Essential Superfoods You Should Incorporate into Your Daily Diet To Boost Your Health
The term superfood has been around for many years, but it wasn’t until the 21st century that it became prevalent in conversations. Nowadays, almost anything that contains a few nutrients is touted as a superfood, ranging from goji berries to turmeric, quinoa to spirulina.
What these foods often have in common is their origin from distant locations, resulting in a substantial carbon footprint, and their inclusion in expensive, extensively marketed products that claim to cure a multitude of ailments.
While there’s nothing inherently wrong with these foods, as they possess many health benefits, it begs the question of whether we truly need to purchase pricey products when there are more affordable options readily available to us.
A recent review published in the Nutrients Journal examined articles from various sources, such as PubMed, MedLine, and Web of Science, that discussed the impact of dried fruits on gastrointestinal health, including gut microbiota, cardiovascular disease risk, type two diabetes, bone health, and diet quality.
The review emphasized the phytochemical composition of dried fruits, their bioavailability, and accessibility, while also exploring the potential mechanisms involved in these processes.
Dried fruits are recognized for their high fiber content and antioxidant properties, making them a valuable source of numerous health benefits. Additionally, their long shelf life makes them a practical alternative to fresh fruits. Dried fruits contain various phytochemicals, including phenolics, carotenoids, stilbenes, chalcones/dihydrochalcones, phytoestrogens, and flavonoids.
Recent studies have revealed a correlation between the consumption of dried fruits and the composition and function of gut microbiota. Since gut microbiota influences metabolic health, it is crucial to identify dietary practices that enhance metabolic health by modifying the gut microbial population.
Moreover, there is a need for a comprehensive examination of the biological activity, bioaccessibility, and bioavailability of the bioactive compounds in dried fruits.
In this narrative review, researchers limited their literature search to articles published from 2000 onwards to enhance current relevance. They focused on seven topics, including the phytochemical composition of commonly consumed dried fruits.
Nevertheless, the researchers conducted a detailed analysis of selected articles to gather evidence from both in vivo and in vitro studies on the impact of commonly consumed dried fruits on gastrointestinal and cardiometabolic health.
This allowed the researchers to provide an update on the phytochemical composition of dried fruits and the potential mechanisms involved in their biological effects. Based on the evidence reviewed, the researchers made recommendations for dried fruit consumption.
Alasalvar et al. reported that dried fruits possess a broad range of phenolic profiles. However, the precise phenolic profiles of dried apples, peaches, and pears are unknown. They found that nine dried fruits, including apples, cranberries, apricots, dates, peaches, pears, figs, prunes, and raisins, contain various phenolic compounds, such as anthocyanins, flavonols, flavones, and phenolic acids.
Carotenoids, such as β-carotene, are plant pigments responsible for the vivid yellow, red, and orange hues in numerous vegetables and fruits, and they are present in all dried fruits except seedless raisins, albeit in varying amounts.
Among dried fruits, apricots are the most abundant source of β-carotene, with 2,163μg/100 g, followed by peaches and prunes with 1,074μg/100 g and 394μg/100 g, respectively. Apricots, dates, prunes, and raisins also contain phytoestrogens, which are absent in dried apples, figs, peaches, and cranberries.
Consuming 20 to 30 grams of dried fruits per day could provide 10 to 16% of the recommended daily fiber intake, depending on the selected dried fruit.
Dried fruits have a relatively high oxygen radical absorbance capacity (ORAC), which varies depending on the type and variety of fruit. For instance, golden seedless raisins have the highest ORAC value of 10,450 µmol Trolox equivalents (TE)/100 g.
Multiple models have been developed to simulate the in vitro gastrointestinal digestion processes of humans, including oral or salivary digestion and gastric digestion, to study the cost-effective bioaccessibility and bioavailability of compounds in dried fruits.
When phytochemicals and micronutrients in food are released in the gastrointestinal tract, they become bioavailable for absorption, enabling them to exert health benefits.
