Different types of milk consumption and the risk of dementia: Analysis from a large-scale cohort study

BACKGROUND & AIMS

Previous studies have investigated whether milk consumption has a role in preventing the development of cognitive impairment, but the results were inconsistent. Importantly, most of them have disregarded the role of different types of milk. This study aimed to examine the associations between different types of milk consumption and the risk of dementia.

METHODS

In this large-scale cohort study, participants without cognitive impairment at baseline were included from the UK Biobank. The type of milk mainly used was self-reported at baseline, including full-cream milk, skimmed-milk, soy milk, other milk, and no milk. The primary outcome was all-cause dementia. Secondary outcomes included Alzheimer's disease and vascular dementia.

RESULTS

Of the 307,271 participants included in the study (mean age 56.3 [SD 8.1] years), 3789 (1.2%) incident all-cause dementia cases were observed over a median follow-up of 12.3 years. After adjustment for potential confounders, only soy milk consumers had a statistically significantly lower risk of all-cause dementia compared with no milk consumers (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.54 to 0.90). When compared with soy milk non-consumers consisting of full-cream milk, skimmed-milk, and other milk consumers, soy milk consumers still showed a lower risk of all-cause dementia (HR, 0.76; 95% CI, 0.63 to 0.92), and there was no significant interaction with genetic risk for dementia (P for interaction = 0.15). Soy milk consumers showed a lower risk of Alzheimer's disease (HR, 0.70; 95% CI, 0.51 to 0.94; P = 0.02), while the association was not significant for vascular dementia (HR, 0.72; 95% CI, 0.47 to 1.12; P = 0.14).

CONCLUSIONS

The main consumption of soy milk was associated with a lower risk of dementia, particularly non-vascular dementia. Additional studies are needed to investigate how this association varies with the dose or frequency of the consumption of soy milk and to examine the generalizability of these findings in different populations.

Association of milk consumption with the incidence of cholelithiasis disease in the US adult population

BACKGROUND

Cholelithiasis is a common digestive system disease that imposes major burden on patients and society. Investigating the relationship between dietary factors and cholelithiasis risk can provide a basis for disease prevention. Previous studies on milk intake and cholelithiasis incidence have been limited.Therefore, the aim of our study was to assess the association between milk consumption and the incidence of cholelithiasis in males and females.

METHODS

We selected 14,722 adults (≥ 18 years old) from National Center for Health Statistics (NHANSE) 2017-2020, and collected general characteristics of patients in the database, such as age, gender, race and body mass index (BMI), as well as dietary information (milk consumption). The occurrence of cholelithiasis was used as the outcome event, and the group was divided into cholelithiasis and non-cholelithiasis groups according to the outcome event. We used logistic regression models in generalized linear model (GLM) functions, controlling for demographic, lifestyle, and dietary factors, to estimate the association between milk intake and the incidence of cholelithiasis in males and females.

RESULTS

A total of 14,722 adults were included. In the present study, the overall weighted prevalence of cholelithiasis was 10.96%, with 15.18% and 6.48% prevalence in females and males, respectively. Compared to infrequent milk intake, frequent milk intake (once a week or more) in females was associated with reduced cholelithiasis risk (OR 0.74, 95% CI 0.61-0.90). Daily milk intake in males was also related to lower cholelithiasis risk (OR 0.69-0.82). As adjusted variables increased in the models, predictive performance was improved (AUC 0.711 in females, 0.730 in males).

CONCLUSIONS

Appropriate milk intake may correlate with decreased cholelithiasis risk. Our study provides a basis for dietary interventions against gallstones, but prospective studies are needed to verify the results.

Milk consumption and risk of twelve cancers: A large-scale observational and Mendelian randomisation study

BACKGROUND & AIMS

Milk consumption is a modifiable lifestyle factor that has been associated with several cancer types in observational studies. Limited evidence exists regarding the causality of these relationships. Using a genetic variant (rs4988235) near the lactase gene (LCT) locus that proxies milk consumption, we conducted a comprehensive survey to assess potential causal relationships between milk consumption and 12 types of cancer.

