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Scientific Writing, HRP 214 Weekly Quiz

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Weekly Quiz Scientific Writing, HRP 214 Weekly Quiz A. It was a secret among friends. B. It was a secret between friends. Scientific Writing, HRP 214 Weekly Quiz A. – PowerPoint PPT presentation

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Title: Scientific Writing, HRP 214 Weekly Quiz


1
Scientific Writing, HRP 214 Weekly Quiz
2
Scientific Writing, HRP 214 Weekly Quiz
  • A. It was a secret among friends.
  • B. It was a secret between friends.

3
Scientific Writing, HRP 214 Weekly Quiz
  • A. It was a secret among friends.
  • B. It was a secret between friends.

4
Scientific Writing, HRP 214 Weekly Quiz
  • A. The close friendship that existed between
    them was quickly dissolved.
  • B. The close friendship that existed among them
    was quickly dissolved.

5
Scientific Writing, HRP 214 Weekly Quiz
  • A. The close friendship that existed between
    them was quickly dissolved.
  • B. The close friendship that existed among them
    was quickly dissolved.

6
Scientific Writing, HRP 214 Weekly Quiz
  • A. She eluded to the fight that occurred earlier.
  • B. She alluded to the the fight that occurred
    earlier.

7
Scientific Writing, HRP 214 Weekly Quiz
  • A. She eluded to the fight that occurred earlier.
  • B. She alluded to the the fight that occurred
    earlier.

8
Scientific Writing, HRP 214 Weekly Quiz
  • A. She eluded the fight.
  • B. She alluded the fight.

9
Scientific Writing, HRP 214 Weekly Quiz
  • A. She eluded the fight.
  • B. She alluded the fight.

10
Scientific Writing, HRP 214 Weekly Quiz
  • A. She lies out in the sun.
  • B. She lays out in the sun.

11
Scientific Writing, HRP 214 Weekly Quiz
  • A. She lies out in the sun.
  • B. She lays out in the sun.

12
Scientific Writing, HRP 214 Weekly Quiz
  • A. She is lying out in the sun.
  • B. She is laying out in the sun.

13
Scientific Writing, HRP 214 Weekly Quiz
  • A. She is lying out in the sun.
  • B. She is laying out in the sun.

14
Scientific Writing, HRP 214 Weekly Quiz
  • A. She laid out in the sun yesterday.
  • B. She lay out in the sun yesterday.

15
Scientific Writing, HRP 214 Weekly Quiz
  • A. She laid out in the sun yesterday.
  • B. She lay out in the sun yesterday.

16
Scientific Writing, HRP 214 Weekly Quiz
  • A. She had laid out in the sun too much as a kid.
  • B. She had lain out in the sun too much as a kid.

17
Scientific Writing, HRP 214 Weekly Quiz
  • A. She had laid out in the sun too much as a kid.
  • B. She had lain out in the sun too much as a kid.

18
Scientific Writing, HRP 214 Weekly Quiz
  • A. She lies the book on the table.
  • B. She lays the book on the table.

19
Scientific Writing, HRP 214 Weekly Quiz
  • A. She lies the book on the table.
  • B. She lays the book on the table.

20
Scientific Writing, HRP 214 Weekly Quiz
  • A. She is lying the book on the table.
  • B. She is laying the book on the table.

21
Scientific Writing, HRP 214 Weekly Quiz
  • A. She is lying the book on the table.
  • B. She is laying the book on the table.

22
Scientific Writing, HRP 214 Weekly Quiz
  • A. She laid the book on the table this morning.
  • B. She lay the book on the table this morning.

23
Scientific Writing, HRP 214 Weekly Quiz
  • A. She laid the book on the table this morning.
  • B. She lay the book on the table this morning.

24
Scientific Writing, HRP 214 Weekly Quiz
  • A. She had lain the book on the table.
  • B. She had laid the book on the table.

25
Scientific Writing, HRP 214 Weekly Quiz
  • A. She had lain the book on the table.
  • B. She had laid the book on the table.

26
Scientific Writing, HRP 214 Weekly Quiz
  • A. Now I lay down to sleep.
  • B. Now I lie down to sleep.

27
Scientific Writing, HRP 214 Weekly Quiz
  • A. Now I lay down to sleep.
  • B. Now I lie down to sleep.

28
Scientific Writing, HRP 214 Weekly Quiz
  • A. Now I lay me down to sleep.
  • B. Now I lie me down to sleep.

29
Scientific Writing, HRP 214 Weekly Quiz
  • A. Now I lay me down to sleep.
  • B. Now I lie me down to sleep.

30
Scientific Writing, HRP 214 Weekly Quiz
  • A. She commented on the clearly defined mutant
    traits.
  • B. She commented on the clearly-defined mutant
    traits.

31
Scientific Writing, HRP 214 Weekly Quiz
  • A. She commented on the clearly defined mutant
    traits.
  • B. She commented on the clearly-defined mutant
    traits.

32
Scientific Writing, HRP 214 Weekly Quiz
  • A. I am disinterested in your results.
  • B. I am uninterested in your results.

33
Scientific Writing, HRP 214 Weekly Quiz
  • A. I am disinterested in your results.
  • B. I am uninterested in your results.

34
Scientific Writing, HRP 214 Weekly Quiz
  • A. We think you should look into an alternative
    career path, i.e. get a new job.
  • B. We think you should look into an alternative
    career path, e.g. get a new job.

35
Scientific Writing, HRP 214 Weekly Quiz
  • A. We think you should look into an alternative
    career path, i.e. get a new job.
  • B. We think you should look into an alternative
    career path, e.g. get a new job.

36
Scientific Writing, HRP 214 Weekly Quiz
  • A. They prefer mixed drinks, e.g. gin and tonic
    or martinis.
  • B. They prefer mixed drinks, i.e. gin and tonic
    or martinis.

37
Scientific Writing, HRP 214 Weekly Quiz
  • A. They prefer mixed drinks, e.g. gin and tonic
    or martinis.
  • B. They prefer mixed drinks, i.e. gin and tonic
    or martinis.

38
Scientific Writing, HRP 214 Weekly Quiz
  • She served as a disinterested party in the
    dispute.
  • She served as an uninterested party in the
    dispute.

39
Scientific Writing, HRP 214 Weekly Quiz
  • She served as a disinterested party in the
    dispute.
  • She served as an uninterested party in the
    dispute.

40
Scientific Writing, HRP 214 Weekly Quiz
  • A. You should eat more sweets, e.g. chocolate.
  • B. You should eat more sweets, i.e. chocolate.

41
Scientific Writing, HRP 214 Weekly Quiz
  • A. You should eat more sweets, e.g. chocolate.
  • B. You should eat more sweets, i.e. chocolate.

