Raspberries contain plenty of antioxidants and are therefore one of the healthiest fruits on earth. We explain how to make raspberry syrup without sugar, why raspberry jam is better than strawberry jam and why cancer cells don’t like raspberries. You can also read about how raspberries work in diabetes, how they have a beneficial effect on intestinal flora, and how they can even be used to prevent dementia.
The raspberry, an ancient fruit, and medicinal plant
Like many other fruit plants (cherry, strawberry, apple, pear), the raspberry (Rubus idaeus) belongs to the rose family. There are several genera in this family. The genus Rosa describes the actual roses (cultivated and wild roses). The Rubus genus – which includes several thousand species – includes raspberries and blackberries.
The Eurasian wild forest raspberry can still be found today in mountainous areas – mostly in forest clearings and at the edges of forests – and knows how to score with particularly aromatic fruits. According to archaeological finds, the wild raspberry was one of the most important fruit plants for humans as early as the Stone Age and has always been valued as a medicinal plant.
The wild raspberry was cultivated in the Middle Ages, the cultivated raspberries were initially bred and cultivated in monastery gardens in particular. Since then, countless varieties have emerged, crossing raspberries from all over the world.
There are countless types of raspberries
In addition to the Eurasian forest raspberry, there are various raspberry species in Asia and North America that are related to each other, but whose fruits can be quite different in terms of their appearance and taste.
These include e.g. B. the Japanese strawberry raspberry, the Chinese climbing raspberry, and plants native to North America such as the magnificent raspberry, the cinnamon raspberry, and the black raspberry (Rubus occidentalis). The latter has also attracted attention in Europe because cancer researchers have recognized great potential in its dark fruits.
Not all raspberries are red
In our climes, it is more or less taken for granted that the raspberry is red. But there are both wild and cultivated plants that bear yellow, orange, or black fruits. Many varieties have been created by crossing Eurasian raspberries with black-fruited raspberries such as Rubus occidentalis, and the fruits are therefore black in color.
Nevertheless, almost only red raspberries are offered for sale in this country. In the garden plant trade, however, countless different colored varieties are available that can be cultivated by passionate hobby gardeners.
Why the raspberry is called raspberry
Depending on the region, the raspberry has many names. In Switzerland, for example, it is known as Haarbeeri or Sidebeeri, in Austria as Imper or Hindlbeer, and in Germany as Himmer or Holbeer.
The term “raspberry” came from the Old High German term “Hintperi”. Translated, this means something like: the berry of the hind. The naming is probably due to the fact that the wild raspberries are in fact an important part of the deer’s diet.
The raspberry is not a berry at all
The fruits colloquially referred to as berries are actually not berries at all, but aggregate drupes like strawberries or blackberries. If you take a closer look at the raspberries, you will see that they are made up of many small drupes that stick together. Each of these individual fruits contains a seed, which also plays an important role in terms of the health value of raspberries.
By the way, the real berries include types of fruit that you probably wouldn’t suspect. Namely bananas, citrus fruits, dates, kiwis, avocados, and melons.
The nutritional values
Like almost every other fruit, the raspberry is rich in water, but compared to many other fruits it contains very little sugar and even less fat. The raspberry also scores in terms of fiber, which is mainly found in the seeds: 100 g of the fruit is enough to cover 13 percent of your fiber requirements.
The fresh (raw) raspberry has the following nutritional values per 100 g:
- water 84.3 g
- Fiber 6.7 g, (1.4 g water-soluble and 5.3 g water-insoluble fiber)
- Carbohydrates (4.8 g, sugars: 1.8 g glucose and 2 g fructose)
- protein 1.3 g
- Fat 0.3g
The calorie content
Raspberries are low in calories and provide only 34 kcal per 100 g of fresh fruit. For comparison: cherries have about twice as many calories, while bananas have 95 kcal. Fruit is therefore a much better snack than milk chocolate (536 kcal) or chips (539 kcal).
The raspberry is really not a vitamin bomb and can be combined with other fruits such as e.g. B. Sea buckthorn berries or plums do not keep up. Nevertheless, with 200 g of raspberries, you can still meet the recommended daily dose of 50 percent of vitamin C and 14 percent of vitamin E. These two antioxidants boost the immune system, counteract inflammation and reduce the risk of cancer.
Per 100 g raspberries contain the following vitamins: Vitamins in raspberries
Although there are many minerals in raspberries, their content is not very high. The content of copper, manganese, magnesium, and iron stands out the most. 200 g of raspberries can cover 22 percent of your copper and manganese requirements.
Raspberries are healthy for the intestines and digestion
Raspberries benefit digestion and may help with constipation. The fruit acids contribute in part to this, but primarily the dietary fibers. Both are important for the metabolism and contribute to the food being digested optimally.
