Micro fungus or wine, the secret of the Italians?

Marianna Rizzo, a member of the Swedish-Italian research team, in Acciaroli.
Photo: Alessio Paduano

In‎‎ a couple of major ‎‎studies ‎‎from the 1990s and early ‎‎2000s,‎‎ the Mediterranean diet has been identified as a diet with a certain preventive effect against cardiovascular diseases. But what exactly it is in the food that would give this effect is still not clear. ‎

This is what a Swedish-Italian research project is now trying to figure out by mapping the food habits of Cilento, a mountainous coastal area south of Naples in southern Italy. The American physiologist Ancel Keys made Cilento famous back in the 1960s, when he explored the significance of the Mediterranean diet for health. So what is it that really characterizes the diet of the people of Cilento? ‎

‎“Above all, you eat small dishes that are quite low in calories. Everything is locally produced, usually by the family itself” says Marianna Rizzo, a nutritionist who is part of the Swedish-Italian research team.‎

‎‎The Swedish-Italian‎‎ research project investigates how the diet in Cilento can affect the blood system and gut microbiota by measuring the imprint food makes in the blood with the help of Metabolomics. Metabolomics entails analyzing small molecules, metabolites, in the blood. These metabolites are a kind of end product of metabolism.‎

‎There is a wide range of metabolites in our blood system – and some of these metabolites can predict the risks an individual has of suffering from, for example, diabetes or cardiovascular diseases in the future.‎

“The purpose of our research is to find out if something can be done about these risks. You can say it is a question of primary prevention. The metabolites have a strong association to what you eat and to the gut microbiota. What you can measure in the blood is the interaction between what you eat and the gut flora” says Olle Melander, professor and consultant in internal medicine at Lund University and Skåne University Hospital.‎

‎‎Recently, a pilot study within the Swedish-Italian research project was carried out. At the end of September this year, two groups of Swedes, between 50 and 80 years old, were on site in the Cilento region during a trip arranged by SvD Accent. For a week, they ate only Mediterranean food to see what the effects would be on the metabolites in the blood as well as on the gut microbiota. ‎

‎Initially, they had submit blood and stool samples, and a number of other examinations have been carried out – including height, weight, BMI, blood fats, blood sugar and blood pressure. After a week’s stay, the study participants were checked again by the research team and provided the same kind of samples as on arrival.‎

“Interestingly, the Cilento residents have much

higher levels of two of the key metabolites

than the Malmö residents”

‎72-year-old Agneta Jarl ‎‎and 74-year-old Ulf Larsson did not hesitate to participate in the pilot study. When SvD meets them, they have just enjoyed the long lunch in the mountain village of Cuccaro Vetere. ‎‎They are satisfied after dining on a menu consisting of a variety of small dishes. The starter soup with chestnuts and beans and the dessert with fruits, berries and goat’s cheese became two favourites. ‎

‎As the thermometer reads 27 degrees, the couple decide to skip the hike in the mountains, in favour of the sofa at the hotel with a cup of espresso. Before retirement, they both worked as dentists and have a great interest in food and health.‎

“We are natural scientists and very keen on validated evidence and conclusions. This is a great way to find out what it is that makes people in areas like this get to be so old and stay healthy” says Agneta Jarl.‎

Olle Melander’s research group has‎‎ been collaborating with Italian researchers from La Sapienza University in Rome for several years. The research groups‎‎ map the metabolic differences‎‎ between a random sample of Malmö residents, aged between 50 and 80 years, and equally old residents of the Cilento region.‎

‎The hypothesis is that the Cilento residents have some kind of protective factor against cardiovascular diseases, since Malmö residents suffer significantly more from cardiovascular problems than Italians do. And it may be the metabolites that are the determining factor, according to the researchers.‎

“What is interesting is that the Cilento residents have much higher levels of two of the key metabolites, ergothioneine and beta-carotene, than the residents from Malmö. The higher the level of these metabolites, the lower the risk of diabetes and cardiovascular diseases” says Olle Melander.‎

