The 5-a-Day Fruits and Vegetables guideline is not just about recommending the appropriate servings for different age groups and genders; it also encourages people to consume a variety of colorful fruits and vegetables, as their nutritional value varies based on their colors. Today, we’ll introduce you to a red-colored vegetable – the pomegranate.
What is a Pomegranate?
The pomegranate (scientific name: Punica granatum) is a small deciduous shrub belonging to the family Lythraceae. It is native to Iran, Afghanistan, and northern India. With improvements in cultivation techniques, pomegranates are now grown in various regions, including Africa, South America, the Middle East, Australia, and countries bordering the Mediterranean Sea, such as Egypt, Spain, and Turkey. The entire plant includes both the fruit parts (peel, arils, and seeds) and non-fruit parts (roots, bark, flowers, leaves). The parts commonly consumed by humans are the juice from the arils and the seeds, which together make up about half of the weight of the whole fruit[1].
Nutritional Components of Pomegranate
Bioactive Compounds
Different parts of the pomegranate contain various bioactive compounds. Below, we will divide the pomegranate into six main parts:
1. Tree Roots and Bark:
Mainly contain hydrolyzable ellagitannins and various alkaloids.
2. Leaves:
Contain tannins, flavonoids, and their glycosides.
3. Flowers:
Contain gallic acid and triterpenoids.
4. Peel:
Contain ellagitannins, gallic acid, catechin, flavonoids, proanthocyanidins, anthocyanidins, and more.
5. Juice:
Contains proanthocyanidins, anthocyanidins, ellagitannins, glucose, vitamin C, catechin, organic acids, amino acids, and minerals.
6. Seeds:
Contain punicic acid unique to pomegranates, multiple unsaturated fatty acids, plant sterols, and vitamin E[2].
Although the first four parts are not directly edible, their bioactive components can be extracted and utilized for their physiological effects.
Nutrient Composition
Per 100 grams of pomegranate, the main nutritional components are approximately 82.5 grams of water, 16.7 grams of carbohydrates, 0.77 grams of organic acids, 0.7 grams of protein, and 0.6 grams of fat. Additionally, pomegranate contains small amounts of minerals and vitamins. The mineral with the highest content is potassium, and the most abundant vitamin is vitamin C[2].
Benefits of Pomegranate
Pomegranate, from its juice to seeds and even its non-edible parts like roots, leaves, and peel, is rich in phytochemicals such as tannins, alkaloids, and organic acids. These components exhibit various bioactivities, making the health benefits of pomegranate multifaceted.
Cardiovascular Protection
- Slowing Atherosclerosis Progression:
For ischemic coronary heart disease patients, daily supplementation of 240 ml of pomegranate juice for three months improved myocardial ischemia compared to non-supplemented patients[3]. Additionally, long-term consumption of pomegranate juice among patients with carotid artery stenosis reduced low-density lipoprotein oxidation and decreased systolic blood pressure and atherosclerosis risk[4]. - Improving Lipid Profile:
In patients with type 2 diabetes and hyperlipidemia, daily intake of 40 grams of concentrated pomegranate juice for two months significantly improved total cholesterol and low-density lipoprotein levels[5]. Another study administering 800 mg of pomegranate seed extract oil daily for four weeks to hyperlipidemia patients resulted in a significant reduction in triglycerides[6]. - Lowering Blood Pressure:
Animal experiments involving oral administration of 100 mg and 300 mg per kg of body weight pomegranate extract for four weeks significantly reduced mean arterial pressure and oxidative stress while enhancing antioxidant enzyme activity[7].
Skin Care
Pomegranate extract reduced inflammatory factors and promoted DNA repair in human skin fibroblast cell experiments[8]. It stimulated the production of type I procollagen and inhibited collagen-degrading enzyme activity, facilitating repair in both epidermal and dermal cells[9]. In animal experiments, pomegranate extract hastened wound contraction and shortened wound healing time[10].
Pomegranate juice supplementation exhibited strong antioxidant activity, significantly reducing ulceration caused by parasite infection[11]. The polyphenolic compounds in pomegranate extract can inhibit melanin production in melanocytes, resulting in a whitening effect[12].
Antidiabetic Effects
After four weeks of supplementation with pomegranate peel extract, an increase in pancreatic β-cell count and enhanced insulin secretion led to blood glucose reduction[13]. Another experiment found that pomegranate extract for two weeks increased liver glycogen content and decreased adrenaline-induced hyperglycemic response, thus delaying blood glucose elevation[14]. Pomegranate was also shown to significantly lower fasting blood glucose, lipids, and lipid peroxidation, while increasing antioxidant enzyme activity and high-density lipoprotein (HDL) levels[15].
Cognitive Decline Mitigation
In Alzheimer’s disease animal models, pomegranate extract administered for three months reduced brain inflammation and β-amyloid deposits in the hippocampus, delaying disease progression[16]. Postoperative cognitive impairment resulting from ischemia-induced oxidative stress during heart surgery was improved with preoperative supplementation of 2 grams of pomegranate extract daily[17].
Liver Protection
Pomegranate peel extract’s free radical scavenging and antioxidant abilities effectively lowered liver inflammation markers, alanine aminotransferase (ALT, GPT), and lipid peroxidation, reducing liver damage[18]. In an animal model of carbon tetrachloride-induced liver injury, which increased liver inflammation and decreased anti-inflammatory factor production and antioxidant enzyme activity, pomegranate juice supplementation enhanced antioxidant enzyme activity, reduced oxidative stress, and prevented liver injury[19].
Are there Side Effects from Excessive Pomegranate Consumption?
Pomegranate has been consumed by humans for a long time, and animal toxicity tests did not reveal any adverse reactions[20]. Human trials supplementing 1.4 grams of pomegranate extract daily for 28 days showed no impact on liver and kidney function[21]. A three-year human study involving pomegranate juice consumption found no toxic reactions in liver, kidney, heart, or blood biochemistry values[4]. Overall, pomegranate and its extracts are generally safe supplements for most individuals.
Summary
Through the above introduction, we’ve highlighted the numerous benefits of pomegranate. It’s often referred to as the “edible ruby” due to its various applications in cardiovascular health, skincare, anti-diabetic effects, cognitive decline prevention, and liver protection. To choose high-quality pomegranate supplements, opt for sources with minimal added sugars or flavorings to ensure genuine health benefits.