42
Scientific Writing, HRP 214 Weekly Quiz
  • A. Runners who develop overuse running-related
    injuries have lower intakes of several key
    nutrients compared to non-injured runners.
  • B. Runners who develop overuse running-related
    injuries have lower intakes of several key
    nutrients compared with non-injured runners.

43
Scientific Writing, HRP 214 Weekly Quiz
  • A. Runners who develop overuse running-related
    injuries have lower intakes of several key
    nutrients compared to non-injured runners.
  • B. Runners who develop overuse running-related
    injuries have lower intakes of several key
    nutrients compared with non-injured runners.

44
Scientific Writing, HRP 214 Weekly Quiz
  • A. Over half the runners sustained an injury
    during the year.
  • B. More than half the runners sustained an injury
    during the year.

45
Scientific Writing, HRP 214 Weekly Quiz
  • A. Over half the runners sustained an injury
    during the year.
  • B. More than half the runners sustained an injury
    during the year.

46
Scientific Writing, HRP 214
  • Lecture 7
  • The Abstract, Introduction, and Discussion

47
Scientific Writing, HRP 214 Abstracts
  • Abstracts (about, traherepull to pull out)
  • Overview of the main story
  • Gives highlights from each section of the paper
  • Limited length (100-300 words, typically)
  • Stands on its own
  • Used, with title, for electronic search engines
  • Most often, the only part people read

48
Scientific Writing, HRP 214 Abstracts
  • Gives
  • Background
  • Question asked
  • We asked whether, We hypothesized that,etc.
  • Experiment(s) done
  • Material studied (molecule, cell line, tissue,
    organ) or the animal or human population studied
  • The experimental approach or study design and the
    independent and dependent variables
  • Results found
  • Key results found
  • Minimal raw data (prefer summaries)
  • The answer to the question asked
  • Implication, speculation, or recommendation

49
Scientific Writing, HRP 214 Abstracts
  • Abstracts may be structured (with subheadings) or
    free-form.

50
Scientific Writing, HRP 214 Abstracts
  • Structured example (The Lancet, 2006 Feb
    11367(9509)475-81.)
  • Development of adenoviral-vector-based pandemic
    influenza vaccine against antigenically distinct
    human H5N1 strains in mice.
  • Hoelscher MA, Garg S, Bangari DS, Belser JA, Lu
    X, Stephenson I, Bright RA, Katz JM, Mittal SK,
    Sambhara S.

51
Scientific Writing, HRP 214 Abstracts
  • INTRODUCTION Avian H5N1 influenza viruses
    currently circulating in southeast Asia could
    potentially cause the next pandemic. However,
    currently licensed human vaccines are
    subtype-specific and do not protect against these
    H5N1 viruses. We aimed to develop an influenza
    vaccine and assessed its immunogenicity and
    efficacy to confer protection in BALB/c mice.
  • METHODS We developed an egg-independent strategy
    to combat the avian influenza virus, because the
    virus is highly lethal to chickens and the
    maintenance of a constant supply of embryonated
    eggs would be difficult in a pandemic. We used a
    replication-incompetent, human adenoviral-vector-b
    ased, haemagglutinin subtype 5 influenza vaccine
    (HAd-H5HA), which induces both humoral and
    cell-mediated immune responses against avian H5N1
    influenza viruses isolated from people.

52
Scientific Writing, HRP 214 Abstracts
  • FINDINGS Immunisation of mice with HAd-H5HA
    provided effective protection from H5N1 disease,
    death, and primary viral replication (plt0.0001)
    against antigenically distinct strains of H5N1
    influenza viruses. Unlike the recombinant H5HA
    vaccine, which is based on a traditional subunit
    vaccine approach, HAd-H5HA vaccine induced a
    three-fold to eight-fold increase in
    HA-518-epitope-specific interferon-gamma-secreting
    CD8 T cells (p0.01).
  • INTERPRETATION Our findings highlight the
    potential of an Ad-vector-based delivery system,
    which is both egg-independent and
    adjuvant-independent and offers stockpiling
    options for the development of a pandemic
    influenza vaccine.

53
Scientific Writing, HRP 214 Abstracts
  • Structured example 2
  • N Engl J Med. 2006 Feb 16354(7)684-96.
  • Calcium plus vitamin D supplementation and the
    risk of colorectal cancer.
  • Wactawski-Wende J, Kotchen JM, Anderson GL,
    Assaf AR, Brunner RL, O'Sullivan MJ, Margolis KL,
    Ockene JK, Phillips L, Pottern L, Prentice RL,
    Robbins J, Rohan TE, Sarto GE, Sharma S,
    Stefanick ML, Van Horn L, Wallace RB, Whitlock E,
    Bassford T, Beresford SA, Black HR, Bonds DE,
    Brzyski RG, Caan B, Chlebowski RT, Cochrane B,
    Garland C, Gass M, Hays J, Heiss G, Hendrix SL,
    Howard BV, Hsia J, Hubbell FA, Jackson RD,
    Johnson KC, Judd H, Kooperberg CL, Kuller LH,
    LaCroix AZ, Lane DS, Langer RD, Lasser NL, Lewis
    CE, Limacher MC, Manson JE Women's Health
    Initiative Investigators.

54
Scientific Writing, HRP 214 Abstracts
  • ABSTRACT
  • BACKGROUND Higher intake of calcium and vitamin
    D has been associated with a reduced risk of
    colorectal cancer in epidemiologic studies and
    polyp recurrence in polyp-prevention trials.
    However, randomized-trial evidence that calcium
    with vitamin D supplementation is beneficial in
    the primary prevention of colorectal cancer is
    lacking.
  • METHODS We conducted a randomized, double-blind,
    placebo-controlled trial involving 36,282
    postmenopausal women from 40 Women's Health
    Initiative centers 18,176 women received 500 mg
    of elemental calcium as calcium carbonate with
    200 IU of vitamin D3 twice daily (1000 mg of
    elemental calcium and 400 IU of vitamin D3) and
    18,106 received a matching placebo for an average
    of 7.0 years. The incidence of pathologically
    confirmed colorectal cancer was the designated
    secondary outcome. Baseline levels of serum
    25-hydroxyvitamin D were assessed in a nested
    case-control study.

55
Scientific Writing, HRP 214 Abstracts
  • RESULTS The incidence of invasive colorectal
    cancer did not differ significantly between women
    assigned to calcium plus vitamin D
    supplementation and those assigned to placebo
    (168 and 154 cases hazard ratio, 1.08 95
    percent confidence interval, 0.86 to 1.34
    P0.51), and the tumor characteristics were
    similar in the two groups. The frequency of
    colorectal-cancer screening and abdominal
    symptoms was similar in the two groups. There
    were no significant treatment interactions with
    baseline characteristics.
  • CONCLUSIONS Daily supplementation of calcium
    with vitamin D for seven years had no effect on
    the incidence of colorectal cancer among
    postmenopausal women. The long latency associated
    with the development of colorectal cancer, along
    with the seven-year duration of the trial, may
    have contributed to this null finding. Ongoing
    follow-up will assess the longer-term effect of
    this intervention.

