In the world of nutrition, health and longevity, we are subjected to an overload of often conflicting dietary advice. So what should we eat and what should we avoid?
The more we understand about the biochemical changes any food undergoes, depending on how it has been treated, heated, processed, modified or even where it comes from (especially in view of the alarming reports about melamine from China), the better able we are to make empowering decisions about the food we choose to eat.
Let's have a look at what baking, roasting, frying, microwaving and heating do to our everyday foods like coffee beans, bread, cereals/grains, baked goods (cakes and biscuits) and proteins. It's increasingly easy to understand why the Raw Food movement is gaining popularity, as there is a lot of wisdom in consuming foods as close to their natural state as possible. And one cautionary tale concerns a substance called acrylamide.
What is Acrylamide?
Acrylamide is a compound most often associated with plastic manufacturing. It is found in coffee and starchy foods like grains and potatoes that have been baked, fried, roasted or toasted. It is formed when frying or baking heats sugars and amino acids to temperatures above 120°C. This process creates the Maillard reaction, also called the browning reaction.
Acrylamide has been classified as a probable human carcinogen by the International Agency for Research on Cancer since 1994 due to its documented carcinogenic effects in laboratory animals. But when a Swedish study released in 2002 revealed that high levels of acrylamide may be created by doing something as simple as baking a loaf of bread, it sent shock waves through the nutrition field.
Now a recent study conducted by researchers from the Netherlands has found that consuming high levels of acrylamide increases people's risk of kidney cancer, the tenth most common cancer.
Researchers looked directly at the effects of dietary acrylamide on cancer risk by studying data from the Netherlands Cohort Study on diet and cancer, which includes more than 120,000 adult female and male participants between the ages of 55 and 69.
Researchers from Maastricht University, the Dutch Food and Consumer Product Safety Authority, and TNO Quality of Life calculated the dietary acrylamide intake of 5,000 random participants based on food frequency questionnaires filled out when the cohort study began.
The researchers found that after 13.3 years, those who had the highest dietary acrylamide intake experienced a 59 percent higher risk of renal cell carcinoma than those with the lowest intake. Renal cell carcinoma is responsible for more than 80 percent of kidney cancer cases.
"We found some indications for a positive association between dietary acrylamide and renal cell cancer risk," the report stated.
A total of 339 cases of kidney cancer, 1,210 cases of bladder cancer and 2,246 cases of prostate cancer were observed among study participants. The researchers did not observe any connection between acrylamide intake and cancer of the bladder or prostate.
The highest average acrylamide intake was 40.8 micrograms per day, while the lowest was 9.5 micrograms per day. Average intake was 21.8 micrograms per day, or slightly less than the amount found in a 75-gram serving of French fries. Every 10 microgram increase in daily intake appeared to increase a person's risk of kidney cancer by 10 percent. Among smokers, the effect of dietary intake was even stronger.
What is interesting to note is that coffee was the biggest source of dietary acrylamide for the study participants.
Studies show that potato chips, crackers, pastries, and powdered coffee all contain high levels of acrylamide, while fried fish and fried chicken contain somewhat lower amounts.
Prior to 2002, acrylamide was known only as an industrial chemical that consumers might be exposed to through cigarette smoke, cosmetics or the breakdown of certain environmental contaminants. Then researchers from the Swedish Food Administration discovered that the chemical also formed at high levels in many popular foods, such as potato chips and bread. Since then, research has suggested that it may also form in dried fruit.
The good news is that no acrylamide was found in fresh fruits and vegetables, cheese, or natural foods that have not been baked or fried or roasted. But fairly high amounts of the compound showed up in black olives, bottled prune juice, sweet potatoes and arrowroot teething biscuits. Other processed foods containing varying amounts of acrylamide included peanut butter, chocolate chip cookies, and prepared meals containing turkey and vegetables.
Although acrylamide is generally accepted to pose health risks in humans, some researchers have questioned whether typical dietary intakes are actually high enough to have an effect. The recent study is only one of the latest to suggest that dietary intake is indeed a significant source of exposure to the chemical.
In earlier research conducted by the same team of scientists and again using data from the Netherlands Cohort Study, dietary acrylamide was found to increase a woman's risk of ovarian cancer by 78 percent and her risk of endometrial cancer by 29 percent. Among women who had never smoked, the increase in risk was much higher: 122 percent for ovarian cancer and 99 percent for endometrial cancer.
