What Hormones Are Affected By Caffeine?
Have you heard different information about caffeine and its effect on hormones? Maybe you are wondering what hormones are affected by caffeine. In this video we look at research behind caffeine and its effect on hormones. We will look at how it affects cortisol, insulin, testosterone, and sex hormone binding globulin.
If you want to know what hormones are affected by caffeine, keep reading.
Hormones Affected By Caffeine
Caffeine excerpts its effect on many different hormones but most effects seems to be on cortisol, insulin, and testosterone. Let's look at cortisol first. In this study, researchers looked at the effects of oral caffeine on plasma ACTH levels and cortisol levels. ACTH comes from the brain and it stimulates the adrenal glands to produce cortisol, DHEA, and other things in the adrenal glands. Following caffeine consumption there was significant elevation of ACTH at all times 30 minutes to 180 minutes. Cortisol is also elevated starting at 60 minutes. For this study it looks like they used about two to three cups of coffee. The main conclusion of the study is the effect of caffeine on hormones and they concluded that caffeine is exerting itself on the pituitary adrenal axis. The caffeine is stimulating the pituitary to produce ACTH which then increases cortisol. There are probably other effects going on in the body as well. This pituitary adrenal axis was the angle of this particular study.
Caffeine Affect On The Hormone Insulin
Caffeine also seems to have an effect on insulin and it makes sense too since insulin and cortisol have posing effects on glucose. There are several studies showing that caffeine consumption does decrease insulin sensitivity and cause higher level of insulin to be produced. This randomized double-blind placebo-controlled trial study looked to understand the relationship between caffeine and insulin. It was a fairly small study so the conclusions should be taken with a grain of salt. They looked at consumption of 200 milligrams of caffeine taken twice a day which is a fairly large amount. The participants took this amount for seven days. They looked at the effects on glucose metabolism, serum cortisol, DHEA-s, insulin, androstenedione, and bedtime salivary melatonin.
They found is that serum insulin levels were significantly higher in those consuming the caffeine than other parameters. Glucose, androstenedione, DHEA and melatonin were not changed. This may be a little confusing by the glucose not changing but allow me to break this down a bit.
Glucose will not go up or down as long as the body has sufficient insulin to keep the glucose in check. Insulin acts to put glucose into the cells and tissues. Cortisol takes glucose out of the tissues and puts it into the blood. So if caffeine is increasing cortisol, we expect the body to also need more insulin. This is what the researchers found. Over time that higher amount of insulin may lead to decreased insulin sensitivity and higher glucose levels, aka insulin resistance.
Caffeine Affect On The Hormone Testosterone
What is the affect of caffeine on testosterone and other androgens and the overall androgenic effect? There are few different angles to consider with this, like sex hormone binding globulin (SHBG) and actual androgen levels. One study looked at the effect of caffeine on testosterone levels and they found that consumption of caffeinated coffee increased total testosterone but decreased free estrogen and testosterone. Among women decaffeinated coffee decreased total and free testosterone and caffeinated coffee decreased total testosterone. This does not present a clear picture of what's going on.
Another study looked at the effect of caffeine on training. Many people take a pre-workout supplement or drink coffee before the gym. What kind of effect does this have on your body? It looks like caffeine has some potential benefit on training outcomes via the anabolic effects. For instance, if you are able to increase the overall output of exercise you do, maybe you could do more sets more reps, this causes your body to produce more testosterone. That increased workload, with the caffeine, causes your tissues and hormone centers in your brain to increase testosterone production. However, that increased testosterone effect may be counteracted by the catabolic effects of caffeine and cortisol.
Caffeine consumption may not always be aligned with your exercise goals. If your goal is purely to increase muscle, high caffeine levels may work against you because of the cortisol. If you're trying to trim down and put on muscle, caffeine may help you with both. This is because higher cortisol has a catabolic effect but increased testosterone from increased work loads has an anabolic effect.
Another important variable when looking at androgens and testosterone is the effect of caffeine on sex hormone binding globulin. SHBG is the thing that binds up your hormones and transports them throughout the body. When you have more SHBG you have less bioavailable testosterone and estrogen. Many studies have looked at the effect of caffeine on SHBG. When comparing caffeinated versus decaffeinated coffee one study found no effect on SHBG. However, several other studies have looked at men who consumed caffeinated coffee and found higher circulating SHBG levels. To me it looks like caffeine does increase SHBG. Taking all information above together what hormones are affected by caffeine?
Caffeine definitely increases cortisol and there's a strong indicator that it increases insulin. Over time it may actually lead to insulin resistance. Caffeine may help you in the gym leading to increased workload and increase the amount of exercise you can do. In doing so can increase your overall testosterone production. However, if there is an increase in SHBG that testosterone is not going to be very useful to you. Because it's not very bioavailable it will not have an overall anabolic or androgenic effect on your tissues. Looking at individual hormones may give the appearance of an isolated effect. However, it is more likely that the effects on one hormone are balanced out by another opposing hormone. It does look like there maybe a negative effect on your overall metabolism if it is increasing your insulin output
Of course all these things are going to be dose dependent. Not many people are having 200 milligrams of caffeine per day. Most cups of coffee are about 80 milligrams or so.
That should give you a better understanding of what what hormones are affected by caffeine. If you have questions about the content in this article, please ask it in the comment section below.
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