1.2. Diet in Blue Zones
The „Blue Zones”are places where people often live for over 100 years. The term was originally invented by demographers Michel Poulain and Gianni Pes, but was popularized by Dan Buettner, an explorer, cyclist and award-winning journalist. The reason for such a long life of people living in these particular areas are not the specific genes or a coincidence. As it turns out, the common factor of these few places scattered all over the world is primarily the diet, of which beans are an important component. Among the preferred varieties are lentils, soya, black and fava. In addition, most of the inhabitants of the Blue Zones regularly consume wine, usually about 1-2 lamps a day, whether for a meal or with friends. The most recommended type of wine is especially Sardinian Cannonau wine. As far as meat is concerned, it is consumed rather sporadically, only about 5 times a month. Supercentenarians prefer pork to beef or poultry.
In addition, people living in Okinawa apply the 80% rule – Hara hachi bu. It means eating a meal until we feel we are 80% full.
It is also important not to eat shortly before bedtime. It is recommended to eat the last meal early in the evening at the latest, and some practice not eating since late afternoon. The last meal should also be our smallest meal of the day.[1]
1.2.1. Okinawa, Japan
The elderly living in Okinawaare among the healthiest in the world. In addition, many people from Okinawa often live beyond 110 years. The key to such a long life turns out to be the Okinawa diet, whose ingredients prevent the occurrence of chronic diseases and delay the ageing process.
Traditional Okinawa diet has many common features, for example, with the Mediterranean diet, consumed in another Blue Zone – Sardinia.
What distinguishes the Okinawa diet from other diets is mainly the very low fat content, especially when it comes to saturated fats, whereas the carbohydrate intake is very high. Sometimes you can also notice the presence of fish, seafood, tea, spices, lean meat, alcohol and fruit. What is hard to find on the tables in Okinawa is dairy products. Okinawans are not in the habit of overeating, due to the fact that their diet provides for a fairly low calorie intake. This is caused by the high consumption of plants, which are not only less calorific, but are also an excellent source of antioxidants and phytonutrients.
The basis is mainly vegetables, which constitute 58% of their diet. Approximately 33% of the calories consumed come from grains, especially those with a low glycemic load. Only less than 1% of the calories consumed are those taken from fruits, which are not very popular in Okinawa and are used rather rarely.
Sweet potato is the vegetable most often consumed by Okinawa inhabitants. It has been recognized by the Centre for Science in Public Interest as the healthiest vegetable. Sweet potato deserved this title thanks to, among other things, high content of antioxidant vitamins, dietary fiber, calcium, iron, protein, potassium and at the same time low incidence of cholesterol, sodium and fats. The vitamins C, E and A present in them have antioxidant properties which favour free radicals. The content of vitamin A in a sweet potato is many times the recommended daily value. It is also a phenomenon that vitamin E, which is usually found in high-fat products, appears in high intensity also in sweet potato, a low-fat vegetable. In addition, it has a relatively low glycemic index, but this may vary depending on how it is prepared.
The high content of valuable nutrients means that eating sweet potatoes can significantly reduce the risk of diseases such as cancer, atherosclerosis, type 2 diabetes, help reduce inflammation and maintain cholesterol levels.
If the inhabitants of Okinawa already reach for fruit, it is usually a bitter melon. We can find in it a high content of vitamin C, fiber and at the same time it is not high in calories. Interestingly, the bitter melon has long been used for medical purposes, mainly in the form of tea to help with metabolic disorders, rheumatic pain, fever and cold. It has also been used by people struggling with diabetes in lowering blood glucose levels. As it turns out, it can also prevent tumours and counteract viruses. Despite numerous applications, its mechanism of action is still fully explained.

Another important ingredient in the diet of Okinawans are soya products, which have antioxidant properties, prevent cancer (especially prostate cancer) and have FOXO3 gene expression activators that help maintain good health to an old age and longevity. They have a high content of vitamins, fiber, minerals and polyunsaturated fats while maintaining low levels of saturated fats. The very rare occurrence of prostate and breast cancer is also often considered as a result of large quantities of soya.
People who use soya products more often turn out to be less exposed to cardiovascular disease, coronary heart disease, and Alzheimer’s disease. It is also worth mentioning that the consumption of soya is recommended to regulate blood sugar and insulin levels.
Sea carotenoids are another item on the Okinawans menu. Among them we can distinguish mainly algae, seaweed and kelp. They are characterized by high content of iron, calcium magnesium, protein, iodine and folates and low calorie content. Their salutary functions include primarily the reduction of blood glucose and insulin, antioxidant properties, help to reduce weight gain and are a response to numerous metabolic disorders. Thus, only this one component, which is marine cartenoid, can bring a number of benefits to our health, reducing the risk of cancer, obesity and showing anti-inflammatory, antioxidant and neuroprotective effects.

