THE BENEFITS OF A HEALTHY DIET
In our sixth instalment on longevity, we look at WHO recommendations on what to eat to extend our years and improve our quality of life
As the world’s population ages, ageing societies – those with more than 10% of its population over 60 – are going to be the norm. Thailand will reach that mark soon. Ageing is pushing people to try to minimize the downsides of a longer lifespan by maintaining their physical condition and improving their quality of life. Many scientific studies have focused on how to improve the quality of old age, and in Elite+ we have covered the subject in a series now in its sixth instalment.
Before we continue, I would like to recap what has been determined by the scientific and medical communities. We started with four healthy behaviours, comprising exercising regularly, eating five portions of fruit and vegetables a day, not smoking and drinking only moderately. Being a winner, eating dark chocolate and being married followed; then we covered the impact of being religious and eating less meat on extending our lives. We also looked at the benefits of being more active and having sex. Then we discussed the benefits of wine and being well educated.
In this issue, I will explore the impacts of a healthy diet on quality of life and longevity.
Healthy diet and survival rate
It is a common understanding that diet plays an important role in extending life expectancy, although we need more research to quantify the role it plays. A well known example of a healthy pattern is the Mediterranean diet, which can reduce the risk of premature death. Population-specific dietary guidelines have helped consumers make informed healthy choices. Adherence to dietary guidelines can be measured by indices such as the American Healthy Eating Index. The 2010 American Healthy Eating Index was found to be inversely associated with all-cause mortality in elderly participants in the US. Those in different cultures around the world, however, may have different practical dietary guidelines. In 2003, the World Health Organization (WHO) updated dietary guidelines according to the latest scientific evidence. Although the association between longevity and healthy diet in the WHO guidelines has not been quantified, the guidelines are being accepted and implemented globally. We will look into the details here.
These dietary guidelines cover certain food components including energy intake, sugar, fat and salt (with focus on sodium and potassium), as well as recommendations to eat more fruits and vegetables, nuts and cereals.
Energy intake, counted in calories from food we consume, should be in balance with energy expenditure. Evidence indicates total fat should not exceed 30% of total energy intake to avoid unhealthy weight gain, and fat consumption should move away from saturated fats to unsaturated fats, and towards the elimination of industrial trans fats.
In a healthy diet, free sugars should be less than 10% of total energy intake, with further reduction to less than 5% for additional health benefits.
Lowering salt intake to less than 5g per day helps prevent hypertension and reduces risk of heart disease and stroke in adults.
WHO member states have agreed to reduce their populations’ intake of salt by 30% and halt the rise of diabetes and obesity in adults and adolescents by 2025.
A healthy diet in the WHO guidelines should contain substantial amounts of fruits, vegetables and legumes such as lentils and beans, nuts and whole grains including unprocessed maize, millet, oats, wheat and brown rice.
At least 400g, or five portions, of fruits and vegetables should be eaten per day. In this diet recommendation, potatoes, sweet potatoes, cassava and other starchy roots are not classified as vegetables since they contain high amounts of carbohydrates rather than fibre. As such, popular snacks such as potato chips are excluded from these health guidelines. In order to improve fruit and vegetable consumption, we can always try to include a variety of vegetables in our meals, eat fresh fruits and raw vegetables as snacks, and eat fresh fruits and vegetables in season.
As for sugar intake, the WHO recommends less than 10% of total energy intake should be from free sugars,equivalent to around 50g, or 12 teaspoons for a person of healthy body weight consuming 2,000 kilocalories per day. There are additional health benefits to reducing sugar intake to less than 5% of total energy intake. Most free sugars are added to foods or drinks by the manufacturer,
cook or consumer, and can also be found in sugars naturally present in honey, syrups, fruit juices and juice concentrates.
Consuming free sugars increases the risk of dental cavities or tooth decay. Excess calories from foods and drinks high in free sugars also contribute to unhealthy weight gain that can lead to obesity.
Sugar intake can be reduced by avoiding foods and drinks such as sweetened beverages, sugary snacks and candies, and by eating fresh fruits and raw vegetables as snacks instead of processed snacks.
Regarding fat, it is scientifically proven that less than 30% of total energy intake should come from fats. Unsaturated fats such as those found in fish, avocado, nuts, sunflower, canola and olive oils are preferable to saturated fats normally found in fatty meat, butter, palm and coconut oil, cream, cheese, ghee and lard. Industrial trans fats found in processed food, fast food, snack food, fried food, frozen pizza, pies, cookies, margarines and spreads are not part of a healthy diet.
Thai foods, by this standard, can be considered healthy since most of our cuisine contains less than 10% fat.
Reducing fat to less than 30% of total energy intake helps prevent unhealthy weight gain in adults. The risk of developing serious diseases is lowered by reducing saturated fats to less than 10% of total energy intake, and trans fats to less than 1%, and replacing unhealthy fats with unsaturated fats.
