Cortisol is the primary stress hormone in the body. The Mayo Clinic says it increases the amount of sugar, or glucose, in the bloodstream, it enhances the brain's ability to use glucose and it helps in the repair of tissues. Cortisol also impacts the immune, digestive and reproductive systems and affects growth processes. Cortisol levels are usually highest in the morning and lowest around midnight. Foods don't contain cortisol, but what you eat can affect the cortisol levels in your body.
Foods to Increase Cortisol Levels
Dr. Pauline Harding, who is certified in family practice and licensed as a dietician/nutritionist, says cortisol levels respond rapidly to the food we eat. She says a food's glycemic index affects the body's cortisol levels for approximately five hours after you've eaten, and the glycemic index reflects how the food will affect the body's blood sugar level. Foods with a high glycemic index cause cortisol levels to rise. These foods include products high in sugar and refined starches. Skipping meals can also boost cortisol levels. Harding says a high cortisol level at night can disrupt sleep.
Foods to Lower Cortisol Levels
If your goal is reduce your cortisol level, look for foods with a low glycemic index. Dr. Pauline Harding tells Nutrition 4 Health that good choices include eggs, meats, poulty, fish and vegetables. If your day begins with a normal cortisol level, Harding says you can keep it on a downward track by eating foods with a low glycemic index approximately every five hours. To prevent an upward swing in cortisol, she recommends balancing sugars and grains at meals with animal proteins. She says vegetables tend to balance themselves in terms of the glycemic index, but she says they're not low enough on the index to offset consumption of grains.
Manufacturers of so-called cortisol blockers claim their products will help you lose weight by reducing cortisol levels. The theory is that cortisol helps your body cope with stress by increasing your appetite and adding abdominal fat, so reducing cortisol levels will help you reduce. Mayo Clinic nutritionist Katherine Zeratsky says there are only a few preliminary studies to support this connection between stress hormones and weight gain, and she says there's no scientific evidence to show blocking cortisol can lead to weight loss. Cortisol blockers have been marketed under names such as CortiSlim, CortiStress and CortiDiet.