The link between dementia & low blood carotenoid status

Dementia is a debilitating condition that affects millions of people worldwide. While the exact causes of dementia are not fully understood, researchers have been exploring various factors that may contribute to the development of this condition. One such factor is blood carotenoid status.

Carotenoids are a group of natural pigments found in many fruits and vegetables. They have been linked to a variety of health benefits, including protection against certain types of cancer, cardiovascular disease, and age-related macular degeneration. Now, a new systematic review and meta-analysis suggests that low blood carotenoid status may be a risk factor for dementia and mild cognitive impairment (MCI)*.

The study, which analysed 20 observational studies involving over 12,000 participants, found that individuals with dementia or MCI had significantly lower levels of blood carotenoids compared to those with normal cognitive function. The association was strongest for two carotenoids called lutein and zeaxanthin, which are found in green leafy vegetables such as spinach and kale as well as in eggs.

How do carotenoids help to protect the brain?

One possible mechanism is through their anti-inflammatory and antioxidant properties. Chronic inflammation and oxidative stress are thought to play a role in the development of dementia and other neurodegenerative diseases. Lutein and zeaxanthin have been shown to reduce inflammation and oxidative stress in the brain, as well as to promote the growth and survival of brain cells.

While the study cannot prove causation, the findings suggest that consuming more foods rich in lutein and zeaxanthin may help to prevent or delay cognitive decline. Other carotenoids, such as beta-carotene and alpha-carotene, may also be beneficial for brain health. These carotenoids are found in orange and yellow fruits and vegetables, such as carrots, sweet potatoes, and pumpkin.

In addition to their potential brain-protective effects, green leafy vegetables are also rich in other nutrients that are important for overall health. For example, they are a good source of vitamin K, which is essential for bone health, as well as folate, which is important for foetal development during pregnancy. Green leafy vegetables are also high in fibre, which can help to promote digestive health and lower the risk of heart disease.

So, how can you increase your intake of lutein and zeaxanthin?

The best way is to eat more green leafy vegetables, such as spinach, kale, and collard greens. Other good sources of lutein and zeaxanthin include egg yolks, corn, and orange peppers. Aim for at least two servings of green leafy vegetables per week, and try to incorporate other colourful fruits and vegetables into your diet as well.

In conclusion, while there is still much to learn about the causes and prevention of dementia and MCI, this study adds to the growing body of evidence suggesting that a healthy diet rich in fruits and vegetables may help to lower the risk of cognitive decline. So, the next time you’re at the grocery store, be sure to stock up on some leafy greens and other colourful produce to help keep your brain healthy and sharp.

*Wang et al. Low blood carotenoid status in dementia and mild cognitive impairment: A systematic review and meta-analysis BMC Geriatrics (2023) 23:195