Strawberry: nearly every trial used the powder

Almost everything known about strawberries and health was tested as a powder. Freeze-dried strawberry, 24 to 40 grams of it a day, stirred into a drink. When a trial reports two cups of fresh strawberries, that is the researchers converting the powder back into fruit on paper. It matters, because the two largest pooled analyses of that powder disagree with each other. One, over eleven trials, found C-reactive protein down by 0.63 milligrams per litre and nothing else moving. The other, over fourteen trials and a wider search, found total cholesterol down 6.49 milligrams per decilitre and diastolic blood pressure down 2.220 millimetres of mercury, along with fasting blood sugar going up by 2.083. Same fruit, overlapping trials, different answers. The one thing here that is actually sold as a strawberry pill, a 300 milligram leaf extract marketed for memory, missed its own primary endpoint in 109 adults aged 60 to 80.

The numbers, per 100 g

How much is actually in it

• Selenium grown into the strawberry reached the blood. The same selenium in a tablet did not. — 35 healthy adults, male and female, eating experimentally selenium-biofortified strawberries for 30 days (n = 35) Evidence B source
  Biofortification raised the selenium content of the strawberries by 419%; eating them raised serum selenium by about 73.6%, while the standard 100 microgram tablet showed no statistically significant effect; fasting glucose and insulin fell, insulin sensitivity and beta cell function improved, and AST and GGT fell within the normal range

What a real portion looks like

• Forty grams of strawberry powder with a heavy meal cut the insulin needed over the next six hours. Ten and twenty grams did not. — 21 adults with abdominal obesity and insulin resistance, with insulin in the blood measured for six hours after one meal and blood glucose unchanged (n = 21) Evidence B source
  6-hour postmeal insulin was significantly lower after the 40 g beverage than after the others (p<0.05) while 6-hour glucose did not differ; the insulin to glucose ratio differed between beverages; pelargonidin-glucuronide in plasma was inversely associated with mean insulin at 20 and 40 g; oxidised LDL fell after 20 g

What your body absorbs

• Strawberry polyphenols were still in the blood before breakfast on day 45 and day 90, not just after eating. — 19 healthy older adults, 24 g of freeze-dried strawberry a day, stated by the authors as equivalent to 2 cups of fresh strawberries (n = 19) Evidence B source
  21 polyphenolic metabolites measured, comprising 3 anthocyanins or their metabolites, 3 urolithins and 15 phenolic acid metabolites; pelargonidin glucuronide was highest at 85.7 nmol/l 2 hours after breakfast on day 90, and concentrations persisted in fasting samples on days 45 and 90

What cooking and storage change

• Washing fruit under the tap removed about two fifths of pesticide residue. Peeling and juicing removed nearly all of it. — published measurements of pesticide residues in fruits before and after processing; the analysis is of fruit generally and does not separate strawberries (n = not stated as a count of studies) Evidence C source
  Response ratios of 0.59 for washing under tap water, 0.71 for boiling and 0.65 for sun drying; 0.11 for peeling and 0.14 for juicing; oven drying gave a ratio above 1, meaning residues concentrated

What it does to your health

• Pooling eleven trials, strawberries moved one inflammation marker and left blood pressure, cholesterol and blood sugar where they were. — 11 randomised controlled trials: 6 for blood pressure, 7 for lipid profile, 7 for fasting blood glucose, 6 for C-reactive protein (n = 11 trials) Evidence A source
  C-reactive protein fell by 0.63 mg/l (95% CI -1.04 to -0.22) with no effect on blood pressure, lipids or fasting glucose in the main analysis; in people starting above 5 mmol/l total cholesterol fell 0.52 mmol/l, and in those starting above 3 mmol/l LDL fell 0.31 mmol/l
• A second pooled analysis of overlapping trials found the cholesterol effect the first one missed, and also found blood sugar going the wrong way. — 20 groups from 14 clinical trials (n = 14 trials) Evidence A source
  Oxidised LDL -5.8 ng/ml (p=0.012), malondialdehyde -0.309 micromol/l (p=0.002), C-reactive protein -0.472 mg/l (p=0.003), total cholesterol -6.49 mg/dl (p=0.019) and diastolic blood pressure -2.220 mmHg (p=0.033); fasting blood sugar rose by 2.083 mg/dl (p=0.040)

What people believe that the data does not support

• A strawberry leaf extract sold for memory missed its own primary endpoint. — 109 adults aged 60 to 80 with subjective memory complaints (n = 109) Evidence B source
  No significant treatment-by-time interactions for any primary or secondary outcome; exploratory analyses showed within-group improvement in one memory test in the extract group and a between-group difference in that test at weeks 6 and 12 and in perceived stress at week 6; the product was well tolerated
• Europe refused the one claim ever submitted for berries and a heart-friendly diet. — — Evidence E source
  The register holds exactly one entry naming strawberry, submitted for berries as a group, and its status is Non-authorised; the refused wording said berries are very suitable for a heart-friendly diet because of their antioxidants, fibre and low energy and sodium

