unit 11

Question 1

Nutrition information intended for the prevention and treatment of disease can be divided into three types. What are they?

Answer 1

1) that which is firmly supported by published evidence, which can be recommended to the public, and which is used by dietitians, physicians, and other health professionals.
2) that which is more controversial but deserves to be taken seriously.
3) that which can be best characterized as food faddism or consumer fraud.

Question 2

Briefly describe Canada’s food guide

Answer 2

it is based on a chart and is simple to use. The food guide has several notable features. The recommended number of servings of fruit and vegetables (which are lumped together in one food group) is higher than of grains. Supplements are recommended for particular groups: 400 IU (10 μg) per day of vitamin D for people over age 50; a multivitamin containing folic acid[1] for women who could possibly become pregnant, and for those are who are, or who are breastfeeding.

The food guide was developed by Health Canada based on a large body of scientific and medical research. It is designed for people over the age of four to ensure that they receive all the necessary nutrients. It also assists in the prevention of nutrition-related problems including coronary heart disease (CHD), cancer, type 2 diabetes, obesity, hypertension, osteoporosis, anemia, dental decay, and some bowel disorders.

Question 3

What are the dietary reference intake?

Answer 3

The Recommended Dietary Allowances (RDA) are estimates of the daily amounts of nutrients considered necessary to meet the needs of most healthy people. For those nutrients where there is insufficient information to establish a RDA, less exact estimates are made, known as Adequate Intakes (AI). Values of RDA and AI are given for 14 vitamins, 15 minerals, energy, carbohydrates, essential (omega-3 and omega-6 polyunsaturated) fatty acids, protein, dietary fibre, and water. Tables are broken down by age and sex.

Another table within the DRI is the Tolerable Upper Intake Levels (UL). The UL is the maximum amount of potentially toxic nutrients that appears safe for most healthy people to consume on a regular basis. Whereas RDA and AI are targets to aim for, UL provides a warning against overconsumption of nutrients.

Question 4

What are seven problems with the average canadian diet?

Answer 4

Lack of fruits and vegetables and high intake of fats and sugars and the unhealthy foods

2) Lacks several key nutrients such as vitamin k and minerals
3) women have low intake of iron, folate, potassium, calcium and B6. This is due to low milk due to high lactose intolerance
4) Most people have low fibre and omega 3 intake
5) Low vitamin D intake due to low intake of milk and fish
6) these problems are worse for people in poverty
7) people have high sodium intake

Question 5

What is the advantage of obtaining minerals and vitamins from food?

Answer 5

Obtaining vitamins and minerals from food has the outstanding advantage that these substances are present in the right balance together with the many other substances found in food, including fibre and essential fats.

Question 6

Why are phytochemical important in your diet?

Answer 6

These substances are organic but as they are non-essential, they cannot be classified as vitamins. There are thousands of different phytochemicals present in food. Much research suggests that phytochemicals have a protective action against disease. Because there are so many different phytochemicals and our knowledge of them is still weak, the only practical way to obtain them is from food, not supplements. I

Question 7

Explain why folic acid has strong evidence to take as a supplement

Answer 7

Canada’s Food Guide recommends that all women who could become pregnant and those who are pregnant or breastfeeding take a multivitamin containing folic acid. The rationale for this is that randomized controlled trials (RCTs) have demonstrated that supplements of folic acid can prevent a substantial proportion of neural tube defects (NTD), such as spina bifida

Question 8

Explain why vitamin D has strong evidence to take as a supplement

Answer 8

A low intake and low blood levels of vitamin D are closely associated with various health problems. In older adults it helps protect against falls and fractures by absorbing calcium. The ideal dose for vitamin D is higher than the RDA (15ug under 70 and 20ug over 70).

Question 9

Explain why multivitamins has strong evidence to take as a supplement

Answer 9

We do need to be realistic and recognize that a substantial fraction of the population eats a diet that is far from ideal. For that reason a case can be made for a general recommendation to take a daily multivitamin, at least for specific population groups. This is important for women who become pregnant, vegans, the elderly, and people who consume one or two drinks a day.

Question 10

Explain why fish oil has strong evidence to take as a supplement

Answer 10

Helps reduce the risk of fatal CHD. The cardioprotective benefits of fish and fish oil appears to be greater in populations at higher risk of developing CHD and in those that habitually consume only small amounts of fish. This is due to the protective features of omega 3

Question 11

Explain why megadoses of vitamins have weak evidence to take as a supplement

Answer 11

Developed from orthomolecular medicine. In this therapy not only vitamins but also minerals, amino acids, trace elements, and fatty acids are given, often in high doses to restore an individuals biochemistry.

