Techniques for Heart-Healthy Cooking

Do your heart a favor by keeping temperatures low
By Robert Leighton

Cooking distinguishes humanity. No other living creature cooks. Food preparation utilizing heat has allowed humankind to develop from a primitive existence to fuller, more enriching lifestyles. Cooked food offers immense sensory pleasure and tastes delicious.

The offering of a wonderful meal, cooked with one’s own hands, can convey love and caring. Cooking offers the opportunity for creative self-expression. Kitchenware provides the tools of the artistry and the plate is the canvas.

The act of cooking helps preserve some foods, allowing us to reserve today’s bounty for the scarcity of tomorrow. Cooking also makes some foods safer to eat. Cooking intensifies the nutritional value of some foods while making other nutrients more easily absorbed.

Yet cooking can also destroy the nutritional value of certain foods. Certain types of cooking can also make healthy food harmful.

Cool Cooking

As a general rule, high temperature cooking destroys the nutritional value of food. It can also cause certain foods to become harmful, generating potentially damaging compounds that promote inflammation, cancer, and cardiovascular disease.

Numerous studies have associated grilled and fried meats with an elevated risk of cancer, including breast, prostate, and colon. The studies emphasize that cancer risks may not be associated with meat specifically, but rather with well-done, overdone, deep-fried meats and the blackening or charring associated with high temperature or direct-flame cooking.

Anything cooked with lots of water will maintain a relatively low heat. As the water reaches the 212 degree boiling point, it will steam, taking the heat with it. Steaming, stewing, poaching, and soup-making are great ways to cook any number of foods, often enhancing their nutritional value. Remember though, as foods dehydrate as they cook, temperatures will rise. Take care to avoid high heat.

Temperatures below 325 degrees are still considered low-heat cooking. Above 325 degrees, the challenge posed by heat often depends on the food itself.

When Good Fats Go Bad

Cooking in oil poses health challenges. Oils have a smoke point, a temperature that causes the chemical composition to break down rapidly and delivers unpleasant flavors. Different oils will start to smoke and burn at different temperatures. Unrefined corn and soy oils have a smoke point of 320 degrees. Extra- virgin olive oil has a smoke point of 325 dedgrees, making it good for salads or light sauté. Refined oils can handle a higher heat.

Overheated oils can contribute to the development of compounds known as free radicals, one or more atoms with at least one unpaired electron that make it unstable and highly reactive. Free radicals can damage cells and accelerate the progression of cancer, cardiovascular disease, and other diseases. This is true not only for the unhealthy saturated and trans fats, but also the healthy monounsaturated and polyunsaturated fats. Free radicals are probably more dangerous than trans fats. And as the food approaches the smoke point, oils may be starting to break down.

Oils heated for extended periods of time at temperatures below their smoke point also degrade, just more slowly.

One study found that reused cooking oil negatively affects the arteries’ ability to open for four hours after a meal, while the same meal cooked in fresh oil did not. Rather than detecting a significant difference between the fresh fat and low-fat meals, the meal made in reused oils had an adverse impact on the arteries. Researchers continue to explore the potential impact of how degraded oil hinders the body’s natural ability to regulate inflammation and harms arterial health.


(Material excerpted from The Kardea Gourmet by Richard Collins, MD, and Robert Leighton with Susan Buckley, RD)