Flashback Friday: Hibiscus Tea vs. Plant-Based Diet for Hypertension & How Much Is Too Much?
Flashback Friday: Hibiscus Tea vs. Plant-Based Diet for Hypertension & How Much Is Too Much?
How do the blood-pressure lowering effects of hibiscus tea compare to the DASH diet, a plant-based diet, and a long-distance endurance exercise? And be aware, the impressive manganese content of hibiscus tea may be the limiting factor for safe daily levels of consumption.
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For more on hypertension, see:
• Whole Grains May Work as Well as Drugs (https://nutritionfacts.org/video/whol…)
• Longer Life Within Walking Distance (https://nutritionfacts.org/video/long…)
• Hearts Shouldn’t Skip a Beet (https://nutritionfacts.org/video/hear…)
• How Not to Die from High Blood Pressure (https://nutritionfacts.org/video/how-…)
• High Blood Pressure May Be a Choice (https://nutritionfacts.org/video/high…)
• Flax Seeds for Hypertension (https://nutritionfacts.org/video/flax…)
And check out my other hibiscus tea videos:
• Herbal Tea Update: Hibiscus (https://nutritionfacts.org/video/herb…)
• Better Than Green Tea? (https://nutritionfacts.org/video/bett…)
• Protecting Teeth from Hibiscus Tea (https://nutritionfacts.org/video/prot…)
• Is There Too Much Aluminum in Tea? (https://nutritionfacts.org/video/is-t…)
Lemon can actually boost the antioxidant content of green and white tea. See Green Tea vs. White (https://nutritionfacts.org/video/gree… And for a comparison of their cancer-fighting effects in vitro, Antimutagenic Activity of Green vs. White Tea (https://nutritionfacts.org/video/anti…
For more on the iron absorption effect, see my video Risks Associated with Iron Supplements (https://nutritionfacts.org/video/risk…
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Thanks for watching. I hope you’ll join in the evidence-based nutrition revolution!
-Michael Greger, MD FACLM
Images thanks to kattebelletje and Pgoyette via Flickr.
Captions for this video are available in several languages; you can find yours in the video settings. View important information about our translated resources: https://nutritionfacts.org/translatio…
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Content
0.021 -> "Hibiscus Tea vs. Plant-Based Diets for Hypertension
& How Much Hibiscus Tea Is Too Much?"
6.117 -> The latest research pitted
hibiscus against obesity,
10.593 -> giving hibiscus to overweight individuals,
and showed reduced body weight,
14.795 -> but after 12 weeks on hibiscus
they only lost like 3 pounds,
18.102 -> and really only one and
a half pounds over placebo—
20.891 -> clearly no magic fix.
23.358 -> The purported cholesterol-lowering
property of hibiscus tea
27.045 -> had looked a bit
more promising.
28.524 -> Some older studies suggested
as much as an 8% reduction
31.28 -> drinking two cups
a day for a month,
32.815 -> but when all the studies are put together
the results were pretty much a wash.
38.084 -> This may be because only about
50% of people respond at all
41.251 -> to drinking the equivalent of
between 2 to 5 cups a day,
44.453 -> though those that do respond may get a
respectable 12 or so percent drop in cholesterol,
49.889 -> but nothing like the
30% drop one can get
53.276 -> within weeks of eating a
healthy enough plant-based diet.
56.674 -> High blood pressure is where
hibiscus may really shine,
61.128 -> a disease affecting a billion
people, killing millions.
64.833 -> Up until 2010, there wasn’t sufficient
high quality research out there
68.846 -> to support the use of
hibiscus tea to treat it,
71.149 -> but there are now randomized double-blind,
placebo-controlled studies
74.434 -> where hibiscus tea is compared to
artificially colored and flavored water
79.153 -> that looks and tastes like hibiscus tea,
and the tea did significantly better.
83.605 -> We’re still not
sure why it works,
86.673 -> but hibiscus does appear to
boost nitric oxide production,
89.642 -> which could help our arteries
relax and dilate better.
92.943 -> Regardless, an updated review acknowledged
that the daily consumption of hibiscus tea
97.495 -> may indeed significantly lower blood
pressures in people with hypertension,
100.547 -> but by how much?
103.046 -> How does this drop in blood pressure
compare to other interventions?
107.066 -> Well, the premier clinical trial when
it comes to comprehensive lifestyle modification
111.885 -> for blood pressure control is
the Premier Clinical Trial.
115.72 -> Realizing that 9 out of 10 Americans
are going to develop hypertension,
119.423 -> they randomized 800 men and women with
high blood pressure into one of three groups.
124.242 -> One was the control group,
the so-called advice only group,
128.059 -> where patients were just told
to lose weight, cut down on salt,
131.195 -> increase exercise and eat healthier...
here’s a brochure.
133.863 -> In the two behavioral intervention
groups they got serious.
137.298 -> 18 face-to-face sessions,
groups meetings, food diaries,
140.199 -> monitored physical activity,
calorie and sodium intake.
