A raspberry is not a single berry. It is a cluster of around 100 tiny fruits called drupelets, each with a seed, that grew from the many separate parts of one flower. Unlike a blackberry, a raspberry leaves its stem core on the plant when you pick it, which is why it is hollow.
That hollow fruit is a good source of fiber. Raw raspberries have 6.5 g of fiber per 100 g, or 8 g in a cup (123 g), which is 29% of the daily value, for only 52 calories per 100 g. They also give 29% of the daily value for vitamin C and for manganese per 100 g.
Most of the research is on small trials, and the blood sugar trials are often funded by the National Processed Raspberry Council, a raspberry industry group. The cards below say so where a paper states it. Many trials used frozen raspberries or freeze-dried powder, a few used black raspberries, a different species, and some used leaf tea, and each card says which. Raspberry ketone supplements are not raspberries and are covered in the questions at the end.
Health benefits of raspberries
The top findings from 19 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★No clear effect on blood pressure or cholesterolEating raspberries did not significantly change blood pressure or LDL cholesterol in 11 trials, or blood pressure in another review of 6 trials. Groups with high cholesterol did show lower total and LDL cholesterol, which needs confirming.
- ★★No clear effect on blood sugarA review of randomized trials found no change in fasting blood sugar, HbA1c (average blood sugar) or insulin resistance. An inflammation marker, TNF-alpha, fell by 3.07 pg/mL.
- ★★No change in weight or waist sizeA review of 9 studies found eating raspberries did not change weight, BMI or waist size. Liver enzymes did not change either.
- ★Smaller blood sugar peak after a meal25 g of freeze-dried raspberry powder in a high-carbohydrate meal lowered peak blood sugar by 8% in older adults with overweight or obesity. In people with prediabetes, 250 g of frozen raspberries (about 2 cups) lowered the peak.
- ★Lower LDL cholesterol in prediabetes, in one trialAbout 125 g of raspberries a day for 4 weeks lowered LDL by 7.2% and liver insulin resistance by 30% in adults with prediabetes. Changes were measured against each person’s own starting point.
All 19 studies, strongest evidence first
Eating raspberries did not change fasting blood sugar, HbA1c or insulin resistance in a meta-analysis of randomized trials
Meta-analysis of randomized trials of raspberry eating in adults, searched to December 2023. TNF-alpha, an inflammation marker, fell by 3.07 pg/mL, while CRP and IL-6 did not change. The authors say studies with larger samples are needed.
Eating raspberries did not significantly change blood pressure or cholesterol in a meta-analysis of 11 trials
Meta-analysis of 11 randomized trials (13 arms). Systolic pressure changed by −0.37 mm Hg and LDL cholesterol by −5.19 mg/dL, neither significant. Subgroups with high cholesterol, metabolic syndrome or andropause symptoms did show lower total and LDL cholesterol, a finding that needs confirming.
Raspberry eating did not significantly lower blood pressure in 6 trials, and neither did blackcurrant in 4
Meta-analysis of 10 randomized trials (420 people) of raspberries and blackcurrants. For raspberries, systolic pressure changed by −1.42 mm Hg and diastolic by −0.53 mm Hg against placebo. The authors say more accurate trials are required.
Eating raspberries did not change weight, BMI or waist size in a meta-analysis of 9 studies
Meta-analysis of 9 randomized studies (10 arms, 355 people). Liver enzymes (AST and ALT) did not change either. The authors say larger trials with more sensitive measures are needed before firm conclusions.
Adding 250 g of frozen raspberries to a high-carbohydrate breakfast lowered peak blood sugar and 2-hour blood sugar in people with prediabetes
Single-blinded crossover trial in 32 adults (21 with prediabetes and insulin resistance, 11 healthy) who ate the meal with 0, 125 or 250 g of raspberries. Even 125 g (about 1 cup) lowered 2-hour insulin, but only 250 g (about 2 cups) lowered glucose, and only in the prediabetes group. The National Processed Raspberry Council, an industry group, funded the trial.
Raspberries eaten with a meal lowered blood sugar 2 and 4 hours later in obese adults with type 2 diabetes
Randomized crossover study with a one-meal phase, then two 4-week periods with and without daily raspberries. IL-6 and TNF-alpha were also lower after the meal and after 4 weeks, while fasting glucose, blood fats and CRP did not change. The abstract does not state the dose or the number of people.
25 g of freeze-dried raspberry powder in a high-carbohydrate meal lowered peak blood sugar by 8% in older adults with overweight or obesity
Single-blinded crossover trial in 36 adults aged 55 to 70. Insulin response was lower too, and people needed fewer attempts on a paired-associates learning task and made fewer errors on a spatial working memory task. Vascular function did not change. It tested a single meal, not long-term eating.
