Raspberries

Raspberries are the edible fruit of a plant species in the rose family.

There are many types of raspberries — including black, purple and golden — but the red raspberry, or Rubus idaeus, is the most common.

Red raspberries are native to Europe and northern Asia and cultivated in temperate areas worldwide. Most US raspberries are grown in California, Washington and Oregon.

These sweet, tart berries have a short shelf life and are harvested only during the summer and fall months. For these reasons, raspberries are best eaten shortly after purchasing.

This article explores the nutritional value and health benefits of raspberries.

Low-Calorie and Packed With Nutrients

Raspberries boast many nutrients despite being low in calories.

One cup (123 grams) of red raspberries contains:

• Calories: 64
• Carbs: 14.7 grams
• Fiber: 8 grams
• Protein: 1.5 grams
• Fat: 0.8 grams
• Vitamin C: 54% of the Reference Daily Intake (RDI)
• Manganese: 41% of the RDI
• Vitamin K: 12% of the RDI
• Vitamin E: 5% of the RDI
• B vitamins: 4–6% of the RDI
• Iron: 5% of the RDI
• Magnesium: 7% of the RDI
• Phosphorus: 4% of the RDI
• Potassium: 5% of the RDI
• Copper: 6% of the RDI

Raspberries are a great source of fiber, packing 8 grams per 1-cup (123-gram) serving, or 32% and 21% of the RDI for women and men, respectively.

They provide more than half of the RDI for vitamin C, a water-soluble nutrient essential for immune function and iron absorption.

Raspberries also contain small amounts of Vitamin A, thiamine, riboflavin, vitamin B6, calcium and zinc.

Antioxidants are plant compounds that help your cells fight and recover from oxidative stress.

Oxidative stress is linked to a higher risk of cancer, diabetes, heart disease and other illnesses.

Raspberries are high in several powerful antioxidant compounds, including vitamin C, quercetin and ellagic acid.

Compared to other berries, raspberries have a similar antioxidant content as strawberries, but only half as much as blackberries and a quarter as much as blueberries.

A review of animal studies suggests that raspberries and raspberry extracts have anti-inflammatory and antioxidative effects that may reduce your risk of chronic diseases, such as heart disease, diabetes, obesity and cancer.

One eight-week study in obese, diabetic mice observed that those fed freeze-dried red raspberry showed fewer signs of inflammation and oxidative stress than the control group.

Another study in mice found that ellagic acid, one of raspberries’ antioxidants, may not only prevent oxidative damage but also repair damaged DNA.

High Fiber and Tannin Content May Benefit Blood Sugar Control

Raspberries are low in carbs and high in fiber, making them a smart choice for anyone watching their carbs.

One cup (123 grams) of raspberries has 14.7 grams of carbs and 8 grams of fiber, which means they have only 6.7 grams of net digestible carbs per serving.

Raspberries also are unlikely to raise blood sugar levels.

The glycemic index (GI) is a measure of how quickly a given food increases your blood sugar. Though the GI for raspberries has not been determined, most berries fall into the low-glycemic category.

Additionally, studies show that raspberries may lower blood sugar and improve insulin resistance.

In animal studies, mice fed freeze-dried red raspberries alongside a high-fat diet had lower blood sugar levels and less insulin resistance than the control group.

The raspberry-fed mice also demonstrated less evidence of fatty liver disease.

Furthermore, raspberries are high in tannins, which block alpha-amylase, a digestive enzyme necessary for breaking down starch.

By blocking alpha-amylase, raspberries may reduce the number of carbs absorbed after a meal, which lessens the impact on your blood sugar.

Raspberries’ high levels of antioxidants may protect against cancer.

Berry extracts — including those of red raspberries — block the growth of and destroy cancer cells in test-tube studies on colon, prostate, breast and oral (mouth) cancer cells.

In one test-tube study, red raspberry extract was shown to kill up to 90% of stomach, colon and breast cancer cells.

Another test-tube study demonstrated that sanguiin H-6 — an antioxidant found in red raspberries — led to cell death in over 40% of ovarian cancer cells.

