What Dietitians say about Raw Diet (from the article "They like it raw" by Joyce Teo in Mind Your Body published on Jun 27, 2013.)

The following has been extracted from the article "They like it raw" by Joyce Teo in Mind Your Body published on Jun 27, 2013.

Note: [ See http://www.straitstimes.com/archive/thursday/supplements/mind-your-body/story/they-it-raw-20130627 ].

WHAT DIETITIANS SAY

However, dietitians say an entirely raw diet is not necessary and may even be harmful as cooking kills food-borne pathogens. They advocate a healthy and well-balanced diet.

Ms Joyce Tan, a dietitian at the nutrition and dietetics department at Tan Tock Seng Hospital, said: "Once people go on a raw food diet, they won't eat processed food. So they may feel good because they have eliminated high-fat and high-sodium food from their diet. A raw food diet is unsustainable in the long term and people on this diet are at risk of nutrient deficiencies. It is not a well-balanced diet as it can be too restrictive, especially if major food groups are eliminated."

The limited scientific studies that look at the benefits of eating raw food show that "getting the maximum nutrients from food really depends on how you prepare the food", she said.
Studies also show that those on raw food diets for a long time tend to be underweight and may have irregular menstruation.

While boiling food for a long period of time or using high heat such as deep frying may lead to increased nutrient losses, cooking does not make food harder to digest or less nutritious, contrary to what raw food advocates say.

Ms Tan said the human body naturally produces digestive enzymes that help to break down food.
"There is limited evidence to show that plant enzymes are beneficial to health. Once the raw food is consumed, the plant enzymes get digested by the human body anyway."

In fact, she said, cooking not only helps eliminate harmful micro-organisms, it also makes it easier for some nutrients to be absorbed. One example is lycopene, the antioxidant in tomatoes, which is absorbed more easily when they are cooked.

Cooking meat softens the muscle fibres, aiding in chewing and digesting, said Ms Gladys Wong, the chief dietitian at Khoo Teck Puat Hospital.

Ms Tan said people on a raw food diet, especially those who avoid meat and dairy products, such as those on a vegan diet, are at risk of deficiencies in vitamin B12, vitamin D and iron. Vitamin B12 is found in meat and dairy products and is key for a healthy nervous system. Vitamin D - which is found in oily fish, egg yolks and organ meat - regulates the immune system and bone growth.

"Additionally, the mineral iron, which plays a vital role in the formation of red blood cells, is better absorbed from animal protein than plant protein," said Ms Tan.

Babies and toddlers should avoid a raw food diet.

"It can be restrictive and may not provide adequate nutrients to ensure optimal growth and development," said Ms Tan.

She also warned that young children, who have immature immune systems, and older adults and people with weakened immune systems, for example, those suffering from alcoholism or cancer, would be more vulnerable to food-borne illness.

These groups of people should ensure that their food is thoroughly cooked to destroy potentially unsafe micro-organisms.

ADVICE FOR NEW RAW FOODISTS

Ms Tan's advice for those keen to convert to a raw food diet is: Ensure you incorporate a wide variety of plant food, such as legumes, nuts and seeds, in addition to fruit and vegetables, to prevent nutrient deficiencies.