Hibiscus Tea Increases HDL, Lowers LDL and Triglycerides

Hibiscus tea is often served cold with sugar 
Hibiscus tea is often served cold with sugar. (Photo by molossoidea)

When it comes to health benefits and drinks, green tea gets most of the publicity. And with good reason – from what we know, it seems to have the widest range of positive effects out of all beverages. But that's not to say that there aren't other less known drinks out there that have health benefits of their own.

One such beverage is hibiscus tea, a herbal infusion made from the calyces of the Hibiscus sabdariffa flower. Hibiscus is also known as sorrel, roselle, karkadé and flor de Jamaica, depending on the region. Earlier this year, I wrote about two studies showing that hibiscus tea reduces blood pressure. In the second study, hibiscus tea was compared with black tea, and guess what – hibiscus tea wone hands down.

In fact, the group that drank black tea saw an increase in blood pressure. That was black tea – as far as I know, there have been no direct comparisons between green tea and hibiscus tea, but even green tea's effects on blood pressure seem to be small or nonexistent. So green and black tea, while very healthy, may not be enough if you want to cover all bases.

I wrote in the earlier posts that to my knowledge, there had been no studies on hibiscus tea and cholesterol, even though the drink is traditionally used to lower cholesterol. Today, however, I found a paper that shows hibiscus tea is good for cholesterol too (link). Granted, the paper appeared in the Journal of alternative and complementary medicine, which has published some papers that seem to be of questionable quality, but this one seems pretty legit.

For the experiment, 60 patients with type II diabetes were randomly assigned into two groups. One group got black tea and the other got hibiscus tea (which the authors refer to as "sour tea"). The participants were told to drink one glass (1 tea bag in boiling water, steeped for 20-30 minutes) twice a day for a month.

The subjects that drank black tea did not show improvement in any of the parameters measured. None of the changes in total cholesterol, LDL, HDL, triglycerides and lipoprotein (a) were statistically signifcant.

Those who drank hibiscus tea, on the other hand, saw several improvements in their cholesterol levels. Total cholesterol went from 236.2 to 218.6 mg/dL. HDL increased from 48.2 to 56.1 mg/dL, while LDL decreased from 137.5 to 128 mg/dL. Triglycerides went down rather dramatically, from 246.1 to 209.2 mg/dL. Lipoprotein (a) was unchanged.

The authors also reference several other papers showing similar results in humans and animals. For example, one study showed a reduction in cholesterol levels in healthy men and women taking a hibiscus extract (link). This would suggest that the beneficial effects of hibiscus are not only limited to diabetic patients.

I'm not sure why I didn't find these papers the last time I did a pubmed search, but I'm glad I came across them now. I guess it's time to put hibiscus tea back on the menu, next to green tea and rooibos tea.

My favourite way to drink it is to make a big glass of hibiscus tea the normal way, then after 15 minutes of steeping pour the tea through a sieve into a larger container, add twice as much cold water and put it in the fridge. It's ready to drink in about an hour. It's especially good in the summer, best enjoyed with ice and a little sugar for taste.

For more information on tea, cholesterol and health, see these posts:

The Many Health Benefits of Rooibos Tea
Black Tea Is More Effective in Activating Superoxide Dismutase (SOD) than Green Tea
Refined vs Red Palm Oil and Cholesterol
Anthocyanins from Berries Increase HDL and Lower LDL

World's Oldest Woman and Oldest Man: 1986–2010

World's Oldest Woman and Oldest Man: 1986–2010
I came across this graph while browsing through the latest issue of Rejuvenation Research. The black line shows the age of the oldest living woman; the grey line shows the age of the oldest living man. The data spans from 1986 to 2010.

A couple of things pop out from this graph. First, during the last 24 years, the oldest person in the world has always been a woman. Not a big surprise there, since women live longer in general. Quite a few men have gotten past 112 years, but reaching 116 seems impossible. For female supercentenarians, reaching 114 is relatively common, and a few have even reached 116.

The second thing that catches the eye is the highest point on the graph: that's Jeanne Calment, who died in 1997 at the age of 122, making her the longest-living person ever in the world. No one else has reached even 121. Shigechiyo Izumi is missing from the graph – he was claimed to have died at the age of 120, but according to the authors, he was in fact 15 years younger.

Looks like there's a slight trend towards longer-living supercentenarians, but I'm not sure it's significant. Certainly we haven't seen anyone like Jeanne Calment in over a decade. What this graph doesn't tell us, of course, is whether the percentage of people who reach 110 years of age has changed significantly during the same time period.

For more information on aging and longevity, see these posts:

Jumping Head First into the Fountain of Youth
Aubrey de Grey Interview in Wired.com
Russian Scientist Claims to Have Found Cure for Aging
The 7 Types of Aging Damage That End up Killing You

Carpe Treeum

I used to take a lot of pictures, especially of landscapes and particularly of trees. Ever since I came to USC as a professor I haven’t done much (or hardly any) photography. One of my favorite places on campus is the historic Horseshoe, which is right across the street from my office.

I keep saying that I’ll go take some photos of the tree-filled Horseshoe one day. That I’ll bring in my SLR and tripod and filters and make some nice images. And I never have. So, today while walking across the Horseshoe I just couldn’t resist snapping a few shots. I just had my iPhone with me so I didn't have much control -- no shutter speed or aperture control, no zoom, no filters. Nada. Just my legs to move me a bit closer or further away. Oh, and no high resolution results from my Nikon D70; just the single megapixel or so that the iPhone will yield.

But I decided to snap away anyway. The result was certainly not set of fantastic images that I can frame and hang in my office (which is one thing I want to do once I take what I hope to be some fantastic images). They're not postcard quality. They're just quick snapshots.

But, they're something and I loaded them up on my photo page so I can remind myself that I need to get back out there and do it again with the right tools. But, it's a start. It felt great to take some pictures again, even if it was with an extremely limited toolset and with just a few minutes of time as I traversed campus.

I tell my dissertation students all the time: If you don't feel like writing, write. Well, today I wrote. Just a bit. But, it's something.