A drink made from 200 g of red raspberries improved blood vessel widening (FMD) by 1.6% 2 hours later in healthy men
Double-blind crossover trial in 10 healthy men who had 200 or 400 g of raspberries as a drink, or a matched control drink. The gain was 1.0% at 24 hours, and 400 g did a little less than 200 g. Blood levels of urolithin compounds made by gut bacteria tracked the gains. Ten men is very small, and the National Processed Raspberry Council was one of the funders.
Eating about 125 g of raspberries a day for 4 weeks lowered LDL cholesterol by 7.2% and liver insulin resistance by 30% in adults with prediabetes
Randomized crossover trial in 26 adults with prediabetes and insulin resistance (and 10 healthy adults) who ate raspberries alone or with 8 g of the prebiotic fiber FOS for 4 weeks each. The changes were measured against each person’s own baseline, and total cholesterol fell 4.9%. Raspberries also doubled one gut bacterium, Eubacterium eligens. The National Processed Raspberry Council funded it.
280 g a day of frozen raspberries for 8 weeks did not change blood sugar, insulin, inflammation markers or blood pressure
Randomized trial in 59 adults with overweight or abdominal obesity and slightly raised insulin or triglycerides, compared with their usual diet. Gene activity and 10 blood metabolites did change, but the authors say the raspberries had no meaningful metabolic effects. A red raspberry commission funded the trial, and the funders had no role in its design or analysis.
Volunteers who ate raspberries absorbed almost no anthocyanin intact, with 0.007% in urine, but its breakdown products reached 15% of intake
Human feeding study that measured compounds in blood and urine after red raspberries. Gut bacteria turned ellagitannins into urolithins A and B, and 7.0% of intake showed up in urine. This tracks what the body does with raspberry compounds, not health effects, and the abstract does not give the number of volunteers.
Black raspberries, a different species from red raspberries, reduced rectal polyp burden in 14 people with an inherited polyp condition
Phase Ib study in familial adenomatous polyposis: 7 people had black raspberry powder by mouth plus suppositories, and 7 had an oral placebo plus suppositories, for 9 months. Polyp burden fell (P = 0.036) but polyp number did not (P = 0.069), the oral powder added no benefit, and 3 people did not respond. It is tiny and says more about suppositories than eating the fruit.
Black raspberry lozenges, from a different species than red raspberries, lowered a DNA damage marker by about 16 to 17% in smokers’ mouth cells
Trial in 21 smokers who took 5 lozenges a day (1 g of black raspberry each) for 8 weeks, compared with their own baseline. The marker, 8-oxodG, fell 16.46% in mouth cells, while the 25.72% drop in urine was not statistically significant and a second marker, 8-isoprostane, did not change.
Raspberry leaf tea, made from the leaf and not the fruit, lowered blood sugar by 2.03 mmol/L 30 minutes after sucrose in healthy adults
Randomized crossover trial in 22 healthy adults who had 50 g of glucose or sucrose with or without 10 g of leaf tea. Insulin was lower too, but with glucose there was no difference. It tested single doses in healthy people, and it says nothing about raspberries themselves.
Raspberry leaf, not the fruit, has a weak evidence base in pregnancy, with no clear benefit or harm in human studies
Systematic integrative review of 13 studies published between 1941 and 2016: 5 lab studies on animal and human tissue, 2 animal experiments and 6 human studies. The leaf acted on uterine muscle in the lab, and high injected doses were toxic in animals. One human study found a shorter second stage of labor that was not statistically significant.
Among 91 women, those who took raspberry leaf (not the fruit) in pregnancy were less likely to have labor medically augmented
Prospective observational study in Australia with 44 women who used the leaf and 47 who did not. Phases of labor were shorter in the leaf group, but the authors say the results cannot be relied on or generalized, and that the absence of safety concerns is not evidence that the leaf is safe.
Mice fed a high-fat diet with 5% freeze-dried raspberries had less liver fat and better insulin response
Study in mice, not people. Male mice ate a control or Western-style high-fat diet with or without 5% freeze-dried raspberries for 12 weeks. Raspberries eased the weight gain late in the study and reduced liver inflammasome activity, a pathway tied to insulin resistance.
Mice fed a diet with 5% raspberries had about 39% less gut damage during repeated bouts of colitis
Study in mice, not people. Twelve mice per group ate a control or 5% raspberry diet for 10 weeks and got two rounds of a chemical that causes colitis. Disease score and tissue damage fell 38.9%, along with inflammation and cancer-related signals. Whether it helps people with ulcerative colitis is untested.
