The old adage says that an apple a day keeps diseases away from me, but new research from the University of Cincinnati (UC) shows the potential benefits of a different fruit for human health. Researchers led by Dr. Robert krikorian of the University of California found that adding blueberries to the diet of some middle-aged people may reduce the risk of dementia in later life** The findings were recently published in nutrient.
Research methods
For several years, krikorian's team has been studying the benefits of berries for people at high risk of Alzheimer's disease and dementia.
Although other berries are not completely different from plants such as red cabbage, krikorian points out that blueberries are particularly high in micronutrients and antioxidants - anthocyanins. Krikorian said anthocyanins help give blueberries the same name and help protect plants from excessive radiation, infectious bacteria and other threats.
Krikorian said that these characteristics that help blueberries survive also provide benefits to humans, such as reducing inflammation, improving metabolic function and enhancing intracellular energy production.
The berry study previously led by krikorian focused on the elderly, but in this study, the team hopes to study middle-aged people in order to focus on the prevention and risk reduction of dementia.
Krikorian pointed out that about 50% of people in the United States have insulin resistance around middle age, which is usually called pre diabetes. He said that pre diabetes has been proved to be a factor in chronic diseases.
Krikorian, an emeritus professor and director of psychology in the Department of psychiatry and behavioral neuroscience at the University of California School of medicine, said they had observed the cognitive benefits of blueberries in previous studies on the elderly and thought they might be effective for young individuals with insulin resistance. "Alzheimer's disease, like all chronic diseases of the elderly, starts in middle age and develops over the years."
Research details and results
The researchers recruited 33 patients aged 50-65 from around the Cincinnati area who were overweight, had pre diabetes symptoms and noticed a slight decline in memory with age. Krikorian pointed out that this population has an increased risk of dementia and other common diseases in later life.
For 12 weeks, the patients were asked to ban any kind of berries, except mixing a packet of supplement powder with water every day - for breakfast or dinner. Half of the participants received a powder containing half a cup of whole blueberries, while the other half received a placebo.
Participants also received tests that measured certain cognitive abilities, which decreased in patients with aging and later dementia.
Krikorian said people in the blueberry treatment group showed improvement in cognitive tasks that relied on executive control. "This is evident in the reduction of interference with irrelevant information in the process of learning and memory."
In addition, patients in the blueberry group also had lower fasting insulin levels, which means that participants' metabolic function was improved and it was easier to burn fat for energy.
Krikorian noted that the blueberry group showed a higher degree of additional moderation of mitochondrial decoupling, a cellular process associated with longer life and reduced oxidative stress. Oxidative stress can lead to fatigue and memory loss.
Looking ahead, krikorian said he was interested in better understanding the exact mechanisms by which blueberries help improve cognitive and metabolic performance. But the main benefit of the current study is that regular supplementation of blueberries in a risky middle-aged diet may reduce the risk of dementia in later life.
"Since sample size is an obvious limitation of the study, it will be important to reproduce these findings, especially by other investigators. At the same time, regular consumption of blueberries may be a good idea," krikorian said