The most common side effects of ginger
Although ginger is praised for its many therapeutic benefits, it is not without side effects. According to scientific studies, these occur mainly when too much is consumed or in people with certain sensitivities. Let’s take a closer look at the most commonly reported problems.
Heartburn and reflux
Ginger has an interesting dual effect on heartburn. On the one hand, its anti-inflammatory properties may soothe inflammation of the oesophagus and reduce stomach acidity. On the other, too much ginger can have the opposite effect.
According to the European Medicines Agency, heartburn (dyspepsia) is a common side effect, affecting 1 to 10 patients in 100. Gingerol, the active compound that gives ginger its pungent, warming taste, can irritate the stomach lining when consumed in large amounts.
Paradoxically, some sources recommend ginger to ease acid reflux because of its anti-inflammatory and digestive properties. However, the effect appears to depend on the dose - relief may give way to discomfort when the recommended amounts are exceeded.
Bloating and gas
Bloating and flatulence are other commonly reported side effects of consuming too much ginger. These digestive problems generally result from a disruption to the gut flora, particularly when the amount consumed is increased too quickly.
There is another therapeutic paradox here, however. In moderate amounts, ginger may actually help reduce bloating thanks to its carminative properties. It aids digestion, relaxes the intestines and supports regular bowel movements. So it is often excess that turns a beneficial plant into a source of discomfort.
To avoid these problems, it is advisable to increase daily amounts gradually, especially if you are not used to consuming ginger.
Digestive problems and nausea
Diarrhoea is one of ginger’s most common side effects, particularly when too much is consumed. This is due to ginger’s stimulating effect on the digestive system. When that stimulation becomes excessive, it can speed up intestinal transit enough to cause diarrhoea.
Interestingly, ginger is often used to combat nausea, particularly during pregnancy. At high doses, however, it can have the opposite effect. This dual action highlights the importance of sticking to the recommended amounts:
- Powder: up to 5 g per day (about one teaspoon)
- Dried root: up to 1 teaspoon per day
- Fresh ginger: 10 to 15 g of rhizome per day
Heavy periods
A less well-known but significant effect concerns ginger’s influence on menstruation. It may increase menstrual flow in some women. This is linked to ginger’s blood-thinning properties.
Periods are considered heavy when they last more than 7 days and/or the total amount of blood lost exceeds 80 ml per day. For women who already experience menorrhagia (heavy periods), consuming ginger could therefore make the problem worse.
Ginger’s anti-inflammatory properties make it useful for menstrual pain, but consuming too much could have the opposite effect. It is generally recommended not to exceed 4 cups of ginger tea per day to avoid increasing menstrual bleeding.
Sticking to the recommended amounts is therefore key to enjoying ginger while minimising its unwanted effects. Too much can quickly turn this spice with its many benefits into a source of significant discomfort.
Medical contraindications to know about
Some people should avoid ginger altogether because of specific medical conditions. Despite its recognised benefits, this root can pose a real health risk in certain circumstances. Let’s look at the main medical reasons to avoid ginger.
Blood-clotting disorders
Ginger has natural anticoagulant properties that inhibit blood clotting. While this can be beneficial in some cases, it becomes problematic for people who already have clotting disorders. Ginger may amplify these problems and worsen existing blood disorders.
The consequences can range from minor bleeding to more serious haemorrhage. Ginger is also strongly discouraged before any surgery or anaesthesia. Its vasodilating properties considerably increase the risk of bleeding during an operation. The FDA (Food and Drug Administration) has issued a specific warning about ginger use in patients taking anticoagulants, particularly warfarin.
Gallstones
Ginger is strictly contraindicated in cases of bile duct obstruction for two main reasons. First, its choleretic properties stimulate bile production by the liver, which can be harmful when gallstones are present. Second, ginger contains minerals such as phosphorus, calcium and sodium that may promote the formation or worsening of gallstones in people with gallbladder problems.
