Berries Beyond Blueberries: Strawberries, Raspberries and Blackberries
What human studies found for strawberries, raspberries and blackberries as foods, with the form studied, the strength of the evidence and what is still unknown.
Content last updated . This page has not been medically reviewed.
Safety first. Natural products can cause side effects and interact with medicines. Read functional food safety before you use anything on this page.
What the studies found
The table separates trials from observational studies and names the form people actually ate, because a result for freeze-dried powder or frozen fruit does not automatically carry over to fresh fruit.| Question | What the source found | Strength of evidence | Form and people studied |
|---|---|---|---|
| Strawberries and cholesterol | LDL cholesterol did not differ after 4 weeks. [2] | No clear effect on this marker | Freeze-dried strawberry powder in a drink (2 x 25 g a day), 34 adults with moderately high cholesterol, crossover trial [2] |
| Strawberries and blood vessel function | Blood vessel function was higher at 1 hour, and systolic blood pressure was 3.1 mmHg lower at 2 hours after a single 50 g serving of the powder. [2] | Promising but limited (short-term, one small trial) | Same trial |
| Strawberries and prediabetes markers | Insulin resistance and related markers improved over 12 weeks compared with no strawberries. [3] | Promising but limited | A daily amount described as 2.5 servings, 25 adults in each period, single-blinded crossover trial with a no-strawberry control [3] |
| Red raspberries and blood sugar after a meal | The largest amount lowered peak insulin and peak glucose after a test breakfast in adults with prediabetes and insulin resistance. [4] | Promising but limited (one meal at a time, a biomarker) | Frozen red raspberries, about 1 cup or 2 cups, 32 adults, crossover trial [4] |
| Berries and type 2 diabetes risk | In three large U.S. cohorts, blueberries were linked to lower risk. Strawberries were not (1.03, 95% CI 0.96 to 1.10, for every three servings a week). [5] | Observational, so it cannot prove cause | U.S. health professionals followed for years [5] |
| Berries overall and diabetes | A review says studies in people who already have type 2 diabetes are few. [6] | Insufficient evidence for people with diabetes | Mixed berries and forms [6] |
| Blackberries | Proper evidence not found. We searched PubMed for human intervention studies of blackberry intake and found no trial we could use. | Insufficient evidence | Not applicable |
Food, powder and extract are different
The strawberry cholesterol trial used a freeze-dried powder mixed into a drink. [2] A review of berry feeding trials notes that trials use different berries in different forms, so results are hard to compare. [6] Berry extracts, capsules and powders sold as supplements are not covered by these studies. See Polyphenols and flavonoids in foods for what the plant compounds are and why one food's result does not stand for another's.Health connections for Strawberries, Raspberries & Blackberries
What research links to eating or drinking this food, and how strong the evidence is. Many studies are observational or use juice, powder, oil or extracts rather than the food as eaten; each card says which.
Berries as part of the fruit group
Established roleU.S. dietary guidance places berries within the fruit group of a healthy eating pattern.
Supplements: Not a supplement topic; this is about eating the whole fruit.
Fiber, vitamin C and manganese in the fruit
Established roleUSDA lists strawberries as high in vitamin C, and raspberries and blackberries as high in fiber and manganese. Values vary with variety and ripeness.
Supplements: Not applicable; these are food nutrient values.
Strawberries and blood vessel function and blood pressure (short term)
Preliminary or mixedAfter a single serving of freeze-dried strawberry powder, blood vessel function was higher at 1 hour and systolic blood pressure was 3.1 mmHg lower at 2 hours in one small trial.
Supplements: Trial used freeze-dried strawberry powder in a drink, not fresh fruit; do not assume the same result for other forms.
Strawberries and insulin resistance markers
Preliminary or mixedInsulin resistance and related markers improved over 12 weeks compared with no strawberries in adults with prediabetes in a small crossover trial.
Supplements: Evidence is limited; markers are not the same as preventing diabetes.
Red raspberries and blood sugar after a meal
Preliminary or mixedThe largest amount of frozen red raspberries lowered peak insulin and glucose after a test breakfast in adults with prediabetes and insulin resistance.
Supplements: Frozen fruit was studied; no long-term outcome was measured.
