What are ‘Blue Zones’?
A National Geographic expedition to uncover the secrets of longevity found the five places in the world where people often live to over 100 years old – and often reach old age without disease or health conditions such as obesity, cancer, diabetes or heart disease.
Research on these ‘Blue Zones’ sought to identify the factors associated with living a long life and determine how they might be transferable to populations in other parts of the world. The locations were coined ‘Blue Zones’ after researchers marked the locations on a map with blue circles.
Here’s what researchers discovered in each of the zone locations:
Home to one of the world’s longest-lived women, the Okinawan diet is low in calories, yet dense in nutrients. The foundation of the diet – accounting for over half its calories – is root vegetables, rather than rice, as with a traditional Japanese diet. One of the main vegetables is a purple sweet potato that is rich in protective polyphenols, while others include soya beans and seaweed. The other components of the diet include fish, lean meat (including pork), and spices. Okinawans adopt the principle of ‘hara hachi bu’ – eat until you are 80 per cent full. They also enjoy secure social networks and a strong sense of purpose.
Nuoro Province, Sardinia
This Italian region is home to some of the world’s longest-lived men, who enjoy a largely plant-based diet of wholegrains, beans, garden vegetables and fruit as well as sheep’s milk and cheese. This community reserves meat for Sundays and special occasions; they enjoy red wine moderately and incorporate exercise into their routine, which includes tending livestock throughout the mountainous local terrain. This diet differs from elsewhere in Europe because it relies on wholegrains and dairy and uses lard (which is rich in vitamin D), rather than olive oil.
Here the diet is more traditionally Mediterranean, with plenty of fruit, vegetables (including leafy greens), wholegrains, beans and olive oil as well as goat’s cheese, honey and herbs. The diet of this island differs to that of the mainland – it has a lower calorie composition, makes extensive use of wild and garden-grown vegetables and includes coffee and herbal tea. This island community is also no stranger to a mid-afternoon break, which is thought to help lower stress and rest the heart.
Nicoya, Costa Rica
With little to no processed foods in their diet, this community enjoys a plentiful supply of antioxidant-rich fruit and vegetables including yams, corn and sweet potato; they also drink the local mineral-rich water which contains calcium and magnesium. The diet includes fish, meat and dairy products, and has low levels of sugar but high intake of coffee. Other aspects that form the foundations of this community include faith, family, an optimistic outlook and an active lifestyle.
Loma Linda, California
Outliving the average American by a decade, this community enjoys a predominantly vegan diet of leafy greens, nuts and legumes; those who choose to eat dairy, eggs and fish do so in moderation and more as a side dish rather than a main. A large proportion of the city’s population are members of the Seventh-day Adventist Church; they tend to avoid smoking and drinking and rest on the Sabbath (but otherwise enjoy an active lifestyle).
How does the Blue Zones diet work?
As you might expect, given the different backgrounds, cultural traditions and environments of the five Blue Zone populations, there is not one ‘Blue Zone diet.’ There are, however, similar themes that run through the diets, the most notable being the reliance on self-produced, locally available foods. These include a high intake of plant foods such as legumes, beans and nuts, some meat (most often pork), seafood and dairy. The research team identified other common factors relating to both how these locations eat and their lifestyle. These nine commonalties were coined the ‘Power 9’ and are divided into four key areas.
1. Moderate, regular physical activity is built naturally into the day. Blue Zone communities do not frequent the gym, they live in environments that require physical activity, whether it’s growing their own food, tending livestock or doing physical chores.
2. Blue Zone communities enjoy a sense of purpose and a positive outlook, which has been estimated to add seven years to life expectancy.
3. They also enjoy routines that allow them to take time out. This may be prayer, afternoon siestas or getting together with friends or family.
4. Moderate calorie intake appears to be key. Whether it’s the Okinawan 80 per cent rule or eating the smallest meal in the evening and fasting overnight, these communities do not over-indulge and naturally practice time-restricted eating.
5. There’s a ‘plant slant’ to their diets. Beans, pulses, root (including potatoes) and green leafy vegetables play a big part in all Blue Zone diets, making up about 95 per cent of the diet.
6. Wine is enjoyed by four out of five of the Blue Zone communities but is drunk moderately and in company.
7. Most of the Blue Zone communities follow a faith.
8. A strong sense of family or commitment to loved ones runs through the communities, whether this is to a life partner, investing time in children or supporting ageing parents.
9. There’s a tribal support for healthy behaviours within the communities, making it easier for individuals to stick to these habits.
What can I eat on the Blue Zones diet?