Fat intake can be reduced by changing the way we cook, such as by removing the fatty parts of meat, using vegetable oil instead of animal oil, and boiling, steaming or baking rather than frying. Try to avoid processed foods containing trans fats and foods containing high amounts of saturated fats, including cheese, ice cream and fatty meat.
It is not easy for Thais to reduce fat intake, even though our diet has less fat than a Western diet, as Thais love deep-fried foods. The least we can do is eat them consciously and moderately.
Sodium and potassium
Most people consume too much sodium through salt, corresponding with an average of 9-12g of salt per day and not enough potassium. High salt consumption and insufficient potassium intake of less than 3.5g contributes to high blood pressure, which in turn increases the risk of heart disease and stroke. People are often unaware of the amounts of salt they consume. In many countries, most salt comes from processed foods such as ready meals; processed meats like bacon, ham and salami; cheese and salty snacks; or food consumed frequently in large amounts such as bread. Salt is also added to food during cooking – in bouillon, stock cubes, soy sauce and fish sauce – or at the table with table salt.
We can reduce salt consumption by adding less salt, soy sauce or fish sauce during food preparation, removing salt from the table, limiting the consumption of salty snacks and choosing products with less sodium.
Potassium, which can mitigate the negative effects of elevated sodium consumption on blood pressure, can be increased by consuming fresh fruits and vegetables. An example we often see is athletes eating fruits high in potassium such as bananas during matches.
The Mediterranean diet is a modern nutritional recommendation originally inspired by the dietary patterns of Greece, southern Italy, France and Spain in the 1940s and 1950s. The principal aspects of this diet include proportionally high consumption of olive oil, legumes, unrefined cereals, fruits and vegetables, moderate to high consumption of fish, moderate consumption of dairy products – mostly consumed as cheese and yoghurt – moderate wine consumption, and low consumption of non-fish meat products.
There is evidence that a Mediterranean diet lowers the risk of heart disease and early death. Olive oil may be the main health-promoting component of the diet. Preliminary evidence shows that regular consumption of olive oil may lower all-cause mortality and risk of cancer, cardiovascular disease, neurodegeneration and several chronic diseases.
The Mediterranean diet is cited as being low in saturated fats and high in monounsaturated fats and dietary fibre. One of the main explanations is thought to be the health benefits of olive oil. Olive oil contains monounsaturated fats, most notably oleic acid, which is under clinical research for its potential health benefits. The European Panel on Dietetic Products, Nutrition and Allergies approved health claims of olive oil, due to protection offered by its polyphenols against oxidation of blood lipids and for maintenance of normal blood LDL-cholesterol levels by replacing saturated fats in the diet with oleic acid. A 2014 meta-analysis concluded that an elevated consumption of olive oil is associated with reduced risk of all-cause mortality, cardiovascular events and stroke, while monounsaturated fatty acids of mixed animal and plant origin showed no significant effects.
Two meta-analyses in 2014 found that the Mediterranean diet was associated with a decreased risk of type-2 diabetes. Another meta-analysis from 2008 found that a Mediterranean diet reduced the risk of dying from cancer by 6%. And another 2014 systematic review found that a Mediterranean diet was associated with decreased risk of death from cancer. There is preliminary evidence that regular consumption of olive oil lowers the risk of developing cancer.
Although there are many different “Mediterranean diets” in different countries and populations along the Mediterranean Sea because of ethnic, cultural, economic and religious diversities, the distinct Mediterranean cuisines generally include the same key components: high intake of extra virgin olive oil as the principal source of fat, vegetables including leafy green vegetables, fresh fruits which can be consumed as desserts or snacks, cereals that are mostly wholegrain, and nuts and legumes.
It includes moderate intake of fish, especially of marine blue species; seafood, poultry, dairy products such as cheese and yoghurt, and red wine; and low intake of eggs, red meat, processed meat and sweets. Egg consumption is always a controversial topic, and we will revisit it in the next issue. Total fat in a diet of this type is 25% to 35% of calories, with saturated fat at 8% or less.
In northern Italy, lard and butter are commonly used in cooking, and olive oil is reserved for dressing salads and cooked vegetables. In North Africa and the Middle East, sheep’s tail fat and rendered butter are traditional staple fats.
Thai people in the past used lard as the main source of fat. Then vegetable oils were introduced and became popular due to ease of use and storage. Vegetable oils, especially palm oil, have replaced most of the animal oil we used to consume.
I have discussed only additional information on diet, but this is important to add more years to our lives, since knowledge of the meals we eat three times a day is indispensable. The next issue will expose more interesting findings on longevity, such as controlling blood pressure and cholesterol level as well as losing weight and staying positive. See you all then!