Apigenin is a naturally occurring compound belonging to the flavonoid class of phytochemicals, widely found in the plant kingdom. Humans regularly consume apigenin through a balanced diet, where it acts as a non-essential but beneficial dietary component. Interest in this compound stems from its potential health-promoting effects, leading to questions about the intake required to gain a benefit beyond typical dietary consumption. This article explores the quantity of apigenin found in common foods, its studied biological effects, and the ranges considered safe and effective for daily intake.
Natural Dietary Sources
The apigenin content in the human diet comes from a variety of vegetables, fruits, and herbs. Dried parsley contains an exceptionally high amount of apigenin, far exceeding most other sources. Other common sources include celery, vine spinach, and specific herbs like oregano, thyme, and basil. Chamomile tea is a well-known source, with the dried flowers of Matricaria chamomilla containing between 0.8% to 1.2% apigenin by weight.
The amount of apigenin available from these foods can vary significantly based on factors like the plant variety, growing conditions, and preparation methods. Apigenin typically exists in plants in a glycosylated form, meaning it is bound to a sugar molecule, which affects how it is absorbed. The average daily dietary intake of apigenin in humans is typically estimated to be quite low, often ranging from approximately 0.45 to 4.23 milligrams per day globally.
Documented Health Benefits
Apigenin is studied primarily for its established biological roles as an antioxidant and an anti-inflammatory compound. Its antioxidant capacity involves scavenging free radicals, which helps to mitigate oxidative stress and cellular damage. This protective function contributes to the overall health benefits associated with a diet rich in flavonoids.
The anti-inflammatory effects of apigenin are attributed to its ability to modulate specific cellular signaling pathways. Research suggests it can suppress the activity of pro-inflammatory mediators, such as those related to the NF-κB pathway. By inhibiting these pathways, apigenin may help reduce chronic, low-grade inflammation, which is implicated in the development of many age-related conditions.
Apigenin has shown promising neuroprotective potential in preclinical models. It has been investigated for its ability to reduce anxiety and promote relaxation, which is a traditional use of apigenin-rich chamomile tea. Furthermore, some studies suggest it may help support cognitive function and offer protection against neurodegenerative processes by reducing neuronal oxidative stress and inflammation.
Apigenin also attracts attention for its role as an inhibitor of the enzyme CD38, which consumes nicotinamide adenine dinucleotide (NAD+) in cells. By preserving NAD+ levels, apigenin may support cellular energy metabolism and DNA repair mechanisms, which are important aspects of healthy aging.
Recommended Daily Intake
There is currently no official Recommended Dietary Allowance (RDA) established for apigenin, as it is a non-essential dietary component. The estimated daily intake from a typical Western diet is generally low, often falling between 0.45 and 1.17 milligrams per day. This amount can increase substantially in diets that frequently include foods such as parsley or chamomile tea.
When apigenin is used as a supplement to achieve specific biological effects, the required intake is significantly higher than what is obtained through diet alone. Human clinical trials have utilized dosages that vary widely depending on the desired outcome. For general health support or antioxidant benefits, common supplemental dosages range from 50 to 250 milligrams daily.
For individuals seeking anxiolytic or sleep-supportive effects, dosages often start in the 50 to 150 milligram range, typically taken in the evening. Higher intakes ranging up to 500 milligrams per day have been explored, though there is no standardized optimal dose for any specific condition. Bioavailability is a significant factor in determining an effective dose, as apigenin has low water solubility, which limits its absorption into the bloodstream. The efficacy of a dose is influenced by the supplement formulation designed to enhance its uptake.
Safety and Contraindications
Apigenin is generally regarded as safe when consumed at levels found in the diet and in common supplemental dosages. No severe toxicity has been reported in human studies, even at higher intakes. Some individuals taking higher doses of apigenin supplements may experience mild side effects, such as stomach discomfort or drowsiness.
A primary safety concern relates to its potential for drug interactions due to its effect on certain liver enzymes. Apigenin has been shown to inhibit an enzyme called CYP2C9, which is responsible for metabolizing many common medications. This inhibition could potentially increase the concentration of drugs metabolized by this enzyme, including certain blood thinners, non-steroidal anti-inflammatory drugs (NSAIDs), and some antidiabetic medications.
Individuals who are pregnant, breastfeeding, or taking prescription medications, particularly blood thinners or sedatives, should exercise caution and consult a healthcare provider before starting apigenin supplementation. As with any bioactive compound, the long-term safety profile of high-dose, concentrated apigenin supplements still requires further human research.