People with gallstones or at risk of bile duct obstruction should therefore consult a healthcare professional before consuming ginger regularly.
Stomach ulcers
Ginger’s active compounds, particularly gingerol and shogaol, can interact with certain medicines, including antacids used to treat stomach ulcers. This interaction may reduce the effectiveness of treatment or worsen symptoms.
Excessive ginger consumption can also irritate the throat and mouth, as well as cause heartburn, which is particularly problematic for people with ulcers. Fresh ginger that has not been chewed also poses a risk of intestinal blockage, a potentially serious complication for people with existing digestive problems.
Medicine interactions to watch for
Although ginger has many therapeutic benefits, its pharmacological action can cause potentially serious interactions with medicines. Understanding these interactions can help prevent dangerous health complications.
Anticoagulants and antiplatelet medicines
Gingerol and shogaol, active compounds in ginger, thin the blood through their vasodilating properties. This can considerably amplify the effects of anticoagulant and antiplatelet medicines.
Diabetes medication
Several studies have shown that ginger lowers blood sugar in people with type 2 diabetes. Although this blood-sugar-lowering effect can be beneficial in some circumstances, it may become problematic when combined with diabetes medication.
Taking ginger and diabetes medication at the same time can therefore cause blood sugar to fall too far. People with diabetes should consequently monitor their blood sugar more closely when consuming ginger.
Treatments for high blood pressure
Because of its vasodilating effects, ginger can lower blood pressure in a similar way to some medicines for high blood pressure. Together, these effects can cause low blood pressure, sometimes severely so.
As a precaution, people taking medication to lower blood pressure should consult their doctor before consuming ginger regularly. Closer monitoring of blood pressure may be needed so that medication doses can be adjusted if necessary.
Other plants and natural supplements
Ginger can also pose risks through interactions with other medicinal plants. For example, consuming ginger alongside plants with anticoagulant properties can considerably increase the risk of bleeding.
These plants include:
- Garlic and onion
- Turmeric
- Ginkgo biloba
- Ginseng
- Tonka bean
- St John’s wort
According to the FDA, combining ginger with turmeric is particularly risky because their anticoagulant effects reinforce each other.
Likewise, plants that affect blood sugar, such as aloe vera or cinnamon, may cause severe hypoglycaemia when combined with ginger.
Given these many interactions, I strongly recommend consulting a healthcare professional before starting any course of ginger, particularly if you are already taking medication.
How to consume ginger safely
A few precautions can help you enjoy ginger while minimising unwanted effects. Following some simple guidelines can help reduce its risks while retaining its medicinal properties.
Stick to the recommended amounts
Ginger is generally safe when consumed in the recommended amounts. However, too much can cause digestive problems such as heartburn and diarrhoea. Experts recommend these maximum daily amounts:
- Fresh ginger: 10 to 15 g per day (a slice 6-7 mm thick)
- Ginger powder: 1 to 4 g per day (about 1 teaspoon)
- Dried ginger: 0.5 to 2 g per day
- Ginger juice: no more than one shot a day
It is also advisable to increase amounts gradually, particularly if you are not used to this spice.
Choosing the right form of ginger
Ginger comes in several forms, each with its own characteristics:
Fresh or dried ginger is ideal for infusions (one slice in boiling water). To relieve nausea, you can also chew a slice of fresh ginger.
Standardised supplements provide a precise concentration of active compounds. However, the daily dose should not exceed 1 g to avoid unwanted effects.
For travel sickness, take ginger 30 to 60 minutes before departure for the best effect.
Avoid prolonged courses without medical reviews
Always consult your doctor before starting a course of ginger. This is essential if you take medication, as ginger can interact with many treatments, particularly anticoagulants and diabetes medication.
The World Health Organization strongly advises against giving ginger to children under six. For pregnant women, the dose should not exceed 250 mg of dried rhizome four times a day.
Finally, stop consuming ginger immediately if you notice adverse effects such as abdominal cramps or persistent heartburn.