Turmeric – A Plant for All Cases?

The extract – the yellow curcumin – is said to be effective against arthrosis, diabetes, Alzheimer’s and cancer. Despite intensive research, most questions remain unanswered.

The essentials in brief:

• Curcumin does not contribute to normal joint function.
• Food supplements containing turmeric or curcumin are considered foods. For them, illness-related statements are generally prohibited.
• If you want to take curcumin to treat diseases, be sure to discuss the product, dosage and possible side effects with your doctor.
• Depending on sensitivity and dosage, turmeric or curcumin extract can cause bloating, nausea or pain in the digestive tract.
• Pregnant and breastfeeding women and patients with gallstones should avoid turmeric supplements.
• In (amounts of) spices, turmeric is unproblematic, but allergic reactions are known.

What is behind the advertising for turmeric?

Turmeric or its yellow coloring agent curcumin / curcumin has long been known not only as an independent spice and curry ingredient. Many manufacturers also advertise that the turmeric tuber has been used in traditional Asian medicine for thousands of years. In fact, positive effects on digestion seem to be undisputed. This means that mild symptoms such as flatulence or a feeling of fullness after eating can be alleviated or avoided with turmeric (as a spice).

In the meantime, however, curcumin food supplements, mostly in the form of capsules or powder, are also on the market for all sorts of ailments and diseases.

Typical online advertising claims or headlines are:

• “India’s sacred plant for osteoarthritis, cancer, diabetes and Alzheimer’s”,
• “Turmeric: moving without pain” or
• “The anti-inflammatory from curry powder”.

Curcumin is also said to have cholesterol-lowering, liver-protecting and antidepressant properties. In most cases, the product itself is not advertised, but it is advertised indirectly by means of advice books, in Internet forums, in “editorial” articles provided by PR agencies or (alleged) field reports on the provider’s homepage or through links to other sites.

But even if the turmeric extracts have already been tested with great promise in numerous cell culture and animal experiments: As a rule, extremely high dosages were used here, which cannot be achieved in humans either through food or dietary supplements. In addition, it is now known that curcumin, as a pan assay interference compound (pain = chemical compounds that often deliver false positive results in high-throughput screenings), can trigger non-specific reactions in standard laboratory methods that are misinterpreted as positive effects. Therefore, many results z. B. from cell culture studies to be treated with caution. Also, the metabolism of cells, rodents and humans is different.

The results are therefore not directly transferrable to humans and, for the most part, have not yet been confirmed in human studies. Most human studies also have major shortcomings (including too few participants, no comparison group, study duration too short) and are therefore only of limited significance.

There is a lack of clear scientific evidence as to whether turmeric extracts have health effects in humans, for example against cancer, joint problems, dementia or depression.

In addition, food supplements – in contrast to  medicines – are not intended to prevent, alleviate or cure a disease. They are only reported to the Federal Institute for Consumer Protection and Food Safety, a proof of effectiveness or safety is not required for this. A dietary supplement must also not be given the appearance of a medicinal product.

The Federal Association of Consumers warned a manufacturer of illegal advertising claims for a turmeric product that also contained vitamin D and promised an effect on the immune system, and was  right in court.

The approval for the advertising claim “curcumin contributes to normal joint function” requested by a manufacturer from the EU was also not approved. The scientific examination by the European Food Safety Authority showed that the consumption of the dietary supplement does not lead to the claimed effect.

What should I look out for when using turmeric products?

• Eaten in normal (spice) amounts, turmeric is considered a safe food . However, allergic reactions are known.
• In the long term, the acceptable daily intake is a maximum of 3 mg curcumin per kilogram of body weight per day from all sources, i.e. around 200 milligrams for a 70 kg person – according to the assessment of the European Food Safety Authority (EFSA) and the Federal Institute for Risk Assessment: “At If this value is exceeded for a longer period of time, even slightly, adverse health effects can occur”.
  Undesirable effects are possible depending on individual sensitivity, type of extract and amount of dosage. This can be flatulence, heartburn, diarrhea / increased stool frequency, nausea or pain in the digestive tract. Complaints have already been observed in the range of 180 milligrams of curcumin.
• Piperine, a pepper extract added to improve bioavailability, can also lead to intolerance (see below).
• If gastrointestinal complaints last longer, are severe or occur frequently, you should definitely seek medical advice!
• Curry and turmeric as spices e.g. for Asian dishes are recommended in the usual doses and can help to prevent or alleviate digestive problems.
• The turmeric extract curcumin has not yet been sufficiently researched and tested as a remedy against diseases, so far this has mainly been done by means of laboratory and animal experiments. There are no approvals as medicinal products in Germany. Editorial contributions on this – especially on cancer and Alzheimer’s disease – should be viewed with caution. Advertising in this regard is prohibited.
• Important: For safety reasons, pregnant and breastfeeding women should avoid turmeric supplements altogether. However, there is nothing wrong with using it as a spice.
• People suffering from gallstones should also avoid taking turmeric extracts. These can promote the production and release of bile and thus trigger biliary colic.

Turmeric or curcumin is not very water-soluble, is very poorly absorbed in “pure” form and only in small quantities via the intestine and quickly excreted from the body. In order to actually achieve an effect, very large amounts would have to be eaten or the bioavailability increased. Therefore , some manufacturers advertise that their products have a “particularly good bioavailability”, for example by adding an extract of black pepper (piperine) or technological processes such as the “packaging” of the curcumin in so-called micelles (transport vehicles).

Even if a higher bioavailability is actually possible, this does not mean that this can also lead to improved abilities and a biological effect in the product that go beyond normal digestive effects.

The Federal Institute for Risk Assessment (BfR) has also assessed the health risks of isolated piperine and recommends: Adults should not take in more than 2 milligrams of isolated piperine per day via dietary supplements. The BfR advises pregnant women not to use such substances.

What is turmeric?

Turmeric belongs to the ginger family. It thrives in the tropical regions of Asia. The subterranean part of the perennial, which can grow to over a meter tall, is used, which looks similar to ginger but is intensely yellow in colour. Turmeric is therefore also called goldenseal. The taste is described as “mildly spicy, with a slightly earthy-bitter note”.

While in Asia fresh turmeric is often used in food preparation, in Western cuisine it is better known as a curry powder ingredient, as a food coloring (E100) or as an egg shell coloring agent.

What ingredients are in turmeric products?

Turmeric powder contains essential oils, resins, proteins and sugar compounds, as well as about 5% curcumin and other curcuminoids that give the yellow color and are considered the biologically active components of the turmeric plant. They are obtained from the dried root tissue (the rhizome) by solvent extraction and belong to the polyphenols.

Depending on the product and supplier, completely different ingredients are used in the dietary supplements: either pure turmeric powder, different “turmeric extracts” that are not defined in more detail, various curcuminoids including curcumin, curcumin alone – or variants with additives such as black pepper extract ( piperine), vitamins (e.g. vitamin D), vitamin-like substances such as choline or other herbal additives. Due to this variety of extracts and compositions, the individual products, effects and study results are hardly comparable.

Since curcumin products with improved bioavailability (e.g. through the addition of piperine) can be regarded as novel foods, according to a current statement by the BVL/BfArM, it must be clarified in each individual case whether the product in question must be approved as a so-called novel food and must undergo a safety assessment. Because: The improved bioavailability could lead to other toxic effects than conventional curcumin.