METHODS

Our analyses were conducted using white British participants of the UK Biobank (n = up to 255,196), the FinnGen cohort (up to 260,405), and available cancer consortia. We included cancers with previous evidence of an association with milk consumption in observational studies, as well as cancers common in both UK Biobank and FinnGen populations (>1000 cases). We evaluated phenotypic associations of milk intake and cancer incidence in the UK Biobank, and then used a Mendelian randomisation (MR) approach to assess causality in the UK Biobank, FinnGen consortium, and combined analyses incorporating additional consortia data for five cancers. In MR meta-analyses, case numbers for cancers of breast, ovary, uterus, cervix, prostate, bladder and urinary tract, colorectum, and lung ranged between 6000 and 148,000 cases, and between 780 and 1342 cases for cancers of the liver, mouth, stomach and diffuse large B-cell lymphoma.

RESULTS

In observational analyses, milk consumption was associated with higher risk of bladder and urinary tract cancer (OR 1.23, 95% CI 1.03-1.47), but not with any other cancer. This association was not confirmed in the MR analysis, and genetically predicted milk consumption showed a significant association only with lower risk of colorectal cancer (0.89, 0.81-0.98 per additional 50 g/day). In the MR analyses conducted among individual cohorts, genetically predicted milk consumption provided evidence for an association with lower colorectal cancer in the FinnGen cohort (0.85, 0.74-0.97), and in the UK Biobank greater risk of female breast cancer (1.12, 1.03-1.23), and uterine cancer in pre-menopausal females (3.98, 1.48-10.7).

CONCLUSION

In a comprehensive survey of milk-cancer associations, we confirm of a protective role of milk consumption for colorectal cancer. Our analyses also provide some suggestion for higher risks of breast cancer and premenopausal uterine cancer, warranting further investigation.

Association of milk consumption with management and incidence of hypertension among South Korean adults: A prospective analysis of the health examinees study cohort

BACKGROUND AND AIMS

Studies have revealed a positive relationship between milk consumption and hypertension. However, few researchers have investigated the association between milk consumption and changes in blood pressure (BP) in South Korean adults. Therefore, we examined the association between milk intake and the management and risk of hypertension in South Korean adults.

METHODS AND RESULTS

Participants were selected from the Health Examinees study. The definition of hypertension was based on the guidelines of the Korean Society of Hypertension. The participants were divided into three groups according to changes between baseline and follow-up BP data. Milk consumption was assessed using food frequency questionnaires. In both men and women, the higher milk consumption group had increased odds of trends of BP improvement (OR: 1.249, 95% CI: 1.043-1.496, p for trend: 0.2271 in men; OR: 1.147, 95% CI: 1.014-1.297, p for trend: 0.0293 in women) and decreased odds of trends of worsening (OR: 0.861, 95% CI: 0.756-0.980, p for trend: <0.0001 in men, OR: 0.866, 95% CI: 0.794-0.943, p for trend: 0.0010 in women) compared to those of the non-consumption group. In the prospective study, milk intake was inversely associated with hypertension risk (HR: 0.900, 95% CI: 0.811-0.999, p for trend: 0.0076 in men; HR: 0.879, 95% CI: 0.814-0.949, p for trend: 0.0002 in women).

CONCLUSION

Increased intake of milk was inversely related to the risk of increased BP, with a decreased risk of hypertension events.

Association between milk consumption and lactose malabsorption in Indonesian children

OBJECTIVES

To study the association between milk consumption and lactose malabsorption in Indonesian children aged 3-12 years.

METHODS

This cross sectional study was conducted in randomly selected presumed healthy children with good nutritional status aged 3-12 years in Central Jakarta, Indonesia (n=174), including 72 children aged 3-5 years and 102 children aged 6-12 years.

