Phytochemical Composition and Health Benefits of Figs (Fresh and Dried): A Review of Literature from 2000 to 2022

Figs (Ficus carica L.), dating back 6000 years, are a significant fruit in the Mediterranean diet. Cultivated globally in warm, dry climates, Turkey leads in production. Figs are consumed fresh or dried, and used in various foods. Their traditional medicinal uses span centuries, addressing gastrointestinal, respiratory, inflammatory, metabolic, and cardiovascular issues. This review comprehensively examines the available literature (2000-2022) on the phytochemical composition and health benefits of figs, focusing on cardiovascular diseases, diabetes, gut/digestive health, cognitive function, obesity, satiety, and dietary patterns. The aim is to evaluate the scientific evidence, identify research gaps, and suggest future research opportunities. Literature from Medline (PubMed), Web of Science, Google Scholar, and cross-referencing was used, utilizing keywords (listed in Table 1).

Existing literature reviews on figs cover phytochemical content [5, 13, 14], fresh and dried fig chemical analyses and health effects [10], and the functional food properties of figs [11]. This review builds upon this existing knowledge by providing an updated and comprehensive assessment considering various factors influencing phytochemical composition and health benefits, while also addressing the gap in knowledge on bioavailability and human studies.

The review examined research published between 2000 and 2022. Data was gathered from Medline with PubMed searches using keywords (Table 1), supplemented by searches in Web of Science and Google Scholar, and cross-referencing of existing publications. The review analyzes data regarding fig chemistry (phytochemical content, extraction methods, factors influencing composition), nutrient content (micro and macronutrients, organic acids, sugars, minerals), bioaccessibility and bioavailability of phytochemicals, and health benefits (cardiovascular risk, diabetes, obesity, cognitive function, gut health, satiety, dietary patterns). Various analytical methods were considered including spectrophotometric assays (TPC, TAC, TFC, TPAC, carotenoids, chlorophylls, tannins, ortho-diphenols, ORAC, DPPH, FRAP, ABTS, and others) and HPLC analysis coupled with MS, DAD, UV/Vis, and PDA to identify and quantify polyphenolic compounds and carotenoids. In vitro gastrointestinal digestion models were assessed to understand bioaccessibility.

Figs are rich in polyphenols (phenolic acids, flavones, flavonones, flavonols, anthocyanins, proanthocyanidins) and carotenoids. Dark varieties generally have higher polyphenol and anthocyanin content and antioxidant capacity than lighter varieties. The peel consistently shows higher concentrations of phenolic compounds than the pulp. Major compounds identified include quercetin-3-O-rutinoside (rutin), (-)-Epicatechin, (+)-catechin, cyanidin-3-O-rutinoside, bergapten, myricetin, and kaempferol, along with various phenolic acids. Different extraction methods (water, acetone, ethanol, methanol, ultrasound-assisted extraction, high-pressure processing) yield varying results, with optimization studies suggesting specific conditions for maximum recovery. Processing methods (drying, freezing, jam making) significantly affect phytochemical content, with sun-drying showing mixed results and microwave drying potentially preserving more polyphenols. Harvest time and ripening stage also influence composition. Figs are nutrient-rich, containing carbohydrates, proteins, fiber, fatty acids (linolenic, linoleic, palmitic, oleic), amino acids (leucine, lysine, valine, arginine), organic acids (malic, citric, oxalic, quinic, ascorbic, shikimic, fumaric), sugars (glucose, fructose, trehalose, sucrose), and minerals (potassium, calcium, sodium, magnesium, phosphorus, iron, manganese, zinc, copper). Bioaccessibility studies show mixed results, depending on the compound, fig type, and processing. Animal studies suggest benefits in cardiovascular health (blood pressure reduction, improved lipid profiles), diabetes (improved glucose control, insulin sensitivity), obesity (weight loss), and gut health (improved gut motility). However, human studies are limited, with findings on cardiovascular health and diabetes showing varied effects. One study suggests fig consumption may improve plasma antioxidant capacity and reduce oxidative stress. Regarding dietary patterns, fig intake can displace less healthy food choices. A study in mice suggested that figs may have a beneficial impact on cognitive function in an Alzheimer’s model. In human IBS-C study, dried figs improved several IBS symptoms.

The review highlights the considerable phytochemical diversity of figs and their potential health benefits. While the phytochemistry of figs grown internationally is well-documented, research on US-grown varieties is limited. Animal studies have shown promising results for various health conditions, suggesting figs' bioactive compounds may offer protection against cardiovascular diseases, diabetes, and obesity, and support healthy digestion. However, human studies are limited and yield inconsistent results. This gap emphasizes the need for well-designed human studies to confirm these potential benefits and explore the bioavailability and mechanisms of action of specific fig compounds.

Figs possess a rich array of phytochemicals and nutrients with potential health benefits. Darker varieties and minimally processed figs generally exhibit higher concentrations of beneficial compounds. However, more research is crucial to determine bioavailability in humans. Future studies should focus on human bioavailability, examining both short-term and long-term effects. The role of the gut microbiome also warrants further investigation. While animal models show promise, robust human trials are needed to solidify the health benefits of fig consumption, particularly concerning cardiovascular health, diabetes, and gut health. Further studies are needed to explore other areas such as satiety and cognitive function.

The review's reliance on existing literature may introduce bias. The limited number of human studies, particularly those focusing on the direct consumption of figs, restricts the strength of conclusions regarding the effects on human health. Variations in fig cultivars, growing conditions, and analytical methodologies across studies make it challenging to establish definitive relationships between fig consumption and specific health outcomes. Further, there is limited data from human studies to corroborate findings from animal studies.