Soy nut butter: a peanut-free spread with a small cholesterol effect

Soy nut butter is mostly bought as a peanut-free spread for lunchboxes, and people who eat it for their heart are counting on soy protein. That effect is real and small. Across 43 controlled trials in adults whose LDL cholesterol started between 110 and 201 mg/dL, a median 25 g of soy protein a day for 6 weeks lowered LDL by 4.76 mg/dL (95% CI 2.80 to 6.71), with moderate differences between trials. Getting 25 g of soy protein from this spread takes about 108 g. A 16 g tablespoon gives about 98 calories and 3.7 g of protein in US survey data, a composite recalculated from 100 g, and brands differ in added sugar, oil and salt. The closest test of the food itself used whole roasted soy nuts, and we found no trial of the ground spread. In a 16-week crossover in 23 healthy adults aged 60 to 70, 2.4 oz (67 g) of soy nuts a day raised flow-mediated dilation by 1.48 percentage points (95% CI 0.08 to 2.89). LDL fell by 6.6 mg/dL (0.77 to 12; metric: 0.17 mmol/L, 0.02 to 0.32) and mean arterial pressure by 3 mmHg (0 to 6), and two of those limits sit close to zero. Soy is itself a declared major allergen, so the spread replaces peanut butter only for people who tolerate soy.

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• USDA survey data put soy nut butter at 613 calories and 23 g of protein per 3.5 oz (100 g), so one 16 g tablespoon gives about 98 calories and 3.7 g of protein. — FNDDS food code 42203200, Soy nut butter, US survey portions Evidence E source
  Per 100 g: energy 613 calories, protein 23.02 g; 1 tablespoon 16 g = 98.1 calories and 3.7 g protein; per sandwich 32 g = 196.2 calories and 7.4 g protein

What your body absorbs

• The soy isoflavones in soy nuts are absorbed: after 16 weeks at 67 g a day, serum genistein was 454 ng/mL and daidzein 128 ng/mL higher than in the no-nut period. — 23 healthy adults aged 60 to 70 in a 16-week soy nut versus no-nut crossover (n = 23) Evidence B source
  Serum daidzein +127.8 ng/mL (95% CI 74.3 to 181.3); genistein +454.2 ng/mL (266.6 to 641.8)

What it does to your health

• In a 16-week crossover trial in 23 adults aged 60 to 70, eating 2.4 oz (67 g) of soy nuts a day raised flow-mediated dilation by 1.48 points and lowered LDL cholesterol by 6.6 mg/dL (0.17 mmol/L) and mean arterial pressure by 3 mmHg. — 23 healthy men and women aged 60 to 70, BMI 20 to 30, 67 g soy nuts a day (25.5 g protein, 174 mg isoflavones) versus no nuts for 16 weeks each, 8-week washout (n = 23) Evidence B source
  Brachial flow-mediated dilation +1.48 percentage points (95% CI 0.08 to 2.89); LDL cholesterol -6.6 mg/dL (0.77 to 12; metric: -0.17 mmol/L, 0.02 to 0.32); mean arterial pressure -3 mmHg (0 to 6); arterial stiffness unchanged
• Across 43 randomized trials, soy protein cut LDL cholesterol by 8.9 mg/dL (0.23 mmol/L) (5.5%) in parallel studies and 6.2 mg/dL (0.16 mmol/L) (4.2%) in crossover studies. — 20 parallel and 23 crossover randomized trials, up to 65 g soy protein a day, LDL measured at 4 to 18 weeks (n = 43 trials) Evidence A source
  LDL -8.9 mg/dL (95% CI -11 to -7; metric: -0.23 mmol/L, -0.28 to -0.18) parallel, -6.2 mg/dL (-8.5 to -4.3; metric: -0.16 mmol/L, -0.22 to -0.11) crossover; triglycerides 10.7% lower and HDL 3.2% higher in parallel studies

Safety, limits and interactions

• Across 18 soy trials, free T3 and T4 did not change and TSH rose by only 0.25 mIU/L, a change of unclear clinical meaning. — participants of randomized trials using soy or soy products as intervention with fT3, fT4 and TSH measured (n = 18 articles) Evidence A source
  FT3 +0.027 pmol/L (95% CI -0.052 to 0.107); fT4 -0.003 pmol/L (-0.018 to 0.011); TSH +0.248 mIU/L (0.001 to 0.494)
• Soy allergy is uncommon in Europe: 0.5% report it over a lifetime and 0.3% have it confirmed by food challenge, compared with 1.5% self-reported for peanut. — 93 European studies of food allergy prevalence across all age groups, published to 2021 (n = 93 studies) Evidence C source
  Soy self-reported lifetime 0.5% (95% CI 0.3 to 0.7), challenge-verified 0.3% (0.1 to 0.4); peanut self-reported 1.5% (1.0 to 2.1)
• A 2017 US outbreak of E. coli O157:H7 traced to one soy nut butter brand sickened 32 people in 12 states, 81% of them children, and 9 developed kidney failure syndrome. — 32 outbreak cases in 12 US states, January to April 2017, ages 1 to 70, median 9 (n = 32) Evidence D source
  26 of 32 (81%) under 18; 12 hospitalized (38%); 9 hemolytic uremic syndrome (28%), 8 of them children; no deaths; over 1.2 million pounds recalled

