New research led by the University of Kent and University of Reading has found that fruit and vegetable consumption and exercise can increase levels of happiness.

While the link between lifestyle and wellbeing has been previously documented and often used in public health campaigns to encourage healthier diets and exercise, new findings published by the Journal of Happiness Studies show that there is also a positive causation from lifestyle to life satisfaction.

This research is the first of its kind to unravel the causation of how happiness, the consumption of fruit and vegetables and exercising are related, rather than generalising a correlation. The researchers, Dr Adelina Gschwandtner (University of Kent’s School of Economics), Dr Sarah Jewell and Professor Uma Kambhampati (both from the University of Reading’s School of Economics), used an instrumental variable approach to filter out any effect from happiness to lifestyle. It showed that it is rather the consumption of fruit and vegetables and exercising that makes people happy and not the other way round.

Findings demonstrate that the ability of individuals to delay gratification and apply self-control plays a major role in influencing lifestyle decisions, which in turn has a positive impact on wellbeing. The research also shows that men appear to exercise more, and women eat more fruit and vegetables.

With it being well known that lifestyle diseases are a leading cause of ill health and mortality worldwide, and the UK having one of the highest obesity rates in Europe, these findings could have significant implications for public health policy.

Dr Gschwandtner said: ‘Behavioural nudges that help the planning self to reinforce long-term objectives are likely to be especially helpful in maintaining a healthy lifestyle. If a better lifestyle not only makes us healthier but also happier, then it is a clear win-win situation.’

Professor Kambhampati said: ‘There has been a bigger shift in recent years for healthier lifestyle choices. To establish that eating more fruit and vegetables and exercising can increase happiness as well as offer health benefits is a major development. This may also prove useful for policy campaigns around environment and sustainability.’

While poor sleep was linked to higher levels of stress during the COVID-19 pandemic, more teens actually obtained the recommended amount of sleep compared to pre-pandemic sleep patterns, according to a new study from McGill University. Changes to daily routines triggered by lockdowns allowed teenagers to follow their biological impulse to wake up and sleep later, reducing daytime sleepiness.

The study, published in Child and Adolescent Psychiatry and Mental Health, explores pre‑pandemic sleep behavior and stress during the COVID-19 pandemic. According to the researchers, encouraging better sleeping habits could help reduce teens’ stress and improve their ability to cope in times of crisis.

“The pandemic has shown that delaying school start times could help and should be implemented by schools interested in supporting the mental health of their students,” says lead author Reut Gruber, a Full Professor in the Department of Psychiatry at McGill University.

Reducing stress by promoting more sleep

During the pandemic, the wake-up and sleep time of teens shifted by about two hours later. Many teens also slept longer and had less of a need to catch up on lost sleep during the weekend.

The elimination of the morning commute, a delayed school start time, and cancellation of extracurricular activities allowed teens to follow their ‘delayed biological rhythm’ – or natural tendency to wake up and go to bed later, the researchers explain.

These changes meant that teens had more ‘useable hours’ during the weekdays to complete their homework and didn’t have to sacrifice sleep to fulfill their obligations during the week. Similar findings have been reported in multiple countries around the world during the COVID-19 pandemic.

Less sleep linked to higher levels of stress

The researchers found a connection between the amount of sleep teenagers were getting before the pandemic and their level of perceived stress during the pandemic.

“Shorter sleep duration and higher level of arousal at bedtime were linked to higher levels of stress, whereas longer sleep and lower level of arousal at bedtime was linked to reduced stress,” says Gruber, who is also the Director of the Attention, Behavior and Sleep Laboratory at the Douglas Research Centre.

“The tendency of teens not getting enough sleep was already a global concern prior to the COVID-19 pandemic. Now more than ever it’s critical we tackle the problem,” says co-author Sujata Saha, a Principal at Heritage Regional High School of the Riverside School Board. “Across the world the pandemic has increased levels of uncertainty and psychological stress. It’s projected that today’s elevated mental health challenges will continue well beyond the pandemic itself.”

“Not sleeping enough and being overly stimulated before bedtime are poor habits that are modifiable. We can target these behaviors with preventative measures to reduce teens’ stress in the face of overwhelming situations like to COVID-19 pandemic,” says Gruber.

Age-related macular degeneration, cataract and diabetes-related eye disease are linked to an increased risk of dementia, suggests research published online in the British Journal of Ophthalmology.

Vision impairment can be one of the first signs of dementia, and reduced stimulation of visual sensory pathways is believed to accelerate its progression.

Some small studies have suggested there may be a link between ophthalmic conditions that cause vision impairment – age-related macular degeneration, cataract, diabetes-related eye disease and glaucoma – and cognitive impairment. The incidence of these ophthalmic conditions increases with age, as does the incidence of systematic conditions such as diabetes, high blood pressure, heart disease, depression and stroke, which are accepted risk factors for dementia.

It is therefore unclear whether these ophthalmic conditions are associated with a higher incidence of dementia independently of these systematic conditions, so to investigate, the authors analysed data on 12,364 adults aged 55-73 years enrolled in the UK Biobank study. 

The participants were assessed between 2006 and 2010 at baseline and followed up until early 2021. During the 1,263,513 person-years of follow-up 2,304 cases of dementia were recorded.

Analysis of these data showed that age-related macular degeneration, cataract and diabetes-related eye disease, but not glaucoma, were independently associated with increased risk of dementia from any cause.

Compared with people who did not have ophthalmic conditions at the start of the study, the risk of dementia was 26% higher in those with age-related macular degeneration, 11% higher in those with cataract, and 61% higher in those with diabetes-related eye disease.

While glaucoma was not associated with increased risk of Alzheimer’s disease, it was associated with a higher risk of vascular dementia.

At the start of the study, participants were asked whether they had ever experienced heart attack, angina, stroke, high blood pressure or diabetes, and were assessed for depression. Diabetes, heart disease, stroke and depression were all associated with increased risk of dementia.

Having one of these conditions (a systemic condition) as well as an ophthalmic condition increased the risk of dementia further, and the risk was greatest when diabetes-related eye disease occurred alongside a systemic condition. Larger relative risk for dementia was observed among individuals with more ophthalmic conditions.

This is an observational study, and as such, can’t establish cause, and the authors also highlight several potential limitations, mostly related to data capture. They point out that ophthalmic conditions were defined based on self-reported and inpatient record data which was likely to underestimate their prevalence, that medical records and death registers may not have captured all cases of dementia, and that some dementia documented during follow-up may have occurred before eye diseases.

Nevertheless, they conclude: “Age-related macular degeneration, cataract and diabetes-related eye disease but not glaucoma are associated with an increased risk of dementia. Individuals with both ophthalmic and systemic conditions are at higher risk of dementia compared with those with an ophthalmic or systemic condition only.”

They add: “Newly developed hypertension, diabetes, stroke, heart disease and depression mediated the association between cataract/ diabetes-related eye disease and dementia.”