Q&A: 'As little as 20 minutes' of daily exercise linked to 43% lower odds of depression
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Key takeaways:
- A new study indicates that exercising at smaller doses — less than guidelines currently recommend — may lower the risk for depression in older adults.
- One of the researchers told Healio what PCPs need to know.
Primary care physicians should recommend at least 20 minutes a day of moderate to vigorous activity 5 days per week to manage the odds of depression in older adults, according to an expert.
It is well known that physical activity has been linked to lower odds for depression. An umbrella review has indicated that all types of exercise were effective in improving depression and anxiety, and an additional meta-analysis revealed that exercise significantly decreased suicide attempts.
Previous research has also suggested that PCPs are well positioned for assessing and treating depression. In fact, the president of the American Academy of Family Physicians has previously said that PCPs play a crucial role in mental health care.
Eamon Laird, PhD, a lifestyle health researcher at the University of Limerick in Ireland, and colleagues conducted a cohort study of 4,016 adults aged 50 years or older to determine the minimal dose of moderate to vigorous physical activity (MVPA) needed to reduce their risk for depression. They noted that a lower dose of MVPA than guidelines currently recommended may be linked to a lower risk for depression among older adults.
Healio spoke with Laird to learn more about the study and what PCPs should know.
Healio: Why did you decide to research this subject?
Laird: Depression is unfortunately increasingly prevalent in the older adult population and is associated with increased risk of chronic conditions, including CVD, cognitive decline, mortality and suicide. The economic burden in the United States alone is estimated to be over $210.5 billion. Therefore, the identification of potentially accessible and low-cost health and lifestyle behaviors that could attenuate risk factors for depression, particularly among those with chronic illnesses, remains a high priority. Physical activity has been previously shown to be associated with reduced risk of depression; however, no one has yet investigated what is the bare minimal dose of physical activity that might provide benefits.
Healio: Will you briefly describe your findings and their importance?
Laird: This is the first longitudinal study across 10 years in older adults to investigate the links of MVPA with depression.
We found that older adults performing as little as 20 minutes a day (for 5 days a week) of MVPA had a 16% lower risk of depressive symptoms and 43% lower odds of depression. Importantly, this was the lowest dose where we observed an association. The higher the physical activity dose, the greater the benefits for depression. Doses equivalent to about 60 minutes a day of MVPA were associated with 16% lower risk of depressive symptoms and 41% lower odds of major depression.
Doses equivalent to about 120 minutes a day of MVPA were associated with 23% lower risk for depressive symptoms and 49% lower odds for major depression. These findings remained significant even after controlling for relevant health-related factors like biological sex, education, age, smoking and alcohol, obesity, antidepressant use and time.
Healio: What are the clinical implications of your findings?
Laird: These findings suggest that physical activity at lower doses than WHO recommendations for overall health may offer protection against depressive symptoms and major depression among older adults. We do not advocate for reduced activity levels in any population, but these findings suggest that even doses lower than recommended may well protect mental health over time in older adults. These doses may be more achievable as many older adults may find it difficult to undertake physical activity for a large number of reasons. But, again, it is important to remember the higher the physical activity dose, the greater the mental health benefits for depression. So, what we are saying is that here is probably the minimal dose, but the more the better!
Healio: What should PCPs take away from your research?
Laird: At a minimum, PCPs should be recommending 20 minutes a day of moderate to vigorous activity at least 5 days per week to try and attenuate the odds of depression in older adults. Try and build it into a routine with hobbies or activities patients enjoy and recommend it with others as social interactions particularly with activity can also have mental health benefits. Remember that it is one component and that nutrition and healthy lifestyle will also give additive benefits in addition to the physical activity.