Casein
In brief
Section titled “In brief”- Issues with cow’s milk (without lactose intolerance) may be related to A1-beta-casein
- A2 dairy (goat, sheep, buffalo, Jersey cow) is often better tolerated
- Casein digests slowly and is therefore suitable as evening or night protein
- A2 is not the same as lactose-free - for lactose intolerance, lactose-free dairy remains necessary
What is casein
Section titled “What is casein”Casein is the main protein in milk. It digests relatively slowly and provides a gradual supply of amino acids over several hours. That’s why casein is often used as ‘nighttime’ protein for recovery and muscle maintenance.
A1 versus A2: what does this mean
Section titled “A1 versus A2: what does this mean”In milk, variants of beta-casein occur, namely A1 and A2. During digestion of A1-beta-casein, a bioactive peptide can form in some people (BCM-7). With A2-beta-casein this does not or hardly happens.
The difference seen most consistently is about tolerability: some people report fewer digestive issues with A2 dairy than with regular cow’s milk.
When to consider A2 or alternative dairy
Section titled “When to consider A2 or alternative dairy”- For recurring digestive issues, bloating or variable bowel movements after regular milk
- For clear worsening of symptoms after milk products and you want to choose the best tolerated variant
Where is A2 found?
Section titled “Where is A2 found?”A2 dairy naturally occurs in milk from:
- Goat
- Sheep
- Buffalo
- Some cow breeds such as Jersey
Casein before sleep
Section titled “Casein before sleep”Protein just before sleep can be digested during the night and contribute to recovery and muscle maintenance. This is especially relevant:
- After strength training
- When aging
- When it’s difficult to get enough protein during the day
Dosing and timing
Section titled “Dosing and timing”- Guideline: 20 to 40 g casein, about 30 minutes before sleep
- Choose preferably low-lactose or lactose-free when lactose plays a role or with strict carbohydrate restriction
Traffic light for practical choices
Section titled “Traffic light for practical choices”| Category | Products | Explanation |
|---|---|---|
| Green | A2 dairy, goat/sheep/buffalo, lactose-free quark/yogurt, micellar casein (powder) | Usually best tolerability |
| Orange | Hard aged cheeses, mixed or sweetened dairy products | Little lactose but often A1 casein; moderation wise if sensitive |
| Red | Regular milk and drinking yogurt with consistent symptoms, processed dairy desserts, sweetened dairy drinks | Better to avoid or replace if symptomatic |
Butter and ghee
Section titled “Butter and ghee”- Butter usually contains little milk protein, but may contain traces
- Ghee (clarified butter) contains practically no milk proteins and is therefore often better tolerated with sensitivity
Integration with TKB or ketogenic eating
Section titled “Integration with TKB or ketogenic eating”Casein usually fits well within carbohydrate restriction as long as total protein intake matches needs. With very strict ketosis, a large protein portion can temporarily lower ketones. If you measure ketones, you can track this and adjust the portion if necessary.
Veelgestelde vragen
What is the difference between A1 and A2 milk?
During digestion of A1-beta-casein, a bioactive peptide (BCM-7) can form in some people that causes digestive issues. With A2-beta-casein this does not or hardly happens. A2 dairy naturally occurs in milk from goat, sheep, buffalo and some cow breeds like Jersey.
Does A2 dairy help against digestive issues from milk?
Some people report fewer digestive issues with A2 dairy than with regular cow's milk. Try 2 to 4 weeks of A2 dairy or goat/sheep/buffalo and keep the rest of your diet the same to assess the effect.
Is A2 dairy the same as lactose-free?
No, A2 dairy is not automatically lactose-free. For lactose intolerance, lactose restriction or lactose-free dairy remains necessary. A2 is about the type of milk protein, not milk sugar.
How much casein before sleep?
Guideline is 20 to 40 grams of casein, about 30 minutes before sleep. This is especially relevant after strength training, when aging, or when it's difficult to get enough protein during the day.
Does casein fit with carbohydrate restriction?
Yes, casein usually fits well within TKB or ketogenic eating. With very strict ketosis, a large protein portion can temporarily lower ketones. Possibly measure your ketones to track this.
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