Buttermilk vs milk: closer than the name suggests

Only one trial here sets buttermilk directly against milk. In 92 adults with mildly raised cholesterol, 2.7 fl oz (80 ml) of traditionally prepared buttermilk a day for 12 weeks left LDL cholesterol no different from skim milk, and a trend toward lower total cholesterol did not reach significance (p = 0.077). A shorter crossover trial in 34 adults gave a firmer number. Four weeks of 45 g a day of buttermilk, probably the dried powder, lowered serum cholesterol by 3.1 percent and triacylglycerol by 10.7 percent. Its comparison drink was matched for nutrients and was not milk. The same 34 people also had systolic blood pressure 2.6 mm Hg lower after buttermilk, which is the same small group measured again and does not count as a second confirmation. Two large cohorts found buttermilk and milk behaving alike. In 54277 Danish adults, swapping one daily serving of buttermilk, whole milk or low-fat milk for whole-fat yogurt was linked with the same 11 percent lower rate of type 2 diabetes. In 35982 Dutch adults followed for 15 years, the same swap showed no link at all.

How much is actually in it

• In USDA Foundation Foods sampling, low-fat buttermilk carried 120.1 mg calcium per 3.5 oz (100 g) (109 to 160 across 8 samples), close to whole milk at 123.0 mg and 1% milk at 126.0 mg. — retail samples analyzed for USDA Foundation Foods, release 2026-04-30 (n = 8 buttermilk samples, 11 whole milk samples, 12 lowfat milk samples) Evidence E source
  Buttermilk 120.1 mg (median 115.8, spread 42%); whole milk 123.0 mg (116-130, spread 11%); 1% milk 126.0 mg (111-143, spread 25%)
• In USDA Foundation Foods sampling, low-fat buttermilk carried 0.196 mg riboflavin per 3.5 oz (100 g) against 0.138 mg in whole milk, while iodine was similar at 34.2 and 37.9 micrograms. — retail samples analyzed for USDA Foundation Foods, release 2026-04-30 (n = 8 buttermilk samples, 12 (riboflavin) and 24 (iodine) whole milk samples) Evidence E source
  Riboflavin buttermilk 0.1963 mg (0.155-0.28) vs whole milk 0.138 mg (0.118-0.178); iodine buttermilk 34.16 ug (25.7-42.4) vs whole milk 37.9 ug (17.6-83.8)

What a real portion looks like

• In the USDA survey food table one cup of buttermilk and one cup of whole milk both weigh 8.6 oz (244 g), and one fluid ounce of either weighs 1.1 oz (30 g). — USDA FNDDS survey foods Buttermilk (food code 11115300) and Milk, whole (food code 11111000), WWEIA category Milk, whole Evidence E source
  1 cup 244 g and 1 fl oz 30 g for both

What your body absorbs

• Laboratory digestion studies suggest that buttermilk-based matrices raise the bioaccessibility of beta-carotene, omega-3 fatty acids and milk membrane phospholipids compared with non-buttermilk systems. — in vitro gastrointestinal digestion studies pooled in a systematic review Evidence D source
  Generally increased bioaccessibility; compound- and matrix-dependent, no single effect size

What cooking and storage change

• The USDA retention table assigns milk heated for about 10 minutes 80 percent retention of vitamin B12 and 85 percent of folate, with calcium and riboflavin fully retained. It has no row for buttermilk. — USDA Table of Nutrient Retention Factors Release 6, group Dairy and Egg Products (code 1), method code 2151, table dated Sep-75 Evidence E source
  Vitamin B12 80%, vitamin C 85%, folate 85%, thiamin 90%, vitamin B6 90%, calcium 100%, riboflavin 100%