56
Scientific Writing, HRP 214 Abstracts
  • Even more subheadings
  • Effect of Rimonabant, a Cannabinoid-1 Receptor
    Blocker, on Weight and Cardiometabolic Risk
    Factors in Overweight or Obese Patients RIO-North
    America A Randomized Controlled Trial
  • F. Xavier Pi-Sunyer, MD Louis J. Aronne, MD
    Hassan M. Heshmati, MD Jeanne Devin, MS Julio
    Rosenstock, MD for the RIO-North America Study
    Group
  • JAMA. 2006295761-775.

57
Scientific Writing, HRP 214 Abstracts
  • Context  Rimonabant, a selective cannabinoid-1
    receptor blocker, may reduce body weight and
    improve cardiometabolic risk factors in patients
    who are overweight or obese.
  • Objective To compare the efficacy and safety of
    rimonabant with placebo each in conjunction with
    diet and exercise for sustained changes in weight
    and cardiometabolic risk factors over 2 years.
  • Design, Setting, and Participants  Randomized,
    double-blind, placebo-controlled trial of 3045
    obese (body mass index 30) or overweight (body
    mass index gt27 and treated or untreated
    hypertension or dyslipidemia) adult patients at
    64 US and 8 Canadian clinical research centers
    from August 2001 to April 2004.
  • Intervention  After a 4-week single-blind
    placebo plus diet (600 kcal/d deficit) run-in
    period, patients were randomized to receive
    placebo, 5 mg/d of rimonabant, or 20 mg/d of
    rimonabant for 1 year. Rimonabant-treated
    patients were rerandomized to receive placebo or
    continued to receive the same rimonabant dose
    while the placebo group continued to receive
    placebo during year 2.

58
Scientific Writing, HRP 214 Abstracts
  • Results  At year 1, the completion rate was 309
    (51) patients in the placebo group, 620 (51)
    patients in the 5 mg of rimonabant group, and 673
    (55) patients in the 20 mg of rimonabant group.
    Compared with the placebo group, the 20 mg of
    rimonabant group produced greater mean (SEM)
    reductions in weight (6.3 0.2 kg vs 1.6 0.2
    kg Plt.001), waist circumference (6.1 0.2 cm
    vs 2.5 0.3 cm Plt.001), and level of
    triglycerides (percentage change, 5.3 1.2 vs
    7.9 2.0 Plt.001) and a greater increase in
    level of high-density lipoprotein cholesterol
    (percentage change, 12.6 0.5 vs 5.4 0.7
    Plt.001). Patients who were switched from the 20
    mg of rimonabant group to the placebo group
    during year 2 experienced weight regain while
    those who continued to receive 20 mg of
    rimonabant maintained their weight loss and
    favorable changes in cardiometabolic risk
    factors. Use of different imputation methods to
    account for the high rate of dropouts in all 3
    groups yielded similar results. Rimonabant was
    generally well tolerated the most common
    drug-related adverse event was nausea (11.2 for
    the 20 mg of rimonabant group vs 5.8 for the
    placebo group).

59
Scientific Writing, HRP 214 Abstracts
  • Conclusions  In this multicenter trial,
    treatment with 20 mg/d of rimonabant plus diet
    for 2 years promoted modest but sustained
    reductions in weight and waist circumference and
    favorable changes in cardiometabolic risk
    factors. However, the trial was limited by a high
    drop-out rate and longer-term effects of the drug
    require further study.

60
Scientific Writing, HRP 214 Abstracts
  • Science. 2006 Feb 17311(5763)1020-2. Causal
    reasoning in rats. Blaisdell AP, Sawa K, Leising
    KJ, Waldmann MR.
  • Empirical research with nonhuman primates
    appears to support the view that causal reasoning
    is a key cognitive faculty that divides humans
    from animals. The claim is that animals
    approximate causal learning using associative
    processes. The present results cast doubt on that
    conclusion. Rats made causal inferences in a
    basic task that taps into core features of causal
    reasoning without requiring complex physical
    knowledge. They derived predictions of the
    outcomes of interventions after passive
    observational learning of different kinds of
    causal models. These competencies cannot be
    explained by current associative theories but are
    consistent with causal Bayes net theories.

61
Scientific Writing, HRP 214 Introduction and
Background
  • Introduction and Background Section

62
Scientific Writing, HRP 214 Introduction and
Background
  • The Literature Search
  • Utilize online databases, such as MEDLINE,
    PubMed, and Ovid.
  • Have a search strategy.
  • Have an organizational system!

63
Scientific Writing, HRP 214 Introduction and
Background
  • The Literature Review
  • Summarize the current state of knowledge in the
    area of investigation.
  • You may have to return to the literature once
    your results are in hand.
  • Assume your reader is knowledgeable about the
    field.
  • Do not provide an exhaustive historical review.
  • Avoid nonessential details.
  • Summarize previous results and conclusions, but
    do not give the methods that generated these
    findings unless they are relevant to your
    research question (i.e., your experiment
    addresses a specific methodologic limitation of
    previous experiments)
  • Refer the reader to general surveys or reviews of
    the topic if available.
  • Cite references that reflect the key work that
    led to your research question.
  • Limit the number of references.

64
Scientific Writing, HRP 214
  • In writing the literature review, summarize
    rather than listing every possible reference and
    example.

65
Scientific Writing, HRP 214 Introduction and
Background
  • Introduction and Background
  • 1. Whats known
  • 2. Whats unknown
  • limitations and gaps in previous studies
  • 3. Your burning question
  • 4. Your experimental approach
  • 5. Why your experimental approach is new and
    different and important
  • From Essentials of Writing Biomedical Research
    Papers by Mimi Zeiger

66
Scientific Writing, HRP 214 Introduction
  • Tell a story
  • Write it in plain English, not tech-speak.
  • Take the reader step by step from what is known
    to what is unknown. End with your specific
    question.
  • (Known?Unknown?Question)
  • Emphasize what is new and important about your
    work.
  • Do not state the answer to the research question.
  • Do not include results or implications.

67
Introduction
  • Overweight, Obesity, and Mortality from Cancer in
    a Prospectively Studied Cohort of U.S.
    Adults Eugenia E. Calle, Ph.D., Carmen Rodriguez,
    M.D., M.P.H., Kimberly Walker-Thurmond, B.A., and
    Michael J. Thun, M.D.  

