Almonds and walnuts: each lowers LDL a little, and no trial ranks them

In a meta-analysis of 36 publications with 2485 adults without heart disease, eating almonds for at least 4 weeks lowered LDL cholesterol by 5 mg/dL (95% CI 2.9 to 7.3; metric: 0.13 mmol/L, 0.075 to 0.19) and apoB by 4.6 mg/dL, in trials where almond industry funding is common. Walnuts have their own meta-analysis of 26 trials with 1059 people, in which walnut-enriched diets lowered LDL by 5.5 mg/dL more than control diets (95% CI 3.3 to 7.7) without weight gain, and walnut industry funding is common there too. We found no trial that puts the two nuts head to head. The separate analyses used different controls and doses, so their numbers cannot be ranked against each other. A third meta-analysis, of 25 randomized trials with 2155 people, found walnuts lowered apoB slightly and made no significant difference to blood pressure, with systolic pressure 1.20 mmHg lower (95% CI 4.02 lower to 1.61 higher).

How much is actually in it

• Per 100 g, raw almonds carry about three times the calcium and twice the fiber and magnesium of raw walnuts, while walnuts carry more fat. — USDA Foundation Foods sample sets (n = 8 samples per food) Evidence E source
  Calcium 254 vs 88 mg, magnesium 258 vs 142 mg, fiber 10.8 vs 5.2 g, fat 51.1 vs 69.7 g (almonds vs walnuts)

What a real portion looks like

• A standard US serving of either nut is 1 ounce, 28 g, but a cup holds 5 oz (141 g) of almonds versus 4.2 oz (120 g) of walnuts. — FNDDS portion records (n = 2 foods) Evidence E source
  1 oz 28 g both; 1 cup 141 g almonds vs 120 g walnuts; 1 nut 1 g almond vs 2 g walnut

What your body absorbs

• Across 21 studies, the body absorbed less energy from almonds and walnuts than labels predict, about 18.5 kJ per gram for raw almonds, and more from butter or flour than from whole nuts. — 21 human and in vitro studies of almonds, cashews, hazelnuts, pistachios, walnuts and peanuts (n = 21 studies) Evidence C source
  Metabolizable energy below Atwater prediction for all nuts studied, raw almonds 18.5 kJ/g; flour > chopped > whole, butter > roasted > raw

What cooking and storage change

• Lab studies suggest roasting may weaken the birch-pollen type allergen in almond, while the seed storage proteins of almond and walnut stay allergenic after heating. — 32 clinical and in vitro studies of processed tree nuts (n = 32 studies) Evidence D source
  PR-10 allergenicity reduced by heat in hazelnut and almond in vitro; nsLTPs and seed storage proteins heat stable in almond and walnut

What it does to your health

• A meta-analysis of 36 publications with 2485 adults found eating almonds for at least 4 weeks lowered LDL cholesterol by 5 mg/dL (0.13 mmol/L) and apoB by 4.6 mg/dL. — 2485 adults without cardiovascular disease in RCTs of at least 4 weeks, nut-free controls (n = 2485) Evidence A source
  LDL-C -5.1 mg/dL (95% CI -7.3 to -2.9; metric: -0.132 mmol/L, -0.190 to -0.075), ApoB -4.552 mg/dL (-6.460 to -2.645), no effect on HDL-C or Lp(a)
• A meta-analysis of 26 trials with 1059 people found walnut-enriched diets lowered LDL cholesterol by 5.5 mg/dL more than control diets, without weight gain. — 1059 participants in 26 controlled trials comparing walnut-enriched with control diets (n = 1059) Evidence A source
  LDL-C -5.51 mg/dL (95% CI -7.72 to -3.29), 3.73% greater reduction; body weight -0.26 lb (-4.7 to 4.1; metric: -0.12 kg, -2.12 to 1.88)
• A meta-analysis of 25 randomized trials with 2155 people found walnuts lowered apoB slightly but did not change blood pressure. — 2155 participants in 25 RCTs (26 arms) of walnut supplementation (n = 2155) Evidence A source
  ApoB WMD -0.06 (95% CI -0.10 to -0.01), SBP -1.20 mmHg (-4.02 to 1.61), DBP -0.44 mmHg (-2.55 to 1.67)