The specific foods relevant to each Blue Zone, and the recipes they use them in, are largely driven by culture and local environment. On the whole, Blue Zone communities enjoy pesticide-free produce that is locally grown or grown in their own gardens as well as meat from free-range or roaming livestock. Interpreting this way of eating for those of us living in a Western, largely urban environment may seem difficult and potentially expensive, however the Blue Zone food guidelines suggest we include the following:
- Wholegrains including oats, barley and wholewheat
- Beans and pulses (such as fava, black and soy beans or lentils): one portion daily
- Vegetables including leafy greens, sweet potato and yams
- Fruit such as tomatoes, oranges, apples, bananas, dates, figs and peaches
- Nuts (including walnuts, almonds and hazelnuts): two handfuls per day
- Some meat, but no more than twice per week, with portion sizes kept small (about 80-90g)
- Fish and seafood, especially the smaller oily varieties such as sardines and anchovies
- Dairy: predominately sheep’s and goat’s milk rather than cow’s. This may include full-fat, naturally fermented products like yogurt but with no added sugars
- Eggs: no more than three per week
- Olive oil
- Herbs and spices, including turmeric
- Wine: 1-2 small glasses per day, preferably with food and in company
- Coffee and tea
What foods to avoid on the Blue Zones Diet?
Despite being different, the various Blue Zone diets minimise or exclude the following:
- Processed food such as ready-to-eat packaged products and salty snacks
- Processed meat and meat products
- High amounts of red meat
- Refined grains
- Refined oils
- Sugar and sweetened food and drinks (limited to celebratory meals).
What is the evidence for the Blue Zones diet?
Evidence specific to the Blue Zones diet is lacking because there is no single diet: the eating patterns of the locations are diverse and vary over time. This lack of evidence and controlled studies makes it difficult to isolate the key elements for health and longevity that can be extended to all of the Blue Zones and adapted to suit our own modern, urban lifestyles.
However, what we do know is that nutrition has the potential to support longevity: studies show generic, healthy plant-rich diets are associated with reductions in the risk of heart disease, type 2 diabetes, certain cancers as well as death from all causes. Although controversial, calorie restriction such the Okinawan 80 per cent rule may also promote longevity, this is certainly seen in many animal species, although the data remains mixed for humans.
Some of the Blue Zone lifestyle factors also appear to be supported by research. A 2018 article suggested that your likelihood of inheriting long-lived genes was as little as 10 per cent while another study suggested 23-25 per cent. Living a physically active lifestyle that combines social connection also favours longevity.
That said, the Blue Zones theory is not without its critics. Dr Saul Newman, a researcher at the Australian National University, suggests there are discrepancies around the age data, and that people in these zones may live no longer than their counterparts – although the paper is yet to be peer reviewed. Other reports also point to the lack of rigorous age validation using death certificates and social security records for at least one of the five Blue Zone locations.
Furthermore, while people in Japan have the highest longevity of any country, men in Okinawa on average don’t live as long as their peers elsewhere in the country. A 2012 study went on to suggest that the Okinawan phenomenon may now be a thing of the past.
Although following the Blue Zones concept has been associated with a lower risk of obesity and weight gain over a relatively short period of time, the longevity effect (if any) of the proposed ‘diet’ and lifestyle will not be measurable until many years have passed. In addition, the suggested ‘diet’ may help improve overall health and longevity, but these results are typically seen when adopted as a community-led programme. All of which suggests that additional evidence is needed before the diet can be recommended.
Will I lose weight on the Blue Zones diet?
The Blue Zones diet is not specifically designed for weight loss. Whether you lose weight or not will depend on your individual circumstances including how you were eating beforehand and the amount of weight you have to lose. Any weight loss is likely to be achieved by switching to a largely plant-based diet that is high in fibre and low in sugar and calories.
Is the Blue Zone’s diet healthy? A nutritionist’s view
The Blue Zones diet essentially replicates much of the current recommendations for healthy eating. There is generic evidence to support the use of a healthy eating pattern for the prevention of heart disease, increased lifespan and for supporting healthy ageing. A healthy diet also appears to reduce the risk of obesity and helps maintain a healthy weight.
In fact, diet is one of the main modifiable factors for the prevention of age-related diseases and for the preservation of good health, but it is not the only one. The Blue Zone communities eat local, seasonal, mainly plant-based produce – but they also eat together, build physical activity into their daily lives and engage in their communities. This seems to help them maintain key capacities including mobility, cognition and a sense of purpose.
Does the Blue Zones diet work?
Without the studies to confirm researchers have selected the key factors within the different Blue Zone communities that encourage a healthy old age, we can’t judge whether following this ‘diet’ will have any effect.
The differences between lifestyle and ability to grow one’s own food between these communities and the majority, urban populations also mean that replicating this way of eating may prove difficult and expensive.
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However, and despite this, significant improvements in medicine, public health, science and technology mean many of us are lucky enough to enjoy a longer life. What we perhaps should be looking to the Blue Zones for is the apparent improvement in health quality during old age, as living longer doesn’t always equate to living healthier elsewhere.
Overall, should I follow the Blue Zones diet?
The food choices of the Blue Zones offer an effective, balanced approach to eating, whilst lifestyle factors recognise other important aspects like the value of social connection and regular physical activity. All of which, if practiced consistently, may benefit your health now and in the years to come.
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