The raw food diet: Scientifically sound or half-baked hype?

The way its advocates talk, raw food can sound like the elixir of life served on a salad plate.

“When I began to nourish my body with raw plant foods, I felt lighter on every level: physically, emotionally, mentally and spiritually,” says Natasha Kyssa, an Ottawa-based raw foods consultant who has followed a raw food diet for 21 years.

Kyssa says the diet lifted her out of a long struggle with clinical depression and helped her shed 35 pounds.  She quickly found herself brimming with energy and gained a new zest for life.

A raw food diet – typically but not always vegan – consists of foods that have not been heated beyond 46 C.  Its adherents shun sugar and other foods that have been processed, refined or pasteurized.

Raw foodists say cooking destroys enzymes critical to digestion and metabolism.  Eating cooked food forces the body to draw on its own limited reserves of enzymes, which taxes the body and contributes to diabetes, weight gain, allergies and other ailments, says Kyssa.

A 2005 study by the University of Washington School of Medicine compared raw foodists with people on the Standard American Diet.  Researchers found that raw foodists had less chronic inflammation, lower cholesterol and less IGF-1, a growth factor associated with increased risk of prostate and breast cancers.

Yet health professionals remain largely unconvinced, pointing to the fact that raw foodists experience health benefits simply because they eat a plant-based diet.

“They’re eliminating all the junk they used to eat from their diet, so of course they will lose weight, have less inflammation and feel healthier,” says Helene Charlebois, a registered dietician in Ottawa.

While the diet’s focus on fruits and vegetables is commendable, Charlebois says eating a pure raw food diet can be problematic.

Many raw foods, especially those high in fibre, are indigestible.

 Although a raw food diet uses fermentation, soaking and dehydration to break down cellulose in plants, vegetables like asparagus and broccoli are more easily digested after heat has broken down the cell wall, says Charlebois.

Some nutrients and antioxidants, like beta carotene in carrots and lycopene in tomatoes, are also better absorbed after they’ve been heated.

Charlebois says while cooking does cause enzymes to unravel, raw foodists are overlooking a key fact: the same thing happens to those enzymes as soon as they hit the stomach’s acidic environment.

Deficiencies common

The increased digestion and elimination that come with eating a completely raw diet are also problematic, says Charlebois.

“The high quantities of fibre and fluid in a raw diet increases transit time from mouth to anus, but people with really fast transit times tend not to absorb as many nutrients because they bypass a lot of absorption sites,” she says.

A raw diet may also cause deficiencies in calcium, vitamin D, iron, zinc and vitamin B12, says Dr. Donald Wilson, an Ottawa-based family physician.

What concerns Wilson most is the increased risk of food poisoning that comes with following a raw diet.

Raw foodists have to soak and sprout grains and legumes in order to eat them, a process that can encourage mould and bacterial growth.

According to a review published by Cambridge University Press in the journal Epidemiology and Infection, scientists now put poisonings caused by raw produce on par with outbreaks caused by E. coli and salmonella.

Such findings lead Wilson to recommend eating a balance of both cooked and raw foods.

“We don’t have to limit ourselves to raw foods to avoid potential cancers and things like that,” says Wilson.

“We have immune systems and antioxidants in our diets, so we already have the checks and balances that buffer these things.”

Front page photo © Ella Myers.  Story produced by Ella Myers



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