What it does to your health

• In a 12-week randomized trial, 2.7 fl oz (80 ml) a day of traditionally prepared buttermilk showed only a non-significant trend to lower total cholesterol against skim milk and no difference in LDL cholesterol. — mildly hypercholesterolemic adults randomized to skim milk or traditionally prepared buttermilk, with or without egg yolk, 2.7 fl oz (80 ml) daily at lunch for 12 weeks (n = 92 (23, 25, 23 and 21 per group)) Evidence B source
  Total cholesterol trend lower in buttermilk groups (p = 0.077); LDL cholesterol not different (p = 0.204)
• In a 4-week crossover trial, 45 g a day of buttermilk lowered serum cholesterol by 3.1 percent and triacylglycerol by 10.7 percent against a nutrient-matched placebo drink. — men and women with serum LDL cholesterol below 193 mg/dL (5.0 mmol/L), 45 g/d buttermilk and 45 g/d matched placebo for 4 weeks each (n = 34) Evidence B source
  Serum cholesterol -3.1% (P = 0.019), LDL-C -3.1% (P = 0.057), triacylglycerol -10.7% (P = 0.007)
• In the same crossover design, 4 weeks of buttermilk lowered systolic blood pressure by 2.6 mm Hg against the matched placebo in people with normal blood pressure. — men and women with plasma LDL cholesterol below 193 mg/dL (5 mmol/L) and blood pressure below 140 mm Hg, 45 g/d buttermilk or placebo for 4 weeks each (n = 34) Evidence B source
  Systolic blood pressure -2.6 mm Hg (P = 0.009), mean arterial pressure -1.7 mm Hg (P = 0.015), ACE -10.9% (P = 0.003)
• In a Danish cohort of 54277 adults, swapping one daily serving of low-fat milk, whole milk or buttermilk for whole-fat yogurt was linked with the same 11 percent lower rate of type 2 diabetes, so buttermilk and milk behaved alike. — Danish Diet, Cancer and Health cohort, men and women aged 50-64 at baseline, median follow-up 15.3 years, 7137 cases (n = 54277) Evidence C source
  HR 0.89 (95% CI 0.83-0.96) for low-fat milk, 0.89 (0.82-0.96) for whole-fat milk, 0.89 (0.81-0.97) for buttermilk, per serving/d replaced by whole-fat yogurt
• In the same Danish population, whole-fat fermented milk in place of low-fat milk, whole milk or buttermilk was linked with a 15 to 17 percent lower rate of ischemic stroke, again with buttermilk and milk in the same range. — 55211 Danish men and women aged 50-64 without previous stroke, median follow-up 13.4 years, 1870 ischemic strokes (n = 55211) Evidence C source
  HR 0.85 (95% CI 0.74-0.99) low-fat milk, 0.84 (0.71-0.98) whole-fat milk, 0.83 (0.70-0.99) buttermilk, per serving/day substituted

What people believe that the data does not support

• The EU register records the claim that cow milk products support dental health as non-authorized, and it holds no claim at all under the name buttermilk. — EU Register on nutrition and health claims, snapshot 2026-09-21 Evidence E source
  Status Non-authorized

Who this works differently for

• In overweight adults aged 45 to 65, six weeks of a high-dairy diet that included semi-skim milk and buttermilk left fasting glucose unchanged and gave slightly higher fasting insulin than a low-dairy diet (8.9 vs 8.1 mU/L). — overweight men and postmenopausal women aged 45-65, 5-6 versus at most 1 dairy portion a day for 6 weeks each; portions were 200 g yogurt, 30 g cheese, 8.5 fl oz (250 mL) semi-skim milk and buttermilk (n = 45) Evidence B source
  Fasting insulin 8.1 +/- 2.8 mU/L after low-dairy vs 8.9 +/- 3.3 mU/L after high-dairy (P = 0.024); fasting glucose similar
• In USDA Foundation Foods sampling, low-fat buttermilk held 3.657 g lactose per 3.5 oz (100 g) against 4.81 g in whole milk and 4.96 g in 1% milk, about a quarter less. — retail samples analyzed for USDA Foundation Foods, release 2026-04-30 (n = 8 buttermilk samples, 12 whole milk samples, 12 lowfat milk samples) Evidence E source
  Buttermilk 3.657 g (3.45-4.0); whole milk 4.81 g (4.42-5.37); 1% milk 4.96 g (4.59-5.84); galactose 0 in all