68
  • The relations between excess body weight and
    mortality, not only from all causes but also from
    cardiovascular disease, are well
    established.1,2,3,4,5,6 Although we have known
    for some time that excess weight is also an
    important factor in death from cancer,7 our
    knowledge of the magnitude of the relation, both
    for all cancers and for cancers at individual
    sites, and the public health effect of excess
    weight in terms of total mortality from cancer is
    limited. Previous studies have consistently shown
    associations between adiposity and increased risk
    of cancers of the endometrium, kidney,
    gallbladder (in women), breast (in postmenopausal
    women), and colon (particularly in
    men).8,9,10,11,12 Adenocarcinoma of the esophagus
    has been linked to obesity.11,13,14 Data on
    cancers of the pancreas, prostate, liver, cervix,
    and ovary and on hematopoietic cancers are scarce
    or inconsistent.7,8,9,10,11,15,16,17 The lack of
    consistency may be attributable to the limited
    number of studies (especially those with
    prospective cohorts), the limited range and
    variable categorization of overweight and obesity
    among studies, bias introduced by reverse
    causality with respect to smoking-related
    cancers, and possibly real differences between
    the effects of overweight and obesity on the
    incidence of cancer and on the rates of death
    from some cancers.18,19
  • We conducted a prospective investigation in a
    large cohort of U.S. men and women to determine
    the relations between body-mass index (the weight
    in kilograms divided by the square of the height
    in meters) and the risk of death from cancer at
    specific sites. This cohort has been used
    previously to examine the association of
    body-mass index and death from any cause.5

69
Scientific Writing, HRP 214
  • Introduction
  • Exogenous estrogens prevent or substantially
    retard the decrease in bone mineral density (BMD)
    that accompanies menopause 1. However, it is
    unclear whether exogenous estrogens, administered
    as oral contraceptives (OCs), can modify
    premenopausal BMD. Several studies suggest that
    exposure to OCs during the premenopausal years
    has a favorable effect on BMD 2-10, whereas
    other studies show no effect 11-18.
  • Past studies of the relationship between OC use
    and BMD have several limitations. Studies have
    focused primarily on crude measures of OC use,
    such as current, past and never. These
    categories combine diverse types of OC use and
    may reduce the power to detect an effect. Many
    studies also failed to take into account
    lifestyle characteristics of study participants.
    Finally, few studies have considered an effect of
    OCs on BMD in women of races other than white.
  • The aim of this study was to evaluate the
    associations of OCs with spine, hip and whole
    body BMD in black and white premenopausal women.
    Our primary hypothesis was that there would be an
    association between cumulative exposure to
    estrogen from OCs and BMD.

70
Scientific Writing, HRP 214
  • Neurohumoral Features of Myocardial Stunning Due
    to Sudden Emotional Stress Ilan S. Wittstein,
    M.D., David R. Thiemann, M.D., Joao A.C. Lima,
    M.D., Kenneth L. Baughman, M.D., Steven P.
    Schulman, M.D., Gary Gerstenblith, M.D.,
    Katherine C. Wu, M.D., Jeffrey J. Rade, M.D.,
    Trinity J. Bivalacqua, M.D., Ph.D., and Hunter C.
    Champion, M.D., Ph.D. T
  • New Engl J Med Volume 352539-548 Feb 10, 2005.

71
Scientific Writing, HRP 214
  • The potentially lethal consequences of emotional
    stress are deeply rooted in folk wisdom, as
    reflected by phrases such as "scared to death"
    and "a broken heart." In the past decade, cardiac
    contractile abnormalities and heart failure have
    been reported after acute emotional
    stress,1,2,3,4,5,6 but the mechanism remains
    unknown. We evaluated 19 patients with "stress
    cardiomyopathy," a syndrome of profound
    myocardial stunning precipitated by acute
    emotional stress, in an effort to identify the
    clinical features that distinguish this syndrome
    from acute myocardial infarction and the cause of
    transient stress-induced myocardial dysfunction.

72
Introduction systematic review
  • Effectiveness of speed cameras in preventing
    road traffic collisions and related casualties
    systematic review
  • Paul Pilkington, lecturer in public health1,
    Sanjay Kinra, lecturer in epidemiology and public
    health medicine2 1 University of the West of
    England, Faculty of Health and Social Care,
    Bristol BS16 1DD, 2 Department of Social
    Medicine, University of Bristol, Bristol .
  • BMJ Feb. 10, 2005

73
  • Road traffic collisions are an important cause
    of death and disability worldwide. Every year
    around the world 1.2 million people are killed
    and up to 50 million are injured or disabled as a
    result of road traffic collisions.1 Morbidity
    from road traffic collisions is expected to
    increase in future years, and it is estimated
    that road traffic collisions will move from ninth
    to third place in the global burden of disease
    ranking, as measured in disability adjusted life
    years.2 3
  • Measures to reduce traffic speed are considered
    essential to reducing casualties on the road.1 4
    5 Speed cameras are increasingly used to help to
    reduce traffic speeds in the belief that this
    will reduce road traffic collisions and
    casualties, and an expansion in the use of speed
    cameras is under way in many countries, most
    notably the United Kingdom.6 The use of speed
    cameras is controversial, however. Vociferous
    opponents, including some motoring associated
    organisations, oppose their use, and cameras are
    often criticised in the media.7-9 The lack of
    readily available evidence of the effectiveness
    of cameras has made it difficult for road safety
    and health professionals to engage in an informed
    debate about the effectiveness of speed cameras.
  • A previous small non-systematic review of six
    studies found a 17 reduction in collisions after
    introduction of speed cameras.10 Non-systematic
    reviews can, however, be limited by bias. We
    aimed, therefore, to systematically assess the
    evidence for the effectiveness of speed cameras
    in reducing road traffic collisions and related
    casualties.

74
Introduction cohort study
  • Adherence to Mediterranean diet and risk of
    developing diabetes prospective cohort study
  • M Á Martínez-González, professor of epidemiology
    and chair,1 C de la Fuente-Arrillaga, research
    assistant,1 J M Nunez-Cordoba, research
    fellow,1,2 F J Basterra-Gortari, research
    fellow,1,3 J J Beunza, assistant professor,1 Z
    Vazquez, research assistant,1 S Benito, research
    assistant,1 A Tortosa, research fellow,1 and M
    Bes-Rastrollo, assistant professor1
  • BMJ June 14, 2008

