Nutrition (29 page)

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Authors: Sarah Brewer

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BOOK: Nutrition
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For some people, especially men, following these guidelines means cutting back on portion sizes and exchanging meat-based meals with fish, bean-based vegetarian meals and swapping some red meat for white meats such as chicken and turkey.
The Mediterranean diet
Researchers became interested in the Mediterranean diet when it was noted that people living in Greece, Crete and southern Italy had unusually low risks for developing coronary heart disease, cancer and other diet-related illnesses such as Type 2 diabetes. These populations also had one of the highest adult life expectancies in the world.
When researchers looked at the results of a number of studies investigating high blood pressure, cardiovascular disease, obesity and cancer, they found that individuals who reported eating foods consistent with the Mediterranean diet were between 10 and 20 per cent less likely to die over the course of the studies from any cause, including heart disease and cancer.
The Mediterranean diet combines relatively large amounts of vegetables, fruit, olive oil, fish, garlic, wholegrains, beans, nuts, seeds, bread and potatoes with a relatively low intake of red meat and a moderate consumption of red wine. Overall, it provides a total fat content of 25 to 35 per cent with a low saturated-fat intake of 8 per cent or less of energy intake. Good intakes of omega-3 fatty acids, monounsaturated fats, dietary antioxidants, vitamins, minerals and phytochemicals are also present.
In the Lyon Diet Heart Study, one group of people who had experienced a heart attack were asked to follow a Mediterranean-style diet, while a similar group were asked to follow a ‘prudent Western-style diet’. Those following the Mediterranean diet were significantly less likely to have a second heart attack than those following the ‘prudent Western diet’. The protective effects were so striking that the study was terminated after 27 months (rather than the planned five years). It was thought unethical not to advise those in the control group also to follow a Mediterranean way of eating which was associated with a 70 per cent reduction in death from any cause.
Researchers have since discovered that following a Mediterranean-style diet influences the activity of genes involved in the production of inflammatory chemicals, the formation of scavenger cells which engulf oxidized LDL-cholesterol (to become trapped in artery walls – see
Chapter 2
) and abnormal blood clotting. Together, these benefits reduce the development and progression of hardening and furring-up of the arteries (atherosclerosis).
Researchers estimate that following a traditional Mediterranean diet could prevent over 80 per cent of heart attacks, 70 per cent of strokes and reduce the incidence of Type 2 diabetes by 90 per cent – as long as you also take regular exercise and refrain from smoking cigarettes. Some evidence also suggests that following a Mediterranean diet may slow the onset of age-related cognitive decline by promoting healthy arteries and blood flow to the brain.
It is relatively easy to start obtaining the health benefits of the Mediterranean diet. Information is available on the website
www.oldwayspt.org
.
In the Lyon Diet Heart Study, participants were simply advised to:
•    eat more bread, more root vegetables, green vegetables and more fish
•    eat less beef, lamb and pork (replace with poultry)
•    have no day without fruit
•    replace butter and cream with a margarine high in alphalinoleic acid
•    cut back on other types of food including biscuits, cakes, sweets and desserts, which are easily replaced with fruit.
To add to that advice, I would suggest selecting wholegrain bread and wholegrain cereals rather than ‘white’ versions, using olive oil rather than other cooking/dressing oils and consuming wine in low to moderate amounts (one to two glasses per day for men, and one glass per day for women).
Healthy cooking methods
By cooking your food in the healthiest ways possible, the fat content of your diet can be minimized and the nutrient content optimized. Preferred methods of cooking include:
•    steaming
•    grilling with only a light brushing of olive oil plus herbs, lemon juices and spices for flavour
•    dry baking
•    baking
en papillotte
(wrapping in greaseproof paper or silver foil) so that food steams gently in its own parcel
•    boiling with only the minimal amount of water and no added salt or bicarbonate of soda
•    poaching in home-made vegetable stock (court bouillon)
•    dry- (stir-) frying using a light brushing of olive oil
•    if roasting meat, placing the meat on a rack within the roasting pan so that all the juices and fats drain away
•    when roasting chicken, using a glass funnel roaster onto which you prop the chicken vertically in the oven. All the fats then drain off so you are left with beautifully flavoured, low-fat meat and virtually fat-free skin
•    when making gravy, reusing the water your vegetables were cooked in to reclaim lost micronutrients.
Checking labels
When buying pre-packaged products, it’s a good idea to get into the habit of checking labels. As well as helping you compare prices and pack weights, these tell you the nutritional value of what you are buying with ingredients listed in descending order of weight. Most labels show the amount of calories, fat, sugar, fibre and sodium or salt in a product, and may display them per 100 g and per serving.
In the UK, manufacturers have adopted front-of-pack food labelling, which focuses on fat, saturates, sugars and salt – the main dietary ingredients that you need to limit to reduce your risk of heart disease. Two main approaches are used – either the traffic-light or the GDA (Guideline Daily Amount) systems.
The traffic light system
This system of labelling shows you at a glance whether a food contains a high (red), medium (amber), or low (green) amount of fat, saturates, sugar or salt. The label tells you how much of these substances is present in a given serving, stated in grams. If that part of the label is red, the amount present is higher than desirable for regular consumption, and best reserved to eat occasionally, in small amounts. If that part of the food label has an amber background, the food is neither high nor low in that substance and is mostly an OK choice – but ‘green’ is ideal as it suggests the food is low in that substance.
