197662 Dietary Control of Cortisol Production by Sodium Intake Regulation

Monday, November 9, 2009

Samuel L. Hoffman, BA , School of Natural Sciences, Hampshire College, Amherst, MA
Cynthia J. Gill, BS, PhD , School of Natural Sciences, Hampshire College, Amherst, MA
Proper cortisol function is necessary for the healthy mammalian response to stressful situations, from occupational pressure to severe trauma. Recently, a number of studies have examined the effects of intravenous cortisol supplementation in patients, resulting in increased survival rates. Intravenous sodium has been shown to increase serum cortisol, and dietary sodium has shown some increase in animal models, but this is the first human diet study examining the effects of dietary sodium on human cortisol levels. Thirty-seven human subjects, ages 18-20, participated in a month-long, double-blind study. Subjects kept diet journals for the duration of the study. Twenty-five journals were returned at the end of the study. Salivary cortisol and blood pressure were measured semiweekly, and subjects reported time since waking, hours of sleep, and perceived stress. Sodium intake alone was significantly different between diet groups. The difference of 961 mg Na/day (3138 mg/day vs. 2177 mg/day) was paired with a trend to higher salivary cortisol (0.545 ug/dL vs 0.490 ug/dL) over the course of the experiment, but was not significant (p = 0.13). The difference was significant over the first 2.5 weeks (0.613 ug/dL and 0.494 ug/dL, p = 0.033). The last 1.5 weeks showed a trend in the other direction (0.387 ug/dL and 0.480 ug/dL, p = 0.090). The data show that for periods of less than three weeks, changes in dietary sodium levels are significantly linked to corresponding changes in cortisol production. Future research may reveal novel treatments using short-term dietary control of cortisol.

Learning Objectives:
Describe the relationship between salt consumption and cortisol levels in these subjects. Discuss possible health applications for short-term dietary control of cortisol. Name five salty foods and five low-salt foods.

Keywords: Endocrine, Nutrition

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I personally designed, conducted, analyzed and summarized all of the research presented, with help from each of my co-authors. The experimental design was submitted to the school ethics board, where it received approval. I also submitted a proposal to the Culture, Brain and Development Program of UCLA, from which I received over $1000 of grant funding for my research. Dr. Cynthia Gill, PhD. oversaw the process and provided me support while teaching me the techniques I used during the experiment. I have presented my project and its results both to members of the School of Natural Sciences at Hampshire College as well as to a conference room of non-science majors and parents.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

See more of: Food, Mood & Behavior
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