The impact of dairy products on anthropometric and cardiometabolic indicatorsA substudy of Dietary I

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The impact of dairy products on anthropometric
and cardiometabolic indicators-A sub-study of
Dietary Intervention Randomized Controlled Trial
(Direct-Dairy)

• Danit R Shahar
• First conference of the Israeli Dairy Council
  Research Foundation
• 18/2/09
• The S. Daniel Abraham International Center for
  health and Nutrition and the Department of
  Epidemiology and Health Sciences Evaluation,
  Ben-Gurion University of the Negev

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Background

• Dietary calcium modulation of blood pressure has
  been well established through numerous
  well-controlled studies over the last 20 years
• Recent studies suggest that dairy products may
  contribute to weight reduction in animal and
  human models
• Although findings are debatable

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Mean Systolic and Diastolic Blood Pressures at
Base Line and during Each Intervention Week,
According to Diet, for 379 Subjects with Complete
Sets of Weekly Blood-Pressure Measurements
Nutrient Targets, Menu Analyses, and Average
Daily Servings of Foods, According to Diet
Appel L et al. N Engl J Med 19973361117-1124
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Calcium and Dairy Acceleration of Weight and Fat
Loss during Energy Restriction in Obese
AdultsObesity Research 12582-590 (2004)

• A randomized controlled trial among 32 obese
  adults
• Isocaloric diets differed in calcium intake (400
  to 500 mg of dietary calcium/d supplemented with
  placebo), a high-calcium diet (standard diet
  supplemented with 800 mg of calcium/d), or
  high-dairy diet (1200 to 1300 mg of dietary
  calcium/d supplemented with placebo)
• Effects of dietary treatments on
• body fat reduction.
• Changes in body fat are
• expressed as a percentage
• of original body fat
• measured by DXA

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Does dairy calcium intake enhance weight loss
among overweight diabetic patients?

• Danit R Shahar, Relly Abel, Asher Elhayany,
  Hillel Vardi, Drora Fraser
• Diabetes care, 2007
• The study was supported by a grant from Tnuva
  Research Institute, Rehovot, Israel.

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Objective

• To examine the impact of low-fat dairy
  consumption, particularly dairy calcium, on
  weight loss and type II diabetes indicators among
  overweight type II diabetic patients

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Percent change (from baseline) in health
indicators after 6 months by dairy calcium intake
tertiles at 6 months (GLM analysis with age and
change in energy intake from baseline in the
model)
P0.02
P0.03
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Logistic regression model to predict percent
weight loss above the median value (gt8 percent)
in 6 months
9

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The Dietary Intervention Randomized Controlled
Trial - DIRECT

Low-fat diet Mediterranean diet Low-carb diet
weight parameters
2 years
n322
Evaluation Of dietary adherence
Metabolic inflammatory biomarkers
Diabetics
In this two-year trial we randomized 322
moderately obese subjects (BMI31kg/m2, age52
years, 86 men) to one of three diets low-fat
restricted-calorie, Mediterranean
restricted-calorie or low-carb non-restricted-
calorie.
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• Location
• The Nuclear Research Center
• Isolated workplace
• Rational
• On site clinic
• Most procedures done in the workplace
• Exclusive, regulated source of lunch

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Mean weight loss was 2.9kg for low-fat, 4.4kg for
Mediterranean, and 4.7kg for low-carb (-3.3kg,
-4.6kg, and -5.5kg, respectively, among 272
completers)
Weight loss phase
Weight loss maintenance phase
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Data used in Direct-Dairy

• FFQ from baseline, 6, 12 and 24 months
• Monthly weight and waist circumference along the
  24 months of the study
• Cardiometabolic indicators including blood
  pressure, lipid measurements, glucose, insulin
  and inflammatory markers at baseline, 6, and 24
  months.
• New data to be collected
• Serum vitamin D (25(OH)D and 1,25(OH)2D) at
  baseline and at 6 months
• Sun exposure questionnaire
• Data regarding dairy intake at baseline, 6, 12
  and 24 months

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Baseline characteristics by dairy intake tertiles
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Changes in weight by tertiles of dairy calcium
0.095
P0.037
P0.045
P for linear trend at 6, 12 and 24 months is
0.028, 0.011, and 0.57

• Data is adjusted for age, gender, physical
  activity, energy intake change,
• diet group

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Changes in waist circumference by tertiles of
dairy calcium
P for linear trend at 6, 12 and 24 months is
0.92, 0.16, and 0.07
Data is adjusted for age, gender, physical
activity, energy intake change, diet group
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Dairy intake and Vitamin D

• Calcitrophic hormones, parathyroid hormone and
  1,25(OH)2D respond to low (increased lipid
  storage) and high calcium diets (inhibits
  adiposity) (Zemel 2004)
• Human adipocytes possess membrane (nongenomic)
  vitamin D receptors that transduce a rapid Ca2
  response to 1,25(OH)2D (Zemel, 2003)
• The treatment of human adipocytes with 1,25(OH)2D
  results in the coordinated activation of fatty
  acid synthase expression and activity and the
  suppression of lipolysis, leading to an expansion
  of adipocyte lipid storage.
• This mechanism, although based on reasonable
  physiological plausibility needs to be proven in
  larger human groups and in epidemiological
  studies.

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Other suggested mechanisms

• Reduced absorption of fat in the gut
• Intracellular calcium has a regulatory role in
  fat metabolism by influencing lipolysis, fat
  oxidation and lipogenesis
• Possible effect on appetite and energy
  expenditure
• Few studies showed an increase in fecal excretion
  of fat when calcium intake increased

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Conclusions

• We have demonstrated in our study that higher
  dairy intake among overweight patients on 3
  dietary regimens enhances the weight loss process
  
• This remained true even after controlling for
  change in total energy and diet type
• We did not find any association between dairy
  calcium intake and other cardiometabolic
  indicators isuch as waist circumference, HbA1C,
  HDL, LDL, and blood pressure
• It is important to take into consideration the
  possible negative effect of dairy
  products-Giovannucci et al. showed that calcium
  intake exceeding 1,500 mg/day may be associated
  with a higher risk of advanced and fatal prostate
  cancer
• Parodi in a review of 40 case control and 12
  cohort studies did not find any association
  between dairy product consumption and the risk of
  breast cancer

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Thanks

• KAMAG participants
• KAMAG researchers particularly Dr Iris Shai and
  Dr Dan Schwarzfuchs
• The S. Daniel Abraham International Center for
  Health and Nutrition teem, particularly Prof
  Drora Fraser, Hillel Vardi and Osnat Rosenthal
• Thanks you for listening