75
  • Diabetes mellitus is an increasingly important
    global public health problem that threatens to
    reach pandemic levels by 2030.1 2 As some
    randomised trials have consistently shown,
    increased physical activity and weight loss are
    efficient approaches for the control and
    prevention of type 2 diabetes.3 4 Diet has also
    long been believed to be an important risk factor
    for diabetes. Many studies have shown that the
    Mediterranean food pattern has a role in
    prevention of cardiovascular disease.5 6 7 8 9
    The similarity of some risk factors and some
    empirical and mechanistic evidence suggest that
    the Mediterranean diet can also protect against
    diabetes. The major protective characteristics
    include a high intake of fibre, a high intake of
    vegetable fat, a low intake of trans fatty acids,
    and a moderate intake of alcohol.4 10 11
    Moreover, a particular feature of the diet is the
    abundant use of virgin olive oil for cooking,
    frying, spreading on bread, or dressing salads.12
    This leads to a high ratio of monounsaturated
    fatty acids to saturated fatty acids. This ratio
    can be used to score adherence to a Mediterranean
    diet8 as the traditional diet. Despite having a
    relatively high total fat content, this food
    pattern is rich in monounsaturated fatty acids
    (from olive oil) and poor in saturated fatty
    acids. Diets rich in monounsaturated fatty acids
    improve lipid profiles and glycaemic control in
    people with diabetes, suggesting that a high
    intake improves insulin sensitivity.13 14 15 16
    Together these associations suggest the
    hypothesis that following an overall pattern of
    Mediterranean diet can protect against diabetes.
    In addition to having a long tradition of use
    without evidence of harm, a Mediterranean diet is
    highly palatable, and people are likely to comply
    with it.17

76
  • Few prospective studies have evaluated the
    specific role of the Mediterranean diet on the
    risk of developing diabetes in initially healthy
    Mediterranean populations. A prospective
    follow-up study recently reported an inverse
    association between adherence to the diet and the
    incidence of diabetes.18 All members of that
    study, however, had survived a previous
    myocardial infarction and the tool to assess
    dietary habits had inherent limitations because
    it included only a short list of items, and the
    authors did not attempt to measure the entire
    diet.
  • We evaluated the association between adherence to
    a Mediterranean diet and the incidence of
    diabetes using a full validated food frequency
    questionnaire to measure the entire diet.

77
Scientific Writing, HRP 214 Introduction and
Background
  • Introduction and Background
  • 1. Whats known
  • 2. Whats unknown
  • limitations and gaps in previous studies
  • 3. Your burning question
  • 4. Your experimental approach
  • 5. Why your experimental approach is new and
    different and important
  • From Essentials of Writing Biomedical Research
    Papers by Mimi Zeiger

78
Scientific Writing, HRP 214 Introduction
  • Tell a story
  • Write it in plain English, not tech-speak.
  • Take the reader step by step from what is known
    to what is unknown. End with your specific
    question.
  • (Known?Unknown?Question)
  • Emphasize what is new and important about your
    work.
  • Do not state the answer to the research question.
  • Do not include results or implications.

79
Scientific Writing, HRP 214 THE DISCUSSION
  • The Discussion is the section that
  • Gives you the most freedom
  • Gives you the most chance to put good writing on
    display
  • Is the most challenging to write

80
Scientific Writing, HRP 214 The Discussion
  • Follow your rules for good writing!

81
Scientific Writing, HRP 214 The Discussion
  • The purpose of the discussion
  • Answer the question posed in the Introduction
  • Support your conclusion with details (yours,
    others)
  • Defend your conclusion (acknowledge limits)
  • Highlight the broader implications of the work
  • i.e., What do my results mean and why should
    anyone care?

82
Framework of the Discussion
Table 2, Adapted From Welch HG. Preparing
Manuscripts for Submission to Medical Journals
The Paper Trail. Effective Clinical Practice.
1999 2 131-137.
83
Scientific Writing, HRP 214 The Discussion
  • The introduction moves from general to specific.
  • The discussion moves from specific to general.

84
Scientific Writing, HRP 214 The Discussion
  • Elements of the typical discussion section

85
  • Key finding (answer to the question(s) asked in
    Intro.)
  • Supporting explanation, details (lines of
    evidence)
  • Possible mechanisms or pathways
  • Is this finding novel?
  • Key secondary findings
  • Context
  • Compare your results with other peoples results
  • Compare your results with existing paradigms
  • Explain unexpected or surprising findings
  • Strengths and limitations
  • Whats next
  • Recommended confirmatory studies (needs to be
    confirmed)
  • Unanswered questions
  • Future directions
  • The so what? implicate, speculate, recommend
  • Clinical implications of basic science findings
  • Strong conclusion (kicker!)

86
EXAMPLE Samaha FF, Iqbal N, Seshadri P, et al.
A low-carbohydrate as compared with a low-fat
diet in severe obesity. N Engl J Med
20033482074-2081.
  • INTRODUCTION
  • The differences in health benefits between a
    carbohydrate-restricted diet and a calorie- and
    fat-restricted diet are of considerable public
    interest. However, there is concern that a
    carbohydrate-restricted diet will adversely
    affect serum lipid concentrations.1 Previous
    studies demonstrating that healthy volunteers
    following a low-carbohydrate diet can lose weight
    have involved few subjects, and few used a
    comparison group that followed consensus
    guidelines for weight loss.2,3 The reported
    effects of a carbohydrate-restricted diet on risk
    factors for atherosclerosis have varied.2,3,4 We
    performed a study designed to test the hypothesis
    that severely obese subjects with a high
    prevalence of diabetes or the metabolic syndrome
    a would have a greater weight loss, b without
    detrimental effects on risk factors for
    atherosclerosis, while on a carbohydrate-restricte
    d (low-carbohydrate) diet than on a calorie- and
    fat-restricted (low-fat) diet.

87
Scientific Writing, HRP 214 The Discussion
  • 1. We found that severely obese subjects with a
    high prevalence of diabetes and the metabolic
    syndrome lost more weight in a six-month period
    on a carbohydrate-restricted diet than on a fat-
    and calorie-restricted diet. answer to a The
    greater weight loss in the low-carbohydrate group
    suggests a greater reduction in overall caloric
    intake, rather than a direct effect of
    macronutrient composition. mechanisms However,
    the explanation for this difference is not clear.
    Subjects in this group may have experienced
    greater satiety on a diet with liberal
    proportions of protein and fat. However, other
    potential explanations include the simplicity of
    the diet and improved compliance related to the
    novelty of the diet. possible mechanisms/unanswer
    ed questions

88
Scientific Writing, HRP 214 The Discussion
  • 2. Subjects in the low-carbohydrate group had
    greater decreases in triglyceride levels than did
    subjects in the low-fat group nondiabetic
    subjects on the low-carbohydrate diet had greater
    increases in insulin sensitivity, and subjects
    with diabetes on this diet had a greater
    improvement in glycemic control. No adverse
    effects on other serum lipid levels were
    observed. answer to b Most studies suggest that
    lowering triglyceride levels has an overall
    cardiovascular benefit.14,15,16 Insulin
    resistance promotes such atherosclerotic
    processes as inflammation,17 decreased size of
    low-density lipoprotein particles,18 and
    endothelial dysfunction.19 Impaired glycemic
    control in subjects with other features of the
    metabolic syndrome markedly increases the risk of
    coronary artery disease.20 As expected, we found
    that the amount of weight lost had a significant
    effect on the degree of improvement in these
    metabolic factors. comparison to previous
    studies and paradigms However, even after
    adjustment for the differences in weight loss
    between the groups, assignment to the
    low-carbohydrate diet predicted greater
    improvements in triglyceride levels and insulin
    sensitivity. unexpected Subjects who lost more
    than 5 percent of their base-line weight on a
    carbohydrate-restricted diet had greater
    decreases in triglyceride levels than those who
    lost a similar amount of weight while following a
    calorie- and fat-restricted diet. supporting
    details