Raspberries are among the fruits with the highest fiber content. The small seeds, which are located directly in the fruit and are therefore eaten, are responsible for this. Raspberries contain water-soluble, but above all water-insoluble fiber such as lignin and cellulose. These increase the volume of the stool, which stimulates intestinal movement and accelerates the transport of leftover food and its excretion.
Apart from the fact that raspberries have a regulating effect on digestive activity, they also increase the feeling of satiety, which reduces the risk of obesity. A large-scale international study showed in 2017 that a high intake of fiber reduces the risk of developing diabetes, high blood pressure, cardiovascular diseases, and colon cancer.
A French study with over 100,000 subjects in 2020 showed that the intake of insoluble and soluble fiber from fruits in particular reduces the risk of chronic diseases and is associated with lower mortality. They, therefore, called for public health nutrition policy to finally put more emphasis on dietary fiber.
Raspberries for the intestinal flora
A number of in-vitro and animal studies have now shown that berries have a positive effect on intestinal flora. There are not many human studies in this regard, but the researchers always came to the same conclusion and even speak of a new kind of prebiotic. This refers to components of food that stimulate the growth and/or activity of intestinal bacteria and thereby improve health.
In an eight-week pilot study, researchers from the Illinois Institute of Technology examined the effects of consuming red raspberry puree and oligofructose (fiber with a prebiotic effect) on gut flora. The subjects ate 125 g of raspberry puree or ingested 8 g of oligofructose daily for 4 weeks. 100 g raspberry puree contained around 50 mg anthocyanins and 40 mg ellagitannins.
In both cases, the researchers found optimization of the composition of the intestinal bacteria. However, the raspberries were more effective. While the number of Firmicutes decreased, the number of Bacteroidetes increased, allowing the balance of these gut bacteria to be optimized. This change could include: helping overweight people since Bacteroidetes strains dominate in normal weight people and Firmicutes strains in obese people.
Only in the raspberry group was an increase in the bacterium Akkermansia muciniphila observed, which benefits the intestinal mucosa and helps with weight loss. Akkermansia muciniphila also counteracts insulin resistance, helps lower cholesterol levels, and inhibits inflammation of the liver. The prebiotic effect was primarily attributed to the anthocyanins.
Raspberries have a very low glycemic load
100 grams of raspberries have a low glycemic load (GL) of 2 (values up to 10 are considered low). The GL indicates the influence of food on the blood sugar level. Foods with a low GL thus help to keep the blood sugar level and, as a result, the insulin level at a low and even level.
The GL is therefore more meaningful than the often used glycemic index (GI), since not only the quality but also the amount of carbohydrates supplied is taken into account.
Due to their very low glycemic load, raspberries have little effect on blood sugar or insulin levels. They are therefore ideally suited for type 2 diabetics. However, patients are often warned against fruit for no reason, as it contains sugar.
Researchers from the Illinois Institute of Technology sharply criticize this approach. Because according to them, certain fruits such as raspberries not only provide essential micronutrients and fiber, but also a considerable content of secondary plant substances (e.g. anthocyanins).
Raspberries for low carb and the ketogenic diet
Low-carb diets, which include ketogenic diets, have one thing in common: it’s basically about reducing carbohydrate intake. But while most low-carb diets allow you to consume between 50 and 130 g of carbohydrates per day, the ketogenic diet has a maximum of 50 g.
Although fruit contains carbohydrates, it also contains vital substances. For this reason, it should not be dispensed with in either diet. Raspberries are an ideal fruit for low-carb diets and even for ketogenic diets, as their carbohydrate content is very low – they only contain 5 g of carbohydrates per 100 g.
Raspberries are basic
Raspberries are sometimes loved because the balanced combination of sweet and sour makes for a particularly harmonious taste experience. Various fruit acids are responsible for the sour note. 100 g raspberries contain around 40 mg malic acid, 25 mg ascorbic acid (vitamin C), and 1,300 mg citric acid. For comparison: in the same amount of freshly squeezed lemon juice, there is about 4,500 mg of citric acid.
It is often assumed that fruit that tastes sour is one of the acidifiers. But no matter how high the content of fruit acids may be: raw fruit is basically metabolized and therefore has a deacidifying effect on the organism.
Are raspberries compatible with fructose intolerance?
Unfortunately, people who suffer from fructose intolerance only tolerate raspberries to a limited extent. During the waiting phase, as little fructose as possible and therefore no raspberries should be eaten for about 2 weeks. If the symptoms have subsided, a nutritionist should be consulted to determine how much fructose the person concerned can tolerate.
100 g raspberries contain 2 g fructose and 1.8 g glucose, so the ratio is at least relatively balanced. This can improve tolerability. The ideal ratio of fructose to glucose is less than or equal to 1 and is 1.2 for raspberries.