RCT’s on this are largely negative. This includes megadoses of Vitamin C for colds and cancer.

Question 12

Explain why anti oxidant vitamins have weak evidence to take as a supplement

Answer 12

Include vitamin C, beta carotene and vitamin E.

Based on the observation that people who take these do not develop CHD or cancer. This is due to the fact they scavenge free radicals.

RCT’s have found otherwise. While fruits and vegetables do transfer this protection, purified supplements do not, suggesting a broad spectrum action

Question 13

Explain why vitamins to lower homocysteine to prevent CHD is bogus

Answer 13

Large study discovered that homeocystene levels predict CHD in patients (higher means higher risk)

Thought that by lowering these levels then CHD risk lowered

B vitamins implicated (Folic acid, b6 and b12) could accomplish this

Studies performed on this found that using these B vitamins could not reduce the risk of CHD

Question 14

Explain why probiotics is weak for taking as a supplement

Answer 14

while positive results have been observed in people for constipation, and IBS, it is early to recommend them Two reasons:

Most research done on people with a health condition but most marketing directed at healthy people

Huge variety of microbes used and we cannot say that one variety will produce positive effects for everyone

Question 15

Explain why Coenzyme Q10 is weak for taking as a supplement

Answer 15

Naturally occurring vitamin found in the body and found in small amounts in meats and seafood

used to treat heart and blood vessel conditions such as CHF and chest pain

Positive results that it helps with these conditions is lacking and cannot be found

Question 16

Explain why glucosamine and Chondroitin is weak for taking as a supplement

Answer 16

Glucosamine: natural amino sugar found in healthy cartilage. Used to treat osteoarthritis and claims to enhance cartilage while enhancing synovial fluid

Chondroitin: couples carbohydrate that helps to retain water in cartilage. Found in cartilage such as shark. Used to treat osteoarthritis

Numerous RCT’s have found that they do not help with hip and knee pain

Question 17

Explain why cell food is weak for taking as a supplement

Answer 17

Claims to contain almost every single element including nitrogen. Only missing poisonous ones

Suppose to enhance the bioavailability of oxygen by dissociating the water molecules in the body

Numerous contradictions: includes thallium and polonium which are poisonous; uses only 8 drops. Very suspicious

Question 18

Explain why exotic fruit juices is weak for supplementation

Answer 18

include juices from acia, goji, mangosteen, and none

sell at a higher price then regular juices

no good evidence to suggest any health benefit

Question 19

Explain why weight loss products are bogus

Answer 19

Green tea does have modest effectiveness (Thavanesan, 2011) as does chromium picolinate (Sharpe et al. 2006). However, there is little or no supporting evidence for other commonly-used ingredients in products claimed to help with weight loss, including guarana, hydroxycitric acid (Garcinia cambogia), and bitter orange (Citrus aurantium)

Question 20

Explain why sex related products are bogus

Answer 20

As with supplements that promise weight loss, manufacturers have energetically marketed supplements that promise to enhance sexual performance, usually for men. The range of products is wide while the effectiveness is probably extremely minimal.

Question 21

Explain the potential hazards posed by supplements

Answer 21

Undeclared active pharmaceutical ingredients (more than 140 contaminants have been found). Most often found in supplements promoted from sexual enhancement, weight loss and athletic improvement

Exemplified in ayurvedic medicines bought over internet where 21% found higher then allowable concentrations of lead, mercury and or arsenic

Question 22

What is the most common marketing theme of Herbal supplements

Answer 22

That they bring about a change in the body

Question 23

What are three mechanisms of action that keep appearing in marketing supplements? Why are they bogus?

Answer 23

1) rich in antioxidant: no benefit from taking these as they don’t work
2) Enables detoxification: no actual proof that this occurs
3) Boosts the immune system: Goes well beyond what is established in scientific literature

Question 24

Why are making claims on super simple mechanisms in the body not true for how supplements work? Give examples

Answer 24

Making claims for the effectiveness of supplements based on super-simple mechanisms creates the appearance that the supplement has a favourable effect on body functioning while the explanation can be easily understood by anyone with a grade 10 education. Super-simple mechanisms have been used many times over the decades to explain health problems and to justify unscientific treatments. In the 1970s a common diagnosis was hypoglycemia. This was an instant explanation for tiredness and an array of other vague symptoms. Rarely was the diagnosis confirmed by measuring the blood glucose level. An intestinal yeast infection provides a similar example. This was a popular diagnosis in the 1980s.

