We may not need to completely overhaul our lives to live healthier for longer, according to a large UK-based study. This is welcome news, particularly as many people will already have abandoned their New Year’s resolutions.
The recent study followed around 590,000 people in the UK, with an average age of 64, over an eight-year period. The researchers confirmed earlier findings that healthier lifestyles are associated with lower risk of disease, including dementia, and with living longer in good health and independence.
The authors reported that even very small changes were associated with such benefits. These included around five additional minutes of sleep per night, two extra minutes per day of moderate to vigorous physical activity, and modest improvements in diet. Together, these changes were associated with roughly one additional year of healthy life. “Healthy life” here refers to years lived without major illness or disability that limits daily functioning.
More substantial changes were linked to larger gains. Almost half an hour of extra sleep per night, combined with four additional minutes of exercise per day, which adds up to nearly half an hour of extra activity per week, along with further dietary improvements, was associated with up to four additional healthy years of life.
This matters because, although women live longer on average than men, those extra years are often spent in poorer health, with significant personal and economic costs. Women face a higher risk of dementia, stroke and heart disease at older ages, as well as conditions that lead to vision loss and bone fractures. These illnesses can reduce quality of life and threaten independence.
Lifestyle change may also reduce the risk of early death. The same lifestyle factors examined in this cohort were analysed last year in a separate study, which focused on mortality (the risk of dying).
In that analysis, people who followed healthier lifestyle patterns over an eight-year period had a 10% lower risk of death in that period. The combination of 15 extra minutes of sleep per night, two additional minutes of moderate to vigorous physical activity per day and a healthy diet was linked to a modest reduction in the risk of dying. A much larger reduction of 64% was seen among people who slept between seven and eight hours per night, ate a healthy diet and engaged in between 42 and 103 additional minutes of moderate to vigorous physical activity per week. Importantly, this benefit was only seen when these behaviours occurred together. Diet alone had no measurable effect, for instance.
Strengths and limitations
One of the key strengths of these studies is that they show health benefits at very low thresholds of behaviour change. This reduces the likelihood that the results are driven only by people who are already healthier or more motivated, and makes the findings more applicable to older adults and those with limited capacity to change their routines.
Another strength is the use of objective measurements rather than self-reported data. Physical activity and sleep were measured using wearable devices, rather than relying on participants to estimate their own behaviour. Self-reporting can be unreliable, particularly for people with memory problems, such as those in the early stages of dementia.
However, there are important limitations. The objective measurements were only collected for three to seven days, which may not reflect people’s long-term habits. From personal experience, wearing activity trackers can lead people to exercise more while they are being monitored, but these changes are often short-lived.
Article continues on The Conversation: www.theconversation.com/small-improvements-in-sleep-physical-activity-and-diet-are-linked-with-a-longer-life-273502