In fact, raspberries are usually – but not always – well tolerated after the waiting or test phase. It is also important to know that there is often a combined fructose-sorbitol intolerance.
The use of raspberry leaves in naturopathy
The raspberry leaves have already been classified as a traditional herbal medicinal product by the Committee on Herbal Medicinal Products. They are recommended, for example, for mild menstrual cramps, mild diarrhea, and for external use (rinses, gargling) for inflammation in the mouth and throat.
In addition, a raspberry leaf tea is used in obstetrics. It is used for episiotomy prophylaxis, as the tea strengthens the uterus and connective tissue and at the same time relaxes the muscles in the abdomen. Thus, raspberry leaves can have a positive effect on the birth process.
To be on the safe side, the tea should not be drunk before the 34th week of pregnancy, as it promotes blood circulation and could therefore stimulate labor.
Preparation of raspberry leaf tea: For a cup of tea you need 2 g of raspberry leaves (about 2 to 3 teaspoons), which are poured over with boiling water. Cover and let the tea steep for 10 minutes, then strain the leaves. You can drink the tea 3 to 4 times a day, preferably warm and between meals, or use it for douching.
Raspberry oil for the skin
Raspberry oil is not obtained from the fruit, but only from the seeds of the raspberry. During production, the hard-shelled seed pods are first separated from the pulp by pressing the whole raspberries through a very fine-meshed sieve.
The tiny, hard seeds are washed, then either air or freeze-dried and cold-pressed. In this way, the nutrients of the seeds are preserved because they are not exposed to heat. More than 10 kilograms of fine seeds are needed to obtain one liter of pure raspberry oil. This explains the high price of up to 30 euros per 100 ml of raspberry seed oil.
Raspberry seed oil is not used in the kitchen, but in traditional medicine. Primarily to do something good for the skin. It can relieve eczema, psoriasis, and dermatitis and is suitable for use on very dry and inflamed skin.
A raspberry seed consists of around 23 percent fat. The raspberry seed oil contains 73 to 93 percent polyunsaturated fatty acids, 12 to 17 percent monounsaturated fatty acids and 2 to 5 percent saturated fatty acids. The valuable omega-3 and omega-6 fatty acids in particular are responsible for the healing effect.
- 50 to 63 percent linoleic acid (omega 6)
- 23 to 30 percent alpha-linolenic acid (omega 3)
- 12 to 17 percent oleic acid (omega 9)
- 1 to 3 percent palmitic acid
- 1 to 2 percent stearic acid
When shopping, make sure that the raspberry seed oil is cold-pressed and comes from organic farming. A high-quality raspberry seed oil contains only raspberry seed oil and no other ingredients. If stored in a cool, dark place, it will keep for up to a year.
The application of raspberry extracts
You have probably already noticed that studies often do not use the fruit itself, but rather extracts. This is because exact dosing is much easier this way. Because in fresh fruit, the content of ingredients – e.g. B. depending on the variety or growing conditions – varies considerably.
If you want to use raspberry extracts as part of a therapy, you should consider the following:
- Ingredients: Make absolutely sure that the raspberries used to come from organic farming and that the ingredients were not simply added, but really come from raspberries.
- Anthocyanins: Analyzes have shown that extracts without anthocyanins obtained from berries, including black and red raspberries, have far less antioxidant activity than extracts with anthocyanins, despite the fact that they contained many other antioxidants such as vitamin C and phytochemicals. With that in mind, it’s important to keep an eye on anthocyanin levels when shopping.
- Dosage: Use the specified anthocyanin values as a guide, between 50 and 100 mg should be taken daily.
- Diversity: The natural ingredients should be included in a wide spectrum. If possible, avoid preparations that only contain a single isolated active ingredient – unless you need this one substance in a specific dose for therapeutic reasons.
The ingredients in raspberries influence each other
In the meantime, many studies have shown that the many ingredients in plants influence each other. This is referred to as the synergetic effect. So if you eat raspberries or take a high-quality extract, you can achieve a better effect than with a single active ingredient.
Compared to fresh raspberries, raspberry extracts have the disadvantage that they only contain part of the ingredients of the original food. More and more researchers are concluding that the health benefits of fruits and vegetables are due to the interactions of the components present in whole foods.
Therefore, from a health perspective, it is better to consume nutrients and bioactive compounds from a variety of foods than to rely on supplements. In connection with therapy, however, it can be advantageous that the content of certain active ingredients in extracts is higher and the dosage can be more precise.
What about the bioavailability of anthocyanins?
There is still a lot of outdated information online that the bioavailability of anthocyanins is so poor that no effect can actually be expected. In the meantime, however, research results have long spoken a completely different language.
According to a 2017 review at North Carolina State University, anthocyanins and other phytochemicals are repeatedly converted into other substances after they have been absorbed by the body. The former assumption of poor bioavailability is based on the fact that direct metabolites (intermediate products) of anthocyanins occur only in very small amounts in the bloodstream and are quickly excreted in the urine.