The most popular spice on Okinawa, which is used not only to add the taste of soup or curry, but also can be drunk as tea, is curcuma. Curcumin is primarily known for its antioxidant properties and for preventing numerous types of cancer. In addition, turmeric can be the key to the fight against Alzheimer’s due to its anti-inflammatory, antioxidant and anti-lodogenic properties. Increasingly, turmeric is being studied for its effect on prolonging human life.

Thanks to a healthy diet, the inhabitants of Okinawa are much less likely to face many diseases. The incidence of diabetes, cardiovascular diseases, specific types of cancer and age-related diseases is much lower than in other populations. At the same time, their chances of living old age in good health and achieving longevity are much higher. Among other things, they are attributed to their consumption of only healthy fats, thanks to which cholesterol is maintained at an optimal level and inflammation is reduced.
In addition, their diet is characterized by low glycemic load and high consumption of antioxidants.[2]
1.2.2. Sardinia, Italy
Another area called Blue Zone is Sardinia. On this Italian island people have a remarkably longer life. Those enjoying longevity are most easily found in municipalities such as Seulo, Arzana, Urzulei, Baunei, Talana and Villagrande Strisaili. The Sardinians have a traditional lifestyle and their main activity is farming. The above-average life expectancy of this population has long been the focus of scientific attention, but all research conducted so far has excluded genetic factors as affecting their longevity.
It is believed that the Sardinians owe such longevity mainly to their diet. To verify this, it was decided to test 150 Sardinians aged 80-109 years.
The most predictable result is that the Sardinians’ diet is characterised by a very high intake of pasta and dairy products. About 80% of the respondents admit that they consume dairy productsevery day. What is important is that they are of sheep and goat origin (less harmful than dairy products from cattle) and they are home-made. The most popular were ripened cheese or casu ajedu. Sardinians also very often eat traditional dishes. The dizzying 100% of the people surveyed confirmed eating Pistokku bread daily. 80% of the respondents declared to drink Cannonau wine 1-2 times a week, the situation with Minestrone is similar (76%). Consumption of myrtle liqueur at least once a week concerns 50% of cases and 91% consume at least 2-3 servings of Culurgiones per month.
Among people living in Sardinia it is very popular to drink coffee, because as many as 75% of the study participants drink it every day. This undoubtedly has a major impact on their health, as it has been repeatedly proven that coffee has a number of benefits, including reduced risk of mortality from all causes, Alzheimer’s disease, Parkinson’s disease, type 2 diabetes or cirrhosis.
According to the study, a quarter of the people surveyed eat meat, most often pork, lamb or goat every day. It should be noted that the meat consumed by the Sardinians is made from animals reared locally and processed into products such as sausages, hams and salami at home. The meat thus processed does not contain the usual chemical additives and preservatives, but only pepper, salt and other spices. As it turns out, the consumption of meat does not always have only negative consequences, as it can have a beneficial effect after the age of 65 as it prevents excessive loss of muscle mass, especially if, as in the case of the Sardinians, it comes from home-bred farms. Although potatoes are not considered to be the most healthy vegetables because of their high glycemic load, their consumption among Sardinians is very high. 60% of the respondents declared to consume 1-2 servings of potatoes per week. As it turns out, Sardinians effectively reduce the risks associated with their consumption by cooking them and seasoning them with fats instead of frying, which results in a lower glycemic index.
What may come as a surprise in the case of this Italian island is the fact that quite occasionally fish and seafood appear on the tables of its inhabitants. Quite rarely they also decide on fruit or legumes. Sweets are not very popular among the people of Sardinia either, as two thirds of those surveyed ate less than two portions a month.
Milk products, meat and potatoes do not necessarily have to be an obstacle to longevity, which the Sardinians are a great example of. As it turns out, eating them does not reduce life expectancy as long as it is ensured that they are prepared in the right way, come from the appropriate source and do not contain harmful chemicals and preservatives.[3]
1.2.3. Nicoya, Costa Rica
Costa Rican peninsula, Nicoya, also belongs to the Blue Zone group. It measures 778 km² and is inhabited with a population of 326,000. Like other Blue Zones, Nicoya can be considered rather isolated from the rest of the country. What distinguishes Nicoya from the rest of Costa Rica is that it has a 5% native population. To determine what is behind the extraordinary longevity of the people living in this part of Costa Rica, a study was carried out on 60 people between the ages of 80 and 109 to determine what the diet of the Nicoyan centenarians includes. As it turned out, as much as 87.4% of men admitted to smoking cigarettes. Interestingly, none of the women surveyed showed nicotine addiction, but 17.2% of them had smoked in the past. The vast majority of people participating in the study lived in their home or rented house. Only 6% of the Nicoyans surveyed lived in nursing homes. A significant proportion of the respondents were married. As in other Blue Zones, the education level of Nicoyans was quite low. By far the most common diet was cereals, followed by legumes. Very often the participants also reached for fruit. No significant differences between men’s and women’s eating were noticed, but about 3-6% of the respondents testified that they never or very rarely reach for this type of food. A similar phenomenon was observed in the case of eating salad – the vast majority of people ate salad 1-2 times a week, but there were also individuals (as much as 15%) who did not eat this type of product at all. Although the great majority of the food consumed is plant-based, there were also few cases of eating meat. Nicoyans who decide to use meat choose pork more often than expected, chicken. About 50% of the respondents declared to consume 3-5 portions of meat per week, and about 25% reported eating meat products even daily.

