A2 Milk for Lactose Intolerance
Recruiting in Palo Alto (17 mi)
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: Purdue University
Must not be taking: Antacids, PPIs, Antibiotics, others
Disqualifiers: Diabetes, HIV, IBD, others
No Placebo Group
Trial Summary
What is the purpose of this trial?Cow's milk contains two types of β-casein: A1 and A2. It is evident from human clinical trials that milk with A1 protein produces more hydrogen and symptoms of lactose intolerance. A pro-inflammatory μ-opioid peptide BCM-7 is released from A1 but not from A2. Milk containing A1 β-casein produced more inflammatory markers than A2 β-casein. This is a double-blinded, randomized, controlled trial conducted to determine if A1 beta-casein containing milk causes acute effects on inflammatory markers following a single milk feeding, as compared to milk containing only A2 beta-casein.
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.
What data supports the effectiveness of A2 milk for lactose intolerance?
Research shows that milk containing only A2 beta-casein causes fewer symptoms of lactose intolerance, like abdominal pain, compared to regular milk with both A1 and A2 proteins. This suggests that A2 milk might be easier to digest for people with lactose intolerance.
12345Is A2 milk safe for people with lactose intolerance?
Research shows that A2 milk causes fewer stomach problems than regular milk in people with lactose intolerance, suggesting it is generally safe for them to consume.
45678How does A2 milk differ from other treatments for lactose intolerance?
A2 milk is unique because it contains only A2 beta-casein protein, unlike regular milk which has both A1 and A2 beta-caseins. This difference is important because A1 beta-casein can release a peptide that may cause digestive discomfort, while A2 milk is associated with fewer symptoms of lactose intolerance.
14569Eligibility Criteria
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
+3 more
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.
+20 more
Trial Timeline
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
Participant Groups
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).
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
Purdue UniversityWest Lafayette, IN
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Who Is Running the Clinical Trial?
Purdue UniversityLead Sponsor
References
Milk Intolerance, Beta-Casein and Lactose. [2018]True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows' milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows' milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows' milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.
Symptom response to lactose-reduced milk in lactose-intolerant adults. [2018]The possible usefulness of low-lactose milk for those lactose-intolerant subjects who develop symptoms from milk consumption was investigated. In the first part of the study, 16 intolerant subjects (blood glucose rise less than 25 mg/100 ml) received low-lactose skim milk containing 15 g lactose (2.5 cups) and 7.5 g lactose (2.5 cups), regular skim milk containing 30 g lactose (2.5 cups), and all three milks plus a small breakfast. The low lactose milks produced significantly fewer symptoms. The food given with the milk had no significant effect on symptomatic response. The second group of 17 subjects received 25 g lactose in water (250 ml), skim milk (500 ml) and whole milk (500 ml); 10 g lactose in lactose-reduced skim (500 ml) and whole milk (500 ml) and whole milk (500 ml); and a placebo (250 ml). There was a significant positive relationship between amount of lactose consumed and symptom response. The form in which the lactose was administered (e.g., whole versus skim milk) was not significantly related to symptoms. It is concluded that in a symptomatic subjects a significantly greater quantity of low-lactose milk than regular milks can be consumed.
Effectiveness of Growing-Up Milk Containing Only A2 β-Casein on Digestive Comfort in Toddlers: A Randomized Controlled Trial in China. [2023]Emerging clinical evidence indicates the potential gastrointestinal (GI) benefits of milk containing only A2 β-casein, but data from randomized controlled trials is sparse among pediatric populations. We aimed to evaluate the effectiveness of growing-up milk (GUM) containing only A2 β-casein on GI tolerance in toddlers.
Effects of Conventional Milk Versus Milk Containing Only A2 β-Casein on Digestion in Chinese Children: A Randomized Study. [2022]In this study, we hypothesized that replacing conventional milk, which contains A1 and A2 β-casein proteins, with milk that contains only A2 β-casein in the diet of dairy or milk-intolerant preschoolers (age 5 to 6 years) would result in reduced gastrointestinal symptoms associated with milk intolerance, and that this would correspond with cognitive improvements.