What is still unknown

• In the Dutch EPIC-NL cohort of 35982 adults followed for 15 years, replacing a 7.1 oz (200 g) serving of whole-fat milk, buttermilk or skim milk with whole-fat yogurt was not associated with type 2 diabetes risk. — EPIC-NL cohort, mean follow-up 15 years, 1467 validated type 2 diabetes cases (n = 35982) Evidence C source
  HR 0.93 (95% CI 0.60-1.44) whole-fat milk, 0.88 (0.58-1.34) buttermilk, 0.87 (0.57-1.32) skim milk; null

The bottom line

In the glass the two are close. Low-fat buttermilk carried 120.1 mg calcium per 3.5 oz (100 g) across 8 USDA samples, with a wider spread than whole milk at 123.0 mg. Riboflavin was higher in buttermilk, 0.196 mg against 0.138 mg per 3.5 oz (100 g), and iodine was similar at 34.2 and 37.9 micrograms. A cup of either weighs 8.6 oz (244 g) in the USDA survey table. The USDA retention table keeps 80 percent of vitamin B12 and all the calcium when milk is heated for about 10 minutes. It has no row for buttermilk, so that figure says nothing about heating buttermilk. Laboratory digestion studies suggest buttermilk mixtures release more beta-carotene and omega-3 fats, and no study in people has checked this. Buttermilk held 3.66 g lactose per 3.5 oz (100 g) against 4.81 g in whole milk, about a quarter less. That is less lactose and still a real amount of it. We found no trial of how people with lactose intolerance handle buttermilk compared with milk. We have no card on allergy, pregnancy, children or medicines for either drink, so this page has no safety section and makes no safety promise. In overweight adults aged 45 to 65, six weeks of a high-dairy diet that included both milk and buttermilk left fasting glucose unchanged and fasting insulin slightly higher, 8.9 against 8.1 mU/L, and that design cannot separate buttermilk from milk. The EU register lists the claim that cow milk products support dental health as non-authorized, and the register snapshot gives no reason for the refusal, so this is not proof that milk does nothing for teeth.

