You probably think of vitamin C as your go-to nutrient when you feel a cold coming, but did you know that vitamin C will also lower cortisol?
Research shows that because vitamin C has a powerful effect on the immune system, it can help to clear cortisol after intense exercise or during serious mental stress. For example, when men consumed 1 gram of vitamin C a day for 2 weeks, they had significantly lower cortisol after a 2.5-hour endurance run than a placebo group.
A second study performed on stressed-out Korean office workers found that giving them a large dose of 10 grams of vitamin C significantly reduced feelings of exhaustion.
Why It Works: Vitamin C is protective because it decreases inflammatory markers that alter the body’s stress response. When inflammatory markers build up, the immune system goes into overdrive and the hypothalamic-pituitary-adrenal axis that regulates the release of cortisol and other hormones becomes dysregulated.
The effects are debilitating: Recovery from training is delayed and muscle mass is compromised. The body spends more of its time in fat-storing mode and body composition is degraded. Sleep is disrupted and chronic fatigue sets in. Ultimately, DNA gets damaged and cellular aging occurs.
How To Get It: Most people can get sufficient vitamin C by eating citrus fruits and leafy greens. Ways to get more C into your diet are to add lemon or lime to water, use citrus in salad dressing and meat and fish marinades, and eat leafy greens at every meal.
The one catch is that you’d have to eat at least 16 servings of citrus and greens a day to equal the 1-gram dose used in the exercise study mentioned above. Therefore, if you’re injured, going through a high-stress time, or are training two-a-days, supplementing may be the way to go.
Davison, G., Gleeson, M. The Effect of Two Weeks Vitamin C Supplementation on Immunoendocrine Responses to 2.5 Hours Cycling Exercise in Man. European Journal of Applied Physiology. 2006. 97(4), 454-461.
Suh, S., et al. Intravenous Vitamin C Administration Reduces Fatigue in Office Workers. Nutrition Journal. 2012. 11(7).