, a soiled surface or a sick person preparing a meal. This is why hand hygiene and refraining from preparing meals if you have digestive symptoms are essential preventive measures.

Parasites

Parasites can also be transmitted via contaminated food or water. The risk varies depending on region, dietary habits, travel and hygiene practices.

Some parasitic infections can cause digestive problems that last longer than usual. In the event of persistent diarrhoea, after returning from a trip, or if you experience unusual symptoms, you should seek medical advice.

Toxins produced by certain microorganisms

Certain bacteria produce toxins capable of causing digestive symptoms. In such cases, symptoms may appear quickly after a meal, sometimes within a few hours.

Toxins may be caused by food being left at room temperature for too long, not being chilled sufficiently, or being reheated incorrectly. Maintaining the cold chain and eating prepared meals promptly are therefore useful steps to minimise the risk.

Poor storage or preparation practices

Food poisoning can be caused by simple everyday habits: not washing your hands before cooking, using utensils on raw food and then reusing them on cooked food, a fridge that’s too warm, leftovers kept for too long, or undercooked food.

Micro-organisms do not always alter the smell, appearance or taste of food. A dish may therefore appear normal whilst still posing a risk if it has been stored or prepared incorrectly.

Which foods are most likely to cause food poisoning?

The foods most commonly involved depend on the microorganism responsible, the cooking method, storage conditions and hygiene during preparation. Raw or undercooked foods of animal origin require particular caution: poultry, meat, eggs, dishes containing raw eggs, fish, seafood, raw milk or raw-milk cheeses.

Dishes prepared in advance, leftovers that have been cooled or stored incorrectly, cold meats, ready-made meals, mixed salads, contaminated raw vegetables or food handled after cooking may also be at risk.

The risk therefore stems not only from the food itself, but also from the handling process: storage temperature, waiting time, cooking, handling and the separation of raw and cooked foods.

Here are the main symptoms associated with food poisoning: 

• Nausea: the urge to vomit, sometimes very soon after a meal depending on the cause

• Vomiting: expulsion of the stomach’s contents, which can lead to fluid loss if episodes are repeated

• Diarrhoea: loose or very watery stools, sometimes occurring frequently throughout the day

• Abdominal cramps: pain or contractions in the stomach, often associated with diarrhoea

• Fever: a rise in temperature which may accompany certain digestive infections

• Chills and aches: general symptoms sometimes experienced when the body reacts to an infection

• Fatigue: a loss of energy linked to digestive problems, lack of food or fluid loss

• Signs of dehydration: intense thirst, dry mouth, infrequent or dark urine, unusual tiredness, dizziness

• Blood in the stools: a symptom requiring medical advice, especially if accompanied by a fever, severe pain or persistent diarrhoea.

The term ‘indigestion’ is often used in everyday language to describe digestive discomfort after a meal. It does not exactly correspond to food poisoning. Simple indigestion may be linked to a meal that is too large or poorly tolerated, whereas food poisoning involves food contaminated by a microorganism, a toxin or a substance.

The duration depends on the cause. Some mild forms of food poisoning improve within a few hours to a few days. Others may last longer, depending in particular on the causative agent, the amount ingested, age, general health and the risk of dehydration.

Persistent diarrhoea, repeated vomiting, a fever, blood in the stools, signs of dehydration or severe fatigue should prompt you to seek medical advice. Duration alone is not always sufficient to assess the situation: the context and associated symptoms are very important.

Relieving nausea and vomiting

Aroma-Zone Organic Digestive Mint Herbal Tea combines seven organic herbs, including peppermint, ginger, fennel, coriander and liquorice, traditionally used to aid digestive comfort after meals. Its fresh and slightly spicy flavour makes it a pleasant infusion to enjoy in cases of heavy digestion, bloating or temporary discomfort. Thanks to the presence of ginger – a herb known to help reduce feelings of nausea – it can also be beneficial when the stomach feels sensitive or queasy. As it is caffeine-free, it can be enjoyed at any time of day.

Directions for use : Shake your herbal tea bag before use. Heat your water until it is simmering but not boiling. Pour the hot water over the herbal blend and leave to infuse for 5 to 10 minutes, depending on your preference. For one cup, we recommend using 1 teaspoon of Organic Digestive Mint herbal tea. We recommend enjoying a cup of herbal tea after your main meals.

Try the Organic Digestive Mint Herbal Tea.

