Silk Vanilla soymilk: what swapping it for cow milk does to cholesterol

By a meta-analysis of 17 randomized trials in 504 adults, replacing a median 17 fl oz (500 mL) a day of cow milk with soymilk lowered LDL cholesterol by 7.3 mg/dL (95% CI 3.5 to 11; metric: 0.19 mmol/L, 0.09 to 0.29) and systolic pressure by 8 mmHg (95% CI 1.1 to 14.9). Some of those drinks carried 17.2 g of added sugar per 250 mL, and the sugar did not meaningfully change the result. That is the relevant finding here, because Silk Vanilla is sweetened. The comparison in every trial was cow milk, and we found no trial of this brand or of the vanilla flavor itself. Per 100 g, USDA lists Silk Vanilla at 41 calories with 2.47 g protein and 2.88 g sugars, in a record from 2019, so the recipe on the shelf may have changed since.

How much is actually in it

• An audit of 129 plant-based milks found 80.6% fortified with calcium but only 27.1% with vitamin B12, while soy milk matched cow milk for protein. — 129 plant-based milk products in Illawarra (Australia) supermarkets, label and ingredient analysis (n = 129) Evidence C source
  Calcium fortified 80.6%; vitamin B12 27.1%; iodine 3.1%; soy vs cow milk protein not different
• Per 100 g, USDA lists Silk Vanilla soymilk at 41 calories with 2.47 g protein, 2.88 g sugars, 123 mg calcium and 1.23 ug vitamin B12, while Very Vanilla carries 6.58 g sugars. — USDA SR Legacy records FDC 175219 SILK Vanilla soymilk and FDC 173774 SILK Very Vanilla soymilk, per 3.5 oz (100 g) Evidence E source
  Vanilla: 41 calories, protein 2.47 g, sugars 2.88 g, calcium 123 mg, vitamin D 1.2 ug, B12 1.23 ug, riboflavin 0.21 mg; Very Vanilla: 53 calories, sugars 6.58 g, calcium 144 mg

What a real portion looks like

• USDA sets one serving of Silk Vanilla soymilk at 1 cup (243 g), which works out to about 100 calories, 6 g protein, 7 g sugars and 3 ug vitamin B12. — USDA SR Legacy FDC 175219, household portion 1 cup = 243 g Evidence E source
  Per 243 g: about 100 calories, 6.0 g protein, 7.0 g sugars, 299 mg calcium, 3.0 ug vitamin B12, 2.9 ug vitamin D

What your body absorbs

• In a randomized crossover test in 12 osteopenic postmenopausal women, calcium from calcium-fortified soymilk was absorbed at the same hourly rate as calcium from cow milk (0.65 vs 0.66). — 12 osteopenic post-menopausal women aged about 57, single-blind acute crossover with radiocalcium tracer (n = 12) Evidence B source
  Hourly fractional calcium absorption 0.65 (soymilk) vs 0.66 (cow milk), p > 0.05
• In a crossover trial of 59 adults, isoflavones from soy milk reached the blood faster than from other soy foods, and only 30% of people produced equol. — 21 premenopausal women, 17 postmenopausal women and 21 men, single dose 0.44 mg isoflavones per kg from soy milk, textured vegetable protein and tempeh (n = 59) Evidence B source
  Soy milk: faster absorption and earlier peak; equol producers 30%, no age or sex difference

What cooking and storage change

• A review of processing studies says antioxidants in plant-based milks can be lost during production through heat, oxidation or leaching into processing water. — Laboratory studies of plant-based milk processing steps: soaking, blanching, grinding, filtration, microbial inactivation Evidence D source
  Qualitative, no pooled estimate