Raspberry puree or juice concentrate at about one serving a day lowered final body weight and liver fat in mice on a high-fat diet
Study in mice, not people. Four groups of 8 mice ate low-fat or high-fat diets, with raspberry puree or juice concentrate making up 2.5% of calories in two of the groups, which the authors liken to one serving a day. The study ran 10 weeks.
Who should be careful with raspberries
Most people can eat raspberries freely. Take a little care if one of these applies:
- Imported frozen raspberries. Frozen raspberries from China carried norovirus into ice cream in a 2016 Minnesota outbreak of 15 cases, and fresh raspberries from Guatemala were linked to outbreaks of Cyclospora infection in 1996 and 1997. Ireland’s food safety authority advises boiling imported frozen berries for one minute, and that advice covers imported frozen berries only.
- Raspberry leaf tea in pregnancy. This is a leaf product, not the fruit. A 2021 review calls the evidence for it weak, and a 2024 study of 91 women says its results should not be taken as proof of safety. Ask your midwife or doctor first.
- Irritable bowel syndrome. Monash University lists a low FODMAP serving of raw raspberries as 30 berries (60 g), so larger portions may bother a sensitive gut. The fruit itself is a small concern.
How to choose, store and eat raspberries
- Frozen: several trials used frozen raspberries. In 32 adults, 125 g (about 1 cup) with a breakfast lowered 2-hour insulin, and 280 g a day for 8 weeks changed no blood sugar markers.
- Freeze-dried powder: 25 g in one meal lowered peak blood sugar by 8% in older adults. That is a trial dose, and it is not the same as a handful of fruit.
- Fresh: a cup (123 g) has 64 calories and 8 g of fiber. No trial here compared fresh with frozen raspberries.
Choose bright, shiny, firm berries of even color, and skip stained containers, mold and soft, dull fruit. Berries are highly perishable, so refrigerate them right away unwashed, in a shallow covered container, and eat them within 1 to 2 days. Rinse them gently in cold water just before eating, without soaking.
Sources
- Berries: advice to boil imported frozen berries. Food Safety Authority of Ireland.
- Saupe AA, Rounds J, Sorenson A, et al. Outbreak of norovirus gastroenteritis associated with ice cream contaminated by frozen raspberries from China-Minnesota, United States, 2016. Clin Infect Dis. 2021.
- Herwaldt BL, Beach MJ. The return of Cyclospora in 1997: another outbreak of cyclosporiasis in North America associated with imported raspberries. Ann Intern Med. 1999.
- Bowman R, Taylor J, Muggleton S, Davis D. Biophysical effects, safety and efficacy of raspberry leaf use in pregnancy: a systematic integrative review. BMC Complement Med Ther. 2021.
- Bowman RL, Taylor J, Davis DL. Raspberry leaf (Rubus idaeus) use in pregnancy: a prospective observational study. BMC Complement Med Ther. 2024.
- Getting enough fibre: low FODMAP foods and IBS. Monash University FODMAP.
- Selecting, storing, and serving Ohio blueberries, blackberries, and raspberries. Ohio State University Extension.
- Xiao D, Zhu L, Edirisinghe I, et al. Attenuation of postmeal metabolic indices with red raspberries in individuals at risk for diabetes: a randomized controlled trial. Obesity (Silver Spring). 2019.
- Franck M, de Toro-Martín J, Garneau V, et al. Effects of daily raspberry consumption on immune-metabolic health in subjects at risk of metabolic syndrome: a randomized controlled trial. Nutrients. 2020.
- Xiao D, Shukitt-Hale B, Rutledge GA, et al. Red raspberry improves postprandial metabolic indices and cognitive function in older adults who are overweight or have obesity. Br J Nutr. 2026.
- Hao L, Bello NT. Sex-specific effects on total body fat gain with 4-week daily dosing of raspberry ketone and ketogenic diet in mice. Nutrients. 2023.
- Raspberry ketone. Wikipedia.
History of raspberries
The red raspberry, Rubus idaeus, is native to Europe and northern Asia. Its species name, idaeus, points to Mount Ida near Troy, in what is now northwest Turkey, where the ancient Greeks knew the plant. In the wild it grows in forests, in open stands under the trees and in denser patches in clearings.
The English word is younger than the fruit. “Raspberry” first appeared in print in 1602, built from “rasp” and “berry.” The “rasp” part probably comes from raspise, a sweet rose-colored wine of the mid-15th century. The idea that it means a “rough berry” is a possible folk etymology, according to the Etymonline reference. People in the north of England and in Scotland still call the fruit a rasp.
Most modern red raspberry varieties are not pure Rubus idaeus. They derive from hybrids between it and the American red raspberry, Rubus strigosus. Crosses with other brambles gave the loganberry first, then later hybrids such as the boysenberry, marionberry and tayberry.
