Sunflower seed kernels: what an ounce really gives you

A systematic review of 13 randomized trials lasting 24 weeks or longer found no evidence that eating nuts, seeds and seed oils improves weight, blood glucose or blood lipids in adults over the long term. Sunflower kernels were pooled with everything else there, the search ended in May 2011, and we found no trial that fed people whole sunflower kernels. What the kernels plainly do is pack minerals into a small, energy-dense handful. An ounce of shelled kernels is 28 g and about 163 calories, recalculated from 100 g. Per 100 g, dry roasted salted kernels hold 358 mg of magnesium, 1.83 mg of copper, 21.0 g of protein and 56.1 g of fat, with little spread across 6 USDA samples. Salt is the number to watch. Salted kernels carry 462 mg of sodium per 3.5 oz (100 g) against 3 mg unsalted, about 131 mg in a salted ounce, and brands range from 405 to 652 mg per 3.5 oz (100 g).

The numbers, per 3.5 oz (100 g)

How much is actually in it

• Per 100 g, dry roasted salted sunflower kernels hold 56.1 g fat, 21.0 g protein, 358 mg magnesium and 1.83 mg copper, with little spread between samples. — — (n = 6 samples) Evidence E source
  Fat 56.1 g (53.5-58.3), magnesium 358 mg (338-386), copper 1.83 mg (1.74-1.92), protein 21.0 g (20.1-22.8), fiber 10.3 g (9.6-11.0, 3 samples)

What a real portion looks like

• An ounce of shelled sunflower kernels is 28 g and about 163 calories, and a cup of seeds in the shell yields only 1.6 oz (46 g) of kernels. — — Evidence E source
  Unsalted kernels 582 calories per 3.5 oz (100 g); 1 oz 28 g about 163 calories; 1 cup without shell 144 g about 838 calories; 1 cup in shell yields 46 g
• Salted sunflower kernels carry 462 mg sodium per 3.5 oz (100 g) against 3 mg unsalted, so an ounce of salted kernels adds about 131 mg sodium. — — Evidence E source
  Sodium 462 vs 3 mg per 3.5 oz (100 g); 1 oz 131 vs 0.9 mg; Foundation dry roasted salted samples 405-652 mg (n=6)

What cooking and storage change

• By the USDA table for Nut and Seed Products, roasting keeps all the magnesium, copper, zinc and iron but about 80% of folate and 85% of thiamin. — — Evidence E source
  Retained: magnesium, copper, zinc, iron, potassium 100%; sodium, riboflavin, niacin, B6 95%; thiamin 85%; folate, phosphorus 80%

What it does to your health

• A systematic review of 13 randomized trials lasting 24 weeks or more found no evidence that long-term intake of nuts, seeds and seed oils improves weight, glucose or lipids in adults. — adults in 13 RCTs of 24 to 52+ weeks (n = 13 RCTs) Evidence A source
  Consistent HDL increase at 24 weeks; no statistical difference in 4 studies of 48 weeks or more
• In a 12-week double-blind RCT in 100 adults with a BMI of 25 to 31.9, 500 mg a day of sunflower seed extract cut body fat by 2 lb (0.9 kg) against 0.22 lb (0.1 kg) on placebo. — 100 adults with BMI 25 to 31.9, 12 weeks, 1 tablet/day of 500 mg extract with 100 mg chlorogenic acids (n = 100) Evidence B source
  Body fat mass -0.9 +/- 1.8 kg vs -0.1 +/- 1.4 kg, P = .043
• In a randomized crossover trial in 11 healthy adults, crackers with 30% sunflower seed flour had a glycemic index of 53 against 90 for conventional crackers. — 11 healthy adults (mean age 23.5, 7 women), single test meals with 50 g available carbohydrate (n = 11) Evidence B source
  GI 53 (sunflower seed flour) vs 77 (30% whole wheat) vs 90 (control); GL 6 vs 11 vs 12 per serving

