How to Avoid the Worst Dangers of Cooked Food
There are nutritional benefits to eating most of your fruits and vegetables raw, mainly in what relates to nutrient and enzyme preservation. However, certain foods do benefit from cooking (e.g., mushrooms) as cooking may help kill potentially harmful bacteria, and some nutrients may become more bioavailable when foods are cooked. It all depends on the method.
At An Oasis of Healing we follow a raw vegan diet for the duration of our patients treatment, and when going back home our recommendation is trying to stay close to 80% raw, 20% cooked. So, the important question when talking about cooking food is which cooking methods are safer and which methods may have some “hidden dangers”.
Why “hidden dangers”?
Naturally, humans are regularly exposed to toxicants from food, and those compounds can be genotoxic. Genotoxic chemicals are agents that damage the genetic information within a cell causing mutations, which may lead to cancer. Genotoxic compounds are primarily found in processed and cooked foods, because their formation is related to the methods used or chemicals added. These gene-environment interactions, when considering genotoxic compounds, may cause different types of DNA damage, including nucleotide alterations and gross chromosomal aberrations. Most genotoxic compounds begin their action at the DNA level by forming carcinogen-DNA adducts, which result from the covalent binding of a carcinogen or part of a carcinogen to a nucleotide1.
High Temperature Cooking
High temperature cooking has proven to have some dangers, especially associated with the cooking method and type of foods you are using. Some potentially mutagenic/carcinogenic compounds are formed during high temperature cooking, namely:
Heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs)
- Mostly with cooking methods such as pan frying or grilling directly over an open flame
- Formation of different varieties and content of HCAs and PAHs depends on cooking method, and “doneness” level.2,3
- HCAs and PAHs have been found to be mutagenic in laboratory testing
- HCAs and PAHs become capable of damaging DNA only after they are metabolized by specific enzymes in the body, a process called “bioactivation.” Studies have found that the activity of these enzymes, which can differ among people, may be relevant to the cancer risks associated with exposure to these compounds4
- Mutagenesis causes DNA changes which increases the risk of cancer – carcinogenesis
How to avoid HCAs and PAHs
- Reduction of HCAs in food can be accomplished by avoiding high-temperature cooking6.
- Avoid prolonged cooking and broiling and direct exposure to flame13.
- Ways to prevent or reduce the production of HCAs in different cooking methods include low temperature pan frying (although this method always has some mutagenic activity associated), the use of a fan-heated ovens, and cover food in grease-proof paper.
- When grilling or barbecuing, place food away from the heat source to avoid contact with flame to try and minimize carcinogenic fumes (preventing PAHs too)14.
- Acrylamide is not only a synthetic material used in industry, but also a carcinogenic, cyto- and genotoxic compound formed in foods during a heat-induced process16.
- The toxicity of acrylamide has been acknowledged since 2002. The identified toxicological effects on humans are neurotoxicity, genotoxicity, carcinogenicity, and reproductive toxicity17.
- Acrylamide is a by-product of the cooking process and is formed when reducing sugars (glucose or fructose) react with the amino acid asparagine during the Maillard reaction18.
- Maillard is a common reaction, responsible for the browning of food during baking, frying, and roasting.
- Mostly found in starchy foods, carbohydrate-rich ingredients, potatoes, other root vegetables and plant derivatives products, and in bakery products (bread, crispbread, cakes, batter, breakfast cereals, biscuits, pies, etc.) and coffee16.
- Created in food when it’s roasted, fried or grilled at very high temperatures for a long time.
- Reaction can be noticed when the starch within those foods starts to darken. Food starts to turn golden brown or to look burnt.
- Exposure to dietary acrylamide depends on the amount of acrylamide present in food, the portion size consumed, and the frequency of consumption, as well as cooking and storage methods18.
- Different factors determine the levels of acrylamide in cooked foods, including the cooking temperature, length of cooking time, moisture content, and the amount of reducing sugar and asparagine in raw foods18.
- Acrylamide can also be found in some industrial processed foods.
- After metabolization, acrylamide is distributed to all organs and tissues in the human Acrylamide was found to cause apoptosis by mitochondrial dysfunction.
- Based on the evidence of carcinogenicity proven in laboratory animal studies, the International Agency for Research on Cancer has classified acrylamide as a group 2A carcinogen, which means a probable carcinogenic agent in humans19.
- Two recent studies based on systematic review of literature and meta-analysis of epidemiological studies found no statistically significant association between dietary acrylamide intake and various cancers, and few studies reported increased risk for renal, endometrial, and ovarian cancers. However, the authors of one of the papers also indicated that exposure assessment in most cases was inadequate which may lead to potential misclassification or underestimation of exposure18,20.
- Acrylamide is also classified as human neurotoxin (effect observed in humans occupationally exposed)16.
How to avoid acrylamide:
- Buy unprocessed or minimally processed foods and when buying processed, check the label to avoid buying foods with added acrylamide.
- Avoid overcooking: when cooking starchy foods aim for “golden yellow” and not “golden brown”.
- Avoid refrigerating starchy foods, such as potatoes, before cooking, since it frees up sugar molecules that will then combine with amino acids to form acrylamide.
- Most importantly, eat the majority of your foods raw
Stay tuned for next week were we cover the dangers of cooking smoke and oils
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Vanessa Pinto graduated with a degree in Biology and Masters in Ecology from Lisbon University. After graduating, she underwent a series of professional and personal growth experiences, including being an officer in the Portuguese Army, working in countries as diverse as Iceland and Costa Rica. Vanessa became certified as a Yoga and Meditation teacher in rural India.
Being a compassionate person by nature, Vanessa is able to bring her connectedness when working with others while enhancing the importance and practicality of a pragmatic evidence-based approach to facilitating lasting and permanent change. Vanessa is a certified health coach whose specialties are nutrition, exercise, and mind/ body connection. She works both in Portugal, Thailand and USA, where she develops her work closely with people diagnosed with cancer, mainly in the areas of nutrition, movement and health education.