How Sweet It Is! Florida Citrus and Brain Health

The Brain Health Initiative (BHI) is working to develop brain-healthy communities, creating a culture that promotes brain health protective factors and decreases risk factors, thereby improving brain health, optimizing brain performance, and preventing and fighting brain illness across the lifespan.

We love our citrus in Florida, and not only because citrus supported 32,542 jobs and contributed nearly $7 billion in output in the state in 2021 (according to the Florida Department of Citrus), though that certainly doesn’t hurt. Citrus growing is especially vital in many rural areas where the economy is centered around its production and where soil and conditions are not ideal for other crops.

Also important, research shows that citrus can contribute to brain health.

It turns out that—beyond starting your day with a little sweetness—oranges contain key ingredients that may lower the risk of cognitive decline. The Centers for Disease Control and Prevention (CDC) reports that only about 12 percent of adults in the United States consume the recommended amount of fruit per day. In this article, we will look at the potential brain health benefits of citrus.

What the research says

A study from the Harvard T.H. Chan School of Public Health, published in the journal Neurology, showed that drinking 100 percent orange juice daily was linked with lower odds of cognitive decline in men than those who consumed orange juice less than once per month.

The 22-year study asked participants, whose average age was 51 at the start, to answer questionnaires every four years about what they ate. The researchers then tested thinking and memory skills when the subjects were an average age of 73. While fruit consumption didn’t appear to affect moderate cognitive problems, drinking orange juice did. Only 6.9 percent of those who drank 100 percent orange juice daily developed poor cognitive function compared to 8.4 percent for those who drank it less than once monthly.

What’s so special about orange juice, you ask? Besides essential micronutrients such as vitamin C, a well-known booster of immune health, oranges are rich in polyphenols, a class of compounds found in citrus plants. Citrus is especially rich in flavonoids. These plant compounds help your body function more efficiently and protect against common toxins and stressors. Specifically, oranges contain a generous amount of hesperidin, which is a specific class of flavonoids called flavanones.

Preclinical studies have demonstrated the brain health protective potential of citrus flavonoids, spotlighting both the anti-inflammatory and anti-oxidative properties and early evidence of positive influence on blood-brain barrier function/integrity mechanistic actions by which these neurological effects are mediated. Human studies, although limited in number, appear to support this preclinical basis, with improvements in cognitive performance and disease risk observed across healthy and diseased states.

Another study published in Neurology found that people whose diets were high in flavonoids were less likely to report instances of confusion or memory loss, which the study’s authors called subjective cognitive decline. The research followed 49,493 women and 27,842 men from two public health studies, measuring their intake of flavonoids as recorded on dietary questionnaires. The study found people who ate the most total flavonoids experienced the lowest odds of subjective cognitive decline compared with those who ate the least.

An English study published in Frontiers in Neuroscience determined that flavonoids found in citrus juices have anti-inflammatory and anti-oxidative properties, which can protect brain tissue from damage due to aging or injury. The research looked at hundreds of studies on citrus flavonoids’ effect on brain cells and nerves and 10 human population studies.

Oranges also are a good source of thiamin (vitamin B1). Thiamin deficiency can cause memory loss, confusion, dementia, and other nervous system problems. Low levels of thiamin and thiamine-dependent enzymes in the blood and brain have been reported in studies of elderly patients with Alzheimer’s disease.

There should be further exploration of citrus polyphenols to establish therapeutic efficacy, particularly in the context of well-designed human interventions. The short answer is no. Some of the fabulous benefits of fruit disappear during the juicing process. The biggest loss is in fiber content, a perk of whole fruit that is great for your digestive system.

To sum it up

Encourage the consumption of whole citrus fruits and 100 percent whole fruit juice with lots of pulp. The whole fruit is lower in calories and sugar, as well as higher in fiber, than orange juice—while still providing 77 percent of the DV for vitamin C. In moderation, juice can provide brain health benefits. One caveat before you begin your drive to the juice aisle at the local grocer (or your stroll to the citrus tree in your back yard): Some orange juices contain a large amount of sugar. Limit your intake to whole-pulp juice that doesn’t contain additives, including sugar.