Safety, limits and interactions

• A case report describes anaphylaxis in a 38-year-old woman within minutes of eating cookies with sunflower seeds, with IgE to heat-resistant 2S albumins. — one 38-year-old woman with asthma and pollinosis, Japan (n = 1) Evidence D source
  Anaphylaxis; skin prick 4+; basophil activation 50.6% at 10 ug/mL

Who this works differently for

• In a pediatric allergy clinic cohort of 235 children with sunflower seed allergy, a quarter of reactions met anaphylaxis criteria and the odds of diagnosis rose 21% a year from 1995 to 2021. — 235 patients with sunflower seed allergy in one pediatric allergy clinic, 1995-2021, median age at diagnosis 3.9 years (n = 235) Evidence C source
  Odds of diagnosis +21% per year (OR 1.21, 95% CI 1.17 to 1.25); cumulative incidence up to 0.38% (2021)

What is still unknown

• Selenium and vitamin E in sunflower kernels vary widely, from 48.2 to 97.7 ug selenium and 14.4 to 22.3 mg vitamin E per 3.5 oz (100 g) across samples. — — (n = 3 samples) Evidence E source
  Selenium 80.4 ug (48.2-97.7, spread 62%); vitamin E 19.6 mg (14.4-22.3, spread 40%) per 3.5 oz (100 g)

The bottom line

Two nutrients sunflower kernels are known for vary a lot from bag to bag. Across only 3 USDA samples, selenium ran from 48.2 to 97.7 mcg per 3.5 oz (100 g) and vitamin E from 14.4 to 22.3 mg. Selenium depends on the soil, and the lowest sample held about half the selenium of the highest. Roasting is gentle on the minerals. By the USDA retention table for roasted nuts and seeds, magnesium, copper, zinc and iron stay at 100%, while thiamin falls to about 85% and folate to about 80%. Those are group factors dated 1975 and not measured on sunflower kernels. The table has no row for vitamin E or selenium, so we cannot say how roasting treats them. Two trials used sunflower seed products other than the kernels you buy. In a 12-week double-blind trial in 100 adults with a BMI of 25 to 31.9, one 500 mg tablet a day of a concentrated sunflower seed extract cut body fat by 2 lb (0.9 kg) against 0.22 lb (0.1 kg) on placebo. That is a small absolute change, from a single trial of an extract. In 11 healthy young adults, crackers made with 30% sunflower seed flour had a glycemic index of 53, against 77 for crackers with 30% whole wheat and 90 for ordinary crackers. Each cracker was tested once, as a single meal, in a very small group. The caution we have evidence for is allergy, and it reaches young children. In one pediatric allergy clinic, 235 patients were diagnosed with sunflower seed allergy between 1995 and 2021, at a median age of 3.9 years. A quarter of their reactions met the criteria for anaphylaxis, and the odds of a diagnosis rose 21% a year (odds ratio 1.21, 95% CI 1.17 to 1.25). This is a single referral center, and part of the rise may reflect sunflower butter replacing peanut butter. Baking did not protect one allergic adult. A 38-year-old woman in Japan had anaphylaxis within minutes of eating cookies containing sunflower seeds, and her IgE targeted 2S albumins, proteins that resist heat. That single case shows the allergen survives baking. It says nothing about how often this happens. We have no card on sunflower kernels with medicines or in pregnancy.