89
Scientific Writing, HRP 214 The Discussion
  • 3. There was a consistent trend across
    weight-loss strata toward a greater increase in
    insulin sensitivity in the low-carbohydrate
    group, although these changes were small and were
    not significant within each stratum. supporting
    details dose/response Although greater weight
    loss could not entirely account for the greater
    decrease in triglyceride levels and increase in
    insulin sensitivity in the low-carbohydrate
    group, we cannot definitively conclude that
    carbohydrate restriction alone accounted for this
    independent effect. mechanisms Other
    uncontrolled variables, such as the types of
    carbohydrates selected (e.g., the proportion of
    complex carbohydrates or the ratio of
    carbohydrate to fiber), or other unknown
    variables may have contributed to this effect. In
    addition, more precise measurements of insulin
    sensitivity than we used would be needed to
    confirm this effect of a carbohydrate-restricted
    diet. limitations/future studies

90
Scientific Writing, HRP 214 The Discussion
  • 4. Many of our subjects were taking
    lipid-lowering medications and hypoglycemic
    agents. Although enrolling these subjects
    introduced confounding variables, it allowed the
    inclusion of subjects with the obesity-related
    medical disorders typically encountered in
    clinical practice. Analyses from which these
    subjects were excluded still revealed greater
    improvements in insulin sensitivity and
    triglyceride levels on a carbohydrate-restricted
    diet than on a fat- and calorie-restricted diet.
    limitations and how they were addressed

91
Scientific Writing, HRP 214 The Discussion
  • 5. Our study included a high proportion of black
    subjects, a group previously underrepresented in
    lifestyle-modification studies. strength As
    compared with the white subjects, the black
    subjects had a smaller overall weight loss.
    Future studies should explore whether greater
    weight loss in this population can be achieved by
    more effective incorporation of culturally
    sensitive dietary counseling. future directions
  • 6. The high dropout rate in our study occurred
    very early and affected our findings. The very
    early dropout of these subjects may indicate that
    attrition most closely reflected base-line
    motivation to lose weight, rather than a response
    to the dietary intervention itself. limitation

92
Scientific Writing, HRP 214 The Discussion
  • 7. Taken together, our findings demonstrate that
    severely obese subjects with a high prevalence of
    diabetes and the metabolic syndrome lost more
    weight during six months on a carbohydrate-restric
    ted diet than on a calorie- and fat-restricted
    diet. The carbohydrate-restricted diet led to
    greater improvements in insulin sensitivity that
    were independent of weight loss and a greater
    reduction in triglyceride levels in subjects who
    lost more than 5 percent of their base-line
    weight. conclusion restate answers to a and b
    These findings must be interpreted with caution,
    however, since the magnitude of the overall
    weight loss relative to our subjects' severe
    obesity was small, and it is unclear whether
    these benefits of a carbohydrate-restricted diet
    extend beyond six months. Furthermore, the high
    dropout rate and the small overall weight loss
    demonstrate that dietary adherence was relatively
    low in both diet groups. big picture This study
    proves a principle and does not provide clinical
    guidance given the known benefits of fat
    restriction, future studies evaluating long-term
    cardiovascular outcomes are needed before a
    carbohydrate-restricted diet can be endorsed.
    take-home message

93
Scientific Writing, HRP 214 The Discussion
  • Things to avoid in the discussion
  • Do not simply repeat what is in the Results
  • Do not try to explain every minor flaw
  • Do not attempt to explain away every unexpected
    result
  • Do not exaggerate or make extravagant claims
  • Dont hedge

94
What NOT to do!
  • Dont start your discussion like this!!
  • Discussion
  • This meta-analysis is subject to a number of
    limitations. The estimates of risk for melanoma
    subsequent to using sunlamps/sunbeds are based on
    published data in a series of 10 articles over a
    period of 20 years. A pooled analysis of original
    observations taken in the 10 studies would have
    provided a more powerful approach

95
Scientific Writing, HRP 214 The Discussion verb
tense
  • Verb Tenses (active!)
  • Past, when referring to study details, results,
    analyses, and background research
  • We found that
  • They lost more weight than
  • Subjects may have experienced
  • Miller et al. found
  • Present, when talking about what the data suggest
  • The greater weight loss suggests
  • The explanation for this difference is not
    clear.
  • Potential explanations include

96
EXAMPLE 2 Low-Fat Dietary Pattern and Risk of
Colorectal Cancer The Women's Health Initiative
Randomized Controlled Dietary Modification Trial.
JAMA. 2006295643-654.
  • INTRODUCTION
  • The Women's Health Initiative (WHI) Dietary
    Modification Trial is a randomized controlled
    trial designed in 1991-1992 to test whether a
    low-fat eating pattern with increased fruits,
    vegetables, and grains reduces the risk of breast
    cancer, colorectal cancer, or, secondarily,
    coronary heart disease in postmenopausal women.
    At that time, international comparisons suggested
    that countries with 50 lower fat intake than the
    US population had approximately one third the
    risk of colorectal cancer.1-2 Migration studies
    supported this hypothesis. Women migrating from
    countries with low fat consumption to countries
    with high fat consumption experienced the higher
    colorectal cancer rates of their new country.3-4
    Fairly consistent evidence existed for an effect
    of dietary fat, vegetables and fruits, and grains
    on colorectal cancer risk from within-country
    observational studies,2, 5-8 although the
    protective effect of lower fat intake was no
    longer clear after adjusting for energy intake.2,
    9 The WHI Dietary Modification Trial is the first
    randomized trial to directly address the health
    effects of a low-fat eating pattern in
    predominantly healthy postmenopausal women from
    diverse racial/ethnic, geographic, and
    socioeconomic backgrounds. This article reports
    the principal results for colorectal cancer. the
    question

97
Scientific Writing, HRP 214 The Discussion
  • 1. An intervention aimed toward a low-fat eating
    pattern did not reduce colorectal cancer risk in
    postmenopausal women. answer to the question
    asked Despite a significant change in fat intake
    and increases in vegetable, fruit, and grain
    consumption, the intervention hazard ratio is in
    the direction of an increased risk. supporting
    evidence from this trial There were no
    substantial differences in tumor characteristics
    or in rates of bowel screening between groups.
    supporting evidence Although self-reported
    incidence of colorectal polyps or adenomas was
    lower in the intervention group, no evidence of a
    trend toward lower colorectal cancer risk with
    time in the intervention group was observed over
    the mean 8.1-year study period.