The fact is, however, that these metabolites have long since formed new substances that reach the large intestine. These are in turn converted by intestinal bacteria into other substances, which enter the bloodstream in higher concentrations. This explains why anthocyanins and co. are ultimately much more bioavailable than previously thought.
According to an international study, e.g. B. ellagitannins from raspberries or their metabolites from the small intestine to the large intestine, where intestinal bacteria convert them into urolithins. These can be detected in the bloodstream for much longer and can develop their effect accordingly. The researchers stated that the gastrointestinal tract and the intestinal flora are key to the bioavailability of anthocyanins and ellagitannins and that the health effect is based on substances that are produced during the digestive process.
How and where raspberries are best stored
Raspberries are very sensitive fruits, so their shelf life is limited. It is best to eat them as fresh as possible. Also, keep in mind that raspberries that are harvested unripe will not ripen after harvesting!
When storing, you should make sure that the fruit is extremely sensitive to pressure. Sort out damaged raspberries immediately. Because if mold forms, all the fruit in the basket will soon be affected and must be disposed of.
Depending on when they are harvested, raspberries can be kept in the vegetable compartment of the refrigerator for up to 3 days. The fruits are not sensitive to cold, the optimal storage temperature is between 0 and 1 degree Celsius. Only wash the raspberries carefully under running water immediately before eating.
What to consider when freezing raspberries
Raspberries are great to freeze if you’ve bought or picked more than you can use up shortly. You can freeze both processed (e.g. raspberry sauce) and unprocessed fruit. Proceed as follows:
- Carefully place the raspberries in a freezer bag. Don’t apply any pressure to avoid crushing the fruit.
- Then carefully squeeze the air out of the freezer bag or use a vacuum pump.
- Seal the freezer bag tightly and place it in the freezer compartment or freezer.
- Frozen raspberries will keep for at least 6 months.
- If you want to defrost the raspberries, put them on a plate and cover them with cling film so that the fruit doesn’t absorb any extraneous smells.
- Raspberries should be thawed in cool temperatures, the refrigerator is best for this.
How to make raspberry syrup without sugar
Raspberries can be preserved in a variety of ways, for example in the form of a delicious raspberry jam or a refreshing raspberry syrup. The disadvantage is that there is usually a lot of sugar involved in the preparation. But there are interesting sugar alternatives that are not harmful to health. This includes e.g. B. birch sugar, which we have already reported on here in detail: Xylitol – birch sugar as a sugar substitute.
That’s how it works:
- 1,200 g organic raspberries
- 600ml of water
- 600 g birch sugar
- 240 ml lemon juice
- Wash the raspberries, put them in a saucepan with the water, and let the mixture simmer over medium heat for 10 minutes.
- Now strain the cooked raspberries with a hand blender, then push them through a sieve and let them drain well.
- Mix the birch sugar with the juice, stir in the lemon juice and let everything boil for a minute.
- Pour the hot syrup into boiled and well sealable glass bottles.
- Prepared this way, the raspberry syrup will keep unopened for 6 months when refrigerated. Once opened, you should use it within 6 weeks.
Processed raspberries are also healthy
There is no question that all sorts of delicacies can be made from raspberries. But what happens during storage, preservation, and preparation with the ingredients and thus with the health effect of the fruit? According to various scientific analyzes processing and preservation can affect the sensitive raspberries less than expected.
According to a 2019 study, the freezing process only slightly affects the phenolic compounds in raspberries. In fresh raspberries, these components even increased 1.5-fold during a one-week storage period.
Also in 2019, analyzes showed that both shock-frozen and pureed raspberries are a very good source of vitamins and minerals. With regard to dietary fiber, it should be noted that this only comes into play if the seeds are not removed during processing.
What raspberry jam has over strawberry jam
In 2020, Norwegian researchers processed strawberries and raspberries into jams at 60, 85, or 93 degrees Celsius and then stored them at 4 or 23 degrees Celsius for 8 or 16 weeks. The higher the processing temperature, the more the vitamin C and anthocyanin levels were reduced in the strawberries, but not in the raspberries.
During storage, the processing temperature had little impact on the bioactive compounds in both jams. The longer the jams were stored, the more vitamin C was broken down, regardless of the storage temperature. However, the phytochemicals were much more stable in the raspberry jam than in the strawberry jam. This also explains why the anthocyanin-dependent color suffered much more in a strawberry jam than in a raspberry jam.
So the bottom line is that while fresh raspberries are the undisputed best choice, processed fruits are also good for health. A study conducted at The Ohio State University in 2020 also supports this. Because according to the researchers, raspberry jam and raspberry nectar are excellent products for future large-scale clinical studies due to the ingredients they contain and their good bioavailability.