Researcher J.G. Hogervorst recommended that people limit their acrylamide intake, including the intake from their diet.
"In preparing food at home, fry potatoes at temperatures below 175 degrees Celsius (347 degrees Fahrenheit) and fry them to gold-yellow, not dark brown," Hogervorst said. "The same goes for making toast and cookies."
The darker a food is fried or baked, the more acrylamide it contains. Foods that are steamed or boiled do not contain acrylamide.
Enzymes in Foods
From a scientific viewpoint, all cooked food is devoid of enzymes that are vital for the digestion and absorption of food. Enzymes are the sparks of life, the living energy contained in food that is essential for all the chemical processes within the body.
Any food heated above 45 degrees Celsius starts to become devoid of its natural enzymes. Once food is heated beyond 50 degrees Celsius (122 degrees Fahrenheit), the much-needed enzymes are totally destroyed. Eating enzyme-dead foods places a burden on your vital organs, especially the pancreas (where enzymes are produced, stored and released for all digestion of protein, fats and carbohydrates).
Many people gradually impair their pancreases and progressively lose the ability to digest their food after years of ingesting processed foods. This is most marked if they start their day with a typical Western breakfast of dry cereal, toast, coffee and pasteurized milk. The only solution is to have a natural, enzyme-rich, high-protein breakfast, as it sets the biochemical pattern for the rest of the day.
In 1930, under the direction of Dr. Paul Kouchakoff, the effect of food (cooked and processed versus raw and natural) on our immune systems was tested and documented at the Institute of Clinical Chemistry in Lausanne, Switzerland. Kouchakoff's discovery concerned the leukocytes, the white blood cells. It was found that after a person eats cooked food, his/her blood responds immediately by increasing the number of white blood cells. This is a well-known phenomenon called digestive leukocytosis, in which there is a rise in the number of white blood cells after eating.
At the same time, the Institute's Swiss researchers made a significant discovery called "pathological leukocytosis" that pointed up the importance of eating more raw foods. They discovered that eating raw, unaltered enzyme-rich foods did not cause an immune reaction in the blood that usually occurred in respond to eating heated food. In addition, they found that if a food had been heated beyond a certain temperature (unique to each food), or if the food was processed, it caused a rise in the number of white cells in the blood—in other words, a toxic reaction.
Let's get back to enzymes. Enzymes are needed for the digestive system to work as specific enzymes break down food particles to be used for energy. The human body makes its own digestive enzymes that are capable of digesting carbohydrates, protein and fats. Yet as we get older and face more stress in our lives, our bodies cease to make enough of these crucial enzymes and that creates digestive problems, fatigue and even allergic reactions.
Mother Nature has come to our rescue by endowing raw vegetables and raw fruit with lots of enzymes to assist our digestion. But this is where we can unwittingly get caught up with extreme approaches, the "all or nothing" attitude. The ideal is to include at least 50 percent of your total food as raw foods wherever possible; most importantly, enjoy enough good quality sources of protein, such as lean grass-fed beef (high in Omega 3, even higher than commercial salmon) and free range eggs; and include a vegetable protein source such as rice or peas for vegetarians/vegans. This is because we all need protein to varying degrees.
Due to the increasing stress factor in our lives, many people need even more bio-available protein. Eggs and raw dairy (unpasteurized milk, cheese, yogurt) are enzyme-rich health foods, and are most beneficial for energy building. Raw eggs are 100 percent bio-available, which means they contain the perfect ratio of amino acids, the building blocks of life.
In summary, avoid as much as possible baked and processed foods such as breads, grains and biscuits. In particular, avoid overcooking proteins, as overheating kills enzymes, the much-needed sparks of life that break down food into energy. Eating raw seasonal and locally grown fruits and vegetables is an ideal way of preserving some of the richest enzymes available in foods. When it comes to potatoes, steaming is better than frying or baking.
We all need digestive enzymes. As we get older it becomes even more important to eat more enzyme-rich raw foods. Not everything can or should be eaten raw, but minimizing heating may still preserve some enzymes. So opt for more raw foods and enjoy a colorfully nutrient-rich diet for building more energy.
Teya Skae is a Sydney, Australia-based clinical kinesiologist, nutritionist and health coach and the founder of website Empowered Living.