RESULTS

The prevalence of lactose malabsorption in children aged 3-5 years and children aged 6-12 years was 20.8% (15/72) and 35.3% (36/102), respectively. There was no association between milk or milk product consumption and lactose malabsorption (P>0.05). In the 51 children with lactose malabsorption, the predominant clinical symptoms were diarrhea (62%), abdominal pain (52%), and nausea (5%) during the hydrogen breath test.

CONCLUSIONS

There is no association between milk consumption and lactose malabsorption in Indonesian children aged 3-12 years, suggesting that genetic predisposition may be more important than adaptive mechanisms to lactose consumption.

High milk consumption is associated with carotid atherosclerosis in middle and old-aged Chinese

Background

Carotid atherosclerosis (CA) can reflect atherosclerotic status of systemic vessels, and is associated with ischemic stroke and cognitive impairment. Milk consumption is growing in China, and data are limited on the association between milk and CA risk.

Methods

Participants aged ≥40 years in China National Stroke Prevention Project were recruited for carotid ultrasound examination, and those with carotid endarterectomy, carotid stenting stroke or coronary heart disease were excluded. Participants were defined as having CA when intima-media thickness (IMT) ≥1 mm or plaques were detected by ultrasonography. For milk consumption, though contents were not analyzed, people were divided into high consumption (≥200 ml/day and ≥5 day/week) and low consumption (occasional or never) groups. Multivariate logistics regression analyses were done in both full and propensity score-matched population to identify the association between milk consumption and CA.

Results

84880 participants were included in the final analysis. After being adjusted by age, gender, living location, smoking habits, drinking habits, physical activity, obesity, hypertension, diabetes, and dyslipidemia, high milk consumption is associated with CA in both full population (odds ratio [OR] = 1.26, 95% confidence interval [CI] 1.19-1.33) and propensity score-matched population (OR = 1.25, 95%CI 1.17-1.34). High milk consumption is also a risk factor for IMT thickening (OR = 1.15, 95%CI 1.08-1.23), carotid plaque formation (OR = 1.17, 95%CI 1.09-1.25) and carotid stenosis over 50% (OR = 1.52, 95%CI 1.10-2.14) in the propensity score-matched population.

Conclusions

High milk consumption is related to CA in middle and old-aged Chinese population. More cautious advice on milk intake should be given in this population for prevention of atherosclerosis.

Genetically proxied milk consumption and risk of colorectal, bladder, breast, and prostate cancer: a two-sample Mendelian randomization study

BACKGROUND

Observational studies have shown that milk consumption is inversely associated with colorectal, bladder, and breast cancer risk, but positively associated with prostate cancer. However, whether the associations reflect causality remains debatable. We investigated the potential causal associations of milk consumption with the risk of colorectal, bladder, breast, and prostate cancer using a genetic variant near the LCT gene as proxy for milk consumption.

METHODS

We obtained genetic association estimates for cancer from the UK Biobank (n = 367,643 women and men), FinnGen consortium (n = 135,638 women and men), Breast Cancer Association Consortium (n = 228,951 women), and Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome consortium (n = 140,254 men). Milk consumption was proxied by a genetic variant (rs4988235 or rs182549) upstream of the gene encoding lactase, which catalyzes the breakdown of lactose.

RESULTS

Genetically proxied milk consumption was associated with a reduced risk of colorectal cancer. The odds ratio (OR) for each additional milk intake increasing allele was 0.95 (95% confidence interval [CI] 0.91-0.99; P = 0.009). There was no overall association of genetically predicted milk consumption with bladder (OR 0.99; 95% CI 0.94-1.05; P = 0.836), breast (OR 1.01; 95% CI 1.00-1.02; P = 0.113), and prostate cancer (OR 1.01; 95% CI 0.99-1.02; P = 0.389), but a positive association with prostate cancer was observed in the FinnGen consortium (OR 1.07; 95% CI 1.01-1.13; P = 0.026).