Safety, limits and interactions

• A 59-year-old woman eating five handfuls of almonds and six tablespoons of chia seeds a day developed oxalate kidney damage that improved on a low-oxalate diet. — one 59-year-old woman with hypertension (n = 1) Evidence C source
  Creatinine rose from 1.3 to 1.8 mg/dL, calcium oxalate deposits on biopsy, improved after diet change

What people believe that the data does not support

• The EU refused the claim that eating 1.1 oz (30 g) of nuts, including almonds and walnuts, a day helps maintain heart health. — EU food labeling Evidence E source
  Non-authorized

Who this works differently for

• A systematic review of 36 studies found challenge-confirmed tree nut allergy in under 2% of people, with walnut and cashew the most common in the US and almond and walnut among the most common in the UK. — 36 population studies of tree nut allergy, 24 in children, 1996 to 2014 (n = 36 studies) Evidence C source
  Challenge-confirmed prevalence <2%, probable 0.05 to 4.9%, with oral allergy syndrome 8 to 11.4%

What is still unknown

• No randomized trial compares almonds and walnuts head to head, so which nut is better for cholesterol or the brain cannot be answered from trials, and the USDA retention table has no data on roasting nuts. — Comparison, cooking and claim searches (n = 0) Evidence E source
  Corpus 0 almond vs walnut RCT; web search 0 head-to-head trial 2024 to 2026; USDA R6 none for nuts; 21 CFR 101 none by name

The bottom line

The nuts differ more on the label. Per 100 g raw, in 8 USDA samples each, almonds carry 254 mg of calcium, 258 mg of magnesium and 10.8 g of fiber. Walnuts carry 88 mg, 142 mg and 5.2 g, and more fat, 69.7 g against 51.1 g. A standard US serving of either nut is 1 ounce, 28 g. A cup holds 5 oz (141 g) of almonds or 4.2 oz (120 g) of walnuts. You likely absorb less energy from whole nuts than the label predicts. A systematic review of 21 human and lab studies found absorbed energy below the standard estimate for every nut it covered, about 18.5 kJ per gram for raw almonds. More was taken up from nut butter than from roasted nuts, and from roasted than from raw. It gives no pooled figure and no number for walnuts. The EU refused a claim that 1.1 oz (30 g) of nuts a day, almonds and walnuts included, helps maintain heart health. Refused means the evidence fell short when it was assessed. Who should be careful: people with tree nut allergy. Across 36 population studies, allergy confirmed by food challenge affected under 2 percent of people, though only seven studies used a challenge. Walnut is among the most common tree nut allergies in the US, and almond and walnut in the UK. Lab studies suggest roasting may weaken the birch-pollen type allergen in almond, while the seed storage proteins of both nuts stay allergenic after heating, so roasting does not make them safe for people with that allergy. One case report describes a 59-year-old woman with hypertension who ate five handfuls of almonds and six tablespoons of chia seeds a day and developed calcium oxalate deposits in her kidneys, which improved on a low-oxalate diet. We have no cards on pregnancy, children or medicines.

