Are the myths about our food really true? With foodies and nutritionists expecting us to farm, process and cook our own foods, some experts believe that we’re being sold a bill of goods. Joe Schwarcz, a nutrition expert and chemistry professor at Canada’s prestigious McGill University and author of An Apple A Day, offers his take on the world of food and nutrition.
Diet Detective: What prompted you to focus on nutrition, especially since your background is in chemistry?
Dr. Schwarcz: Nutrition is a branch of chemistry. Our food, of course, is a collage of chemicals, as is our body. I have always been fascinated by how our body handles the phenomenally diverse array of compounds found in food as well as the role those compounds play in the various reactions that go on in our body all the time and that basically constitute what we call “life.” I also like to cook, and that, of course, is another branch of chemistry.
Diet Detective: What are the most common myths about nutrition?
Dr. Schwarcz: Perhaps the most common myth is that there are “healthy” foods and “unhealthy” foods. There certainly are healthy diets and unhealthy diets, but individual foods should not be looked at as devils or angels. It is as possible to never eat an apple and have a healthy diet as it is possible to eat lots of apples and have a terrible diet. It is the overall composition of the diet that matters. That being said, there are, of course, foods we should try to incorporate into a healthy diet and ones that should be curbed. It is a good idea to strive for seven to 10 servings of fruits, vegetables and whole grains a day and to cut down on fatty meats and soft drinks. A second widespread myth is that if something is “natural” it is superior to “artificial.” There is no such relationship. The safety or efficacy of any chemical is not determined by its ancestry; it can only be determined by proper testing. Nature is not benign; botulin, for example, possibly the most toxic substance known, is produced by the perfectly natural Clostridium botulinum bacterium.
Diet Detective: What would you say is the biggest misconception about organic food and pesticides?
Dr. Schwarcz: The popular, and wrong, belief is that organic producers do not use pesticides. There are a number of pesticides that are approved for organic use, and all come from “natural” sources. That has little meaning since, as I mentioned before, “natural” does not equate with “safe.” Rotenone, for example, a pesticide derived from the derris plant, is allowed in organic agriculture and has been linked with Parkinson’s disease, just like some synthetic pesticides. There is also the belief that organic foods are more nutritious, which is not necessarily so. Nutritional qualities are determined by a variety of factors including weather, seed type, soil conditions and transportation.
Diet Detective: What about enhanced foods (e.g., added vitamins, DHA, etc.)?
Dr. Schwarcz: To a large extent, this is marketing hype. The amounts added do not make a significant contribution to the diet but can lead to a false confidence about nutrient intake. An area where such enhancement may be useful is with probiotics. Certain bacterial cultures when added to food may help control disease-causing bacteria.
Diet Detective: Antioxidants?
Dr. Schwarcz: Again, the benefits have been overhyped. It has been assumed that the reason populations that consume lots of fruits and vegetables are healthier has to do with the antioxidant content of these foods. This is too simplistic a view, as becomes obvious by the failure of antioxidant supplements to deliver the goods in controlled trials. The free radical theory of disease and aging is interesting and plausible, but there is less evidence than consumers think. This is not to say that antioxidants that can neutralize free radicals are not important, but they appear to work effectively only when they are part of the food itself, not as isolated supplements.
Diet Detective: Artificial sweeteners?
Dr. Schwarcz: Artificial sweeteners, as any food additive, have to jump over a variety of hurdles before they can be approved. In fact, the regulations for additives are much more stringent than for the natural components of foods. No substance is safe for everyone under all conditions. For example, aspartame can trigger headaches in some people, but the incidence of this is minute. The venom expressed against sweeteners by the anti-sweetener movement is unfounded. They do not cause brain tumors or multiple sclerosis. Stevia, recently approved, has a good safety profile, but that does not mean individuals cannot have an adverse reaction. My problem with sweeteners is that they have not solved the obesity problem. Furthermore, they encourage the consumption of artificially sweetened soft drinks and snacks that have no redeeming nutritional value. These sweeteners can, however, sweeten life for diabetics.
Diet Detective: Food additives and preservatives?
Dr. Schwarcz: Additives are strictly regulated. Preservatives make an important contribution to health. Molds and bacteria are not desirable components of food. It is, however, true that, in general, foods with lots of additives are nutritionally inferior to fresh foods — not because of the additives, but because additives are used in foods that are nutritionally weak. For example, monosodium glutamate allows chicken soup to be made with less chicken. Some food dyes can cause behavioral problems in children (sugar, contrary to popular belief, is not a culprit) and sulfites can trigger adverse reactions in sulfite-sensitive individuals. In general, emphasizing foods with fewer additives leads to a better diet.
Diet Detective: Genetically modified foods?
Dr. Schwarcz: We do not produce enough of these. The technology holds great promise for both the farmer and the consumer. Reducing herbicide and pesticide use is advantageous, as is improved nutritional profile. Producing crops with higher levels of omega-3 fats is a distinct possibility, as is growing vegetables that have higher concentrations of anti-cancer compounds. Alarmists often misrepresent the risk/benefit ratio. While there are some environmental issues, nutritional and farming benefits stand to trump these.
Diet Detective: What’s always in your fridge?
Dr. Schwarcz: Orange juice, apples, berries of some kind.
Diet Detective: What food would we never find in your fridge?
Dr. Schwarcz: Soft drinks.
Diet Detective: The single healthiest food?
Dr. Schwarcz: There is no “single healthiest food,” but I try to eat blueberries, broccoli, tomatoes and, of course, apples with regularity.
Diet Detective: Is there a particular fictional character you relate to?
Dr. Schwarcz: No doubt about it … Sherlock Holmes.
Diet Detective: Last meal?
Dr. Schwarcz: Chicken paprikas with whole-grain rice, tomato and cucumber salad, cherries and a nectarine.
Diet Detective: What’s your favorite “junk food?”
Dr. Schwarcz: Smoked meat.
Diet Detective: If you were not an author and chemistry professor, what would you be doing – your other dream job?
Dr. Schwarcz: Playing center for the Montreal Canadiens or shortstop for the Yankees or performing magic in Las Vegas.
Diet Detective: What was your worst summer job?
Dr. Schwarcz: Steam ironing textiles.
Diet Detective: As a child you wanted to be?
Dr. Schwarcz: Up to about age 10, a famous soccer goalie. After that … a chemistry prof!