US researchers have found that individuals with greater optimism are more likely to live longer and to achieve “exceptional longevity,” that is, living to age 85 or older.

Optimism refers to a general expectation that good things will happen, or believing that the future will be favourable because we can control important outcomes. Whereas research has identified many risk factors that increase the likelihood of diseases and premature death, much less is known about positive psychosocial factors that can promote healthy aging.

The large study, published in PNAS journal, was based on 69,744 women and 1,429 men. Both groups completed surveys to assess their level of optimism, as well as their overall health and health habits such as diet, smoking and alcohol use. Women were followed for 10 years, while the men were followed for 30 years.

When individuals were compared based on their initial levels of optimism, the researchers found that the most optimistic men and women demonstrated, on average, an 11-15% longer lifespan, and had 50-70% greater odds of reaching 85 years old compared to the least optimistic groups. The association between optimism and longevity held even after accounting for age, and other influential factors such as educational attainment, chronic diseases, depression and also health behaviours, such as alcohol use, exercise, diet and primary care visits.

The results are relevant to public health, explains co-author Lewina Lee, PhD, clinical research psychologist at the National Center for PTSD at VA Boston Healthcare System and assistant professor of psychiatry at Boston University School of Medicine (BUSM) because they show that optimism is a “psychosocial asset that has the potential to extend the human lifespan.” She suggests also that it is a kind of learned behaviour and that  levels of optimism can be modified using relatively simple techniques or therapies.

It is still unclear how exactly optimism helps people attain longer life. “Other research suggests that more optimistic people may be able to regulate emotions and behaviour as well as bounce back from stressors and difficulties more effectively,” said co-author Laura Kubzansky, PhD, MPH, Lee Kum Kee Professor of Social and Behavioral Sciences and co-director, Lee Kum Sheung Center for Health and Happiness at the Harvard T.H. Chan School of Public Health.

The researchers behind the current study suggest also that more optimistic people tend to have healthier habits, such as being more likely to engage in more exercise and less likely to smoke, which could extend lifespan.

As a result, say the scientists who reviewed hundreds of studies to reach their conclusions, it can even slash the chance of an early death by 16%.

The report was originally compiled by the Institute for European environmental policy (IEEP). Researchers there spent a year reviewing more than 200 academic studies on the links between nature and health resulting in one of the most wide-ranging examinations to date on this topic.

That document was published autumn 2016 and picked up by the environmental NGO Friends of the Earth Europe which further augmented it by focussing on the links between nature-related health outcomes and income inequality.

This showed further benefits even in deprived neighbourhoods where risks of both obesity and poor mental health are statistically much higher.

Vital to health

According to a growing body of evidence, health inequalities are linked to access to nature and access to nature is vital for good mental and physical health at all ages.

The FOE report cites research that 26% of England’s black and minority ethnic populations visit natural environments less than three times a year, compared with 15% of the rest of the population.

It points to a strong link between lack of access to nature areas and poor health outcomes and inequality. It associates nature deprivation with higher obesity levels, mental health problems, and mortality rates.

As a result, it says, access to nature as being inextricably linked to wealth inequality, because deprived communities typically have fewer natural environments within easy reach.

It calls for access to nature to be recognised as a fundamental human right, and for increased efforts to provide accessible and well maintained natural areas for particularly disadvantaged groups.

Previous research

There is now a huge amount of data to show that time in nature is important for our wellbeing.

Exposure to nature has been shown to switch the body into “rest and digest” mode where it can nourish, repair and promote well-being

In 2016 scientists from Australia and the UK say a ‘minimum dose’ of nature for us all could significantly reduce rates of depression and high blood pressure.

In another study, taking your exercise regime out of the gym and in the park was found to cut to the risk of suffering from poor mental health by half.

Previous US research has found that that simply giving hospital patients a window with a view of trees meant they recovered faster and were discharged a day earlier than those whose rooms faced walls.

How nature helps is multifaceted but one intriguing study found that ‘forest bathing’ – essentially walking in a forest environment – exposes you to ‘friendly bacteria’ and other natural substances that can help protect your health.

“The evidence is strong and growing that people and communities can only thrive when they have access to nature,” said Robbie Blake, a nature campaigner for Friends of the Earth Europe, which commissioned the analysis.

“We all need nature in our lives, it gives us freedom and helps us live healthily; yet deprived communities are routinely cut off from nature in their surroundings and it is suffocating for their well-being.”

Results from the study – which analysed data from two long-term observational studies – appears in JAMA Internal Medicine.

Previous studies have promoted vegetarian diets for their health benefits, while others have cautioned against meat consumption for potential health risks.

Recent studies for example, suggests that a vegetarian diet could lower the risk of colorectal cancer and type-2 diabetes while other evidence suggests that higher red meat consumption (as opposed to poultry, fish, eggs, or dairy products) is linked to kidney failure.

Lowering risk of early death

The current study which analyses more than 30 years of data from two large US studies, focuses on the types of protein we eat and its impact on health.

The researchers looked at the rates of death from all causes as well as form specific diseases, and at influential aspects of lifestyle and compared these to the participants’ diets.

Results showed that every 10% increase in animal protein (expressed as a proportion of total calories) was linked with a 2% higher risk of death from any cause and an 8% increased risk of death from cardiovascular disease.

This increased risk of death linked to eating more animal protein was more conclusive among those who were obese and those who drank larger quantities of alcohol.

In comparison, for every 3% increase in plant protein in the diet there was a 10% lower risk of death from all causes and a 12% lower risk of death from cardiovascular disease.