Coffee was also very popular in this area, as 85% of the respondents declared to drink it daily. In the case of daily consumption of products, very high results were also reported for typical dishes in this region. The results were slightly different between the sexes. As many as 86.7% of men ate daily Gallo Pinto, 76.7% tortillas, 50% Cuajada and 46.7% Pinto con huevos. These results for women were 79.3%, 69%, 62.1% and 55.2% respectively.
Unlike another Blue Zone, Okinawa, on the Nicoya peninsula, dairy products proved to be consumed frequently and willingly. This is especially true for cuajada and fresh cheese, which, according to research, was consumed daily by about 50% of the corresponding people.
One of the characteristics that links the diet of the Nicoyans and Sardinians, inhabitants of another Blue Zone, is the very frequent eating of potatoes. In the case of Nicoya, 50% of the respondents replied that the potato is on their plate at least 1-2 times a week. The Nicoyans also consumed sea foodfrom time to time, but not as often as products from other food groups. Only 10% of the respondents said they eat 1-2 portions of fish per week. Other products rarely consumed by the Nicoyans include Guaro alcoholic beverages. According to the results of the study, men used them only 2-3 times during the month, women never used them. Gender differences also occurred in the case of eating sweets, but this time there was a reverse dependence. With the consumption of 1-2 servings per month by about 50% of men, women responded that they reach for sweets a little more often.[4]
1.2.4. Ikaria, Greece
Ikaria is a small-sized island in the Aegean Sea. An extremely high percentage of people over 90 years of age and one of the highest life expectancies in the world ensured its inclusion in the Blue Zones group. Thanks to its longevity population, which is so large compared to the rest of the world, Ikaria has become an object of scientific interest. One of the studies to reveal the secrets of Ikara’s longevity took place in 2009. The research considered only people over 80 years old. A total of 98 women and 89 men were examined. People over 80 years of age represent less than 5% of the Greek population and about 1% of the world population. In the case of Ikaria, on the other hand, this group represented as much as 13% of the surveyed sample. In addition, as many as 1.6% of the participating men and 1.1% could boast of being over 90 years old.
According to the results achieved, the level of education of people living in Ikaria was very low – 20.3% of the respondents did not manage to complete primary school and 10.1% were illiterate.
However, this is not an element of surprise, as it is similar in other Blue Zones as well. As far as marital status is concerned, most men turned out to be married, while most women were widows. As many as 27.6% of the women and 3.4% of men were still doing housework and 4.1% of women and 3.3% of men were active. This may be due to the fact that a large proportion of Ikarians are deprived of a pension. Moreover, about 50% of the respondents declared low income. Almost all surveyed lived in their homes which they shared with their family members.