CONCLUSIONS

Our findings strengthen the evidence for a protective role of milk consumption on colorectal cancer risk. There was no or limited evidence that milk consumption affects the risk of bladder, breast, and prostate cancer.

Unpasteurised milk consumption as a potential risk factor for toxoplasmosis in females with recurrent pregnancy loss

In women with a bad obstetric history, certain infections are associated with recurrent foetal loss. One of the common infectious agents is a protozoan parasite, Toxoplasma gondii. The aim of this study was to assess unpasteurised milk consumption as a potential risk factor for toxoplasmosis in females with recurrent pregnancy loss from the province of Khyber Pakhtunkhwa, Pakistan. In this study, we recruited a total of 360 females, comprising a study group of 180 females with previous history of recurrent pregnancy loss and a control group of 180 females with no such history. Blood serum from the participants was analysed for Toxoplasma gondii IgM antibodies by enzyme linked immunosorbent assay. Among the study group, 23 (12.8%) females were serologically positive for IgM antibodies against Toxoplasma gondii, whilst 157 (87.2%) were IgM negative. In the control group, only two (4.8%) females were IgM positive, whilst 178 (95.2%) were IgM negative. Bad pregnancy outcome in the study group and control group was observed to be significantly different (p < .0001). In both of these groups, unpasteurised milk consumption was found as a major risk factor for Toxoplasma gondii infection. A routine serological investigation should be carried out in pregnant women to rule out toxoplasmosis and reduce the risk of recurrent pregnancy loss as well as congenital toxoplasmosis in newborns.Impact statementWhat is already known on this subject? Seropositivity for Toxoplasma gondii antibodies ranges from 7% to 51% in different regions of the world. The prevalence rate varies because of differences in climate, culture, food habits, behaviour, personal hygiene and cooking habits of different societies and ethnic groups. Various risk factors have been identified that contribute to a high prevalence rate of the disease, including consumption of raw or poorly cooked meat, physical contact with cats or cat litter, consumption of unwashed raw vegetables and fruits, drinking of contaminated water and milk. We presumed that consuming unpasteurised milk could be a potential risk factor for developing toxoplasmosis in pregnant women.What the results of this study add? This study demonstrates high seroprevalence of Toxoplasma gondii antibodies in females of child bearing age that have consumed unpasteurised milk and is a potential risk factor for developing toxoplasmosis.What the implications are of these findings for clinical practice and/or further research? Our findings suggest that primary preventive measures (personal hygiene, frequent hand washing and consuming pasteurised milk) should be taken by health surveillance authorities to focus on families, especially pregnant women, to educate them about personal hygiene, contact with cattle or using their milk and milk products. The latter is especially important to aware them about the hazards of consuming unpasteurised and contaminated milk.

Milk handling practices and consumption behavior among Borana pastoralists in southern Ethiopia

BACKGROUND

Safety and wholesomeness of milk intended for human consumption are influenced by various interlinked factors. However, information on what these factors are, especially in the pastoral traditional communities of Ethiopia, is largely lacking. The objective of this study is to assess the hygienic milk production, processing and consumption practices, and behaviors of Borana pastoralists.

METHODS

The study used qualitative participatory research methods. Individual semi-structured interviews, focus group discussions, informal discussions, and observations were carried out on (1) milk handling practices, (2) perceptions of quality and safety of milk, including perceived criteria for good milk, (3) awareness of milk-borne diseases, and (4) perception towards milk boiling practices. The interviews and discussions were audio recorded, transcribed, and analyzed by identifying themes.

RESULTS

Some risky behaviors related to milk handling and consumption were identified. These include unhygienic conditions in handling milk and milk products, consumption behaviors such as consuming raw milk purchased from markets, and children directly consuming milk from the udder of animals (e.g., goats). There was a very strong reluctance to boil milk before consumption mainly because of the misconception that nutrients in the milk are destroyed when milk is boiled and "boiled milk is dead". On the other hand, potential risk mitigation practices were identified such as smoking of milk containers (which may help reduce microbial growth), processing milk through fermentation, consuming milk in boiled tea, and a recent trend towards boiling milk for babies. However, the latter was not motivated by concern over microbial hazards but the belief that raw milk could form curds in children's stomach which might then suffocate them.