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. [2023]Acute-feeding and multiple-day studies have demonstrated that milk containing A2 β-casein only causes fewer symptoms of lactose intolerance (LI) than milk containing both A1 and A2 β-caseins. We conducted a single-meal study to evaluate the gastrointestinal (GI) tolerance of milk containing different concentrations of A1 and A2 β-casein proteins. This was a randomized, double-blind, crossover trial in 25 LI subjects with maldigestion and an additional eight lactose maldigesters who did not meet the QLCSS criteria. Subjects received each of four types of milk (milk containing A2 β-casein protein only, Jersey milk, conventional milk, and lactose-free milk) after overnight fasting. Symptoms of GI intolerance and breath hydrogen concentrations were analyzed for 6 h after ingestion of each type of milk. In an analysis of the 25 LI subjects, total symptom score for abdominal pain was lower following consumption of milk containing A2 β-casein only, compared with conventional milk (p = 0.004). Post hoc analysis with lactose maldigesters revealed statistically significantly improved symptom scores (p = 0.04) and lower hydrogen production (p = 0.04) following consumption of milk containing A2 β-casein only compared with conventional milk. Consumption of milk containing A2 β-casein only is associated with fewer GI symptoms than consumption of conventional milk in lactose maldigesters.
Effects of cow's milk beta-casein variants on symptoms of milk intolerance in Chinese adults: a multicentre, randomised controlled study. [2022]A major protein component of cow's milk is β-casein. The most frequent variants in dairy herds are A1 and A2. Recent studies showed that milk containing A1 β-casein promoted intestinal inflammation and exacerbated gastrointestinal symptoms. However, the acute gastrointestinal effects of A1 β-casein have not been investigated. This study compared the gastrointestinal effects of milk containing A1 and A2 β-casein versus A2 β-casein alone in Chinese adults with self-reported lactose intolerance.
An approach on detection, quantification, technological properties, and trends market of A2 cow milk. [2023]The genetic variant A2 β-casein integrates the casein protein group in milk and has been often associated with positive health outcomes. Therefore, this review explores the present understanding of A2 β-casein, including detection methods and the market trends for dairy from A2 milk. Also, the interaction of A2 β-casein with αs1-casein and κ-casein genotypes was examined in terms of technological impacts on A2 milk. A limited number of preliminary studies has aimed to investigate the sensorial and technological impacts of β-casein variants in milk matrices, for instance, in yogurt and other derivatives. Nevertheless, considering studies carried out so far, it is concluded that the manufacture of dairy products from A2 milk is perfectly feasible, as the products presented slight differences when compared to those derived from traditional milk. In one of the works, sensitive drops in rennet coagulation time and curd firmness values were observed in cheese traits. However, it is relevant to point out that variant A of κ-casein plays a negative role in the coagulation features of milk. Therefore, alterations in the pattern of cheese-making properties are not uniquely related to β-casein variants. Attempts to produce A2 β-casein in laboratory (non-natural source), through biosynthesis, for example, have not been found so far. This knowledge gap offers a promising area for future studies concerning proteins and bioactive peptide production.
Determination of Total and A1-Type β-Casein in Milk and Milk-Derived Ingredients by Liquid Chromatography-Mass Spectrometry Using Characteristic Tryptic Peptides. [2021]Gastrointestinal digestion of A1-type β-casein is conducive to β-casomorphin-7 with potential adverse digestive health effects. Monitoring of A1-type β-casein concentration in milk and milk-derived ingredients used in the formulation of A2-type nutritional products with associated health claims is important from a quality standpoint.
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. [2022]Cows' milk generally contains two types of β-casein, A1 and A2 types. Digestion of A1 type can yield the peptide β-casomorphin-7, which is implicated in adverse gastrointestinal effects of milk consumption, some of which resemble those in lactose intolerance. This study aimed to compare the effects of milk containing A1 β-casein with those of milk containing only A2 β-casein on inflammation, symptoms of post-dairy digestive discomfort (PD3), and cognitive processing in subjects with self-reported lactose intolerance.