Storage : Store away from heat and moisture. Close the sachet tightly after each use.

Precautions: Not recommended for pregnant or breastfeeding women or children. Contains liquorice; people with high blood pressure should not consume this product. To be consumed as part of a varied and balanced diet and a healthy lifestyle.

Reducing diarrhoea

Aroma-Zone Organic Blond Psyllium is a dietary supplement made from whole isphagul husks, rich in soluble fibre and mucilage. On contact with water, these fibres form a gel that increases stool volume and helps regulate bowel movements, whether they are too slow or too fast. In the case of temporary loose stools, this absorbent action can help improve their consistency without causing irritation. It must always be taken with plenty of water.

Directions for use: Take 1 teaspoon (approximately 3 g), stir well into a glass of water or another drink, and drink immediately. Then drink a large glass of water. If necessary, the dose may be increased to up to 6 g per day (approximately 2 teaspoons), to be taken in 2 to 3 doses with sufficient water. 

Try Organic Blond Psyllium.

Storage: Store in a cool, dry place away from light. Close the sachet tightly after opening.

Precautions: Not a substitute for a varied and balanced diet and a healthy lifestyle. Do not exceed the recommended daily intake. Keep out of reach of children. For adult use only. Not recommended for pregnant or breastfeeding women. Not recommended in cases of undiagnosed rectal bleeding and inability to pass stools associated with the use of a laxative, in cases of abnormal narrowing of the gastrointestinal tract, in cases of oesophageal or cardia disorders, potential or existing bowel obstruction, bowel paralysis or megacolon, or in cases of swallowing difficulties. Risk of gastrointestinal obstruction. Do not take at the same time as medication (allow at least 1 hour between doses). If you are taking medication, seek advice from a healthcare professional. Do not take with medication that inhibits peristaltic movements.

Supporting the immune system

Aroma-Zone Chlorella Tablets are a dietary supplement made from 100% pure chlorella, a microalgae naturally rich in nutrients. Its vitamin B12 content helps to support you during periods of low energy, as this vitamin helps to reduce tiredness. It also contributes to the normal functioning of the immune system – that is, the body’s natural defences as a whole. Available in additive-free tablets, it fits easily into a vitality regimen, particularly when your diet is irregular or following a demanding period.

Directions for use : Take 6 to 12 tablets a day, either chewed or swallowed with a glass of water.

Try Chlorella tablets.

Storage: Store in a cool, dry place away from light. Close the jar tightly after opening

Precautions: Keep out of reach of children. Not a substitute for a varied and balanced diet and a healthy lifestyle. Do not exceed the recommended daily dose. For adult use only. Not recommended for pregnant or breastfeeding women. There have been reports of allergies to chlorella, including a possible cross-reaction with seafood and seaweed. Do not consume if you are allergic to chlorella. May contain traces of sulphites.

Restoring balance with probiotics

Aroma-Zone’s Probiotics for Gut Comfort combine five patented probiotic strains, including the SynbÆctive® SmilinGut blend, with prebiotic fibres. Following an episode of nausea, vomiting or diarrhoea, the gut microbiota – that is, the digestive flora – may be temporarily out of balance. This formula is designed to support the balance of this flora and help restore daily gut comfort. Each capsule provides 16 billion CFU, with a gastro-resistant coating that promotes targeted release in the gut.

Directions for use: Take one capsule a day, to be swallowed with a glass of water.

Try the Gut Comfort Probiotics.

Storage : Store away from light, heat and moisture. Close the jar tightly after each use.

Precautions: Not a substitute for a varied and balanced diet and a healthy lifestyle. Do not exceed the recommended daily dose. For adults only. Not recommended for pregnant or breastfeeding women. Keep out of reach of children.

Here are the things to avoid during food poisoning: 

• Forcing yourself to eat too quickly: when experiencing nausea or vomiting, you should resume eating gradually, depending on how well you tolerate food

• Drinking large quantities all at once: if you feel nauseous, it is often more comfortable to drink in small, regular sips rather than filling your stomach quickly

• Neglecting hydration: diarrhoea and vomiting can lead to a loss of water and minerals, particularly in children, the elderly or frail individuals

• Drinking alcohol: alcohol can irritate the digestive tract and contribute to dehydration

• Eating fatty or very spicy foods too soon: these foods may be harder to tolerate when the gut is still sensitive

• Taking an anti-diarrhoea medicine without seeking advice if you have a fever or blood in your stools: some medicines are not suitable for all situations and may be inappropriate depending on the circumstances

• Using anti-inflammatory drugs without seeking advice: these may be poorly tolerated by the digestive system and are not suitable for all situations

• Cooking for other people whilst experiencing symptoms: this may facilitate the transmission of microorganisms, particularly in the event of vomiting or diarrhoea

• Eating leftovers from the meal in question: if a food appears to be the cause, it must not be eaten again

• Waiting too long if warning signs appear: a high fever, blood in the stools, repeated vomiting, severe diarrhoea, feeling unwell or signs of dehydration require medical advice.