Raspberry is now a global crop. World production in 2023 was 940,979 tonnes, led by Russia with 23% of the total. Other major producers were Mexico, Serbia and Poland. Production also has a safety history. In spring 1996 an outbreak of Cyclospora infection in the United States and Canada was linked to fresh Guatemalan raspberries, and in spring 1997 another outbreak brought 1,012 cases. It ended after Guatemala voluntarily suspended exports of fresh raspberries at the end of May.
Science has caught up recently. In 2022, researchers published a chromosome-level genome of the variety ‘Anitra’, with seven chromosomes and about 292 million base pairs of DNA, and in 2023 others added the cultivars ‘Autumn Bliss’ and ‘Malling Jewel’. The authors call variety development long and challenging, which is why genome tools matter to breeders.
One more thing: blowing a raspberry, the rude tongue-and-lips noise, comes from rhyming slang. “Raspberry tart” rhymed with a rude word for passing gas, and the sound has been called a raspberry in English since at least 1890.
Sources
- Raspberry. Wikipedia.
- Rubus idaeus. Wikipedia.
- Blowing a raspberry. Wikipedia.
- Davik J, Røen D, Lysøe E, et al. A chromosome-level genome sequence assembly of the red raspberry (Rubus idaeus L.). PLoS One. 2022.
- Price RJ, Davik J, Fernández Fernández F, et al. Chromosome-scale genome sequence assemblies of the ‘Autumn Bliss’ and ‘Malling Jewel’ cultivars of the highly heterozygous red raspberry (Rubus idaeus L.) derived from long-read Oxford Nanopore sequence data. PLoS One. 2023.
- Herwaldt BL, Beach MJ. The return of Cyclospora in 1997: another outbreak of cyclosporiasis in North America associated with imported raspberries. Ann Intern Med. 1999.
Frequently asked questions about raspberries
Are raspberries good for you?
For most people, yes, mainly for their fiber. Raw raspberries have 6.5 g of fiber and 26.2 mg of vitamin C per 100 g, with 52 calories. Meta-analyses of randomized trials found no clear change in blood pressure, cholesterol or weight, while small trials found lower blood sugar after a high-carbohydrate meal. No raspberry finding here reaches strong evidence.
Are raspberries high in fiber?
Yes. A cup (123 g) has 8 g of fiber, which is 29% of the daily value, and 100 g has 6.5 g. That is high for a fruit with 64 calories a cup. Monash University lists 30 raspberries (60 g) as a low FODMAP serving if fiber or fermentable carbs trouble your gut.
How many raspberries should you eat a day?
No study here sets an ideal amount. Trials used about 1 to 2 cups (125 to 250 g) of frozen raspberries with a single meal, 125 g a day for 4 weeks, and 280 g a day for 8 weeks. A cup is an ordinary serving, and 30 berries (60 g) is the low FODMAP limit for people with IBS.
Are raspberries good for people with diabetes?
They can fit, but the evidence is thin. A cup has 5.44 g of sugars. In a 32-adult trial funded by the National Processed Raspberry Council, 250 g of frozen raspberries with breakfast lowered peak blood sugar in people with prediabetes. A meta-analysis found no change in fasting blood sugar or HbA1c, and 280 g a day for 8 weeks changed neither. Check portions and choices with your care team.
Do raspberries help you lose weight?
No study here shows that. A meta-analysis of 9 studies found no change in weight, BMI or waist size from eating raspberries. Raw raspberries have 52 calories and 6.5 g of fiber per 100 g, so they fill a bowl cheaply, but that is a swap effect and not a proven effect of the fruit.
Are frozen raspberries as healthy as fresh?
Probably, though no study here compared them directly. Several trials used frozen raspberries, including the one where 250 g with breakfast lowered peak blood sugar. If your frozen raspberries are imported, Ireland’s food safety authority advises boiling them for one minute because of norovirus and hepatitis A risk.
Do raspberry ketone supplements work?
There is no good evidence that they do. Raspberry ketone is a flavor compound that raspberries hold at only about 1 to 4 mg per kilogram, and the supplements are made in a factory and are not raspberries. The published studies are in mice and cells, including a 2023 mouse study of a supplement marketed for weight control, and no human trial supports weight loss.
Is raspberry leaf tea safe in pregnancy?
Nobody can say for sure. It is made from the leaf, not the fruit, and a 2021 review called the evidence for it weak, with no clear benefit or harm in human studies. A 2024 study of 91 women saw shorter labor phases but says its results should not be taken as evidence of safety, so talk to your midwife or doctor first.