This is an archived self case study I originally published in June 2019. Note that in these early studies I used RHR (resting heart rate) and blood pressure as separate measures. In more current research I use MAP (mean arterial pressure) and CVL (cardiovascular load = RHR * MAP).
This is the third installment in my nutrition series on blood pressure. Part One looked at the effect of sodium reduction while Part Two looked at magnesium supplementation. This time around, I'm changing the form of magnesium supplement and looking at the effects of moderately reducing caffeine. The research is somewhat conflicting as caffeine can cause a high (temporary) increase in blood pressure when consumed in the form of coffee, but in some cases other forms of caffeine do not have them same effect. Additionally, long term use may actually lessen the effects of coffee (Healthline reference).
BHB and Caffeine:
I've been in the keto world since January 2019 (and in paleo circle for many years longer), so I wondered about "killing two birds with one stone" and supplementing with a Magnesium BHB compound rather than magnesium by itself. See references below for more information on what BHB is and how it works. At the start of this experiment I was consuming an average of 3 cups of coffee per day (about 350 mg caffeine / day). Initially I replaced the two of the three cups of coffee with a higher caffeine tea (Yerba Mate) blended with Green Tea. The specific tea I used was (Yogi Positive Energy), available at most grocery stored. Later, I moved explicitly to green team on the weekdays, while I did enjoy a cup of coffee on the weekends.
- 1 scoop (Nutricost Magnesium BHB) daily. Each scoop has 722 mg magnesium which is notably more than the 500 mg supplement in Part Two.
- Caffeine: see gradual reduction in table below.
- Note on exercise: This hadn't changed much from Part Two. I was doing BJJ about 7 hours per week and about two hours per week doing yoga or other movement drills.
- 3/24/19 : BP 139 / 78 : RHR 69 | 350 mg caffeine (3 cups of coffee daily)
- 5/4/19 : BP 125 / 80 : RHR 69 | 250 mg caffeine (M-F 1 coffee + 1 Yerba Mate Tea, +1 Coffee on Weekends)
- 5/31/19 : BP 136 / 74 : RHR 76 | 160 mg caffeine (M-F 3 green teas, +1 coffee on weekends
Verdict: There seems to be a very small effect. Though the 125 systolic is impressive, it is likely that some other variable is responsible, as the third week yielded a more predictable result. While the effect on blood pressure may be small, it is definitely a positive lifestyle change to not be chemically dependent on something to function in daily life. That is, I ingest a little bit of caffeine each day, but my body lets me know very well when I'm tired now rather than being wired awake (whether I was cognitively aware of my biological process or not). Additionally, I have to note anecdotally that my dental hygiene has improved as well. Less coffee means less staining on my teeth which means less brushing / cleaning to remove the coffee alone.