Sources

1. ssk6-01 · food composition dataset
   Seeds, sunflower seed kernels, dry roasted, with salt added, FDC 325524: Total lipid (fat) 56.1 g range 53.5-58.3 n=6 | Protein 21.0 g range 20.1-22.8 | Magnesium 358 mg range 338-386 n=6 | Copper 1.83 mg range 1.74-1.92 n=6 | Fiber, total dietary 10.3 g range 9.6-11.0 n=3 per 100 g
   USDA FoodData Central, Foundation Foods, release 2026-04-30, Seeds, sunflower seed kernels, dry roasted, with salt added, FDC 325524 · checked 2026-10-02
2. ssk6-03 · food composition dataset
   Sunflower seeds, plain, unsalted, FNDDS 43102000, fdc_id 2707582: 1 cup, without shell 144 g | 1 cup, in shell, yields 46 g | 1 oz, without shell 28 g | 1 oz, in shell, yields 15 g || Energy 582 kcal per 100 g
   USDA FNDDS (FoodData Central survey 2024-10-31), Sunflower seeds, plain, unsalted 43102000 fdc_id 2707582; plain, salted fdc_id 2707583 · checked 2026-10-02
3. ssk6-04 · food composition dataset
   Sunflower seeds, plain, unsalted, fdc_id 2707582: Sodium, Na 3 mg per 100 g, 1 oz without shell 28 g 0.9 mg; Sunflower seeds, plain, salted, fdc_id 2707583: Sodium, Na 462 mg per 100 g, 1 oz without shell 28 g 131.0 mg
   USDA FNDDS (FoodData Central survey 2024-10-31), Sunflower seeds, plain, unsalted 43102000 fdc_id 2707582; plain, salted fdc_id 2707583 · checked 2026-10-02
4. ssk6-05 · nutrient retention table
   USDA-RETN-R6:2203 NUTS,ROASTED (Nut and Seed Products): folate_total_ug 80% | thiamin_mg 85% | phosphorus_mg 80% | magnesium_mg 100% | copper_mg 100% | zinc_mg 100% | iron_mg 100% | potassium_mg 100%
   USDA Table of Nutrient Retention Factors, Release 6 (2007), Nut and Seed Products, NUTS,ROASTED, Retn_Code 2203 · checked 2026-10-02
5. ssk6-06 · systematic review of RCTs
   Thirteen studies met the inclusion criteria; eight studies had a 24 weeks intervention period, one had 42 weeks, one had 48 weeks, and for the other three the intervention lasted 52 or more weeks. ... CONCLUSION: No evidence of long-term improvement of NSO on weight, glucose or lipids in the adult population was found.
   Nutr Hosp, 2012 · checked 2026-10-02
6. ssk6-07 · randomized controlled trial
   The group that received SUN-CA daily showed decreases in body fat mass greater than those in the placebo group (-0.9 ± 1.8 kg vs. -0.1 ± 1.4 kg, P = .043).
   Nutr Res, 2024 · checked 2026-10-02
7. ssk6-08 · randomized crossover trial
   The SFC crackers provided low GI and GL values (GI: 53 on the glucose scale, GL: 6 per serving), whereas the WWC and CC crackers provided high GI (GI: 77 and 90 on the glucose scale, respectively) and medium GL values (11 and 12 per serving, respectively).
   Eur J Clin Nutr, 2024 · checked 2026-10-02
8. ssk6-10 · case report
   A 38-year-old woman developed throat discomfort, dyspnea, and generalized urticaria within minutes of ingesting cookies containing sunflower seeds and was diagnosed with anaphylaxis.
   J Dermatol, 2026 · checked 2026-10-02
9. ssk6-09 · retrospective cohort
   Half of the reactions consisted of mild urticaria or rash, and a quarter met criteria for anaphylaxis. The cumulative incidence ranged from 0% (1995-1999, 2001-2004, and 2006) to 0.38% (2021). From 1995 to 2021, the odds of sunflower seed allergy diagnosis increased annually by 21% (odds ratio, 1.21; 95% CI, 1.17-1.25).
   J Allergy Clin Immunol Pract, 2024 · checked 2026-10-02
10. ssk6-02 · food composition dataset
    Seeds, sunflower seed kernels, dry roasted, with salt added, FDC 325524: Selenium, Se 80.4 ug range 48.2-97.7 median 95.4 n=3 | Vitamin E (alpha-tocopherol) 19.6 mg range 14.4-22.3 median 22.3 n=3 per 100 g
    USDA FoodData Central, Foundation Foods, release 2026-04-30, Seeds, sunflower seed kernels, dry roasted, with salt added, FDC 325524 · checked 2026-10-02