A2 Milk for Lactose Intolerance

Overseen By Tracy Eaton, MSW

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Purdue University

Must not be taking: Antacids, PPIs, Antibiotics, others

Disqualifiers: Diabetes, HIV, IBD, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether milk containing only A2 protein is gentler on the stomach than regular milk, which has both A1 and A2 proteins. The goal is to determine if A1 protein increases inflammation and causes more symptoms in individuals with dairy sensitivity. Participants will try different types of milk to compare their effects. This trial suits those who avoid dairy due to discomfort like gas, bloating, or cramps but are not allergic to milk. As an unphased study, it offers a unique opportunity to explore potential dietary solutions for dairy discomfort.

Will I have to stop taking my current medications?

The trial requires participants to stop using treatments and products for dairy intolerance, like Lactaid® Dietary Supplements, during the study. It also excludes those using certain medications like chronic antacids, PPIs, and recent antibiotics. If you're on these, you may need to stop them to participate.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that A2 milk is usually easier for people sensitive to milk to handle. Studies have found that milk containing only A2 protein causes fewer stomach issues than milk with A1 protein. For those with lactose intolerance, A2 milk often leads to less discomfort, such as bloating or gas, compared to regular milk.

Additionally, A2 milk appears to cause less inflammation than milk with A1 protein, making it gentler on the stomach. Overall, evidence suggests that A2 milk is safe for people who typically have problems with regular milk. ^{1 2 3 4 5}

Why are researchers excited about this trial?

A2 milk is unique because it contains only A2 beta-casein, unlike regular milk, which typically has both A1 and A2 beta-caseins. Researchers are excited about A2 milk for lactose intolerance because it may be easier to digest for those sensitive to A1 beta-casein, potentially reducing symptoms like bloating and discomfort. While most treatments for lactose intolerance involve avoiding dairy or using lactase enzyme supplements, A2 milk offers a promising alternative that could allow people to enjoy milk without the usual digestive issues.

What evidence suggests that A2 milk is effective for lactose intolerance?

Research has shown that milk containing only A2 protein causes fewer symptoms of lactose intolerance than milk with both A1 and A2 proteins. Studies have found that people who drink A2 milk experience less stomach pain, urgency to use the bathroom, and stomach noise. Unlike regular cow's milk, A2 milk does not increase gut symptoms. The A1 protein in regular milk is believed to release a substance that causes inflammation, which A2 milk does not. This difference may make A2 milk gentler on the stomach for those with lactose intolerance. ^{2 3 4 6 7}

Who Is on the Research Team?

Dennis Savaiano, PhD

Principal Investigator

Purdue University

Are You a Good Fit for This Trial?

This trial is for adults aged 18-65 who have a history of dairy intolerance and have avoided dairy for at least a month. Participants must be non-smokers, not pregnant or lactating, without recent drug abuse, and free from certain medical conditions like diabetes, heart failure, gastrointestinal surgeries that affect digestion, or any immune disorders.

Inclusion Criteria

You have avoided dairy or had trouble tolerating dairy in the past month.

I am willing to attend all study visits and complete all required procedures.

Able to understand and provide written informed consent in English

Exclusion Criteria

I have a history of digestive system diseases that could affect study results.

I have had a high colonic enema in the last 30 days.

I weigh less than 16.5 kg and my BMI is over 35.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Phone screening and 1 in-person visit for HBT

Intervention

Participants undergo two in-person visits to consume randomized milk and provide breath and blood samples

2 weeks

2 in-person visits, at least 6 days apart

Follow-up

Participants are monitored for safety and effectiveness after intervention

1-2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• A1 beta-casein containing milk
• Milk containing only A2 beta-casein

Trial Overview The study tests whether milk containing A1 beta-casein increases inflammation compared to milk with only A2 beta-casein in people with dairy intolerance. It's a controlled experiment where participants are randomly assigned to receive one type of milk without knowing which one it is (double-blinded).

Who Is Running the Clinical Trial?

Purdue University

Lead Sponsor

Trials

239

Recruited

72,200+

Published Research Related to This Trial

In a study involving preschoolers with mild-to-moderate milk intolerance, switching from conventional milk to A2 β-casein milk significantly reduced gastrointestinal symptoms, such as stool frequency and consistency.

Consumption of A2 β-casein milk also led to improvements in cognitive performance, as indicated by better scores on the Subtle Cognitive Impairment Test, with no severe adverse events reported.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Conventional Milk Versus Milk Containing Only A2 β-Casein on Digestion in Chinese Children: A Randomized Study. Sheng, X., Li, Z., Ni, J., et al.[2022]

In a study involving 600 Chinese adults with self-reported lactose intolerance, consuming milk with A2 β-casein resulted in significantly lower gastrointestinal symptoms compared to conventional milk containing A1 β-casein, especially within the first 3 hours after consumption.

The findings suggest that A1 β-casein may exacerbate gastrointestinal issues, indicating that some individuals may experience milk-related symptoms due to A1 β-casein rather than lactose intolerance itself.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of cow's milk beta-casein variants on symptoms of milk intolerance in Chinese adults: a multicentre, randomised controlled study. He, M., Sun, J., Jiang, ZQ., et al.[2022]

In a study involving 45 participants with self-reported lactose intolerance, milk containing A1 β-casein led to significantly worse digestive discomfort, increased inflammation markers, and slower cognitive processing compared to milk containing only A2 β-casein.