Sources

1. btmk-r4-09 · reference dataset
   Buttermilk, low fat | Calcium, Ca | 120.1 MG | range 109.0-160.0, median 115.8, 8 samples, spread 42% || Milk, whole, 3.25% milkfat, with added vitamin D | Calcium, Ca | 123.0 MG | range 116.0-130.0, median 122.0, 11 samples, spread 11% || Milk, lowfat, fluid, 1% milkfat, with added vitamin A and D | Calcium, Ca | 126.0 MG | range 111.0-143.0, median 127.0, 12 samples, spread 25%
   USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-28
2. btmk-r4-11 · reference dataset
   Buttermilk, low fat | Riboflavin | 0.1963 MG | range 0.155-0.28, median 0.185, 8 samples || Milk, whole, 3.25% milkfat, with added vitamin D | Riboflavin | 0.138 MG | range 0.118-0.178, median 0.136, 12 samples || Buttermilk, low fat | Iodine, I | 34.16 UG | range 25.7-42.4, 8 samples || Milk, whole, 3.25% milkfat, with added vitamin D | Iodine, I | 37.9 UG | range 17.6-83.8, 24 samples
   USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-28
3. btmk-r4-13 · reference dataset
   Buttermilk | FNDDS code 11115300 | fdc_id 2705393 | 1 cup 10205 = 244 g | 1 fl oz 30000 = 30 g || Milk, whole | FNDDS code 11111000 | fdc_id 2705385 | 1 cup 10205 = 244 g | 1 fl oz 30000 = 30 g
   USDA FNDDS, Buttermilk food code 11115300 (fdc_id 2705393) and Milk, whole food code 11111000 (fdc_id 2705385) · checked 2026-09-28
4. btmk-r4-08 · meta-analysis of in vitro studies
   We identified a limited but growing body of in vitro evidence indicating that buttermilk-based matrices generally increase the intestinal bioaccessibility of curcuminoids, β-carotene, omega-3 fatty acids, vitamin and MFGM phospholipids relative to non-buttermilk systems, with particularly pronounced effects in structured emulsions, yogurts, ultrafiltered buttermilk and MFGM-enriched nanosystems.
   Molecules, 2026 · checked 2026-09-28
5. btmk-r4-12 · reference dataset
   MILK,HEATED APPROX 10MIN | Dairy and Egg Products (1) | Retn_Code 2151 | vitamin_b12_ug 80% | folate_total_ug 85% | calcium_mg 100% | riboflavin_mg 100%
   USDA Table of Nutrient Retention Factors, Release 6, 2007, code USDA-RETN-R6:2151 · checked 2026-09-28
6. btmk-r4-01 · randomized controlled trial
   There was a trend towards significant lower total-C (p = 0.077), but not LDL-C (p = 0.204) concentrations in the buttermilk groups.
   Nutr Metab Cardiovasc Dis, 2015 · checked 2026-09-28
7. btmk-r4-02 · randomized crossover trial
   Consumption of buttermilk led to reduction in serum cholesterol (-3.1%, P = 0.019), LDL-C (-3.1%, P = 0.057) and triacylglycerol (-10.7%, P = 0.007).
   Nutr Metab Cardiovasc Dis, 2013 · checked 2026-09-28
8. btmk-r4-03 · randomized crossover trial
   Buttermilk consumption significantly reduced systolic blood pressure (-2.6 mm Hg; P = 0.009), mean arterial blood pressure (-1.7 mm Hg; P = 0.015), and plasma levels of the angiotensin I-converting enzyme (-10.9%; P = 0.003) compared with the placebo, but had no effect on plasma concentrations of angiotensin II and aldosterone.
   Nutrition, 2014 · checked 2026-09-28
9. btmk-r4-05 · prospective cohort
   Whole-fat yogurt products in place of low-fat milk, whole-fat milk or buttermilk were associated with a lower rate of type 2 diabetes (HR 0·89; 95 % CI 0·83, 0·96; HR 0·89; 95 % CI 0·82, 0·96; HR 0·89; 95 % CI 0·81, 0·97; per serving/d substituted, respectively).
   Br J Nutr, 2017 · checked 2026-09-28
10. btmk-r4-06 · prospective cohort
    substitutions of whole-fat fermented milk for low-fat milk, whole-fat milk or buttermilk were associated with a lower rate [low-fat milk: HR = 0.85 (95% CI 0.74-0.99), whole-fat milk: HR = 0.84 (95% CI 0.71-0.98) and buttermilk: HR = 0.83 (95% CI 0.70-0.99)]
    Eur J Epidemiol, 2018 · checked 2026-09-28
11. btmk-r4-14 · regulatory register entry
    POL-HC-6549 (Cow’s) Milk And dairy products for which milk is the principle ingredient and no sugar has been added – e.g. yogurt, cheese. (Cow’s) Milk products help support dental health. (Cow’s) Milk helps support the normal and healthy development of teeth. (Cow’s) Milk contributes to dental health. Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6549, snapshot 2026-09-21 · checked 2026-09-28
12. btmk-r4-04 · randomized crossover trial
    Fasting glucose concentrations were similar, whereas fasting insulin concentrations were lower after the LDD (LDD: 8.1 ± 2.8 mU/L; HDD: 8.9 ± 3.3 mU/L; P = 0.024).
    Am J Clin Nutr, 2019 · checked 2026-09-28
13. btmk-r4-10 · reference dataset
    Buttermilk, low fat | Lactose | 3.657 G | range 3.45-4.0, median 3.603, 8 samples, spread 15% || Milk, whole, 3.25% milkfat, with added vitamin D | Lactose | 4.81 G | range 4.42-5.37, median 4.82, 12 samples, spread 20% || Milk, lowfat, fluid, 1% milkfat, with added vitamin A and D | Lactose | 4.96 G | range 4.59-5.84, median 4.94, 12 samples, spread 25%
    USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-28
14. btmk-r4-07 · prospective cohort
    After adjustment for demographic and cardiovascular risk factors, replacement of one serving (200 g) of whole-fat milk [hazard ratio (HR) = 0.93, 95% confidence interval (CI) = 0.60-1.44], buttermilk (HR = 0.88, 95% CI = 0.58-1.34), skimmed milk (HR = 0.87, 95% CI = 0.57-1.32) or skimmed fermented milk (HR = 0.99, 95% CI = 0.63-1.54) with whole-fat yogurt was not associated with T2D risk.
    J Hum Nutr Diet, 2021 · checked 2026-09-28