Diagnosis by fingernails?

Can you recognise the state of a person's health by the condition of their fingernails? "Many people seem to think so. But this has not yet been taken a course," says Marc Birringer. He now wants to change that.

For ten years, the professor of applied biochemistry for nutrition and the environment has been interested in the question of what is true about the fingernails' ability to predict health. "I am interested in whether the structures of the nails provide information about how well we are supplied with minerals such as calcium, magnesium or selenium. If we can take an academic voucher for this, then we can detect a defect or deficiency at an early stage without the need for more complex examinations and take countermeasures, for example with tailored nutritional programmes, before diseases develop."

However, reliable findings require large amounts of data, which must also be correlated with each other: Nail images need to be correlated with the results of chemical analyses of mineral content as well as nutrition, health and lifestyle data. Until now, this has been the problem: it has been almost impossible for humans to recognise correlations in large amounts of data. This is the reason why the idea did not become a project for a long time.

The idea: an app

Artificial intelligence (AI) is now changing the framework conditions. It enables precise diagnoses, as is already the case with skin cancer, for example. Could it soon be used to detect nutritional deficiencies and diseases in fingernails, such as bone health from the calcium content in the nails? In the NutriNAIL project, Marc Birringer, his team and colleagues from applied computer science are investigating this methodological approach for the first time. The idea: to develop an app that makes diagnostics via images possible.

In summer 2024, interested people from the region were invited to hand in nail samples and anonymously complete a questionnaire about their health and lifestyle. "We need citizen participation for such projects," emphasises Marc Birringer. "Alongside AI, it is the second important factor for the success of our project, because it is the only way we can capture as many different age groups and lifestyles as possible."

In the meantime, the scientists from the Nutritional, Food and Consumer Sciences department have resolved the nail samples in a special device and carried out chemical analyses. The Applied Computer Science department used the photos to assess the structure of the nails. "We combine this data with the answers from the questionnaires to train our artificial intelligence," says Jan-Torsten Milde, Professor of Library IT and Web Technologies, and emphasises the advantages of AI: "Artificial intelligence makes it possible to recognise patterns that would be impossible to detect with the naked eye."

Recognisable correlations

Initial preliminary analyses of the data already show correlations, for example with the essential trace element selenium, which supports the immune system, supports cell protection and contributes to the function of thyroid hormones: people who eat a vegan diet have the lowest levels, while people who regularly eat fish, meat or eggs have higher selenium levels.

It can also be recognised that age leaves its mark. Older participants tended to have lower levels of potassium and sodium, but increasingly higher levels of chromium in their nails. As an essential trace element, chromium supports carbohydrate and fat metabolism as well as insulin action in the body.

Although only a fraction of the data has been analysed, it is already clear: The study has potential. "The fingernail samples can be used to draw initial conclusions about lifestyle, nutrition and diseases," says Marc Birringer. "We will clarify how the correlations can be interpreted in further studies."

The question of whether the calcium content in the nails correlates with bone health and whether the calcium content in the nails can serve as a biomarker for bone health cannot yet be answered on the basis of the available sample material. "We are definitely planning further university studies with different population groups."

This text was first published in slightly abridged form on the regional science website of Fulda University of Applied Sciences in Marktkork (issue 3 May). (in German)
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