Diet plays an essential role in the way that we can live our healthiest lives, mentally and physically, in almost every life stage. A recent study found that people with high levels of three major antioxidants in their blood are less likely to develop dementia. Two of the compounds, lutein and zeaxanthin, are found in many vegetables and leafy greens, as well as in peas and spinach. Oranges and papaya are the main sources of the third ingredient, beta-cryptoxanthin.
The study's lead researcher, Dr. May Beydoun, an expert on aging at the National Institutes of Health in Bethesda, Maryland said that expanding people's cognitive functioning is an important challenge to public health and that "antioxidants may help protect the brain from oxidative stress, which can damage cells," she said.
However, she added that more research is needed to test whether antioxidants really "can help protect the brain from dementia."
How does food affect dementia?
In a study published in the journal Neurology, Beydoun and the other researchers analyzed blood samples from more than 7000 Americans. All participants were at least 45-years-old and were physically examined, then interviewed at the beginning of the study. They were then followed up for 16 years, on average, so researchers could check if they developed dementia. Participants were divided into three groups based on the level of antioxidants lutein, zeaxanthin and beta-cryptoxanthin in their blood.
The findings showed that an increase of 15.4 micromoles per liter of lutein and zeaxanthin levels was associated with a 7% decrease in the risk of dementia. An increase of 8.6 micromoles per liter of beta-cryptoxanthin reduced the chance of developing dementia by 14%.
The effect of antioxidants on dementia diminished when other factors were taken into account, including education, income, and exercise, the study found. "These factors may help explain the association between antioxidant and dementia levels," Beydoun added. The team clarified that the findings are limited because they are based on a single blood test taken at the beginning of the study which means that "they may not reflect people's levels during their lifetime.”
Dozens of studies have already shown that a diet rich in fruits and vegetables can help reduce the risk of dementia, from which tens of millions of people suffer worldwide. Experts have said that eating a particular diet may affect biological mechanisms that trigger dementia.
So what can you do?
What a person eats can also be indirectly linked to dementia by increasing the risk of diabetes, obesity and heart disease, which are known to be linked to dementia. Past studies have found that a Mediterranean diet rich in vegetables, fruits, legumes and fish lowers blood pressure, which is a risk factor for the disease.
Dr. James Connell, who researches Alzheimer’s in the UK, said that previous findings on the link between antioxidants and the risk of dementia showed "mixed" results. When lifestyle factors, socioeconomic status and physical activity were taken into account, the reduced risk found in the new study was smaller. Connell added that it’s important that researchers continue to study the protective effects of antioxidants in the context of other risk factors and work to understand how they’re connected.
Connell added that “the diseases that may cause dementia to develop over many years, but this study examined only antioxidant levels at one point in time.
Although this study highlights an interesting potential finding, it’s important that the study take a long-term view of factors that may influence the risk." He added that "we know that the risk of dementia is complex and includes factors like age and genetics as well as lifestyle factors such as diet. Making positive lifestyle changes can reduce our risk of developing the diseases that cause dementia.”