Question 25

What is the problem with health food stores?

Answer 25

A large study was carried out in Canada to determine whether customers are being given honest and accurate advice (Temple et al., 2009). Visits were made to 260 HFS and drugstores (or the pharmacy section of supermarkets). In each case a student posed as a customer and asked for advice on the use of a supplement. The results reveal that on 88% of times that questions were asked in HFS, the recommendations made were either unscientific (6%) or were poorly supported by the scientific literature (82%). By contrast, this occurred for only 27% of questions in drugstores/supermarkets. Conversely, on two-thirds of visits to drugstores/supermarkets, staff gave advice considered to be fairly accurate or accurate, but this seldom occurred in HFS (68% vs 7%). The findings clearly show that HFS are an extremely unreliable source of information on the use of supplements.

Question 26

What is the purpose of marketing supplements?

Answer 26

to maximize profits

Question 27

What are the regulations for selling supplements in Canada?

Answer 27

The regulations require a pre-market review of products to confirm that label information is truthful and that health claims are supported by appropriate types of scientific evidence.

The regulations mean that packages of supplements now contain what the label says they contain

But that still leaves another major problem, namely the widespread practice of dishonest marketing. Despite the rules that Health Canada claims to be following, the reality is that Canadians are still being continually exposed to widespread dishonesty.

Question 28

Describe the approach to fasting for diet and nutrition

Answer 28

Fasting is advocated based on the rationale that it induces “detoxification.” Many people believe that occasional fasting for a day, perhaps with the consumption of juices, somehow “cleans” the body. However, there is no credible evidence that detoxification can be induced by fasting or that fasting has any beneficial effects on health. Moreover, as stated in Unit 9, fasting may be detrimental in certain conditions and may even be life threatening if it takes place over a long period of time.

Question 29

What are the four most common forms of the vegetarian diet?

Answer 29

1) Macrobiotics has a limited diet. Its purpose is to achieve a balance of yin and yang in order to fend off disease
2) A vegan diet excludes all foods of animal origin
3) Lacto-vegetarians include milk and milk products but omit all other animal sources of food
4) Lacto-ovo-vegetarians consume milk, milk products, and eggs as animal sources of protein

Question 30

Wha is the key to vegetarian diets?

Answer 30

The key feature of all vegetarian diets is the absence of meat as well as of fish. At the same time vegetarian diets typically have a high consumption of fruit, vegetables, grains, legumes, and beans; each of these may be independently associated with a positive health outcome.

Question 31

What ha consumption of red meat been linked to?

Answer 31

cancer (especially colon), type 2 diabetes and cardiovascular disease. Strongest link with processed meats

Question 32

What do vegetarian diets lack?

Answer 32

Vegetarian diets that exclude animal products can be deficient in vitamin B12 and low in iron and zinc. However, carefully planned vegetarian and vegan diets can provide adequate nutrients for optimum health

Question 33

What is the ideal diet?

Answer 33

Based on the evidence as a whole the ideal diet has a low content of meat, especially processed meat. If meat is desired, then chicken and turkey are preferable to red meat. As discussed earlier in the unit, fish is valuable in the diet as it is clearly associated with a reduced risk of heart disease. In summary, therefore, the ideal diet is a variation of a vegetarian diet so that it is low in meat but contains fish. This dietary pattern is essentially the same as the Mediterranean diet. Such a diet can be constructed around Canada’s Food Guide.

Question 34

What is the reason weight loss diets have taken off?

Answer 34

The reason for the rapid growth of the weight-loss industry and its current size is obviously related to the huge epidemic of obesity that has imposed a heavy burden on much of the world. At the same time medical science has failed to come up with any drugs, diets, or other therapies that offer real hope. The only effective treatment is bariatric surgery but this is only suitable for severely obese persons.

Question 35

What is the Atkins diet?

Answer 35

The diet restricts processed and refined carbohydrate foods, such as those high in sugar, breads, pasta, and starchy vegetables, and emphasizes food of animal origin that are higher in protein and fat.

Question 36

What do supporters of Atkins diet claim?

Answer 36

The supporters of this diet claim that foods high in carbohydrates increase insulin levels and thus convert food into body fat. Atkins argued that people having carbohydrate meals eat more and become hungrier sooner. Atkins and his colleagues claim that persons on this diet experience improved blood pressure and lower cholesterol.

Question 37

How do low carb diets work?