What people believe that the data does not support

• Pooling the 43 usable trials the FDA itself named, a median 25 g of soy protein a day for 6 weeks lowered LDL cholesterol by 4.76 mg/dL, about 3 to 4%. — adults with baseline LDL cholesterol 110 to 201 mg/dL in 43 of the 46 controlled trials identified by the FDA (n = 43 trials) Evidence A source
  LDL cholesterol -4.76 mg/dL (95% CI -6.71 to -2.80); total cholesterol -6.41 mg/dL (-9.30 to -3.52); no dose-response
• US rules let a food label say that diets low in saturated fat and cholesterol that include 25 g of soy protein a day may reduce the risk of heart disease. — US food labeling, authorized health claim for soy protein Evidence E source
  Authorized claim with a 25 g a day threshold; one tablespoon of soy nut butter supplies about 3.7 g of protein
• The EU refused the same heart claim that the US allows: soy protein lowering blood cholesterol is non-authorized on European labels. — European Union food labeling, claim on soy protein Evidence E source
  Claim status non-authorized; no authorized EU claim for soy protein or soybean

Who this works differently for

• IgE-mediated soy allergy was estimated at 0.27% in the general population but 2.7% among children who already have other allergies. — 40 studies of soy sensitization and allergy, mostly children and infants fed soy-based formula (n = 40 studies) Evidence C source
  Weighted prevalence 0.27% general population (range 0 to 0.5), 1.9% referred population, 2.7% allergic children (range 0 to 12.9)
• In children with leukemia on maintenance chemotherapy, 1.1 oz (30 g) of soy nut a day for 12 weeks improved weight, hemoglobin and fatigue more than cowpea nut. — 56 children with B-cell acute lymphoblastic leukemia aged about 6, randomized to 30 g/day soy nut or cowpea nut powder for 12 weeks (n = 56) Evidence B source
  Energy and protein intake, body weight, BMI, red cells, hemoglobin, hematocrit and fatigue significantly better with soy nut (P<0.05); sizes not given in the abstract

What is still unknown

• In a meta-analysis of 21 nut trials, only pistachios lowered systolic pressure on their own, by 1.82 mmHg, and soy nuts did not show a significant effect. — adults 18 and over in 21 randomized trials of walnuts, almonds, pistachios, cashews, hazelnuts, macadamias, pecans, peanuts and soy nuts, at least 2 weeks (n = 21 trials) Evidence A source
  Pistachios systolic -1.82 mmHg (95% CI -2.97 to -0.67); other nut types including soy nuts not significant

The bottom line

Labels tell two stories. US rules still let a food say that 25 g of soy protein a day, in a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. The EU register lists the same cholesterol claim for soy protein as non-authorized. That means the evidence did not carry for that wording when it was assessed, and the 4.76 mg/dL effect above still stands. Blood pressure is the open question. A meta-analysis of 21 nut trials found a significant drop in systolic pressure only for pistachios, 1.82 mmHg, and soy nuts did not reach significance. Few soy nut trials sat inside that subgroup, so the result is imprecise, and the single later trial found mean arterial pressure 3 mmHg lower. Soy is a declared major allergen, so the spread replaces peanut butter only for people who tolerate soy. In pooled European studies 0.5% of people reported a soy allergy over their lifetime (95% CI 0.3 to 0.7), against 1.5% for peanut. Pooled observational studies put IgE-mediated soy allergy at 0.27% in the general population and 2.7% in children who already have other allergies, the group most likely to be handed this spread. Across 18 randomized soy trials, mostly with supplements and isolated soy, free T3 and T4 did not change and TSH rose by 0.25 mIU/L (95% CI 0.001 to 0.494). The authors call the clinical meaning of that rise unclear. In 2017 one brand of soy nut butter contaminated with E. coli O157:H7 made 32 people ill in 12 US states. The investigation traced it to a single contaminated plant. Even so, 26 of the 32 were under 18 and 9 developed hemolytic uremic syndrome, a form of kidney failure. The one trial in sick children gave 1.1 oz (30 g) a day of soy nut powder to 56 children with leukemia for 12 weeks, and weight, hemoglobin and fatigue improved more than with cowpea. Its abstract reports only P values, with no sizes of effect.