As it was found out, the diet of Ikarians is very similar to the Mediterranean diet, but there are slight modifications. First of all, the subjects consume olive oil very often, approximately 5-7 times a week. In fact, they are also much more likely to use fruit and vegetables, because they consume them 4-5 times a week.
Like many other Blue Zones residents, they are not too much of a meat enthusiasts, because on average they consume them about 1-2 times a week.
Fish appeared on the plates of the people involved about twice a week. Fish consumption has a number of benefits due to the presence of omega-3 fatty acids that have anti-inflammatory and antioxidant properties. In addition, regular consumption of fish has beneficial effects on kidney function and has a good effect on the cardiovascular system. Ikarians enjoy consuming wine, in case of men it is about 200 ml and women 100 ml per day. It certainly has some effect to support their longevity, as it contains polyphenols responsible for vasodilation and antioxidant effects. Like, among others, people living in Nicoya, the people of Ikaria are keen to drink coffee during the day, in quantities of about 300 ml per day. Its health properties are very similar to those of wine.
It is also worth mentioning the Pythagorean diet, adopted by the famous Greek philosopher from the region of Samos-Ikaria, Pythagoras. It was very similar to the Mediterranean diet, which consisted mainly of focusing on eating cereals, fruits and vegetables – so it was a model very similar to how the Ikarians eat nowadays.
Already in the distant past, this type of diet was considered to be the reason for the extraordinary longevity of Greek philosophers.[5]
1.2.5. Loma Linda, California. USA
Loma Linda is the least investigated region of all the Blue Zones so far. Located in California, it is inhabited by Seventh Day Adventists. This small group has a tendency to live significantly longer than the average life expectancy for Americans, with a difference of 10 years. To examine the phenomenon of their longevity and considerable life extension, Loma Linda University decided to conduct two studies. Only Adventists who were permanently resident in California were considered.

The first study was initiated in 1960. It lasted 25 years, until 1985, when a total of 22,940 people were studied. The aim of the study was to determine how often popular diseases such as cancer occur in this population and how much longer the Adventists live on average from those who do not belong to them.
Overall, according to the results of this study, Adventists live on average more than 6 years longer for men and almost 4 years longer for women.
The second study conducted on Adventists focused on their famous diet, which was supposed to be the reason for their extended life. Between 1974 and 1988, 34,000 people were surveyed to see what type of products this group eats and avoids. People under 25 years of age were excluded from the study. As it appeared, the diet of most Adventists consists mainly of plant products, which makes them similar to inhabitants of other Blue Zones. They are particularly popular with fruits, which eat on average over 2 portions a day. According to research, this makes them 70% less likely to develop lung cancer than the rest of the Americans on average. In the case of women, an interesting relationship between tomato consumption and ovarian cancer has also been noted, as Adventist women who consumed them about 3-4 times a week were about 70% less exposed to the disease. Men also reported significant health benefits from tomato consumption, as this reduced their risk of prostate cancer by 40%. In addition, legumes also contribute to Adventists’ longevity, reducing the risk of colorectal cancer by 30-40%.
Adventists prefer to use beans and peas. Eating a few portions of nuts per week, as with wholemeal bread, reduced the risk of heart attack by 50% and 45% respectively.
In addition, Adventists who often drank soya milk more than once a day were 70% less likely to suffer from prostate cancer. In the case of meat, the results were clear because the reduction in both red and white meat significantly reduced the risk of colorectal cancer. Drinking water was also important. To be 60-70% less likely to have a fatal heart attack, it is enough to drink about 5-6 glasses of water during the day, according to studies. Some dependence was observed – a large part of the subjects had low BMI. It is probably related to the diet consisting mainly of plant products and the tendency to eat by this group of dinners quite early and in small amounts. People who keep BMI low tend to have a lower risk of blood pressure diseases, lower cholesterol and blood pressure.[6]
[1] Buettner, D., Skemp, S. 2016, ‘Blue Zones: Lessons From the World’s Longest Lived’, American Journal of Lifestyle Medicine, vol 10, no. 5, pp.318–321

[2] Willcox, DC., Scapagnini, G., Willcoxb, B. ‘Healthy aging diets other than the Mediterranean: A Focus on the Okinawan Diet’, Mechanisms of Ageing and Development, vol. 136–137, March–April 2014, pp. 148-162

[3] Nieddu, A.; Vindas, L.; Errigo, A.; Vindas, J.; Pes, G.M.; Dore, M.P. Dietary Habits, Anthropometric Features and Daily Performance in Two Independent Long-Lived Populations from Nicoya peninsula (Costa Rica) and Ogliastra (Sardinia). Nutrients 2020, 12, 1621.

[4] Nieddu, A.; Vindas, L.; Errigo, A.; Vindas, J.; Pes, G.M.; Dore, M.P. Dietary Habits, Anthropometric Features and Daily Performance in Two Independent Long-Lived Populations from Nicoya peninsula (Costa Rica) and Ogliastra (Sardinia). Nutrients 2020, 12, 1621.

[5] Panagiotakos, D., Chrysohoou, C., Siasos, G., Zisimos, K., Skoumas, J., Pitsavos, C., Stefanadis C. ‘Sociodemographic and Lifestyle Statistics of Oldest Old People (>80 Years) Living in Ikaria Island: The Ikaria Study’, Cardiology Research and Practice, Volume 2011, Article ID 679187

[6] Oliveira, R., ‘Living Long in Loma Linda’, UC DAVIS Integrative Medicine, May 10 2017