What it does to your health

• By a meta-analysis of 17 RCTs in 504 adults, swapping 17 fl oz (500 mL) a day of cow milk for soymilk lowered LDL cholesterol by 7.3 mg/dL (0.19 mmol/L), and added sugar in the soymilk did not change the result. — 504 adults with a range of health statuses in 17 randomized trials of at least 3 weeks, median 17 fl oz (500 mL) soymilk a day with 17.2 g or 6.9 g added sugars per 250 mL (n = 504) Evidence A source
  LDL -7.3 mg/dL (95% CI -11 to -3.5; metric: -0.19 mmol/L, -0.29 to -0.09); non-HDL -0.26 (-0.43 to -0.10); SBP -8.00 mmHg (-14.89 to -1.11); CRP -0.82 mg/L; no effect modification by added sugars
• By a network meta-analysis of 14 RCTs in 543 people, replacing 17 fl oz (500 mL) a day of cow milk with soy drink may lower LDL cholesterol by 18 mg/dL (0.47 mmol/L) and systolic pressure by 8 mmHg, with low certainty. — 543 participants in 14 randomized trials of at least 3 weeks comparing soy, rice and oat drinks and cow milk (n = 543) Evidence A source
  LDL MD -18 mg/dL (-33 to -3.9; metric: -0.47 mmol/L, -0.85 to -0.10); SBP -8.23 mmHg (-10.90 to -5.55); DBP -7.82 mmHg (-13.61 to -2.02); low certainty
• In an 8-week RCT of 66 patients with fatty liver disease on a calorie-reduced diet, 8.1 fl oz (240 ml) of soy milk a day lowered HOMA-IR by 0.45 versus 0.14 and systolic pressure by 3.8 versus 1.5 mmHg. — 66 patients with non-alcoholic fatty liver disease, 500 calories deficit diet, 240 ml/day soy milk for 8 weeks vs diet alone (n = 66) Evidence B source
  Insulin -3.44 vs -1.09 uIU/ml; HOMA-IR -0.45 vs -0.14; SBP -3.81 vs -1.48 mmHg; fasting glucose unchanged
• In a crossover RCT of 12 healthy men, drinking soy milk 30 minutes before white bread lowered post-meal glucose more than drinking it with the bread. — 12 healthy Chinese men, 5 test occasions, white wheat bread with water as reference (n = 12) Evidence B source
  Preload lowered glycemia and insulinemia vs co-ingestion; co-ingested soy milk raised insulin response vs dairy

Safety, limits and interactions

• The FDA lists soybeans among the nine major food allergens in the US, so a soy drink carries a declared allergen. — US consumers, Federal Food, Drug, and Cosmetic Act major food allergens Evidence E source
  Soybeans are 1 of 9 major allergens
• A case report describes a 70-year-old man stable on warfarin whose INR fell below range after he started soy milk and recovered within 2 weeks of stopping it. — 1 patient, 70-year-old man on stable warfarin therapy (n = 1) Evidence D source
  Subtherapeutic INR on soy milk; therapeutic within 2 weeks after stopping; causality possible to probable

What people believe that the data does not support

• A systematic review of 74 studies found that soy milk did not prevent food allergy in people at high or normal allergy risk. — 74 studies of food allergy prevention in children and adults, searched to September 2012 (n = 74 studies) Evidence C source
  No preventive benefit of soy milk
• US rules allow a heart claim for soy protein only at 25 g a day within a diet low in saturated fat, and one cup of this drink supplies about 6 g. — 21 CFR 101.82 authorized health claim, soy protein and coronary heart disease Evidence E source
  25 g soy protein a day in the model claim; SR Legacy 175219: 2.47 g protein per 3.5 oz (100 g) x 243 g cup = about 6.0 g

What is still unknown

• A systematic review of 8 randomized trials with 263 people found the lipid-lowering effect of soy milk limited and inconsistent, with 3 trials showing no change in any blood lipid. — 263 subjects in 8 randomized clinical trials of soy milk and serum lipids, searched to May 2018 (n = 263) Evidence A source
  No pooled estimate; LDL fell in 3 of 8 trials, no lipid change in 3
• Observational data link each daily cup of plant-based drink in five-year-olds with about 0.08 in (0.2 cm) less height and 0.22 lb (0.1 kg) less weight, and no randomized trial has compared these drinks with cow milk in children. — Infants, children and adolescents in cross-sectional and cohort studies of plant-based milk alternatives Evidence C source
  Per cup: height-for-age z -0.04 (-0.07 to -0.01), BMI-for-age z -0.06 (-0.09 to -0.03), about -0.08 in (-0.2 cm) and -0.22 lb (-0.1 kg)

