Understanding How Much Resveratrol is in Mulberry

While red grapes and wine are widely known sources of the antioxidant resveratrol, studies show that certain mulberry varieties can contain significant and sometimes higher amounts of this beneficial compound. This article explores how much resveratrol is in mulberry by examining different plant parts, varying species, and crucial influencing factors.

Quick Summary

This article details the resveratrol content found in mulberries, comparing the levels across different parts of the plant and various species. It contrasts mulberry's resveratrol with that of grapes and explains factors influencing its concentration.

Key Points

• Resveratrol is in mulberry: Mulberries, particularly the roots and leaves, contain significant and sometimes higher amounts of resveratrol than grapes.

• Content varies by plant part: Mulberry roots and leaves are typically richer sources of resveratrol than the fruit.

• Species and variety matter: The specific mulberry species (e.g., Morus rubra vs. Morus alba) and cultivar significantly influence resveratrol concentration.

• Influenced by environment: Resveratrol production is naturally increased in mulberry plants by environmental stressors like UV light and fungal infections.

• Supports general health: Resveratrol from mulberries offers potent antioxidant, anti-inflammatory, and cardioprotective benefits, similar to that from grapes.

The Resveratrol Content in Mulberry Fruits and Roots

Resveratrol is a natural phenolic compound produced by several plants, including the mulberry tree (Morus genus), in response to stress such as fungal infections or ultraviolet (UV) radiation. Research has revealed that the concentration of this potent antioxidant varies greatly depending on the plant part, species, and environmental conditions.

Quantitative Findings from Scientific Studies

Several studies have quantified the resveratrol content in different parts of the mulberry plant:

• Mulberry Fruit: A study on the whole fruit extract of Red Mulberry (Morus rubra) reported a significant resveratrol concentration of 50.61 µg per gram of dry weight. This is notably higher than the amount found in the seed extracts of grapes within the same study. However, another study on White Mulberry (Morus alba) fruit found a much lower concentration of just 0.48 µg per gram of fresh weight. These findings illustrate the vast differences between species.
• Mulberry Roots: Research has consistently shown that the roots of the mulberry tree contain a far higher concentration of resveratrol than the fruit. A 2021 study on White Mulberry found the roots contained 32.45 µg of resveratrol per gram, which is over 68 times the amount found in the fruit. Another analysis confirmed this, noting that the underground parts of Morus alba contained a higher concentration of resveratrol and oxyresveratrol than the other parts.
• Mulberry Leaves: The leaves are another part of the plant rich in stilbene compounds. A study on wild-type mulberry leaves reported high resveratrol contents, particularly in autumn and in fully matured leaves. Certain varieties showed exceptionally high levels, suggesting the leaves are a valuable source, especially when dried and processed.

Mulberry vs. Grape: A Comparison of Resveratrol Content

When considering resveratrol, grapes and red wine are the most frequently cited sources. However, as the research indicates, mulberries are a competitive source, and in some contexts, a richer one. The following table provides a comparison of resveratrol content based on available research.

Source	Resveratrol Content (approx.)	Part of Plant	Notes
Mulberry (Morus rubra)	50.61 µg/g dry weight	Whole Fruit Extract	Higher than grape seed extract in one study
Mulberry (Morus alba)	0.48 µg/g fresh weight	Fruit	Varies significantly by species
Mulberry (Morus alba)	32.45 µg/g	Roots	Found to be a much richer source than the fruit
Mulberry (Morus alba)	Up to 3.45 mg/g dry weight	Leaves	Specific varieties can have high levels
Grape (Vitis vinifera)	5.89 µg/g dry weight	Seed Extract	Lower than Morus rubra fruit in comparative study
Grape (Vitis vinifera)	5–10 mg/kg fresh weight	Skins	Content can be increased by environmental stress

Factors Influencing Resveratrol Levels

Several intrinsic and extrinsic factors can cause the variability observed in resveratrol concentrations across mulberry plants and products.

