In a nutshell, the anti-inflammatory flavonoid found in citrus called hesperidin may help with cardiovascular health and preventing neuroinflammation.
What is hesperidin?
Hesperidin is a flavonoid found in citrus fruits. Its active metabolite is hesperetin, and you will see both mentioned almost interchangeably in studies.
Orange juice contains 200-600 mg/L of hesperidin, making up about 90% of the flavonoid content.[ref]
As usual, human studies aren’t quite as clear-cut.
One study using orange juice with increased flavonoids found that it helped vascular function after a meal.[ref]
Another placebo-controlled study found that hesperetin increased vascular function and decreased inflammatory biomarkers.[ref]
A double-blind clinical trial in people with diabetes found that hesperidin (500 mg/ day) decreased blood pressure, IL-6, and CRP levels.[ref]
One aspect of neurodegenerative diseases, such as Alzheimer’s or Parkinson’s, is inflammation in the brain cells. This neuroinflammation involves certain cell types, such as astrocytes and glial cells, which protect the neurons from insults.[ref]
There are several possible causes of neuroinflammation, including pathogens and oxidative stress. Sources of oxidative stress can include heavy metals, pollution, smoking, mold exposure, and more.
Recent animal studies and cell studies show that hesperetin protects neurons in the brain from pathogens and oxidative stress. Specifically, hesperetin decreased TNF-α and LR4 (inflammatory cytokines). It reduced reactive oxygen species (ROS) in the hippocampus and cortex.[ref]
Several studies on Parkinson’s disease show promise for hesperidin in animal models.[ref]
A clinical trial of hesperidin enriched orange juice (vs an orange-flavored drink) improved cognitive function in older adults.[ref]
Hesperidin supplements (500 mg, 2x a day) reduced fasting glucose, blood pressure, triglycerides, and TNF-α in a placebo-controlled trial on people with metabolic syndrome.[ref]
Another clinical trial using 1g/day of hesperidin also showed decreased triglycerides and lower blood pressure.[ref]
A 12-week trial of 1g/day of hesperidin resulted in lower triglycerides, decreased liver fat, and lower inflammatory cytokine markers.[ref]
Additional animal studies show that hesperidin also decreases pro-inflammatory cytokines in the lung after lung injury.[ref]
Preliminary studies in chronic rhinosinusitis show that hesperidin increases the mucosal clearance. This is being looked at for people with cystic fibrosis mutations.[ref]
Numerous studies (mostly animal and cell studies) show that hesperidin inhibits cancer cell proliferation. There are current studies underway investigating the addition to hesperidin to chemotherapy regimens.[ref][ref][ref]
SARS-CoV-2 and SARS-CoV inhibition:
In silico studies can look at how the structure of the SARS-CoV-2 virus interacts with compounds (drugs, natural supplements, etc).
These computational models show hesperidin binding to the main protein need for replication of the SARS-CoV-2 virus. Additionally, hesperidin counteracts the oxidative stress created by the infection.[ref]
Studies on SARS-CoV from 2005 also show that hesperetin is a potent inhibitor.[ref]
Traditional Chinese medicine herbal blends containing hesperidin also show promise against SARS-CoV-2.[ref]
Clinical trials are needed to see how effective hesperidin is against SARS-CoV-2 in vivo and at what dosage.
Being investigated for Pelvic organ prolapse:
A recent preprint study looked at gene expression in vaginal epithelial cells in women with pelvic organ prolapse (POP). The results showed that inhibiting TGFB1 signaling may be a target to explore for POP. Hesperitin has been shown to decrease TGFB1 signaling. [ref]
Bioavailability and Metabolism:
Absorption: Hesperidin is ranked as one of the most bioavailable flavonoids. When you eat foods containing hesperidin (or take it as a supplement), it isn’t broken down very well in the stomach or small intestines. Instead, your colon’s microbiome converts it to the more bioavailable aglycone hesperetin for easier absorption in the colon. It is thought that the metabolites are what give the health benefits, rather than the original hesperidin molecule.[ref]
Metabolism: After absorption (mainly in the colon), the UGT enzymes can metabolize hesperetin. These metabolites may also be biologically active.[ref] Hesperetin can also be metabolized via CYP1A1 and CYP1B1.[ref]
Hesperetin is an inhibitor of CYP2C9. You can check your genetic variants here, and then use caution when combining with medications that are metabolized through that pathway.
Half-life: Hesperidin’s absorption rate takes a bit of time since it has to make it to the colon. Studies show elimination occurs in about 24- hours.
Topical absorption: In the right solvent, topical absorption of hesperetin is possible. Studies on this method often point out that orange peels have been traditionally in topical solutions.[ref]
Improving absorption: The bioavailability of hesperidin is dependent on your gut microbiome. A study showed that chronic use of Bifidobacterium longum probiotics increased the bioavailability of hesperidin from orange juice.[ref]
Safety: Animal safety studies show that it is non-toxic and non-mutagenic.[ref] Talk with your doctor if you have any questions about your particular situation.
Sources of hesperidin:
Oranges and orange juice are the best food-based sources of hesperidin.
If you don’t like oranges or don’t want to drink juice every day, hesperidin is also available as a supplement in capsules or as a powder.
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