You’re probably well aware of the relationship between nutrition and health! It is well-documented! An adequate diet filled with nutrient-rich foods can absolutely help to prevent conditions like obesity and type 2 diabetes, and avoid diseases that stem from nutrient deficiencies.
But did you know that, in addition to improving general health, certain diets can promote longevity?
Some of these longevity-promoting dietary habits have been studied for decades. Others are just coming to the forefront of scientific research. Many popular dieting techniques are even formulated off the back of these studies.
So, what exactly are these diets, and are they really able to increase life expectancy?
Let’s take a look at the options in a little more detail.
The Diets That Can Help You to Live Longer:
The idea that reducing the number of calories you take in can delay the process of aging, is one that originates from studies on rats. After a vast amount of research, the same effect has been demonstrated in numerous organisms. However, the exact underlying mechanisms still remain unclear.
Nevertheless, in humans, prolonged caloric restriction (CR) — reducing daily energy intake by 10-40% — could lead to metabolic changes that inhibit the development of various age-associated diseases.
Two studies investigated the effect of CR on rhesus monkeys — primates that are very close to humans in terms of physiology and biological mechanisms. One study found that CR was associated with improved health outcomes as well as increased lifespan. The other only observed improvements to health.
The reasons for the differences could be due to differing types of food fed during the CR intervention, or genetic differences between individual monkeys. That’s an important point to consider when applying CR to human diets; the effects may differ from person to person.
In a human study, a 25% calorie reduction for 2 years appeared to reduce biological markers of inflammation. It also decreased risk factors for diabetes, stroke and heart disease.
Researchers advise that further human studies are needed before any definitive conclusion can be drawn.
- Can be applied to any diet. CR reduces the number of calories consumed each day, so doesn’t rely on factors like the availability of certain foods. Put simply, you don’t necessarily have to change what you eat with this one, just eat less of it!
- Can be difficult to sustain for many people; reducing daily energy intake by up to 40%, for a prolonged period of time, is quite a drastic measure!
- If cutting a significant amount of your food intake each day without careful consideration and planning, you could be at risk of developing a nutrient deficiency. It’s important to make sure you still eat a wide range of nutrient-rich foods. That way your diet will still contain essential vitamins and minerals.
Methionine restriction (MR) is a dietary method that produces similar results to caloric restriction (CR) in terms of lifespan extension. However, unlike CR, it doesn’t require food intake reduction.
Methionine is a type of amino acid — the compounds that form the building blocks of proteins. It’s considered an essential amino acid, meaning the body isn’t able to produce it on its own. Therefore, you must consume it in your diet.
MR reduces body weight and adipose (fat) tissue by increasing energy expenditure (the energy cost of carrying out bodily functions). This results in benefits such as increased insulin sensitivity and other improvements in metabolic health.
In animal studies, these effects have been shown to increase longevity by delaying age-related diseases. Yet human studies are lacking, so it’s unclear how effective or achievable this type of diet would be in people.
Without studies that investigate the changes induced by MR over long periods of time in humans, it’s unclear what the exact effects of this could be.
- Unlike CR, you wouldn’t need to count calories or reduce your daily food intake.
- In order to restrict methionine in the diet, intake of animal products should be very low; a vegan diet is naturally low in methionine. Restricting meat and dairy may be difficult for some people, and factors like religion or culture could be a barrier.
- The studies talk of restricting methionine, rather than cutting it out completely. Methionine is an essential amino acid, so ensuring you consume the right amount could be difficult without the help of a medical professional.
In Mediterranean countries, the traditional diet is rich in fruit and vegetables, legumes, whole grains, olive oil, nuts, and fish. It also contains moderate amounts of red wine. On the other hand, it tends to be low in dairy products and meat and doesn’t include any processed foods.
Research shows that those who still follow this traditional diet are less likely to develop chronic illnesses such as heart disease. As a result, they’re more like to live longer and healthier lives.
But these positive effects aren’t exclusive to those living in Mediterranean countries.
One population-based study reviewed data gathered from American women with diets that closely resembled the traditional Mediterranean diet. They then used this information to determine the effects of these food choices on telomere length.
Telomeres are protective caps at the ends of DNA strands, that enable each cell to function normally. Once they wear down, telomeres no longer protect the cell’s DNA and allow the DNA to become damaged. That’s why researchers think that shorter telomeres may promote accelerated aging — they can’t preven DNA damage.
The analyses in the study on American women showed that there was, indeed, a relationship between how well the women followed a Mediterranean diet and the length of their telomeres. The closer the women’s nutrition intake to the traditional Mediterranean diet, the longer their telomeres were. This suggests that this type of diet could delay the onset of cellular aging.
And it’s not just a North American phenomenon, either! In a Swedish study, following a Mediterranean-style diet appeared to reduce mortality from all causes in an elderly population. Similar results have also been demonstrated in young Swedish women.
- The foods that feature in the Mediterranean diet are generally widely available and affordable.
- It doesn’t rely on any sort of diet fad — you don’t need to go hungry!
- May be far more difficult to follow in Western countries where processed foods are so easily available. In rural Mediterranean regions, food is generally homegrown or locally-sourced.
- There are many other lifestyle factors that may help increase the life-span in people who eat this diet. They might engage in more physical activity, be less likely to smoke, or have stronger social ties, for example.
On the Japanese island of Okinawa, inhabitants have low rates of chronic and age-related diseases. They also have a higher life expectancy compared with those living on the main island.
The majority of their food energy comes from sweet potatoes, and along with this they regularly eat plant-based foods such as sea vegetables and bitter melon. Soy products, like tofu and edamame, also feature heavily in their diet. The traditional diet is 80-90% carbohydrates, with lean meat eaten from time to time. They also drink lots of green and jasmine tea, and use medicinal herbs and spices, like turmeric.
Some researchers suggest it is the low calorie content of this diet that is likely to be responsible for any diet-related health benefits. Others point to its low-protein, high-carbohydrate properties.
Additional health-promoting aspects of the diet include its low saturated fat content, high antioxidant content and inclusion of foods with anti-inflammatory properties.
- This diet includes a variety of foods.
- Many of the foods are region-specific, and may be difficult to get hold of in Western countries.
- Transitioning to a considerably lower calorie diet could be a big leap for lots of people.
- It may be far more difficult to follow in different environments — even younger-generation Okinawans eat less and less traditional foods, as Western dietary habits become increasingly widespread.
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Take Home Message
When it comes to promoting longevity, rather than focusing on one specific food or nutrient, it is more effective to look at adapting your diet as a whole.
Each of the diets described here have pros and cons, though, so it’s important to think about which diet would best suit your lifestyle. Otherwise, it’s unlikely that it will be sustainable in the long-term.
While further research would definitely be useful, the reported benefits of these diets do have scientific backing. Together with good levels of physical activity and other health-promoting lifestyle choices, these diets may well be the key to a longer and healthier life!
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