Eliminating A1 β-casein from the diet reduced gastrointestinal symptoms and inflammation, suggesting that some issues attributed to lactose intolerance may actually be related to the effects of A1 β-casein.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows' milk. Jianqin, S., Leiming, X., Lu, X., et al.[2022]

A2 β-casein, a variant of the casein protein in milk, is associated with positive health outcomes and can be used to produce dairy products that are similar in quality to those made from traditional milk, with only slight differences in properties.

While A2 milk products are feasible to manufacture, the presence of the A variant of κ-casein negatively affects milk coagulation, indicating that cheese-making properties are influenced by multiple genetic factors, not just β-casein variants.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An approach on detection, quantification, technological properties, and trends market of A2 cow milk. Dantas, A., Kumar, H., Prudencio, ES., et al.[2023]

In a study of 387 toddlers aged 12-36 months, growing-up milk (GUM) containing only A2 β-casein was found to be well-tolerated and associated with lower constipation scores compared to conventional milk after 14 days.

For toddlers with minor gastrointestinal distress at the start of the study, those consuming A2 GUM experienced significant improvements in overall digestive comfort and GI symptoms within just one week.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effectiveness of Growing-Up Milk Containing Only A2 β-Casein on Digestive Comfort in Toddlers: A Randomized Controlled Trial in China. Meng, Y., Zhou, Y., Li, H., et al.[2023]

In a study involving 25 lactose intolerant subjects, milk containing only A2 β-casein resulted in significantly lower abdominal pain compared to conventional milk containing both A1 and A2 β-caseins.

Lactose maldigesters also experienced fewer gastrointestinal symptoms and lower hydrogen production after consuming A2 β-casein milk, indicating it may be a better option for those with lactose intolerance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Milk Containing A2 β-Casein ONLY, as a Single Meal, Causes Fewer Symptoms of Lactose Intolerance than Milk Containing A1 and A2 β-Caseins in Subjects with Lactose Maldigestion and Intolerance: A Randomized, Double-Blind, Crossover Trial. Ramakrishnan, M., Eaton, TK., Sermet, OM., et al.[2023]

True lactose intolerance is less common than thought, and A1 beta-casein, a protein found in milk from many European cattle, may also contribute to cows' milk intolerance by affecting gastrointestinal function.

A study showed that consuming A1 beta-casein milk led to worse stool consistency and increased abdominal pain compared to A2 beta-casein milk, suggesting that A1 beta-casein may trigger negative gastrointestinal effects through opioid receptor activation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Milk Intolerance, Beta-Casein and Lactose. Pal, S., Woodford, K., Kukuljan, S., et al.[2018]

In a study with 16 lactose-intolerant subjects, low-lactose milk resulted in significantly fewer symptoms compared to regular milk, indicating it is a safer option for those with lactose intolerance.

A second group of 17 subjects showed a clear link between the amount of lactose consumed and the severity of symptoms, suggesting that low-lactose milk allows for greater consumption without adverse effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Symptom response to lactose-reduced milk in lactose-intolerant adults. Jones, DV., Latham, MC., Kosikowski, FV., et al.[2018]

New analytical methods have been developed to accurately measure total and A1-type β-casein in milk and milk-derived ingredients, which is crucial for ensuring the quality of A2-type nutritional products.

The study found that A2-type milk products contained between 0.26% and 5.0% A1-type β-casein, highlighting the importance of monitoring A1-type levels due to potential adverse health effects associated with its digestion.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Determination of Total and A1-Type β-Casein in Milk and Milk-Derived Ingredients by Liquid Chromatography-Mass Spectrometry Using Characteristic Tryptic Peptides. Ehling, S., Wang, M., Weber, L.[2021]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10806982/

A2 milk consumption and its health benefits: an update - PMC Milk containing only A2 β-casein induces fewer symptoms of lactose intolerance than milk containing both A1 and A2 β-caseins. Andiran et al ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7766938/

Milk Containing A2 β-Casein ONLY, as a Single Meal ... Acute-feeding and multiple-day studies have demonstrated that milk containing A2 β-casein only causes fewer symptoms of lactose intolerance (LI) ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S002203022500476X

Tolerance of protein-hydrolyzed lactose-free A1 milk and ... Some studies have shown that only A2 β-casein–containing milk (A2 milk) causes fewer gut symptoms in milk-sensitive individuals compared with milk ...

4. jcpjournal.org jcpjournal.org/journal/view.html?uid=946&vmd=Full

The Effect of A2 Milk on Gastrointestinal Symptoms in ... A2 milk caused less abdominal pain (P = 0.050), fecal urgency (P < 0.001) and borborygmus (P = 0.007) compared to A1/A2 milk in questionnaire for digestive ...

5. nutritionj.biomedcentral.com nutritionj.biomedcentral.com/articles/10.1186/s12937-016-0147-z

Effects of milk containing only A2 beta casein versus milk ... By contrast, the consumption of milk containing only the A2 β-casein type did not increase gastrointestinal symptoms compared with the baseline ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9407547/

A2 Milk: New Perspectives for Food Technology and Human ... Consumption of milk containing only A2 β-casein did not aggravate postdairy digestive discomfort symptoms relative to baseline. [13]. Randomized, double-blinded ...

7. webmd.com webmd.com/diet/health-benefits-a2-milk

A2 Milk: Is it Good For You?, Health Benefits, Nutrition ... If you're not sure if you're lactose intolerant, but you don't feel well after having milk, trying A2 milk may help. If you can tolerate it, ...