The reintroduction of food should be gradual. Hydration remains a priority whilst vomiting or diarrhoea persist.

Here are the steps you need to know to prevent food poisoning: 

1. Wash your hands before cooking: washing your hands reduces the transfer of microorganisms to food

2. Avoid preparing meals if you have digestive symptoms: vomiting and diarrhoea increase the risk of contaminating food or surfaces

3. Keep raw and cooked foods separate: use separate chopping boards, knives and dishes to avoid cross-contamination

4. Cook high-risk foods thoroughly: meat, poultry, fish, eggs and other sensitive products must be cooked properly

5. Maintain the cold chain: fresh food must be transported and stored at the correct temperature

6. Refrigerate leftovers promptly: a prepared dish should not be left at room temperature for long

7. Consume leftovers promptly: the longer a dish is kept, the greater the risk of microbial growth

8. Clean the fridge regularly: soiled surfaces must be cleaned straight away, especially after food has spilled

9. Wash fruit and vegetables that are eaten raw: this helps to reduce some surface contamination

10. Follow use-by dates and storage instructions: the information on the packaging helps ensure food safety

11. Exercise caution with high-risk foods for vulnerable people: pregnant women, young children, the elderly and immunocompromised individuals should avoid certain more sensitive foods, in accordance with health recommendations.

You should seek medical advice if symptoms are severe, persistent or accompanied by unusual signs. Severe or prolonged diarrhoea, repeated vomiting, a high fever, blood in the stools, severe abdominal pain or extreme fatigue are all reasons to seek medical advice.

Signs of dehydration also require particular attention: intense thirst, a dry mouth, infrequent or dark urine, dizziness, drowsiness, malaise or marked weakness. In the case of a child, an elderly person, a pregnant woman, or someone who is immunocompromised or suffering from a chronic illness, medical advice should be sought more readily.

A consultation is also necessary if several people experience the same symptoms after sharing a meal. This may indicate a collective case of food poisoning. The healthcare professional will be able to advise on the appropriate course of action depending on the circumstances.

Food poisoning should not be dismissed as mere digestive discomfort when symptoms are severe. The priority is to prevent dehydration, especially in the event of repeated vomiting or diarrhoea.

Natural remedies are no substitute for medical advice if warning signs are present. They do not enable the causative agent to be identified, nor do they rule out the possibility of a more severe form of the condition.

Anti-diarrhoea, anti-emetic or anti-inflammatory medicines should not be taken routinely without professional advice. Their suitability depends on the circumstances, age, associated symptoms and general state of health.

In the event of pregnancy, immunosuppression, chronic illness, high fever, blood in the stools, persistent diarrhoea or repeated vomiting, seek advice promptly.

If food poisoning is suspected, the circumstances surrounding the meal often provide useful information. Note the time of the last suspected meal, the foods consumed, how long it took for symptoms to appear, and the number of people affected.

It may also be useful to monitor hydration: frequency of urination, thirst, a dry mouth, dizziness or unusual tiredness. These signs help to assess how well the body is coping with the digestive upset.

If several people are unwell after the same meal, if the symptoms are severe, or if a vulnerable person is affected, do not wait for the situation to take its course. A healthcare professional will be able to advise on the appropriate course of action.

Sonia Caillol Mérité holds a doctorate in pharmacy and a university diploma in dietetics, nutrition and health.

Sonia has always been passionate about nutrition and its effects on our health. Diet is paramount for her, and she adjusts nutritional regimes to suit her patients' lifestyles, medical treatments, preferences and hopes to help them regain and maintain their well-being.

Sonia is a pharmacy assistant, nutrition coach and writer for Aroma-Zone. She shares advice on rebalancing your diet and using natural supplements to support a healthy lifestyle — all while still enjoying food that tastes good. And that really matters.

You can find all her advice on her Instagram page: nutrisonia13