98
Scientific Writing, HRP 214 The Discussion
  • 2. These findings are consistent with the
    findings from the Polyp Prevention Trial,31 a
    secondary prevention trial of polyp recurrence,
    which had a similar goal for fat, fruit, and
    vegetable intake but also included a goal of 18
    g/1000 kcal of dietary fiber.32 The Polyp
    Prevention Trial observed no effect on polyp
    recurrence in the 2079 participants followed up
    for 4 years.32 A small trial in Toronto, Ontario,
    of high fiber and low fat showed no effect on
    recurrence of neoplastic polyps, but, within an
    intensive counseling subgroup, concentrations of
    fecal bile acids appeared to be reduced.33 A
    small factorial trial in Australia of a low-fat
    intervention, -carotene supplementation, or
    wheat bran supplementation found no reduction in
    recurrence rates of adenomas but suggested that
    the combination of low fat and wheat bran reduced
    the transition from smaller to larger adenomas.34
    supporting evidence other TRIALS

99
Scientific Writing, HRP 214 The Discussion
  • 3. Since the WHI Dietary Modification Trial was
    designed, the hypothesized relationship between
    dietary fat and risk of colorectal cancer has
    been questioned.35 More recently, higher red meat
    consumption has been associated with increased
    colorectal cancer risk,23, 36-39 particularly in
    the distal colon.23 The putative mechanism may be
    related to heme, the iron carrier of red meat,
    rather than to its fat content.23 In the WHI, the
    dietary intervention reduced red meat consumption
    (Table 2), with no apparent overall benefit on
    colorectal cancer risk but, perhaps, some shift
    in risk in distal vs proximal colon cancers.
  • consistency with the latest paradigm
  • mechanisms is red meat more important than
    fat?

100
Scientific Writing, HRP 214 The Discussion
  • 4. Mixed support exists for an influence of
    vegetables and fruits on colorectal cancer
    risk.37, 40-42 Some of the antioxidants they
    contain have not proved efficacious in reducing
    colorectal adenomas or preventing incident
    colorectal cancer in randomized trials.43-45
    Regular consumption of alcohol has been
    associated with elevated risk of colorectal
    cancer in some prospective studies, particularly
    among persons with low folate status.46 This
    pattern was not found in the comparison group of
    this study. Observations in East Africa by
    Burkitt47 led to the hypothesis that very high
    fiber reduces colorectal cancer risk. This has
    mixed support from observational studies48-50 and
    polyp and adenoma recurrence trials.31,
    33-34,51-52 A European trial found an adverse
    effect of soluble fiber on colorectal adenoma
    recurrence,51 while an Arizona trial found no
    effect of wheat bran supplement on colorectal
    adenoma recurrence.52 Our study is consistent
    with lack of association in that women in the
    intervention group modestly increased their fiber
    (Table 2) with no apparent benefit over 8.1 years
    of follow-up.
  • existing paradigms does fiber matter?

101
Scientific Writing, HRP 214 The Discussion
  • 5. The observed interactions between the
    intervention and baseline aspirin use, and
    between intervention and use of combined hormone
    therapy, are consistent with synergistic effects
    of a low-fat dietary pattern and these
    potentially protective agents. However, given the
    large number of interactions tested, these
    findings could also have occurred by chance.
  • Could the null finding be wrong? Maybe low-fat
    diet matters for some groups

102
Scientific Writing, HRP 214 The Discussion
  • 6. From National Health and Nutrition
    Examination Survey (NHANES) data, in 1977, women
    reported consuming 40.5 of their energy from
    fat, while in 1987, the average was only 35.9,54
    and in 2000, the average was 33 (NHANES
    1999-2000). Organizations including the National
    Cancer Institute, American Cancer Society, and
    Institute for Cancer Prevention have recommended
    both lower fat intake and increased vegetable and
    fruit use.55-56
  • 7. One explanation for a lack of intervention
    effect on colorectal cancer could be that the
    intervention did not achieve a large enough
    difference between the intervention and
    comparison groups. Although the changes achieved
    were substantial, and likely as large as could be
    achieved in a trial of free-living individuals,
    they fell short of the original design
    assumptions based on the Women's Health Trial
    studies.27 Using food frequency data, the WHI
    intervention on average achieved only about 70
    of the designed reduction in fat. If design
    assumptions are revised to take into account this
    departure from goal, the predicted HR would have
    been 0.86, an effect size excluded by these
    results. The power to detect this effect size
    under the observed comparison group incidence
    rate and the achieved adherence is approximately
    40. Could the null finding be wrong?
    Alternative explanations to no association

103
Scientific Writing, HRP 214 The Discussion
  • 8. Whether greater adherence, intervention of
    longer duration, or initiation of change at an
    earlier age would influence colorectal cancer
    risk remain unanswered questions. The
    self-reported first occurrence of polyps or
    adenomas was lower in dietary intervention women,
    suggesting that longer follow-up (currently
    planned) may reveal delayed benefit in favor of
    the intervention. Yet no time trends regarding
    colorectal cancer risk over 8 years of follow-up
    have been seen. To the extent that the WHI
    Dietary Modification Trial intervention addressed
    the recommendations from national organizations,
    the current results suggest that changing dietary
    patterns to meet these recommendations in mid to
    late life will have limited or no benefit in
    preventing colorectal cancers in postmenopausal
    women. Defending their results

104
Scientific Writing, HRP 214 The Discussion
  • 9. The strengths of this study are its
    randomized design, long-term follow-up, large
    numbers of participants, diversity of
    race/ethnicity and socioeconomic status, and high
    retention rate. The limitations of this study
    include not attaining intervention goals as
    designed for reducing fat intake or achieving
    large separation from the comparison group in
    increased fruit, vegetable, or grain intake. Thus
    the potential intervention effect of the WHI
    low-fat dietary pattern may be underestimated.
    Furthermore, there was no study-specified
    colonoscopy, nor was there systematic screening
    for adenomatous polyps hence, the incidence of
    both colorectal cancer and polyps or adenomas
    would be underestimated. Strengths and
    limitations

105
Scientific Writing, HRP 214 The Discussion
  • 10. In conclusion, there is no evidence that
    a low-fat dietary pattern intervention reduces
    colorectal cancer risk over an average of 8.1
    years of follow-up. Restatement of findings
    Evidence from this study, along with that from
    polyp prevention trials, strongly suggests that
    lowering dietary fat intake and increasing fruit,
    vegetable, and fiber intake in mid to late life
    cannot be expected to reduce the risk of
    colorectal cancer in this length of time.
    Take-home message

106
EXAMPLE Adherence to Mediterranean diet and
risk of developing diabetes prospective cohort
study BMJ June 2008
  • END OF INTRODUCTION
  • We evaluated the association between adherence
    to a Mediterranean diet and the incidence of
    diabetes using a full validated food frequency
    questionnaire to measure the entire diet.