CONCLUSION

The findings highlight the need to promote hygienic handling practices of milk and closely engage with local communities to improve their understanding of milk safety to facilitate change in practices. Educating pastoralists on good milk production practices should be given priority. One of the ways to do this could be by strengthening the integration of milk hygiene in research and development programs as an entry point for behavioral change towards the safe handling and consumption of milk and milk products.

Dairy product consumption and risk of hip fracture: a systematic review and meta-analysis

BACKGROUND

Dairy product consumption may affect the risk of hip fracture, but previous studies have reported inconsistent findings. The primary aim of our meta-analysis was to examine and quantify the potential association of dairy product consumption with risk of hip fracture.

METHODS

We searched the databases of PubMed and EMBASE for relevant articles from their inception through April 17, 2017. The final analysis included 10 cohort studies and 8 case-control studies. Random-effects models were used to estimate the pooled risk. Subgroup and dose-response analyses were conducted to explore the relationships between the consumption of milk and the risk of hip fracture.

RESULTS

After pooling the data from the included studies, the summary relative risk (RR) for hip fracture for highest versus lowest consumption were 0.91 (95% CI: 0.74-1.12), 0.75 (95% CI: 0.66-0.86), 0.68 (95% CI: 0.61-0. 77), 1.02 (95% CI: 0.93-1.12) for milk, yogurt, cheese, and total dairy products in cohort studies, respectively. Higher milk consumption [Odds ratio (OR), 0.71, 95% CI: 0.55-0. 91] was associated with lower risk of hip fracture for highest versus lowest consumption in case-control studies. After quantifying the specific dose of milk, the summary RR/OR for an increased milk consumption of 200 g/day was 1.00 (95% CI: 0.94-1.07), and 0.89 (95%CI: 0.64-1.24) with significant heterogeneity for cohort and case-control studies, respectively; There was a nonlinear association between milk consumption and hip fracture risk in cohort, and case-control studies.

CONCLUSIONS

Our findings indicate that consumption of yogurt and cheese was associated with lower risk of hip fracture in cohort studies. However, the consumption of total dairy products and cream was not significantly associated with the risk of hip fracture. There was insufficient evidence to deduce the association between milk consumption and risk of hip fracture. A lower threshold of 200 g/day milk intake may have beneficial effects, whereas the effects of a higher threshold of milk intake are unclear.

The relationship between fat and progesterone, estradiol, and chorionic gonadotropin levels in Quebec cow's milk

PURPOSE

The majority of milk in industrialized countries is obtained from pregnant cows, which contains increased levels of estrogen and progesterone compared to non-pregnant cows. The aim of this study was to quantify the amount of hormones present in milk with different fat content because previous studies on humans have shown potential effects of increased milk consumption on serum and urine hormone levels as well as on sperm parameters. However, it is unclear whether consumption of milk at the currently recommended levels would lead to systemic effects.

METHODS

Samples of cow's milk of varying fat concentrations (0, 1, 2, 3.25, 10, and 35%) were analyzed via competitive ELISA assays.

RESULTS

Progesterone concentrations were significantly correlated to increasing fat content of milk (r = 0.8251, p = 0.04).

CONCLUSIONS

Research on conditions in which additional progesterone may have an effect on human health should consider inclusion of limitation of milk intake and its effects. Further studies are needed to determine the concentration of progesterone in milk of different fat content in other regions and countries and to quantify the potential pathophysiologic role.

Suckling induced activation pattern in the brain of rat pups

OBJECTIVES

The aim of the study was to understand the effects of suckling on the brain of the pups by mapping their brain activation pattern in response to suckling.

