I used to suppose of seaweed as only a useful whole-food supply of minerals like iodine, for which it’s the most concentrated dietary supply. Indeed, only a day by day half-teaspoon of delicate seaweeds, like arame or dulse, or two sheets of nori ought to web you all of the iodine you want for the day. But, the consumption of seaweeds is suggested not solely as a whole-food supply of iodine, but in addition, evidently, “for the prevention of lifestyle-related diseases, including cancer, cardiovascular and cerebrovascular disease….” Based on what?
As I focus on in my video Wakame Seaweed Salad May Lower Blood Pressure, the reasoning is that the Japanese stay lengthy and eat seaweed, so there may be hypothesis that seaweed may need “influence on life expectancy,” primarily based on suggestive stories. But once we see lengthy lists of the supposed advantages a selected food is presupposed to have, akin to “compounds found in [seaweed] have various biological activities including anticoagulant, anti-viral, antioxidant, anti-allergic, anti-cancer, anti-inflammatory, anti-obesity, and neuroprotective properties,” we have to know if they’re primarily based on medical knowledge, which means research with precise individuals, or so-called preclinical knowledge, that’s, from check tubes and lab animals. I imply, what are we imagined to do with a examine speaking in regards to the results of “seaweed-restructured pork diets” on rats? Those researchers tried to make use of seaweed, in addition to different substances, to “improv[e] the ‘image’ of meat product.” Researchers additionally tried so as to add grape seeds to meat, they tried flaxseeds, they tried walnuts, they tried purple rice, they usually even tried “thong-weed.”
When you take a look at epidemiological research, the place you evaluate the diets and illness charges inside a inhabitants, you see that Japanese pre-schoolers who eat seaweed are likely to have decrease blood pressures, suggesting “seaweed might have beneficial effects on blood pressure among children.” That may make sense given all of the minerals and fiber in seaweed, however trigger and impact can’t be confirmed with this sort of examine. Perhaps different parts of the weight loss program that went together with seaweed eating that made the distinction.
It’s even more durable to do these sorts of research on adults, since so many individuals are on hypertension medicines. University of Tokyo researchers took an modern strategy by evaluating the diets of individuals on totally different intensities of medicine: low-dose of a single blood stress drug, high-dose of a single drug, and a number of medicine. And, though all of them had artificially normalized blood stress “as a result of effective medication,” those that ate essentially the most fruits and sea greens tended to be those on the decrease dose of a single drug, supporting a dietary position for seaweed. An fascinating discovering, however why not simply put it to the check?
A double-blind, crossover trial discovered that seaweed fiber lowered blood stress, apparently by pulling sodium out of the system. Real seaweed couldn’t be used within the examine, as a result of the topics wouldn’t have the ability to be fooled with a placebo, however why not simply put complete powdered seaweed into capsules? That was lastly tried ten years later. Compared to doing nothing, topics receiving a day by day dose of dried wakame powder in capsules had stunning drops in blood stress. The researchers, nevertheless, desalinized the seaweed, taking out about two-thirds of the sodium naturally present in it. So, we nonetheless don’t know if eating seaweed salad is definitely going to assist with blood stress. What we’d like is a randomized, managed trial with plain, straight seaweed. No one had ever completed that analysis, till…they did!
Six grams of wakame, with all of its pure sodium, led to a big drop in blood stress, particularly in those that started out with excessive stress. The topics skilled solely minor unwanted side effects and ones that may very well be anticipated with rising fiber consumption. A pleasant factor about whole-food, plant-based interventions is that we typically get good unwanted side effects, such because the decision of gastritis (abdomen irritation) some topic had been having, in addition to the disappearance of persistent complications.
What different meals may assist with hypertension? See:
For extra on stopping and treating hypertension, one of our main killers, see:
Want extra on seaweed and iodine? Check out:
My video Salt of the Earth: Sodium and Plant-Based Diets additional addresses the sodium query.
Michael Greger, M.D.
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