Again, the link between eating more plant protein and lower risk of death was stronger among those with lifestyle risk factors such as smoking and drinking  or if they were overweight and /or physically inactive. Higher intake of plant protein was also more protective in people age 65+.

Protein sources matter

But the analysis also showed that not all proteins are created equal.

“Although substituting plant foods for various animal foods was associated with a lower mortality, red meat, especially processed red meat, showed a much stronger association than fish and poultry, which themselves were not associated with mortality” say the scientists.

They add that, “protein from certain fish, such as cod, has been suggested to improve the lipid profile, glycaemic control, and insulin sensitivity.”

The researchers also discovered that substituting just 3% of calories from animal protein with plant protein was linked with a lower risk of death from all causes.

One good source of vegetable protein is pulses. Indeed 2016 is the International Year of Pulses, focussing on the health and environmental reasons for eating more pulses. Whereas recent evidence suggests that our continued high intake of meat is contirbuting to obesity, other evidence shows that adding healthy yellow peas, chickpeas, navy beans and lentils to your diet can significantly reduce your risk of metabolic syndrome.

Many fo us are not yet in the habit of substituting plant for animal protein. However, the authors of the current study conclude: “Substitution of plant protein for animal protein, especially from processed red meat, may confer substantial health benefit. Therefore, public health recommendations should focus on improvement of protein sources.”

• For more on this topic see our article Q&A: Do ‘meat-reducers’ get enough protein?

Even for people who are generally active, swapping out just a few more minutes of sedentary time with some sort of movement was associated with reduced mortality, according to the research, published in the journal Medicine & Science in Sports & Exercise.

The researchers looked at data from approximately 3,000 people aged 50 to 79 who participated in the National Health and Nutrition Examination Survey conducted by the US Centers for Disease Control and Prevention (CDC).

Tracking activity

For the study, subjects wore ultra-sensitive activity trackers, called accelerometers, for seven days, generating data which was then compiled by the CDC. The agency then tracked mortality over the next eight years for these same people.

The results were striking. The least active people were five times more likely to die during that period than the most active people and three times more likely than those in the middle range for activity.

“When we compare people who exercise the same amount, those who sit less and move around more tend to live longer,” said Ezra Fishman, the lead author of the paper.

“The folks who were walking around, washing the dishes, sweeping the floor tended to live longer than the people who were sitting at a desk.”

Previous activity-tracking studies have drawn similar conclusions. But, according to Fishman, such studies usually ask participants to monitor their own exercise frequency and quantity – numbers they notoriously over-report. Using electronic trackers provided the researchers with more precise data.

“Because the device captures the intensity of activity so frequently, every minute, we can actually make a distinction between people who spent two hours a day doing those activities versus people who spent an hour and a half,” he said.

Even 10 minutes a day matters

Though the scientists didn’t discover any magic threshold for the amount a person needs to move to improve mortality, they did learn that even adding just 10 minutes per day of light activity could make a difference. Replacing 30 minutes of sedentary time with light or moderate-to-vigorous physical activity produced even better results.

“You didn’t have to even get a good sweat to experience the reduced likelihood of mortality,” Fishman said. “Activity doesn’t have to be especially vigorous to be beneficial. That’s the public health message.”

In an ideal world, Fishman said the research would continue with an experiment that randomly assigned people to two groups – one that received an incentive to increase physical activity, one that didn’t – to establish conclusively that replacing sedentary behaviour with light exercise can reduce mortality risk.

He said he would also like to see public health officials get more creative about ways to encourage people to move more. Until these happen, however, it’s up to individuals to substitute movement for sitting still.

“When it comes to physical activity,” Fishman said, “more is better than less, and anything is better than nothing.”

The Mediterranean diet plan is not a diet, per se. It is a way of eating characterised by the consumption of fruit, vegetables, pulses (beans, peas, chickpeas, lentils, etc) , fish and nuts, and tends to be very sparing with foods like meat and dairy. It eschews convenience foods for freshly prepared meals and crucially its main source of fat is olive oil.

It’s emphasis on a variety of fresh foods not only makes it delicious but delivers acknowledged health benefits including lower rates of a variety of health conditions, including cardiovascular disease, type 2 diabetes, and even some types of cancer. There is also some evidence that the Mediterranean diet provides some protection against cognitive impairment and dementia.

The Mediterranean Diet Food Pyramid (click to enlarge)

Increased well being

A new study from the Canary Islands sought to find out what else this kind of diet could do for us. Lead researcher Patricia Henríquez Sánchez and colleagues analysed the influence of the Mediterranean diet on the quality of life of a sample of more than 11,000 university students over a period of four years.

Researchers gave participants a 136-item food frequency questionnaire at the start of the study, then again at two and four years, taking note of portion sizes for each of the food items.

Adherence to the Mediterranean diet was determined using a scoring system that included nine components: vegetables, legumes, fruits and nuts, cereals, fish, meat and meat products, dairy products, moderate alcohol intake, and the ratio of monounsaturated fatty acids to saturated fatty acids.

At the end of the study, participants with the highest adherence to the Mediterranean diet reported:

• Better physical functioning
• Less pain
• Better general health
• Greater vitality and social functioning
• More energy

Additionally, those who followed the Mediterranean diet also happened to avoid cigarettes more frequently than those who did not.

Sánchez concludes,  “the Mediterranean diet is an important factor associated with better quality of life and can be considered as a healthy food model.”

The study is published in the European Journal of Clinical Nutrition.