METHODS

The c-fos method was applied to identify activated neurons. Fasted rat pups were returned to their mothers for suckling and sacrificed 2 hours later for Fos immunohistochemistry. Double labeling was also performed to characterize some of the activated neurons. For comparison, another group of fasted pups were given dry food before Fos mapping.

RESULTS

After suckling, we found an increase in the number of Fos-immunoreactive neurons in the insular and somatosensory cortices, central amygdaloid nucleus (CAm), paraventricular (PVN) and supraoptic hypothalamic nuclei, lateral parabrachial nucleus (LPB), nucleus of the solitary tract (NTS), and the area postrema. Double labeling experiments demonstrated the activation of calcitonin gene-related peptide-ir (CGRP-ir) neurons in the LPB, corticotropin-releasing hormone-ir (CRH-ir) but not oxytocin-ir neurons in the PVN, and noradrenergic neurons in the NTS. In the CAm, Fos-ir neurons did not contain CRH but were apposed to CGRP-ir fiber terminals. Refeeding with dry food-induced Fos activation in all brain areas activated by suckling. The degree of activation was higher following dry food consumption than suckling in the insular cortex, and lower in the supraoptic nucleus and the NTS. Furthermore, the accumbens, arcuate, and dorsomedial hypothalamic nuclei, and the lateral hypothalamic area, which were not activated by suckling, showed activation by dry food.

DISCUSSION

Neurons in a number of brain areas are activated during suckling, and may participate in the signaling of satiety, taste perception, reward, food, and salt balance regulation.

Milk Consumption and Framingham Risk Score: Analysis of the Korea National Health and Nutrition Examination Survey Data (2008-2011)

PURPOSE

The benefit of milk intake remains controversial. The association between milk consumption and Framingham Risk Score (FRS) in a population consuming relatively low amounts of dairy products is undetermined.

MATERIALS AND METHODS

A total of 13736 adults (5718 male and 8018 female) aged 20-80 years from the Korea National Health and Nutrition Examination Survey (2008-2011) were divided into groups according to milk consumption (rarely, monthly, weekly, and daily) and compared according to FRS after relevant variable adjustments.

RESULTS

The mean FRS in males and females were 6.53 and 5.74, respectively. Males who consumed milk daily (15.9%) had a significantly lower FRS than males having milk rarely (31.6%) or monthly (17.4%; p=0.007). Females who consumed milk daily (22.3%) also had significantly lower FRS than rarely (29.8%), monthly (13.8%), or weekly (34%; p=0.001) consumers. In particular, males ≥60 years old who consumed milk daily had a significantly lower FRS than males who consumed less milk (p<0.001). The odds ratio in this age group showed a significant and gradual increase in the weekly [OR=2.15; 95% confidence interval (CI) 1.14-4.03], monthly (OR=2.29; 95% CI 1.15-4.54), and rarely (OR=3.79; 95% CI 2.01-7.14) milk consumption groups when compared with the daily milk consumption group.

CONCLUSION

Milk consumption was associated with a lower FRS in a low milk-consuming population. In particular, daily milk consumption in males over 60 years old may be beneficial for those at risk for cardiovascular disease.

Influence of nutrition on somatotropic axis: Milk consumption in adult individuals with moderate-severe obesity

BACKGROUND & AIMS

Nutrition is the major environmental factor that influences the risk of developing pathologies, such as obesity. Although a number of recent reviews pinpoint a protective effects of milk on body weight and obesity related co-morbidities, an inaccurate estimate of milk might contribute to hamper its beneficial effects on health outcomes. Seven-day food records provide prospective food intake data, reducing recall bias and providing extra details about specific food items. Milk intake stimulates the somatotropic axis at multiple levels by increasing both growth hormone (GH) and insulin-like growth factor-1 (IGF-1) secretion. On the other hand, obesity is associated with reduced spontaneous and stimulated GH secretion and basal IGF-1 levels. Aim of this study was to evaluate the milk consumption by using the 7-days food record in obese individuals and to investigate the association between milk intake and GH secretory status in these subjects.