142.765 -> Now, one intervention group
just concentrated on exercise
145.802 -> and the other one included
exercise and diet.
148.586 -> They pushed the DASH diet,
high in fruits, and vegetables,
151.337 -> and low in full-fat
dairy products and meat.
153.773 -> And in six months achieved a 4.3 point
drop in systolic blood pressure,
160.458 -> compared to the control, slightly better than
the lifestyle intervention without the diet.
164.675 -> Now, a few points might
not sound like a lot—
168.177 -> that’s like someone going from a blood pressure
of 150 over 90 to a blood pressure of 146 over 90—
173.628 -> but on a population scale a 5 point
drop in the total number
179.603 -> could result in a 14% fewer stroke deaths,
9% fewer fatal heart attacks, and 7% fewer deaths every year overall.
187.809 -> But a cup of hibiscus tea with each meal didn’t
just lower blood pressure by 3, 4 or 5 points
193.828 -> but by 7 points, 129 down to 122.
199.826 -> And in fact tested head-to-head against a
leading blood-pressure drug, called Captopril,
204.639 -> two cups of strong
hibiscus tea every morning,
207.952 -> using a total of 5 tea bags
for those 2 cups,
210.254 -> was as effective in
lowering blood pressure
212.555 -> as a starting dose of 25 mg of
Captopril taken twice a day.
215.773 -> So as good as drugs,
without the drug side-effects,
220.085 -> and better than
diet and exercise?
222.933 -> Well, the lifestyle interventions
were pretty whimpy.
227.604 -> As public health experts noted,
the Premier study
231.306 -> was only asking for 30 minutes
of exercise a day,
235.124 -> whereas the World Health Organization
is more like an hour a day minimum.
238.809 -> And diet-wise, the lower
the animal fat intake,
244.443 -> and the more plant sources of protein
the Premier participants were eating,
248.913 -> the better the diet
appeared to work,
250.447 -> which may explain why vegetarian diets
appear to work even better,
255.014 -> and the more plant-based the lower
the prevalence of hypertension.
259.115 -> On the DASH diet, they were
told to cut down on meat,
263.57 -> but were still eating
meat every day,
265.419 -> so would qualify as the non-vegetarians
here in the Adventist 2 study,
268.823 -> which looked at
89,000 Californians
270.791 -> and found that those who instead only
ate meat on more like a weekly basis
274.592 -> had 23% lower rates
of high blood pressure.
276.942 -> Cut out all meat except fish
and the rate is 38% lower.
279.963 -> Cut out all meat period—the vegetarians
have less than half the rate
283.495 -> and the vegans—cutting out
all animal protein and fat—
286.646 -> appeared to have thrown three quarters of their
risk of this major killer out the window.
292.6 -> One sees the same kind of step-wise
drop in diabetes rates
296.9 -> as one’s diet gets more and more plant-based
and a drop in excess body weight
301.806 -> such that only those eating completely
plant-based diets fell into the ideal weight category.
306.739 -> But could that be why those eating
plant-based have such great blood pressure?
311.376 -> Maybe it’s just because they’re
so skinny on average.
314.177 -> I’ve shown previously how those
eating plant based diets
316.962 -> have just a fraction of the diabetes
risk even at the same weight,
320.346 -> even after controlling for BMI.
322.28 -> But what about hypertension?
324.265 -> The average American has
what’s called prehypertension,
329.243 -> which means the top number of your blood
pressure is between 120 and 139.
332.951 -> Not yet hypertension,
which starts at 140,
335.23 -> but it means we may
be well on our way.
337.838 -> Compare that to the blood pressure of those
eating whole food plant-based diets.
342.207 -> Not 3 points lower, 4 points lower, or even
7 points lower, but 28 points lower.
347.86 -> Now, but the group here eating the
standard American diet was, on average,
352.529 -> overweight with a BMI over 26,
still better than most Americans,
357.115 -> but while the vegans were a trim 21
over here—that's 36 pounds lighter.
365.516 -> So maybe the only reason those eating meat,
eggs, dairy, and processed junk
369.921 -> had such higher blood pressure
was because they were overweight,
373.054 -> maybe the diet per se
had nothing to do with it.
375.121 -> To solve that riddle we
would have to find a group
377.976 -> still eating the standard American diet
but as slim as a vegan.
380.693 -> To find a group that fit and trim, they
had to use long-distance endurance athletes,
385.863 -> who ate the same
crappy American diet —
388.161 -> but ran an average of 48 miles
a week for 21 years.
392.232 -> They ran almost two marathons
a week for 20 years.
395.733 -> So, if you do that, you know, anyone can be
slim as a vegan—no matter what they eat.
402.598 -> So where did they
fall on this graph?
405.871 -> Both the vegans and the conventional
diet group were sedentary—
408.64 -> less than an hour
of exercise a week.
410.556 -> The endurance runners were here.
413.642 -> So it appears if you run about
a thousand miles every year
418.394 -> you can start to rival
some couch potato vegans.