“There are two problems with this pilot study…

But it’s still important to do this test”

‎While beta-carotene‎‎ is a substance known to be linked to a diet with a lot of fruit and vegetables, the origin of ergothioneine is more complex – and it is not a substance that the body can produce itself.‎

“There is a connection to the intake of vegetables and mushrooms. But it is not the case that people eat particularly large amounts of mushrooms in either Cilento or in Sweden. What we believe – and it is more faith than knowledge – is that there are micro fungi in the soil causing ergothioneine to be produced, and then absorbed by various food plants” says Olle Melander.‎

The food in Cilento‎

‎Some well-known features in the so-called Mediterranean diet are olive oil, fish, nuts, legumes, vegetables and fruit. Red wine is served with both lunch and dinner and the wine is made from grapes grown at high altitude to avoid insects and thus the need for spraying insecticides.‎

‎Bread and pasta are often made from chickpea flour, which is high in protein. Rosemary and chicory are common herbs in many dishes.‎

‎Goat’s or sheep’s cheese, sourdough bread and yogurt are some of the breakfast ingredients. Snacks can be figs or various fruits, picked directly from the trees.‎

‎Fish often ends up on the plate, but there is also meat from pigs and goats. Sweets and desserts are treats that the Cilento residents enjoy perhaps once a month – in connection with birthday or wedding lunches, for example.‎

‎Source: Marianna Rizzo, nutritionist in Cilento and co-worker of the research project.‎

‎The researchers believe that ergothioneine may‎‎ also have something to do with the Italian wine drinking. Either the element exists in certain wine varieties or the body absorbs it more easily when drinking wine. ‎

‎Both the theory of micro fungi and the wine intake are on the growing list of hypotheses to be investigated by the researchers. “The more knowledge we acquire about these protective factors that Cilento residents seem to have against various welfare diseases, the easier it will be to develop a primary prevention study for a group of Swedes” Olle Melander points out.‎

‎Dietary research is difficult to carry out because there are so many variables that affect the results. The fact that the 60 participants in the pilot study in Cilento probably are more interested in food and health than the general population, and thus already have a better diet and exercise more, could be complicating factors.‎

“There are two problems with this pilot study, Firstly, the participants are only there for one week, and secondly, we have to assume that these individuals are quite health conscious. But it’s still important to do this test. It can take a long time to alter gut bacteria, but in the blood you should be able to see differences in metabolites” says Olle Melander.‎

‎It will be some time before the analyses of the pilot study in Cilento are completed. The research teams in Sweden and Italy hope that in the future they will be able to conduct a larger study with more participants and for a longer period of time.‎

The research project‎

‎Lund University/Skåne University Hospital and La Sapienza University in Rome have had a joint research project since 2017.‎

‎The aim is to explore the factors that increase or decrease the risk of cardiovascular disease.

Olle Melander, professor and consultant in internal medicine at Lund University and Skåne University Hospital, leads ‎the research group in Skåne. Salvatore Di Somma, Professor of Internal Medicine and Cardiology at La Sapienza University leads the corresponding research group in Italy

‎In Skåne, the study participants were drawn from a random sample from a previous large population study in Malmö that mapped dietary habits and health (Malmö Diet and Cancer Study and Malmö Offspring Study).‎

‎In Italy, too, a random sample of study participants has been made, mainly from those listed at various health centers in the area.‎

‎In the study “Comparison of cardiovascular disease and cancer prevalence between Mediterranean and north European middle-aged populations”, the research teams have been able to show that Malmö residents have a significantly higher incidence of cardiovascular diseases and cancer than Cilento residents, taking risk factors into account. The comparison was made between 809 Cilento residents and 1025 Malmö residents.‎

‎Sources: Olle Melander, Lund University, and Salvatore Di Somma, La Sapienza University‎.

Published in Svenska Dagbladet 2021-10-31

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