Who this works differently for

• In the same trial, processing speed improved on strawberries and memory improved on the placebo. — 35 healthy older adults, 17 women and 18 men, average age 72, average BMI 26.4; the dose was stated as the equivalent of 2 cups of fresh strawberries a day (n = 35) Evidence B source
  Processing speed improved during the strawberry phase (p<0.001) while episodic memory improved during the control phase (p=0.002); systolic blood pressure fell with strawberries (p=0.044), serum triglycerides rose in the control phase but not with strawberries, and total antioxidant capacity rose with strawberries and fell in the control phase

The bottom line

Dose showed up once, cleanly. Taken with a heavy meal, 40 grams of strawberry powder lowered the amount of insulin in the blood over the following six hours in 21 adults with abdominal obesity and insulin resistance. Ten grams did nothing. Twenty grams did nothing. Blood glucose itself did not differ at any dose, so what changed was how hard the pancreas had to work for the same result. That is a hormone measured in the blood after one meal. If you inject insulin, nothing on this page says anything about your dose, and that belongs with the person who prescribes it. One finding here used actual fruit. Strawberries grown on purpose to carry more selenium, which is an experiment and not anything on a shelf, 100 grams a day for 30 days, raised blood selenium by about 73.6 percent. A standard 100 microgram selenium tablet, taken in the same trial by another group, did not shift it significantly. Thirty five people and thirty days, so treat that as a lead worth following rather than a result to act on. On washing, we can only give you fruit in general, because the meta-analysis did not separate strawberries out. Rinsing under the tap left about 59 percent of the pesticide residue behind, peeling left about 11 percent and juicing about 14. You cannot peel a strawberry, so rinsing is what you have. Oven drying was the one method that made residues worse, by concentrating them. What this page still cannot tell you is who should be careful with strawberries. We hold no evidence card on allergy or on any other reason to avoid them, so we have written nothing there rather than fill the line from memory.

Sources

1. str-dr-08 · randomised controlled trial
   Biofortification increased the selenium concentration in strawberries by 419%. Supplementation with biofortified strawberries increased serum selenium levels by about 73.6%, while standard selenium supplementation showed no statistically significant effect.
   Nutrients, 2026 · checked 2026-09-22
2. str-dr-03 · randomised controlled crossover trial
   Postmeal insulin concentrations (6 h) were significantly reduced after the 40-g FDS beverage compared to other beverages (p < 0.05). Postmeal 6 h glucose concentrations were not different, although mean insulin:glucose ratio was significantly different among beverages (p < 0.05).
   Mol Nutr Food Res, 2016 · checked 2026-09-22
3. str-dr-04 · randomised controlled trial
   Persistent concentrations of anthocyanins/metabolites, urolithins and some phenolic acids were observed in fasting (t = 0 h) plasma samples on day 45 and 90 after strawberry drink consumption suggesting a role of enteric, enterohepatic recycling or upregulation of gut microbial and/or human metabolism of these compounds.
   Food Funct, 2018 · checked 2026-09-22
4. str-dr-05 · meta-analysis of processing studies
   The response ratios for washing by tap water, boiling and sun drying were 0.59, 0.71 and 0.65, respectively, indicating that they could reduce the pesticide residues effectively.
   Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2014 · checked 2026-09-22
5. str-dr-01 · meta-analysis of randomised controlled trials
   Overall, the strawberry interventions significantly reduced CRP levels by 0.63 (95 % CI -1.04, -0.22) mg/l but did not affect blood pressure, lipid profile or fasting blood glucose in the main analyses.
   Br J Nutr, 2020 · checked 2026-09-22
6. str-dr-02 · systematic review and meta-analysis of randomised controlled trials
   The pooled effect size showed that strawberry supplementation decreased circulating oxidized LDL (MD = -5.8 ng ml-1, p = 0.012), malondialdehyde (0.309 μmol L-1, p = 0.002), C-reactive protein (MD = -0.472 mg L-1, p = 0.003), total cholesterol (MD = -6.49 mg dL-1, p = 0.019), and diastolic blood pressure (MD = -2.220 mmHg, p = 0.033). It also demonstrated raised fasting blood sugar (MD = 2.083 mg dl-1; p = 0.040), but had no effect on other CVD risk factors examined.
   Food Funct, 2019 · checked 2026-09-22
7. str-dr-07 · randomised controlled trial
   No significant treatment-by-time interactions were observed for the primary or secondary outcomes in the mixed-effects models.
   J Nutr Health Aging, 2026 · checked 2026-09-22
8. str-dr-09 · regulatory register entry
   POL-HC-6680 Berries (lingonberry, cloudberry, blueberry, currants, raspberry and strawberry) Natural berries contain plenty of natural antioxidants (polyphenolic compounds, Vitamin C and carotenoids) and fibre but only a small amount of energy and sodium. For this reason they are very suitable for a heart-friendly diet. Non-authorised
   EU Register on nutrition and health claims, заява POL-HC-6680, знімок 2026-09-21 · checked 2026-09-22
9. str-dr-06 · randomised controlled crossover trial
   Processing speed (p < 0.001) improved during the strawberry phase and episodic memory (p = 0.002) improved during the control phase.
   Nutr Metab Cardiovasc Dis, 2025 · checked 2026-09-22