Answer 37

Diets that are very low in carbohydrate are characterized by initial rapid weight loss due to excessive water loss. In the first few days, the body breaks down all available glycogen and protein stores for energy. For each gram of glycogen or protein breakdown, the body releases three grams of water from inside the cells, and this leads to dehydration. The body must then rely almost entirely on its fat stores for energy. However, fat is oxidized to a by-product called ketones to provide fuel. High blood levels of ketones is a condition known as ketosis. As a result there is a high acid load from the ketones on the kidneys; this causes the kidney to excrete an excessive amount of sodium, potassium, and water. Dieters cherish rapid initial weight loss, so this diet can be appealing.

Question 38

What are complications of low carb diets?

Answer 38

Complications associated with low-carbohydrate, high-protein, high-fat diets include ketosis, dehydration, electrolyte loss, calcium depletion, weakness (due to inadequate dietary carbohydrates), and nausea (due to ketosis). The lack of fibre leads to constipation.

Question 39

What are two criticisms of the atkins diet and other low carb diets?

Answer 39

The diet has for many years been widely criticized in medical and nutritional circles, mainly on two grounds: first, that the increased intake of saturated fat would raise the blood cholesterol level and increase the risk of heart disease. However, detailed studies have revealed, to the surprise of many, that this does not happen. The other criticism is that the diet does not achieve useful weight loss: the rapid weight loss seen in the first few days will be reversed as soon as carbohydrates are reintroduced and the body rehydrates.

Question 40

What has research shown about low carb diets?

Answer 40

over 6 months moderate weight loss but over longer term there is no more effectiveness than a regular diet

Question 41

how would you test a weight loss diet? What is the most important factor to losing weight?

Answer 41

Overweight subjects were fed diets with widely varying amounts of fat (20% vs 40%), protein (15% vs 25%), or carbohydrate (35% vs 65%) (Sacks et al., 2009). Most previous studies stopped after 6 months or a year but this one continued for two years. The investigators saw no evidence that varying the amounts of macronutrients had any meaningful effect on weight loss. But what they did observe was that persons who attended most sessions were the ones who achieved most weight loss. Motivation is the most important part of weight loss

Question 42

What are three lessons to atkins weight loss diets?

Answer 42

1) In the long term (one to two years) a low-carbohydrate, high-protein, high-fat diet is no more effective than diets with much larger amounts of carbohydrate, and much less protein and fat.
2) Despite the fact that the subjects in this study were provided with intense counselling by well-trained professionals, the average participant lost only 4 kg in two years. This underlines how tough it is for most people to lose weight and how false are the promises of quick-and-easy weight loss.
3) Nevertheless, significant weight loss is possible. The key determinant appears to be motivation.

Question 43

How do weight loss books demonstrate the dangers of untested CAM theories?

Answer 43

These books, and thousands of others of the same general type, illustrate the dangers of unscientific CAM therapies, namely that they distract from therapies that may be effective. For example, a person with heart disease who puts his faith in a book with the title “Cardiovascular Disease: Fight it with the Blood Type Diet” may decide that the dietary recommendations in that book make more sense than using such proven treatments as the consumption of more fish and a reduced intake of salt and saturated fat.

Question 44

Outline the risks and benefits of preventing heart disease and cancer with supplements containing high doses of anti-oxidant vitamins.

Answer 44

There is no evidence that high doses of anti-oxidant vitamins are of value in the prevention of either heart disease or cancer. However, these supplements may cause some excess mortality.

Question 45

Nutrients that are often lacking in the Canadian diet include each of the following, except

Answer 45

sodium

Question 46

Explain what is meant by a phytochemical.

Answer 46

Phytochemicals are non-vitamin organic substances found in fruit, vegetables, and other plant foods. They may lower the risk for various diseases.

Question 47

Nutrients most likely to be present in inadequate amounts on a vegetarian diet include each of the following, except:

Answer 47

Vitamin C

Question 48

Which of the following supplements has the most supporting evidence for the indicated condition?

Answer 48

vitamin D in the prevention of colon cancer

Question 49

Each of the following products is regulated by Health Canada under regulations governing natural health products except:

Answer 49

orange juice

Question 50

Which of the following supplements has the most supporting evidence for the indicated condition?

Answer 50

fish oil for the prevention of heart disease

Question 51

Supplements of folic acid and vitamins B6 and B12 are able to lower the blood level of homocysteine and by this means prevent heart disease. Is this an accurate statement?

Answer 51

It is correct that supplements of folic acid and vitamins B6 and B12 are able to lower the blood level of homocysteine. However, this has no effect on the risk of heart disease.