The traffic-light system isn’t foolproof, as a food such as fresh salmon, which is high in healthy oils, will have its fat content highlighted on a red background, and yet most of us would bene fit from eating more oily fish. In addition, the traffic-light system doesn’t show you how much of a substance is present as a percentage of the daily recommended amount.
Guideline Daily Amounts (GDAs)
Guideline Daily Amounts focus on calories, sugar, fat, saturates and salt. These show you at a glance how much of each substance is present in a portion of the food and the percentage of an adult’s guideline daily amount it represents (based on a healthy weight, average activity level and no special dietary requirements for females, and assuming a calorie need of 2,000 kcals per day). Of course everyone is different, and men will have different average GDAs to women, but they still give you a good idea of what’s in the food you’re buying and what you are eating. So if you’re trying to cut back on salt or fat, compare labels in similar items and select the product that provides the lowest percentage of your GDA. For more information on how to use GDAs, visit the
www.whatsinsideguide.com
.
Ideally you want to aim for products that are both low-fat and low-sugar – but be careful, as many low-fat products are actually quite high in sugar content. When checking labels, useful benchmarks are that per 100 g food (or per serving if a serving is less than 100 g):
2 g
of sugar or less is
a little
sugar
10 g
of sugar or more is
a lot
of sugar.
3 g
of total fat or less is
a little
fat
20 g
of total fat or more is
a lot
of fat
1 g
of saturated fat or less is
a little
saturated fat
5 g
of saturated fat or more is
a lot
of saturated fat
0.1 g
sodium or less is
a little
sodium
0.5 g
sodium or more is
a lot
of sodium
Although meat is an important food group, many people choose to avoid it. Most non-meat-eaters are very food-aware and know how to obtain a healthy, balanced diet. As a result, vegetarians tend to enjoy some protection against common Western diseases such as obesity, gallstones, diverticular disease, high blood pressure, diabetes, coronary heart disease and even cancer (especially of the lung and colon). These beneficial effects may partly be due to other healthy lifestyle choices such as the fact that vegetarians are statistically more likely to take regular exercise and less likely to smoke cigarettes or drink excessive amounts of alcohol than meat eaters.
However, a bad vegetarian diet is just as harmful to health as a bad omnivore diet. Some people switch to vegetarianism by simply removing meat (and sometimes dairy products) from their diet without taking steps to substitute other dietary sources of important nutrients. In some cases, vegetarians – especially teenagers and those living alone – have been found to live on a diet of pastries, cakes, quiches, chips, peanuts and crisps while eating hardly any fruit or vegetables at all. Such a regime will quickly increase the risk of future problems such as osteoporosis, anaemia and other dietary deficiency diseases.
Degrees of meat avoidance
Some people prefer not to eat certain meats from certain animals (e.g. veal, pork). This may be due to personal food dislikes, or for religious, cultural or ethical reasons. For example, many Hindus, particularly Brahmins, are vegetarian, but those that do eat meat avoid beef, as the cow is sacred in their religion. Similarly, those who follow the Jewish or Muslim faiths abstain from eating pork. In the West, some people who are not vegetarian prefer to avoid veal and/ or cage-reared chickens as they object to the conditions in which these livestock are reared. Their remaining diet includes other meats and fish, and no additional risk of a nutrient deficiency is incurred.
Some people prefer not to eat red meat or poultry, but do eat fish and dairy produce. This is a healthy-eating option and there is little additional risk of nutritional deficiency. This way of eating is sometimes described as fishitarian, pescatarian or piscivorean.
A large number of people choose not to eat meat or fish but do eat milk and eggs. This is described as ovo-lacto vegetarianism. Lacto vegetarianism is similar, except eggs are also excluded. Those following this way of eating need to ensure that they obtain alternative sources of the important micronutrients found in meat and fish, such as iron, zinc and vitamin B12.
Diets that exclude all meat and dairy products derived from animals (which may include honey) is known as veganism. Some vegan diets emphasize eating only organically grown foods, with no chemical additives or salt. Problems arise because vitamin B12 deficiency is almost universal among vegans without regular supplementation. Other nutrients of which intakes are likely to be low when following a vegan diet include iron, calcium and zinc.
Avoiding nutrient deficiencies
Meat is a source of a number of important nutrients including protein, iron and vitamin B12. Vegetarians, and particularly vegans, must therefore obtain these nutrients from other dietary sources.
Protein
It is unlikely that vegetarians will be deficient in protein. Even people who eat meat or fish daily get half their protein from non-meat sources such as cereals (mainly bread and pasta), milk products, fish and eggs. Vegans, however, will need to ensure they consume pulses or grains at each meal.
Vitamin B12
Vitamin B12 is chiefly derived from animal sources, and most vegetarians are aware of the need to watch their intake of this important nutrient. Several sources of vitamin B12 are suitable for vegetarians. Non-meat sources of vitamin B12 include eggs, milk, yogurt and cheese. Vegans should consider supplements derived from vitamin B12-enriched yeasts, preparations made by bacterial fermentation and extracts derived from microalgae.
Iron
Eggs are a good non-meat source of haem iron, but vegetables contain the less absorbable non-haem iron. This is partly compensated for by their higher intake of vitamin C, which increases absorption of non-haem iron by keeping it in the ferrous rather than the ferric form. Some types of plant fibre, especially phytates, decrease the absorption of minerals such as iron, zinc and calcium. Ovo-lacto vegetarians, especially women with heavy periods or who are pregnant, need to ensure they obtain enough iron.
Non-meat sources of iron include brewer’s yeast, wheatgerm, wholemeal bread, fortified breakfast cereals, prunes and other dried fruit, green leafy vegetables, parsley, cocoa and curry powder.
Over-boiling vegetables decreases their iron availability by up to 20 per cent. Vitamin C increases the absorption of inorganic iron, while tannin-containing drinks (e.g. tea) decrease it. Coffee can reduce iron absorption by up to 39 per cent if drunk within an hour of eating.

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