Let's Vego

By Dr Rosemary Stanton

If you’re thinking of switching to a vegetarian diet, you might want to consider the pros and cons to ensure that you can adapt your lifestyle to cope.

Hardly a week goes by without someone asking me whether a vegetarian diet is healthy or not. But the answer isn't as straightforward as you might think. It invariably depends on the type of vegetarian diet being followed.

Overall, only about two per cent of the population are strict vegetarians (vegans) who avoid animal products of all kinds, usually for religious reasons or to support animal rights. A much larger percentage of people classify themselves as vegetarians because they prefer to avoid red meat - at least most of the time - as they believe a meatless diet is healthier. (For more information see Know your vegos.)

For instance, around 30 per cent of teenage girls avoid meat, although most don't worry too much about a little ham on their pizza. Some make good vegetarian choices by consuming plenty of healthy foods, but others court dietary disaster by living largely on chips, chocolate, pastries, biscuits and soft drinks. For a small percentage of teenage girls, being vegetarian is a smokescreen for anorexia nervosa. However, it's silly to assume that every teenager who refuses to eat meat is headed for an eating disorder. Most just don't like the thought of killing animals and some jump on the bandwagon if that's what their friends are doing.

What are the pros?

There are many positive benefits of being a vegetarian. A well-chosen vegetarian diet that includes legumes, tofu, grains, nuts, low-fat dairy products and plenty of fruits and vegetables is likely to have:

• a better balance of essential fats
• less saturated fat
• more phytonutrients (protective anti-cancer compounds found in vegetables, fruits, nuts and wholegrains)
• more dietary fibre.

There are also plenty of studies which show that vegetarians have:

• less coronary heart disease
• lower blood pressure
• less chance of strokes
• fewer bowel and prostate cancers
• less constipation
• less chance of developing gallstones
• less diverticulitis (small pockets of tissue that occur in the lining of the bowel that can cause pain and constipation)
• reduced chance of type-2 diabetes.

However, it's not known whether these benefits are due to a lack of meat or the result of a high intake of plant foods.

What are the cons?

The main disadvantage of a vegetarian diet is the potential for vitamin or mineral deficiencies. In general, vegetarians who consume dairy products and eggs are more likely to have an adequate diet, while fussy eaters with a narrow range of acceptable foods are at risk of having a poor diet. The key is to make certain you consume a wide range of foods and ensure the quantities are adequate.

Protein deficiency:

Many people worry that vegetarians won't get enough protein, but this is largely a myth. You can get plenty of protein from grains and cereals, legumes, nuts and seeds. Eggs and dairy products are also rich sources if these are part of the vegetarian diet you choose. Over the course of a day, your body will mix and match amino acids from different foods, so the idea that you need to combine certain foods at each meal is also not valid.

Vitamin B12 deficiency:

Vitamin B12 plays a vital role in supporting the nervous system and brain cells, so a lack of it is a potentially serious problem for vegetarians. It's also needed to convert a hazardous amino acid called homocysteine (which increases the risk of heart attack and stroke) into a harmless amino acid and to convert other B-complex vitamins to their active form. Vitamin B12 is only found in animal foods (meat, poultry, fish, eggs and dairy products). Mushrooms grown in compost may absorb a small amount of vitamin B12, but not enough to supply the body's needs, while comfrey and spirulina (often claimed to be sources) contain a form of B12 that can't be absorbed by humans. Fermented foods such as tempeh (a fermented soy-bean product) or fermented fish sauces supply some B12. Low iron levels or high doses of vitamin C (ascorbic acid) will also reduce the amount of B12 that can be absorbed.

The solution:

• Consume some milk, yoghurt, cheese, eggs or fish.
• Choose soy products that have added B12.
• Consume some fermented foods, such as tempeh or fermented fish sauces.
• Take a B12 supplement, especially during pregnancy. (Some elderly people have difficulty absorbing B12 from the intestine, so they may need it given by injection.)

Iron deficiency:

This important mineral is needed for making red blood cells. Women need more than twice as much iron as men due to menstrual blood loss and pregnancy. Growing teenage girls also have especially high iron requirements. And if you constantly feel tired and lethargic, a lack of iron could be one of the causes (other causes include a lack of sleep and stress).

Unfortunately for vegetarians, the haem iron in meat, poultry and seafood is absorbed much better than the non-haem iron in vegetables, legumes, grains, cereals, nuts and eggs. Dairy does not provide iron.

The solution:

• Eat a small amount of fish, which will increase absorption of non-haem iron from a meal.
• Consume plenty of green vegetables, legumes, wholegrains and tempeh or tofu every day.
• Eat fresh fruit or vegetables at every meal (for example, fruit with your breakfast cereal, salad with lunch and fresh vegetables at dinner) because their vitamin C content increases absorption of non-haem iron.
• Avoid drinking strong tea or peppermint tea with meals as their tannins decrease iron absorption.
• Don't take iron supplements unless a blood test has confirmed an iron deficiency as excess iron intake can cause gastrointestinal problems including constipation and diarrhoea.

Calcium deficiency:

Calcium is vital for strong, healthy bones and a deficiency might not show up until bone strength declines to hazardous levels in old age. Sadly, there's no early-warning test for low levels of calcium.

Dairy products are the major source of calcium so lacto vegetarians usually don't have deficiencies of this important mineral (and surprisingly often have much better bone density than meat eaters. However, ovo vegetarians and vegans are the ones more likely to have a low calcium intake, which increases their risk of bone-related diseases such as osteoporosis.

The solution:

• Drink calcium-fortified soy, rice or oat beverages.
• Take a calcium supplement.
• Buy tofu that's set with a calcium salt rather than nigari.
• Don't rely on sesame seeds for calcium as they have much less than some people think and it isn't well absorbed.
• Expose a portion of your skin to sunlight for 10 minutes each day (avoiding the middle of the day). Vitamin D made under the action of sunlight helps calcium absorption.
• Get plenty of exercise (this helps calcium uptake by bones).

Zinc deficiency:

Zinc helps the body fight infection and plays a role in many of the body's enzyme systems. Seafood and meat are rich sources of zinc and their zinc is absorbed better than the zinc found in plant foods. Foods are preferable to pills as high-dose supplements can interfere with iron absorption.

The solution:

• Good plant sources of zinc include wheatgerm, pumpkin seeds (pepitas), sunflower seeds, soy beans, green peas, legumes, muesli and wholemeal pasta.
• Pescatarians should eat oysters or mussels occasionally as they're good sources of zinc
• Lacto vegetarians can obtain some zinc from dairy foods.

Know your vegos

While all vegetarian diets exclude meat and poultry, some are not as strict as others. Lacto-ovo vegetarian: Permits dairy products and eggs
but excludes meat, poultry and seafood.

Lacto vegetarian

Permits dairy products but excludes meat, poultry, seafood and eggs.

Ovo vegetarian

Permits eggs in the diet but excludes all meat, poultry, seafood and dairy products.

Pescatarian

Permits seafood but excludes meat, poultry, eggs and dairy foods.

Vegan*

Excludes all animal products, including dairy, meat, poultry, seafood, eggs and honey.

Fruitarian**

Consumes only fruit, nuts and seeds.

* Not recommended for children.

**Not recommended for any age group.

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