Animal studies with raspberries also observe protective effects against cancer.

In one 10-week study on mice with colitis, those fed a diet of 5% red raspberries had less inflammation and a lower risk of cancer than the control group.

In another study, red raspberry extract prevented the growth of liver cancers in mice. The risk of tumor development decreased with larger doses of raspberry extract.

Human studies are necessary before raspberries can be conclusively linked to cancer prevention or treatment.

Because raspberries are high in many nutrients and antioxidants, they may provide other health benefits as well.

May Improve Arthritis

Raspberries have anti-inflammatory properties which may reduce symptoms of arthritis.

In one study, rats treated with red raspberry extract had a lower risk of arthritis than rats in the control group. Additionally, those that developed arthritis experienced less severe symptoms than the control rats.

In another study in rats, those given raspberry extract had less swelling and joint destruction than the control group.

Raspberries are believed to protect against arthritis by blocking COX-2, an enzyme responsible for causing inflammation and pain.

May Aid Weight Loss

One cup (123 grams) of raspberries has only 64 calories and 8 grams of fiber. What’s more, it’s made up of more than 85% water. This makes raspberries a filling, low-calorie food.

Additionally, their natural sweetness may help satisfy your sweet tooth.

The chemical substances naturally found in raspberries may also aid weight loss.

In one study, mice were fed a low-fat diet, a high-fat diet or a high-fat diet supplemented with one of eight berries, including raspberries. Mice in the raspberry group gained less weight than mice only on a high-fat diet.

Raspberry ketone supplements are widely promoted for weight loss. However, little research has been conducted on them.

In one animal study, mice fed a high-fat diet and given high doses of raspberry ketones gained less weight than mice in the control group.

The only human-based study on raspberry ketones and weight loss used a supplement containing several other substances, including caffeine, making it impossible to determine whether raspberry ketones were responsible for any positive effects.

While little evidence suggests that raspberry ketone supplements aid weight loss, eating whole, fresh raspberries may help you shed weight.

May Combat Aging

Raspberries are high in antioxidants, which can help reduce signs of aging by fighting free radicals in your body.

Antioxidants have been linked to longer lifespans in various animal models and show anti-aging effects in humans.

Raspberries are also high vitamin C, which is necessary for healthy skin. It may improve collagen production and reverse damage to skin caused by UV rays.

In one eight-week study, aging rats fed a diet with 1% or 2% raspberries showed improved motor functions, including balance and strength.

Fresh raspberries have a short shelf life, so you should purchase locally grown berries whenever possible and eat them within one to two days.

Since raspberries are harvested during the summer and fall, fresh raspberries will be best at those times.

When choosing raspberries, be sure to avoid any that look crushed or moldy.

Raspberries should be refrigerated in packaging that protects them from damage.

Keep in mind that you can eat raspberries year-round by buying them frozen. These berries are frozen immediately after harvesting. Read labels closely to ensure you’re not getting added sugar.

Raspberries are also a popular ingredient in jams and jellies. Look for all-fruit spreads without added sweeteners.

Here are some ways to incorporate raspberries into your diet:

Eat fresh raspberries as a snack.
Top yogurt with fresh raspberries and granola.
Add raspberries to cereal or oatmeal.
Top whole-grain pancakes or waffles with raspberries.
Add frozen raspberries to a smoothie.
Make a fresh berry salad with raspberries, blueberries, strawberries and blackberries.
Add raspberries to a salad with chicken and goat cheese.
Blend raspberries with water and use as a sauce for meat or fish.
Make a baked raspberry crumble with rolled oats, nuts, cinnamon and a drizzle of maple syrup.
Stuff raspberries with dark chocolate chips for a sweet treat.