METHODS

Cross-sectional observational study carried out on 281 adult individuals (200 women and 81 men, aged 18-74 years) with moderate-severe obesity (BMI 35.2-69.4 kg/m²). Baseline milk intake data were collected using a 7 day food record. Anthropometric measurements and biochemical profile were determined. The GH/IGF-1 axis was evaluated by peak GH response after GHRH + ARGININE and IGF-1 standard deviation score (SDS).

RESULTS

The majority of individuals (72.2%) reported consuming milk; 250 mL low-fat milk was the most frequently serving of milk consumed, while no subjects reported to consume whole milk. Milk consumers vs no milk consumers presented the better anthropometric measurements and metabolic profile. At the bivariate proportional odds ratio model, after adjusting for BMI, age and gender, milk consumption was associated the better GH status (OR = 0.60; p < 0.001). Among milk consumers, subjects consuming 250 mL reduced-fat milk vs 250 mL low-fat milk presented the better anthropometric measurements and metabolic profile. At the bivariate proportional odds ratio model, after adjusting for BMI, age and gender, the consume of 250 mL reduced-fat milk was associated better GH status (OR = 0.54; p = 0.003).

CONCLUSIONS

A novel positive association between milk consumption, GH status, and metabolic profile in obese individuals was evidenced. Regardless of the pathogenetic mechanisms, this novel association might be relevant in a context where commonly obese individuals skip breakfast, and suggests the need of a growing cooperation between Nutritionists and Endocrinologists in the management of the obese patients.

Prevalence of lactase persistent/non-persistent genotypes and milk consumption in a young population in north-west Russia

AIM: To estimate the prevalence of the lactase non-persistent genotype (C/C-13910) in a northern Russian population in accordance with ethnicity, and to evaluate self-reported milk consumption depending on lactase activity.

METHODS: Blood samples for genotyping lactase activity, defining the C/T-13910 variant by polymerase chain reaction, and direct sequencing were taken from 231 medical students of Russian origin aged 17-26 years. We analyzed milk product consumption by questionnaire which was specially designed for the estimation of milk consumption and abdominal complaints.

RESULTS: We found that the prevalence of the C/C-13190 genotype in the northern Russian population was 35.6%. The other genotypes nearby C/T-13910 and associated with lactase activity were not present in the study population. The consumption of milk among people with the non-persistent genotype tended to be lower than among the lactose tolerant subjects, but was not statistically significant.

CONCLUSION: An investigation of the lactase persistent genotype in a northern Russian population has not been performed before. The genotype did not affect the consumption of milk products in this population which could be explained by low consumption of milk products among the entire study population.

Molecularly defined adult-type hypolactasia among working age people with reference to milk consumption and gastrointestinal symptoms

AIM: To study milk consumption and subjective milk-related symptoms in adults genotyped for adult-type hypolactasia.

METHODS: A total of 1900 Finnish adults were genotyped for the C/T_-13910 variant of adult-type hypolactasia and filled in a structured questionnaire concerning milk consumption and gastrointestinal problems.

RESULTS: The C/C_-13910 genotype of adult-type hypolactasia was present in 18% of the study population. The prevalence of the C/C_-13910 genotype was higher among subjects who were undergoing investigations because of abdominal symptoms (24%, P < 0.05). Those with the C/C_-13910 genotype drank less milk than subjects with either the C/T_-13910 or the T/T_-13910 genotype of lactase persistence (18% vs 38%; 18% vs 36%, P < 0.01). Subjects with the C/C_-13910 genotype had experienced more gastrointestinal symptoms (84%) during the preceding three-month period than those with the C/T_-13910 (79%, P < 0.05) or the T/T_-13910 genotype (78 %, P < 0.05). Only 9% (29/338) of the subjects with the C/C_-13910 genotype consumed milk and reported no symptoms from it.

CONCLUSION: Gastrointestinal symptoms are more common among adults with the C/C_-13910 genotype of adult-type hypolactasia than in those with genotypes of lactase persistence.