The bottom line

USDA sets a serving at 1 cup, 243 g. Worked out from the per 3.5 oz (100 g) values, that cup gives about 100 calories, 6 g protein, 7 g sugars, 299 mg calcium and 3 ug vitamin B12. Silk Very Vanilla carries 6.58 g sugars per 3.5 oz (100 g). Fortification depends on the carton. In an audit of 129 plant milks in Australian supermarkets, 80.6% were fortified with calcium and only 27.1% with vitamin B12, and soy milk matched cow milk for protein. In a crossover test in 12 women after menopause with low bone density, calcium from calcium-fortified soymilk was absorbed at the same hourly rate as from cow milk, 0.65 against 0.66. That soymilk used calcium phosphate, and Silk may use a different calcium salt. The size of the cholesterol effect is less settled than the direction. A 2026 network meta-analysis of 14 trials in 543 people put the LDL drop at 18 mg/dL (95% CI 3.9 to 33; metric: 0.47 mmol/L, 0.10 to 0.85), with low certainty. A 2018 review of 8 smaller trials with 263 people found the effect limited and inconsistent: LDL fell in 3 trials, and 3 showed no change in any blood lipid. US rules allow a heart claim for soy protein only at 25 g a day in a diet low in saturated fat. One cup of this drink gives about 6 g, by our own calculation from the USDA record. In 66 patients with fatty liver disease on a diet 500 calories below their needs, 8.1 fl oz (240 ml) of soy milk a day for 8 weeks lowered HOMA-IR by 0.45 against 0.14 on diet alone, with no placebo drink and fasting glucose unchanged. In 12 healthy men, soy milk drunk 30 minutes before white bread lowered post-meal glucose more than the same soy milk drunk with the bread. In 59 adults given a single dose, isoflavones from soy milk reached the blood faster than from textured soy protein or tempeh, and only 30% of people produced equol. That study measured blood levels only. Soy milk as allergy prevention was checked, and it did not work. A systematic review of 74 studies found no preventive benefit from soy milk in people at high or normal allergy risk. Who should be careful. Soy is one of the nine major food allergens in the US, so this drink carries a declared allergen. One case report describes a 70-year-old man stable on warfarin whose INR fell below range after he started soy milk and returned to range within 2 weeks of stopping it. A single case cannot show how often this happens, so if you take warfarin, tell whoever manages your dose before you start or stop drinking it. For children the data are thin. Observational studies link each daily cup of plant-based drink at age five with about 0.08 in (0.2 cm) less height and 0.22 lb (0.1 kg) less weight, with soy drinks not separated from the others. No randomized trial has compared these drinks with cow milk in children.