In a recent study by Scrob et al., researchers observed the highest bioaccessibility of phenolics in prunes and the lowest in dates and cranberries. Following in vitro digestion, the total sugar content of coconuts, raisins, and dates increased, whereas it decreased for cranberries, prunes, and bananas. However, in vitro digestion increased the antioxidant activity of most dried fruits.
Another study by Ma et al. examined the biological activities of kiwifruits, including dried slices, during simulated gastrointestinal in vitro digestion. Although dried kiwi slices and jams had the highest mineral content per unit weight among other forms, dried slices demonstrated the lowest biological activity compared to raw fruit, juice, yogurt, wine, and jelly.
There is limited information available regarding the impact of dried fruits on metabolite production and their functions in the gut. Nevertheless, it is clear that consuming dried fruits modifies the gut microbiota, which can influence health.
It is probable that the phytochemicals in dried fruits undergo significant biotransformation by gut microbiota to generate metabolites that affect health. Future studies should aim to investigate these questions in greater detail to better understand the mechanisms involved.
Insufficient fruit consumption is a significant contributor to cardiovascular diseases, type 2 diabetes, and neoplasms. Thus, the World Health Organization recommends a healthy diet that includes five servings of fruits and vegetables per day, excluding starchy fruits. Additionally, the current dietary guidelines for Americans suggest consuming four servings of fruit per day, where one-fourth cup of dried fruits is equal to half a cup of fruit.
Unfortunately, fruit consumption in many countries, including the United States and some European nations, falls below the recommended daily intake of 20 to 30 grams per day, as per the Global Burden of Disease Study 2017.
Human studies have shown that dried fruits have a low-to-moderate glycemic index, owing to their high mineral content, notably potassium and magnesium, as well as their increased fiber content and high levels of antioxidants and phytochemicals.
Frequent consumption of dried fruits is beneficial for cardiovascular, gut microbiota, and bone health. Additionally, their consumption may have therapeutic advantages. However, further research is necessary to understand how dried fruits reduce the severity of chronic metabolic diseases.
A recent study indicated that prunes can prevent and reverse bone loss in postmenopausal women and potentially in men. Phytochemicals, such as chlorogenic acid and catechin, have osteoprotective effects, but the mechanisms underlying these effects remain unknown.
A limited number of epidemiological studies have reported favorable associations between dried fruit and cardiovascular diseases, type 2 diabetes, and body weight, but the results are inconsistent. Additionally, the overall dietary quality of the participants confounded the observed associations.
Future epidemiological studies investigating dried fruit consumption should make more comprehensive adjustments for dietary and lifestyle factors. Furthermore, these studies should include populations that frequently consume greater quantities of dried fruits to gather more robust evidence regarding the associations between dried fruit intake and health benefits.
The evidence regarding the impact of dried fruit consumption on cardiovascular disease risk factors is mixed. Some clinical studies have demonstrated that consuming dried fruits reduces cholesterol and blood pressure without compromising glycemic control. However, further randomized controlled trials, accounting for the potential confounding effect of body weight, are necessary to establish the cardiovascular benefits of consuming dried fruits.
Clinical trials conducted in postmenopausal women have shown that consuming 50 to 100 grams of prunes daily for three to 12 months has some osteoprotective effects. Additionally, four clinical trials have demonstrated the potential anti-inflammatory effects of dried fruits, as well as their beneficial impact on bone formation and resorption markers.
Another study by Hooshmand et al. revealed that consuming 100 grams of prunes per day for one year increased bone mineral density in the ulna and spine compared to consuming 75 grams of dried apple.
Although it is an emerging area of research, the current evidence on the effects of dried fruits on the human microbiome, bone health, diet quality, and cardiovascular disease risk is scarce and requires further investigation. While the phytochemical profiles of various dried fruits have been adequately studied, our understanding of their bioaccessibility and bioavailability is limited.
The positive outcomes observed in studies investigating the benefits of dried fruits, fresh fruits, and juices warrant further research. Such research could provide a more comprehensive understanding of the biological effects of dried fruits on major chronic diseases and their underlying biological mechanisms, thus informing future dietary guidelines for dried fruits.
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