Sources

1. alwn-r1-08 · USDA Foundation Foods, dataset
   Nuts, almonds, whole, raw: Calcium 253.6 mg; Magnesium 257.6 mg; Fiber, total dietary 10.78 g; Total lipid 51.09 g. Nuts, walnuts, English, halves, raw: Calcium 88.26 mg; Magnesium 142.4 mg; Fiber, total dietary 5.21 g; Total lipid 69.74 g (8 samples each)
   USDA FoodData Central, Foundation Foods, release 2026-04-30 (8 samples per food) · checked 2026-10-02
2. alwn-r1-09 · USDA FNDDS, dataset
   Almonds, unroasted (FNDDS 42101000): 1 nut = 1 g; 1 cup = 141 g; 1 oz = 28 g. Walnuts, excluding honey roasted (FNDDS 42116000): 1 nut = 2 g; 1 cup = 120 g; 1 oz = 28 g
   USDA FNDDS 2021-2023, food codes 42101000 (FDC 2707486) and 42116000 (FDC 2707531) · checked 2026-10-02
3. alwn-r1-04 · systematic review
   The ME of nuts was consistently lower than that predicted by Atwater factors for investigated nut types (almonds, cashews, hazelnuts, pistachios, walnuts, and peanuts). ... ME was influenced by nut type (ME = 22.6 kJ/g for pistachios; ME = 18.5 kJ/g for raw almonds), physical form (flour > chopped > whole nuts), heat processing (butter > roasted > raw) and dose of consumption.
   Adv Nutr, 2023 · checked 2026-10-02
4. alwn-r1-06 · systematic review, mostly in vitro
   Thermal processing may reduce allergenicity of PR-10 proteins in hazelnut and almond, in contrast to nsLTPs and seed storage proteins.
   Allergy, 2013 · checked 2026-10-02
5. alwn-r1-01 · meta-analysis of randomized trials
   36 publications (48 almond-control datasets) representing 2485 participants were included. Almond consumption significantly reduced LDL-C (-0.132 mmol/L; 95% CI: -0.190, -0.075 mmol/L; p < 0.001)
   Nutrients, 2025 · checked 2026-10-02
6. alwn-r1-02 · meta-analysis of controlled trials
   Twenty-six clinical trials with a total of 1059 participants were included. The following weighted mean differences (WMDs) in reductions were obtained for walnut-enriched diets compared with control groups: -6.99 mg/dL (95% CI: -9.39, -4.58 mg/dL; P < 0.001) (3.25% greater reduction) for total blood cholesterol (TC) and -5.51 mg/dL (95% CI: -7.72, -3.29 mg/dL; P < 0.001) (3.73% greater reduction) for low-density lipoprotein (LDL) cholesterol.
   Am J Clin Nutr, 2018 · checked 2026-10-02
7. alwn-r1-03 · meta-analysis of randomized trials
   Twenty-five RCTs comprising 26 intervention arms with 2155 patients were included. Walnut significantly decreased ApoB (WMD = -0.06; 95% CI: -0.10, -0.01, p = 0.002), but did not affect ApoA1 (WMD = -0.50; 95% CI: -1.34, 0.33, p = 0.249), systolic blood pressure (SBP) (WMD = -1.20; 95% CI: -4.02, 1.61, p = 0.401) and diastolic blood pressure (DBP) (WMD = -0.44; 95% CI: -2.55, 1.67, p = 0.682).
   Endocrinol Diabetes Metab, 2026 · checked 2026-10-02
8. alwn-r1-07 · case report
   Diet included six tablespoons of chia seeds and five handfuls of almonds daily to manage IBS symptoms. ... Renal biopsy showed glomerulosclerosis, fibrosis and calcium oxalate deposition.
   BMJ Case Rep, 2020 · checked 2026-10-02
9. alwn-r1-10 · EU claim register
   POL-HC-7666 Nuts - peanuts and tree nuts (almonds, hazelnuts, pecans, pistachios and walnuts), excluding brazil, macadamia and cashew nuts Eating 30g of nuts per day as part of a balanced diet helps maintain heart health. Non-authorised
   EU Register on nutrition and health claims, claim POL-HC-7666, snapshot 2026-09-21 · checked 2026-10-02
10. alwn-r1-05 · systematic review
    Challenge-confirmed IgE-mediated tree nut allergy prevalence was less than 2 % (although only seven studies used this gold standard) while probable tree nut allergy prevalence ranged from 0.05 to 4.9 %. ... Prevalence of individual tree nut allergies varied significantly by region with hazelnut the most common tree nut allergy in Europe, walnut and cashew in the USA and Brazil nut, almond and walnut most commonly reported in the UK.
    Curr Allergy Asthma Rep, 2015 · checked 2026-10-02
11. alwn-r1-11 · search record
    entity_brief.py almonds | walnuts: R6 — product unknown; 21 CFR — no mention; corpus — no almond vs walnut randomised trial
    Bioma corpus and dataset search (PubMed corpus, USDA R6, 21 CFR 101) and web search, 2026-10-02 · checked 2026-10-02