Strawberries and LDL cholesterol
Not enough evidenceLDL cholesterol did not differ from control after 4 weeks of freeze-dried strawberry powder.
Supplements: No clear effect shown on LDL cholesterol.
Berries and type 2 diabetes risk (observational)
Not enough evidenceIn three large U.S. cohorts, blueberries were linked to lower risk but strawberries were not (1.03, 95% CI 0.96 to 1.10, per three servings a week).
Supplements: Not a supplement topic; association only.
Berries in people who already have type 2 diabetes
Not enough evidenceA review says studies in people who already have type 2 diabetes are few.
Supplements: Evidence is too thin to say.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Body systems (1)
- Blood Sugar SupportPreliminary or mixed
Small trials found short-term improvements in insulin and glucose markers with strawberries and red raspberries in adults with prediabetes; observational data for strawberries and diabetes risk showed no link.
Biomarkers (2)
- Blood GlucosePreliminary or mixed
Peak glucose after a test breakfast was lower with the largest amount of frozen red raspberries in one crossover trial of 32 adults with prediabetes.
- InsulinPreliminary or mixed
Peak insulin after a test meal was lower with the largest amount of frozen red raspberries in adults with prediabetes; strawberries improved insulin resistance markers over 12 weeks in another small trial.
Conditions & symptoms (2)
- Insulin ResistancePreliminary or mixed
Insulin resistance markers improved with daily strawberries over 12 weeks in one small trial; evidence is limited.
- Prediabetes SyndromePreliminary or mixed
Small crossover trials in adults with prediabetes found better insulin and glucose measures with strawberries (12 weeks) and red raspberries (after one meal). These are markers, not prevention of diabetes.
Documented risks and interactions (1)
- Allergy, medicines and pregnancy: no cautions found in sources read. The sources read for the site page did not describe medicine interactions, pregnancy, breastfeeding, kidney or allergy cautions for these berries eaten as food. That is not proof of safety.
Frequently asked questions
Are strawberries, raspberries and blackberries good for you?
They are fruits, and U.S. dietary guidance groups them with fruit. [1] Small trials found short-term changes in some blood markers for strawberries and raspberries. [3][4] These do not show the fruit prevents disease.
Do berries lower cholesterol?
In one crossover trial of freeze-dried strawberry powder, LDL cholesterol did not differ from the control. [2]
Do berries help with blood sugar?
Red raspberries lowered insulin and glucose responses to one test meal in adults with prediabetes. [4] A review says studies in people with type 2 diabetes are few. [6] People who take diabetes medicine should ask their prescriber or pharmacist about changes in what they eat.
Is there evidence for blackberries specifically?
Proper evidence not found. We searched PubMed for human intervention studies of blackberry intake and did not find a trial to report.
Is a berry powder or extract the same as eating the fruit?
No. Results for one form do not transfer to another form. [6] See Polyphenols and flavonoids in foods.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read these findings
- Trial or cohort? A trial gives people a food and compares them with a control. A cohort study watches what people already eat. Cohorts can be shaped by other habits. See Observational studies vs trials in nutrition.
- Marker or outcome? Insulin and blood pressure readings are markers. None of the trials above followed people long enough to count heart attacks or new diabetes.
- Added or swapped? The trials compare berries with a control. They do not show what happens when berries replace another food.
Safety and who should ask a professional
References
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. Read 2026-10-23.
- Basu A, et al. Strawberry consumption, cardiometabolic risk factors, and vascular function: a randomized controlled trial in adults with moderate hypercholesterolemia. J Nutr. 2021. Read 2026-10-23.
- Basu A, et al. Strawberries improve insulin resistance and related cardiometabolic markers in adults with prediabetes: a randomized controlled crossover trial. J Nutr. 2025. Read 2026-10-23.
- Xiao D, et al. Attenuation of postmeal metabolic indices with red raspberries in individuals at risk for diabetes: a randomized controlled trial. Obesity (Silver Spring). 2019. Read 2026-10-23.
- Muraki I, et al. Fruit consumption and risk of type 2 diabetes: results from three prospective longitudinal cohort studies. BMJ. 2013. Read 2026-10-23.
- Calvano A, et al. Dietary berries, insulin resistance and type 2 diabetes: an overview of human feeding trials. Food Funct. 2019. Read 2026-10-23.