The Okinawa diet: Can it really help you live to 100?

The Okinawa diet has gained popularity around the world for its supposed ties to drastically extending the lifetimes.

Okinawa - located off the south-west coast of Japan - is the largest of the Ryukyu Islands. The region is one of just five that belong to the 'Blue Zone' list - a global list that identifies areas in which the average life expectancy is abnormally high. (1)

People who reside in Okinawa tend to live exceptionally long and healthy lives, compared to the rest of the world. Despite many genetic, lifestyle and environmental factors likely contributing to the extended lifespans, some experts believe that the local diet is perhaps the strongest influence.

For comparison, Okinawans don't just live longer, they are also extremely healthy even at old age. Okinawa has:

• 6-12 times fewer heart disease deaths than the US
• 2-3 times fewer colon cancer deaths than the US
• 7 times fewer prostate cancer deaths than the US
• 5.5 times lower risk of dying from breast cancer than the US

Today we're going to break down the diet's benefits, drawbacks, food sources and more.

What is the Okinawa diet?

The Okinawa diet describes the traditional eating patterns of those living on the Okinawa island, but it has since spread beyond the borders and is now adopted by those looking to live a long life.

The traditional Okinawa diet is low in calories and fat while high in carbohydrates. There's a great emphasis on vegetables and soy products, as well as small amounts of noodles and fish. The traditional diet has varied over time as the modern food production process has greatly influenced our eating habits. The modern take on the Okinawa diet still focuses on low calorie, high-carb intake but incorporates more protein and fats.

The macronutrient breakdowns are like so:

	Traditional	Modern
Carbs	85%	58%
Protein	9%	15%
Fat	6% (2% saturated fat)	28% (7% saturated fat)

The diet also makes use of many theories from traditional Chinese medicine - treating various foods as medicine, which is why you will also find herbs and spices known for their health benefits in the diet, such as turmeric and mugwort. (2)

The westernised version of this diet has started to promote weight-loss as its main goal. Though this may be an effect of eating a nutrient rich, balanced diet, it is extremely influenced by western culture. The intended goal for the Okinawa diet is simply to achieve a healthy life, but it is joined by a culture that encourages daily physical activity and mindful eating practices. There will certainly be more to the secret of living longer than simply eating more vegetables - it is very likely that the Japanese culture is a great influence upon longevity.

Primary Foods

This Japanese diet delivers nutrient-dense, antioxidant food which could be key to the Okinawa people living much longer.

Antioxidants protect the body from cellular damage while your body requires essential nutrients to function.

The Okinawa diet differs from traditional Japanese diets, as it encourages very little rice in its meals. Instead, the main source of calories come from the sweet potato,whole grains, legumes, and fibre-rich vegetables.

• Vegetables ~60%: orange and purple sweet potato, pumpkin, seaweed, kelp, mushrooms, bamboo shoots, radish, cabbage, carrots, pumpkin, papaya.

• Grains ~33%: millet, noodles, rice, and wheat.

• Soy-based foods ~5%: edamame, tofu, miso and fermented soybeans.

• Meat and seafood ~2%: fish, seafood, and pork.

• Grains ~2%: millet, noodles, rice, and wheat.

• Other ~1%: alcohol, tea and spices.

Foods to Avoid

The modern take on this diet isn't quite as restrictive, but the traditional Okinawa diet limits intake of a range of foods. This is largely due to the geographical restriction faced by such a small island - Okinawa has not had access to a variety of foods in its' history, and as such the diet has developed around the region's primary foods, ignoring many others, including:

• Animal products: eggs and dairy, including milk, cheese, butter and yoghurt.

• Processed foods: processed meats, refined sugars, grains, breakfast cereals, snacks and processed cooking oils.

• Legumes: most legumes, other than soy beans.

• Other foods: most fruit, as well as nuts and seeds.

Benefits of the Okinawa Diet

Longevity

Okinawa is famous for its extraordinary life expectancy. The island is home to more people over the age of 100 than any other place on earth. (3) We cannot rule out the idea that environmental, cultural and genetic factors play a large role, but it would be safe to assume that a poor diet would have an adverse effect upon life expectancy. As such, we can presume, if anything, that the Okinawa diet only contributes to living a long healthy life, whether or not it is aided by other factors.

Research suggests that high amounts of free radicals can speed up the ageing process as they cause stress and cellular damage in your body. (4) Other research suggests that antioxidants can slow the ageing process by protecting our bodies from free radicals and their effects, as well as being anti-inflammatory. (5)

When considering this, it becomes clear why the Okinawa diet may have a strong influence on longevity. The traditional diet is heavily centered around plant-based foods which contain high amounts of antioxidants.

Though the correlation between the Okinawa people and longer life expectancy is strong, there is much more research needed to prove a causality between the two.

Reduced risk of diseases

Besides living longer, Okinawans also experience fewer chronic diseases such as heart disease, cancer, and diabetes.

It comes as no surprise that a diet low in saturated fats, sugars and highly processed foods will contribute to a healthy diet. While promoting this, the Okinawan diet also encourages nutrient and fibre rich foods, which reduce inflammation.

Sweet potato and other vegetables play a key role in the traditional diet, which have been found to boast high amounts of compounds known as carotenoids.

Research shows that carotenoids also have antioxidant and anti-inflammatory properties, which are key to preventing heart disease, as well as type 2 diabetes. (6) (7)

Research also suggests that some soy-based foods - incorporated in the Okinawa diet - can reduce the risk of chronic illnesses such as heart disease, but also certain cancers, such as breast cancer. (8)

Downsides

Restrictive

While the traditional Okinawa diet does include a variety of foods which provide necessary nutrients your body needs to function properly, it also excludes many foods. Depending on your own preferences you may find these foods to be restrictive and you may feel as though you are missing out. Others may not notice the restriction if these foods are not staples in your regular diet.

The traditional diet limits intake of fruits, nuts, seeds and dairy - all of which contribute essential nutrients, like fibre, vitamins, minerals, and antioxidants that can boost your health. (9) (10) (11)

Restriction of these foods may have an adverse effect on your health and wellbeing, so it may be more beneficial for some to follow the western version of the diet which is less limiting of certain food groups.

Sodium

The biggest drawback of the Okinawa diet could be the sodium content.

The diet naturally contains very high amounts of sodium, with some versions dishing up 3,200 mg of sodium per day. If you have high blood pressure, this much sodium could be detrimental to your health. (2) (12)

The recommended daily intake of sodium for a person with average blood pressure is roughly 2,300mg, while those with high blood pressure are recommended just 1,500 mg per day (per the American Heart Association).

Is the Okinawa diet right for you?

Though the Okinawa diet does provide many health benefits and essential nutrients to the body, some people may prefer a less restrictive diet - especially if you are an avid fan of carb-heavy meals.

An emphasis on vegetables and an avoidance of highly-processed foods is never a bad thing, but the limiting of proteins and fruits may not suit your individual needs. The low amount of meat and restricted protein intake could certainly slow the muscle growth process for those of you that are working hard in the gym. The low-carb aspect may also have a negative effect on endurance exercise, where your body requires high amounts of calories to burn off during the workout.

If you're unsure about whether the Okinawa diet is right for you, talk to a dietitian or medical professional before trying it.