NUTR*4090 Functional Foods and Nutraceuticals - Midterm 2

Lecture 8-?

What are the 3 types of human studies?

1. Observational

2. Intervention

3. Meta-analysis

What is the purpose of observational studies?

• measure associations between foods or food components and disease —> however it cannot determine cause & effect

• reflect a “free-living” situation

• generate hypotheses and associations to test in interventional studies

What are the 3 types of observational studies?

1. Cohort studies (prospective)

2. Case-control studies (retrospective)

3. Cross-sectional studies (prevalence)

Properties of cohort studies

• most reliable

• longitudinal - exposure to FFN —> development of disease

• incidence of disease in subjects who consumed a food vs those who do not consume the food

Properties of case-control studies

• retrospective - development of disease —> exposure to FFN

• Key assumption: disease does not affect eating habits

• subjects w/ disease are compared to subjects w/o disease based on past dietary habits

Properties of cross-sectional studies

• collect info on food consumption at a single point in time in individuals w/ and w/o a specific disease

• “snapshot” in time

What are the pros and cons of human observational studies?

How are intervention studies done?

1. subjects are provided w/ a food or food component of interest to consume

2. researchers measure development of disease or biomarkers

3. typically —> experimental group vs control group

Evaluating human intervention studies

How should we deal with conflicting evidence?

• subject characteristics (e.g. age, gender, ethnicity, body weight, etc.)

• study design issues (e.g. sample size, duration, randomization, etc.)

What are the pros and cons of human intervention studies?

What are the specific effects of therapeutics?

• talks about what happens to the body

• influenced by factors such as dose, duration, pharmacodynamics, etc.

What are the non-specific effects of therapeutics?

• influenced by factors such as natural history of the diseases, expectations and belief in the treatment, etc.

• e.g. placebo/nocebo effects

Overall response results from the combination on specific effects and non-specific effects (T/F)

True

What is the placebo effect?

• beneficial

• occurs when persons w/ a specific illness demonstrate clinical improvement when treated w/ an inert substance

• everything but the bioactive substance should be identical (e.g. taste, texture, visual, etc.)

Mechansism behind placebo effect

• repeated exposure to neurosensory suggestions

• reinforced by verbal suggestions

• Pavlovian conditioning

What is the nocebo effect?

• harmful

• detrimental outcome associated w/ intervention (opposite of placebo)

• harmless substance that when taken by a patient is associated w/ harmful effects due to negative expectations or the psychological condition of the patient

Mechanisms behind nocebo effect

may be caused by factors such as distrust of the medical personnel or lack of confidence in a treatment

What are some possible contributing factors to placebo and nocebo effect?

• time spent w/ practitioner

• claims made by practitioner

• money spent for treatment

• environment

• physical manipulations

• personalized approach

• belief that treatment is free of adverse effects

• disillusionment w/ conventional treatment

Is selling stuff that cause a placebo effect acceptable?

• context dependent —> can be helpful but also in part deceiving the consumer

• data supporting the products is minimal

What does CONSORT stand for?

consolidated standards of reporting trials

What are the CONSORT guidelines?

• its initiatives were developed to improve reporting of randomized trials

• its statement provides minimum set of recommendations for reporting RCTs

It is more difficult to develop a placebo for an herbal product (T/F)

True

• lack of blinding may influence response rate

How to select an herbal placebo product?

1. same or closely resembles the product found to be effective in clinical trials (e.g. same brand, plant species, preparation, etc.)

2. must be approved by Health Canada (should have NPN)

3. found on Licensed Natural Health Product Database

4. scoring system
   - rating solely on scientific evidence
   - based on safety, effectiveness and product quality

5. Cochrane Review
   - systematic reviews of primary research in human health care and health policy
   - internationally recognized as the highest standard in evidence-based health care
   - investigate the effects of interventions for prevention, treatment and rehabilitation

What is homeopathy?

Alternative medical system

• developed by Samuel Hahnemann in Germany

Alternative to harsh therapies

• e.g. chinchona bark

Homeopathic substances are approved by Health Canada (T/F)

True

FDA and HC regulate homeopathic remedies (T/F)

True

• includes safety and efficacy

What are the 2 principles of homeopathy?

1. “like cures like”
   —> disease can be cured by the substance that produces similar (disease) symptoms in healthy people

2. law of minimum dose
   —> lower dose = greater effectiveness (more diluted)
   —> “dose makes the poison”

Where do homeopathic remedies come from?

derived from plants, animals and minerals

• final diluted preparation = nosodes

• extract that is diluted to create the nosode = tincture

What is the term for the final diluted preparation?

Nosodes

What is the term for the extract that is diluted to create the nosode?

Tincture

Homeopathic treatments/remedies are highly individualized (T/F)

True

• remedies based not only on symptoms but lifestyle, emotional and mental states

What is the concept of potentisation?

more diluted = more effective (law of minimal doses)

Why are homeopathic substances regulated by Health Canada?

as long as they are free of negative components on the monographs

e.g. bacteria and heavy metals