421.663 -> Doesn’t mean you can’t do both,
but it may be easier to just eat plants.
429.477 -> Over the counter antacids are
probably the most important source
432.06 -> for human aluminum exposure
in terms of dose.
434.6 -> Maalox, for example, taken as directed,
can exceed the daily safety limit
438.218 -> more than 100-fold,
439.834 -> and nowhere on the
label does it say not take
442.503 -> with acidic beverages
such as fruit juice.
444.622 -> Washing an antacid down with
orange juice, for example,
447.723 -> can increase aluminum
absorption 8-fold,
450.023 -> and citric acid
was worse—
451.792 -> the acid found naturally
concentrated in lemon and limes.
454.71 -> Just as sour fruits can enhance
the absorption of iron,
458.111 -> which is a good thing,
through the same mechanism
460.578 -> they may enhance the
absorption of aluminum,
462.963 -> raising the question what happens
when one adds lemon juice to tea?
466.399 -> Previously, I concluded that the
amount of aluminum in tea
469.449 -> is not a problem for most people
because it’s not very absorbable,
471.95 -> but what if you
add lemon?
473.784 -> No difference between
tea with lemon,
476.936 -> tea without lemon,
or no tea at all
478.939 -> in terms of the amount of
aluminum in the bloodstream,
481.338 -> suggesting that tea drinking does
not significantly contribute
484.312 -> to aluminum actually getting inside
the body-lemon juice or not.
487.444 -> Now, they’re talking about black tea,
green tea, white tea, oolong tea.
491.278 -> What about the red zinger
herbal tea, hibiscus?
494.013 -> The reason it’s called sour tea is because it
has natural acids in it like citric acid—
497.998 -> might that boost the absorption
of any of its aluminum?
501.081 -> Well, a greater percentage of aluminum gets
from the hibiscus into the tea water,
505.168 -> but there’s less
aluminum overall.
508.019 -> The question is does the aluminum then
get from the tea water into our body?
511.886 -> We don’t have that data so to be on the
safe side we should assume the worst -
516.09 -> that hibiscus tea aluminum, unlike
green and black tea aluminum,
519.656 -> is completely absorbable.
521.309 -> In that case, based on this data and the
World Health Organization weekly safety limit
524.895 -> we may not want to drink more than
like 15 cups of hibiscus tea a day
529.692 -> That’s based on someone
who’s about 150 pounds.
532.18 -> So if you have a 75 pound
10-year-old,
536.099 -> a half gallon of tea a day may
be theoretically too much.
540.549 -> And more extensive testing
more recently suggests
543.135 -> levels may be as high
as twice as much,
545.251 -> so no more than about two quarts
a day for adults,
549.522 -> or a quart a day for kids
every day or pregnant women.
553.56 -> And hibiscus tea should be completely
avoided by infants under 6 months—
558.028 -> who should only be getting
breast milk anyway—
561.76 -> as well as kids with kidney failure,
who can’t efficiently excrete it.
566.078 -> The study also raised concern
about the impressive
569.231 -> manganese level
in hibiscus tea.
571.766 -> Manganese is an essential
trace mineral,
573.991 -> a vital component of some of our
most important antioxidant enzymes,
576.908 -> but we probably only need
2 to 5 milligrams a day,
580.011 -> and 4 cups of hibiscus tea can have
as much as 17, averaging about 10.
584.785 -> Is that a problem?
586.154 -> Well, women given 15 a day
for 4 months, if anything,
590.371 -> only saw an improvement in their
anti-inflammatory, anti-oxidant enzyme activity.
595.675 -> This study using 20 a day similarly
showed no adverse short-term effects,
600.942 -> and importantly showed that the retention
of dietary manganese is regulated.
605.295 -> Our body’s not stupid;
if we take too much in,
607.896 -> our body decreases the absorption,
and increases the excretion.
611.698 -> So, even though tea drinkers may
drink 10 times more manganese,
616.201 -> you get 10 times more a day,
10 or 20 milligrams a day,
621.196 -> the levels in their blood
is essentially identical.
624.861 -> So, there is little evidence that
dietary manganese poses a risk.
629.554 -> That was regular tea, though, we don’t
know about the absorption from hibiscus,
633.888 -> so to err on the side of
caution we should probably
635.156 -> not routinely exceed the reference
dose of 10 mg per day,
638.193 -> so that’s only about a
quart a day for adults,
641.375 -> a half quart for
a 75 pound child.
643.476 -> So, that’s actually changed
my family's consumption.
646.925 -> Given the benefits of the stuff, I was using
it as a substitute for drinking water,
651.464 -> so like 2 liters a day, and I was
blending the hibiscus petals in,
655.9 -> not throwing them away, effectively
doubling aluminum content,
658.764 -> and increasing manganese
concentrations by about 30%.
661.752 -> So, given this data I’ve cut back to no more than
about a quart of filtered hibiscus tea a day.
Source: https://www.youtube.com/watch?v=s-Jcw4-xmTs