Sources

1. slkv-daily-r3-12 · cross-sectional
   Of these, 80.6% were fortified with calcium; however, fortification with other micronutrients was less common, ranging from 27.1% being fortified with vitamin B12 and 3.1% being fortified with iodine. ... However, there was no significant difference in protein content between soy milk and cow's milk.
   Nutr Diet, 2025 · checked 2026-09-29
2. slkv-daily-r3-14 · reference dataset
   175219 SILK Vanilla, soymilk | energy 41 kcal | protein 2.47 g | sugars 2.88 g | calcium 123 mg | vitamin D 1.2 ug | vitamin B12 1.23 ug | riboflavin 0.21 mg || 173774 SILK Very Vanilla, soymilk | energy 53 kcal | sugars 6.58 g | calcium 144 mg
   USDA FoodData Central, SR Legacy (2019), FDC 175219 SILK Vanilla, soymilk · checked 2026-09-29
3. slkv-daily-r3-15 · reference dataset
   175219 SILK Vanilla, soymilk | portion 1 cup 243 g | per 100 g: energy 41 kcal, protein 2.47 g, sugars 2.88 g, calcium 123 mg, vitamin B12 1.23 ug, vitamin D 1.2 ug
   USDA FoodData Central, SR Legacy (2019), FDC 175219 SILK Vanilla, soymilk · checked 2026-09-29
4. slkv-daily-r3-05 · RCT
   The mean hourly fractional calcium absorption from fortified soymilk was found to be comparable to that of cows' milk: alpha = 0.65+/-0.19 and alpha =0.66+/-0.22, p>0.05, respectively.
   Asia Pac J Clin Nutr, 2010 · checked 2026-09-29
5. slkv-daily-r3-06 · RCT
   However, soy milk was absorbed faster and peak levels of isoflavones were attained earlier than with the other soy foods. Only 30% of the subjects were equol producers and no differences in equol production with age or gender were observed.
   J Nutr, 2006 · checked 2026-09-29
6. slkv-daily-r3-16 · systematic review (mechanistic)
   Presumably, antioxidants in PBM could be potentially lost due to thermal degradation, oxidation or leaching into processing water.
   Crit Rev Food Sci Nutr, 2024 · checked 2026-09-29
7. slkv-daily-r3-01 · meta-analysis
   The substitution of soymilk for cow's milk resulted in moderate reductions in non-HDL-C (mean difference, - 0.26 mmol/L [95% confidence interval, - 0.43 to - 0.10]), systolic blood pressure (- 8.00 mmHg [- 14.89 to - 1.11]), and diastolic blood pressure (- 4.74 mmHg [- 9.17 to - 0.31]); small important reductions in LDL-C (- 0.19 mmol/L [- 0.29 to - 0.09]) and c-reactive protein (CRP) (- 0.82 mg/L [- 1.26 to - 0.37]); and trivial increases in HDL-C (0.05 mmol/L [0.00 to 0.09]). No other outcomes showed differences. There was no meaningful effect modification by added sugars across outcomes.
   BMC Med, 2024 · checked 2026-09-29
8. slkv-daily-r3-02 · network meta-analysis
   Replacing 500 mL/d of cow's milk with soy drink may reduce low-density lipoprotein (LDL) cholesterol [MD: -0.47 mmol/L (-0.85; -0.10); low certainty], but showed no effect for high-density lipoprotein (HDL) cholesterol [MD: 0.01 mmol/L (-0.03; 0.05); moderate certainty].
   Adv Nutr, 2026 · checked 2026-09-29
9. slkv-daily-r3-04 · RCT
   After 8-weeks of intervention, soy milk group had a greater significant reduction in serum insulin(-3.44 ± 5.02 vs. -1.09 ± 3.77 μIU/ml, P = 0.04), HOMA-IR (-0.45±0.64 vs -0.14 ± 0.47, P = 0.03), systolic (-3.81±4.15 vs -1.48±2.93 mmHg, P = 0.01) and diastolic (-2.39±2.80 vs. -0.94±2.76 mmHg, P = 0.04) BP
   Complement Ther Med, 2019 · checked 2026-09-29
10. slkv-daily-r3-07 · RCT
    Preloads (30 min prior to bread) significantly lowered postprandial glycemia and insulinemia compared to co-ingestion.
    Eur J Nutr, 2017 · checked 2026-09-29
11. slkv-daily-r3-08 · agency guidance
    The major food allergens are milk, eggs, fish, Crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame.
    US FDA, Food Allergies (page), 2026 · checked 2026-09-29
12. slkv-daily-r3-09 · case report
    A 70-year-old white man who was stable on warfarin therapy developed subtherapeutic INR values after ingesting soy protein in the form of soy milk. ... INR values returned to therapeutic concentrations within 2 weeks after discontinuation of the soy milk.
    Ann Pharmacother, 2002 · checked 2026-09-29
13. slkv-daily-r3-11 · systematic review
    Soy milk and delaying the introduction of solid foods beyond 4 months did not have preventive benefits in those at high or normal risk.
    Allergy, 2014 · checked 2026-09-29
14. slkv-daily-r3-13 · regulatory decision
    Diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease.
    21 CFR 101.82, Health claims: Soy protein and risk of coronary heart disease (CHD) · checked 2026-09-29
15. slkv-daily-r3-03 · systematic review
    Eight eligible trials comprising a total of 263 subjects were included in this review. Three studies reported no significant improvement in any of the serum lipid parameters following soy milk consumption. A significant decrease in serum TG, TC, and LDL-C was reported by 1, 1 and 3 trials.
    Complement Ther Med, 2019 · checked 2026-09-29
16. slkv-daily-r3-10 · review
    The height-for-age z-score was -0.04 [-0.07; -0.01] and the BMI-for-age z-score was -0.06 [-0.09; -0.03] for each cup of PBMA in five-year-olds, corresponding to reductions of 0.2 cm in height and 0.1 kg in weight. ... Our search did not retrieve any longitudinal studies on long-term outcomes or any randomized intervention trials comparing the consumption of cow's milk and PBMA.
    Dtsch Arztebl Int, 2026 · checked 2026-09-29