107
Scientific Writing, HRP 214 The Discussion
  • 1. This large prospective study shows that a
    traditional Mediterranean food pattern is
    associated with a significant reduction in the
    risk of developing type 2 diabetes. answer to
    question asked

108
Scientific Writing, HRP 214 The Discussion
  • 2. Interestingly, among participants with the
    highest adherence to the diet, there was a high
    prevalence of important risk factors for
    diabetes, such as older age, higher BMI, family
    history of diabetes, and personal history of
    hypertension and a higher proportion of
    ex-smokers. Therefore, we would have expected a
    higher incidence of diabetes among these
    participants. These higher risk participants with
    better adherence to the diet, however, had a
    lower risk of diabetes, suggesting that the diet
    might have a substantial potential for
    prevention. bonus finding/additional
    evidence This finding is consistent with our
    previous report of an inverse association between
    a Mediterranean diet and the metabolic
    syndrome.24 fits with previous research The
    metabolic syndrome is closely associated with a
    generalised metabolic disorder of insulin
    resistance, which is one of the underlying causes
    of type 2 diabetes. Therefore a high biological
    plausibility exists to support the causality of
    our findings. biological mechanisms In
    addition, a previous cohort study of survivors of
    myocardial infarction also reported that a higher
    adherence to a Mediterranean diet was associated
    with a reduction in the risk of type 2
    diabetes,18 fits previous research despite use
    of a relatively inaccurate tool for the dietary
    assessment. The inverse graded dose-response
    pattern and the significant inverse trend that we
    observed also support a causal relation.
    dose-response evidence

109
Scientific Writing, HRP 214 The Discussion
  • 3. Diet and disease
  • Experimental evidence suggesting that a diet
    similar to the Mediterranean diet and rich in
    plant based foods might protect against diabetes
    can also be found in the Indian diabetes
    prevention programme. That trial promoted a plant
    based diet (together with increases in physical
    activity) and found a significant reduction in
    the incidence of diabetes,28 although there are
    clear differences between the Mediterranean and
    Indian food patterns. There is an analogy between
    coronary heart disease and diabetes because
    patients with type 2 diabetes and no coronary
    heart disease have a risk of coronary heart
    disease similar to patients without diabetes but
    with prior coronary heart disease.29 There is
    evidence that a Mediterranean diet protects
    against coronary heart disease, and the analogy
    between coronary heart disease and diabetes
    suggests that this diet might also prevent
    diabetes. It has been shown to provide protection
    against coronary mortality8 9 30 31 and the
    incidence of non-fatal myocardial infarction.32
    In addition, both cohort studies33 34 35 and
    randomised trials36 have found that adherence to
    a Mediterranean diet protects against mortality
    in patients who already have established coronary
    heart disease. more supporting background
    evidence

110
Scientific Writing, HRP 214 The Discussion
  • 4.The potential mechanisms explaining the
    protective effect of a Mediterranean diet on
    diabetes have been reviewed elsewhere.37 38 39 40
    Two trials have shown that virgin olive oil
    protects against insulin resistance and the
    metabolic syndrome.6 7 Indexes of insulin
    resistance were significantly improved among
    participants allocated to a Mediterranean diet
    rich in virgin olive oil. Olive oil is rich in
    monounsaturated fatty acids, and a diet rich in
    monounsaturated fatty acids is beneficial among
    those with diabetes and might lead to improved
    insulin sensitivity and better lipid profiles
    than diets rich in carbohydrate.13 15 39 People
    allocated to a Mediterranean diet secrete more
    glucagon-like peptide-1,16 a finding also seen in
    animals.14 The non-fat minor components of virgin
    olive oil also exert a beneficial effect on
    pro-inflammatory cytokines.40 41 42
  • Apart from olive oil, adherence to an overall
    Mediterranean-type food pattern is related to
    lower plasma concentrations of inflammatory
    markers and markers of endothelial dysfunction.43
    44 These biomarkers are predictive of the future
    occurrence of type 2 diabetes.45 46 In addition,
    a large cross sectional study nested in the
    nurses health study found that increased
    adherence to a Mediterranean diet was associated
    with higher levels of adiponectin,47 and higher
    levels of adiponectin are associated with a
    reduced risk of diabetes.

supporting evidence in the literature/biological
mechanisms
111
Scientific Writing, HRP 214 The Discussion
  • Limitations
  • The number of new cases of diabetes was small,
    despite the follow-up of several thousand people
    for over four years. This small number of
    incident cases is a major drawback and can
    compromise the statistical power of our study.
    Nevertheless, our participants had high absolute
    levels of consumption of the typical food items
    of the Mediterranean diet, even among those
    participants classified as poorly compliant
    (score lt3). For example, among those in the
    lowest category of adherence to the diet, the
    estimated mean daily absolute consumption (g/day)
    of olive oil (12), vegetables (308), fruits
    (176), cereals (77), and legumes (17) can be
    considered as healthy for the standards of
    nutritional epidemiological studies. This high
    consumption of plant based foods in our cohort
    could be because our participants were from a
    Mediterranean country and were highly educated
    and health conscious. The small number of new
    cases observed in this study should therefore not
    be surprising. If the Mediterranean diet is
    actually protecting against diabetes, we would
    expecta low incidence in a young cohort (mean age
    is 37.8 years) with these characteristics. The
    low number of observed cases precluded assessment
    of the specific role of single dietary factors
    because we would have needed
  • ..
  • A potential limitation, inherent to every
    observational design, is the possibility of
    residual confounding by unmeasured or unrecorded
    factors. Our major confounders, however, were sex
    and age. Additional adjustment for other factors
    made only negligible changes in the estimates,
    suggesting that residual confounding is
    unlikely.in the nurses health study found that
    increased adherence to a Mediterranean diet was
    associated with higher levels of adiponectin,47
    and higher levels of adiponectin are associated
    with a reduced risk of diabetes.

Limitations5 paragraphs!!
112
Scientific Writing, HRP 214 The Discussion
  • Conclusion
  • Our prospective cohort study suggests that
    substantial protection against diabetes can be
    obtained with the traditional Mediterranean diet,
    rich in olive oil, vegetables, fruits, nuts,
    cereals, legumes, and fish but relatively low in
    meat and dairy products. The limited number of
    cases of diabetes and the possibility of
    under-reporting, however, requires that further
    larger cohorts and trials are needed to confirm
    our findings.

Restatement of the
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