Cultivation
Flower

Various kinds of raspberries can be cultivated from hardiness zones 3 to 9. Raspberries are traditionally planted in the winter as dormant canes, although planting of tender, plug plants produced by tissue culture has become much more common. A specialized production system called “long cane production” involves growing canes for a year in a northern climate such as Scotland or Oregon or Washington, where the chilling requirement for proper bud break is attained, or attained earlier than the ultimate place of planting. These canes are then dug, roots and all, to be replanted in warmer climates such as Spain, where they quickly flower and produce a very early season crop. Plants are typically planted 2-6 per m in fertile, well drained soil; raspberries are usually planted in raised beds/ridges, if there is any question about root rot problems.

All cultivars of raspberries have perennial roots, but many do not have perennial shoots. In fact, most raspberries have shoots that are biennial (meaning shoots grow in the first growing season and fruits grow on those shoots during the second growing season).The flowers can be a major nectar source for honeybees and other pollinators.

Raspberries are vigorous and can be locally invasive. They propagate using basal shoots (also known as suckers), extended underground shoots that develop roots and individual plants. They can sucker new canes some distance from the main plant. For this reason, raspberries spread well, and can take over gardens if left unchecked. Raspberries are often propagated using cuttings, and will root readily in moist soil conditions.

The fruit is harvested when it comes off the receptacle easily and has turned a deep color (red, black, purple, or golden yellow, depending on the species and cultivar). This is when the fruits are ripest and sweetest.

High tunnel bramble production offers the opportunity to bridge gaps in availability during late fall and late spring. Furthermore, high tunnels allow less hardy floricane-fruiting raspberries to overwinter in climates where they would not otherwise survive. In the tunnel plants are established at close spacing usually prior to tunnel construction.

Nutritional values

Fruit

Raspberries are grown for the fresh fruit market and for commercial processing into individually quick frozen (IQF) fruit, purée, juice, or as dried fruit used in a variety of grocery products such as raspberry pie. Traditionally, raspberries were a midsummer crop, but with new technology, cultivars, and transportation, they can now be obtained year-round. Raspberries need ample sun and water for optimal development. Raspberries thrive in well-drained soil with a pH between 6 and 7 with ample organic matter to assist in retaining water. While moisture is essential, wet and heavy soils or excess irrigation can bring on Phytophthora root rot, which is one of the most serious pest problems facing the red raspberry. As a cultivated plant in moist, temperate regions, it is easy to grow and has a tendency to spread unless pruned. Escaped raspberries frequently appear as garden weeds, spread by seeds found in bird droppings.

An individual raspberry weighs 3–5 g (0.11–0.18 oz), and is made up of around 100 drupelets, each of which consists of a juicy pulp and a single central seed. A raspberry bush can yield several hundred berries a year. Unlike blackberries and dewberries, a raspberry has a hollow core once it is removed from the receptacle.

Nutrients

Raw raspberries are 86% water, 12% carbohydrates, and have about 1% each of protein and fat (table). In a 100 gram amount, raspberries supply 53 calories and 6.5 grams of dietary fiber.

The aggregate fruit structure contributes to raspberry’s nutritional value, as it increases the proportion of dietary fiber, which is among the highest known in whole foods, up to 6% fiber per total weight.[25] Raspberries are a rich source (20% or more of the Daily Value, DV) of vitamin C (32% DV), manganese (32% DV) and dietary fiber (26% DV), but otherwise have low content of micronutrients (table). Raspberries are a low-glycemic index food, with total sugar content of only 4% and no starch.

Phytochemicals

Raspberries contain phytochemicals, such as anthocyanin pigments, ellagic acid, ellagitannins, quercetin, gallic acid, cyanidins, pelargonidins, catechins, kaempferol and salicylic acid. Yellow raspberries and others with pale-colored fruits are lower in anthocyanin content.[26] Both yellow and red raspberries contain carotenoids, mostly lutein esters, but these are masked by anthocyanins in red raspberries.

Raspberry compounds are under preliminary research for their potential to affect human health.
Leaves

Raspberry leaves can be used fresh or dried in herbal teas, providing an astringent flavor. In herbal and traditional medicine, raspberry leaves are used for some remedies, although there is no scientifically valid evidence to support their medicinal use.