Sources

1. snbt-r4-01 · USDA FNDDS, dataset
   Soy nut butter (FNDDS 42203200, fdc_id 2707545, WWEIA Soy and meat-alternative products): Energy 613 kcal per 100 g; Protein 23.02 g per 100 g; 1 tablespoon = 16 g (98.1 kcal, 3.7 g protein); Guideline amount per sandwich = 32 g (196.2 kcal, 7.4 g protein)
   USDA FNDDS, FoodData Central survey food 2707545, code 42203200 · checked 2026-09-29
2. snbt-r4-03 · randomized controlled trial in humans
   Serum isoflavone concentrations were higher after the intervention as compared with the control period (daidzein: 127.8 ng/mL; 95% CI: 74.3-181.3 ng/mL; p < 0.001 and genistein: 454.2 ng/mL; 95% CI: 266.6-641.8 ng/mL; p < 0.001).
   Clin Nutr, 2022 · checked 2026-09-29
3. snbt-r4-02 · randomized controlled trial in humans
   Brachial artery flow-mediated vasodilation was 1.48 percent points (pp; 95% CI: 0.08-2.89 pp; p = 0.040) higher following soy nut intake. The carotid artery reactivity response and arterial stiffness did not differ. Serum LDL-cholesterol was lower (0.17 mmol/L; 95% CI: 0.02-0.32 mmol/L; p = 0.027), while HDL-cholesterol and triacylglycerol concentrations were comparable. Mean arterial pressure (MAP) was lower (3 mmHg; 95% CI: 0-6 mmHg; p = 0.035).
   Clin Nutr, 2022 · checked 2026-09-29
4. snbt-r4-05 · meta-analysis of RCTs
   Soy protein intake was associated with net changes in serum LDL-cholesterol values of -0.23 mmol/l (95% CI, -0.28 to -0.18 mmol/l) or a 5.5% reduction in parallel studies and -0.16 mmol/l (95% CI, -0.22 to -0.11 mmol/l) or a reduction of 4.2% with crossover studies (p < 0.001 for parallel vs crossover).
   J Am Coll Nutr, 2011 · checked 2026-09-29
5. snbt-r4-07 · meta-analysis of RCTs
   Soy supplementation has no effect on the thyroid hormones and only very modestly raises TSH levels, the clinical significance, if any, of the rise in TSH is unclear.
   Sci Rep, 2019 · checked 2026-09-29
6. snbt-r4-08 · meta-analysis of observational studies
   The overall pooled estimates for all age groups of self-reported lifetime prevalence were as follows: cow's milk (5.7%, 95% confidence interval 4.4-6.9), egg (2.4%, 1.8-3.0), wheat (1.6%, 0.9-2.3), soy (0.5%, 0.3-0.7), peanut (1.5%, 1.0-2.1), tree nuts (0.9%, 0.6-1.2), fish (1.4%, 0.8-2.0) and shellfish (0.4%, 0.3-0.6).
   Allergy, 2023 · checked 2026-09-29
7. snbt-r4-11 · outbreak investigation
   We identified 32 cases from 12 states [Figure 1]. Illness onset dates ranged from January 4, 2017 – April 18, 2017 [Figure 2]. Case-patients were 41% female, and ages ranged from 1–70 years (median: 9). Twenty-six (81%) case-patients were children < 18 years old, including 11 (34%) < 5 years. Twelve (38%) hospitalizations and no deaths were reported. Nine (28%) case-patients developed HUS; of these, 8 (89%) were children < 18 years old, including 3 (33%) children < 5 years old.
   Pediatrics, 2019 · checked 2026-09-29
8. snbt-r4-04 · meta-analysis of RCTs
   Soy protein at a median dose of 25 g/d during a median follow-up of 6 wk decreased LDL cholesterol by 4.76 mg/dL (95% CI: -6.71, -2.80 mg/dL, P < 0.0001; I2 = 55%, P < 0.0001) and decreased TC by 6.41 mg/dL (95% CI: -9.30, -3.52 mg/dL, P < 0.0001; I2 = 74%, P < 0.0001) compared with non-soy protein controls.
   J Nutr, 2019 · checked 2026-09-29
9. snbt-r4-12 · regulatory health claim
   (2) Diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease. One serving of [name of food] provides ____ grams of soy protein.
   21 CFR 101.82, Health claims: Soy protein and risk of coronary heart disease · checked 2026-09-29
10. snbt-r4-13 · regulatory register entry
    POL-HC-6260 Soy protein Soy protein has been shown to lower/reduce blood cholesterol; blood cholesterol lowering may reduce the risk of (coronary) heart disease -/- Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6260, snapshot 2026-09-21 · checked 2026-09-29
11. snbt-r4-09 · meta-analysis of observational studies
    The 40 studies identified established weighted prevalence of soy allergies of 0 to 0.5 % (0.27) for the general population, 0.4 to 3.1 % (1.9) for the referred population, and 0 to 12.9 % (2.7) for allergic children.
    Clin Rev Allergy Immunol, 2014 · checked 2026-09-29
12. snbt-r4-10 · randomized controlled trial in children
    The total energy and protein intake, and physical activity as well as body weight, body mass index, number of red blood cells, hemoglobin and hematocrit levels, and fatigue were significantly improved in the soy nut group compared to patients who consumed cowpea nut (P < 0.05).
    Nutr Cancer, 2018 · checked 2026-09-29
13. snbt-r4-06 · meta-analysis of RCTs
    Subgroup analyses of different nut types suggest that pistachios, but not other nuts, significantly reduce SBP (MD: -1.82; 95% CI: -2.97, -0.67; P = 0.002).
    Am J Clin Nutr, 2015 · checked 2026-09-29