1. Plant Variety and Species: Different species of mulberry, such as Morus alba (white), Morus rubra (red), and Morus nigra (black), and even different cultivars within the same species, produce varying amounts of resveratrol.
2. Environmental Stress: Resveratrol is a phytoalexin, meaning it is produced by the plant as a defense mechanism. Stressors like fungal infection, UV light exposure, or heavy metal ions can trigger increased production.
3. Part of the Plant: As highlighted by research, the root and bark often contain significantly higher concentrations of resveratrol and related compounds than the fruit.
4. Ripeness and Season: The stage of maturity and the season of harvest can impact resveratrol levels. For instance, mulberry leaves harvested in autumn have been shown to have higher content than those harvested in spring.
5. Processing and Preservation: Processing methods, including freeze-drying or specific wine-making techniques, can affect the final resveratrol content. For example, adding mulberry peel during fermentation can increase the resveratrol level in mulberry wine.

The Health Benefits of Mulberry Resveratrol

Like the resveratrol from grapes, the compound found in mulberries is associated with numerous health advantages, largely due to its powerful antioxidant properties.

• Cardiovascular Support: Resveratrol helps promote cardiovascular health by protecting blood vessels, reducing inflammation, and improving circulation.
• Anticancer Properties: Research indicates that mulberry extract, and its resveratrol content, may help inhibit the growth and proliferation of certain cancer cells and induce programmed cell death (apoptosis) in tumors.
• Anti-inflammatory Effects: Mulberries contain natural supporters of a healthy inflammation response in the body, including resveratrol. Chronic inflammation is a contributing factor to many diseases.
• Anti-Aging and Longevity: The antioxidant effects of resveratrol protect cells from oxidative stress and DNA damage, which are key factors in the aging process. This contributes to anti-aging and longevity benefits.
• Blood Sugar Regulation: Some studies suggest that resveratrol and other mulberry compounds can help regulate blood sugar levels, which is beneficial for managing and preventing type 2 diabetes.

Conclusion

While grapes and wine remain popular sources, mulberries are a potent, and often overlooked, dietary source of resveratrol, with concentrations that can exceed those found in grapes depending on the variety and part of the plant. Scientific evidence confirms that the roots and leaves of the mulberry tree are particularly rich in this beneficial compound, though the fruit is still a valuable source, especially certain red mulberry varieties. The amount of resveratrol is highly variable and depends on factors like species, harvest time, and processing. Including mulberries, in their various forms, into your diet can provide a natural and effective way to increase your intake of this powerful antioxidant, contributing to cardiovascular health, anti-inflammatory effects, and other vital functions.

For more detailed information on resveratrol, its mechanisms, and clinical trials, the National Institutes of Health (NIH) is a valuable resource. For instance, this NIH study on antioxidant activity and mechanism of resveratrol from mulberry offers additional scientific insight.

Frequently Asked Questions

Which has more resveratrol, mulberry or grape?

Scientific studies show mixed results. One study found that Red Mulberry (Morus rubra) fruit extract had a higher resveratrol content (50.61 µg/g dry weight) than grape seed extract (5.89 µg/g dry weight). However, the levels can vary dramatically depending on the plant species, variety, and which part is measured.

Is resveratrol in mulberry leaves?

Yes, resveratrol is present in mulberry leaves. Research indicates that the leaves, particularly when mature and harvested in autumn, can be a rich source of this compound.

What parts of the mulberry plant contain the most resveratrol?

Based on scientific studies, the roots and bark of the mulberry tree contain significantly higher concentrations of resveratrol than the fruit.

Are black mulberries higher in resveratrol than white mulberries?

Resveratrol content is highly dependent on the specific species and cultivar. While Black Mulberry (Morus nigra) is known for potent antioxidant properties, including resveratrol, studies comparing Morus rubra (red) and Morus alba (white) fruit show that the red variety can contain significantly more resveratrol.

How do environmental factors affect resveratrol in mulberries?

As a natural defense compound, resveratrol production increases in response to environmental stressors such as UV light exposure and fungal infections. These conditions can lead to higher concentrations in the plant.

Can processed mulberry products like juice or powder provide resveratrol?

Yes, processed products can contain resveratrol. While some processing, like pasteurization, can reduce content, methods like freeze-drying are effective at preserving or even concentrating resveratrol levels. Mulberry wine can also be fortified to increase its content.

What health benefits are linked to resveratrol in mulberries?

Resveratrol in mulberries offers antioxidant, anti-inflammatory, cardiovascular, and potentially anti-cancer benefits. It helps protect cells from damage and supports overall health, similar to resveratrol from other sources.