I used to think about seaweed as only a useful whole-food supply of minerals like iodine, for which it’s the most concentrated dietary supply. Certainly, only a day by day half-teaspoon of delicate seaweeds, like arame or dulse, or two sheets of nori ought to internet you all of the iodine you want for the day. However, 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 illnesses, together with most cancers, cardiovascular and cerebrovascular illness….” Based mostly on what?
As I talk about in my video Wakame Seaweed Salad Could Decrease Blood Strain, the reasoning is that the Japanese stay lengthy and eat seaweed, so there’s hypothesis that seaweed might need “affect on life expectancy,” based mostly on suggestive experiences. However once we see lengthy lists of the supposed advantages a selected meals is presupposed to have, comparable to “compounds present in [seaweed] have numerous organic actions together with anticoagulant, anti-viral, antioxidant, anti-allergic, anti-cancer, anti-inflammatory, anti-obesity, and neuroprotective properties,” we have to know if they’re based mostly on scientific information, which means research with precise individuals, or so-called preclinical information, that’s, from check tubes and lab animals. I imply, what are we speculated to do with a research speaking concerning the results of “seaweed-restructured pork diets” on rats? These researchers tried to make use of seaweed, in addition to different substances, to “improv[e] the ‘picture’ 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.”
While you take a look at epidemiological research, the place you examine 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 need useful results on blood strain amongst kids.” That might make sense given all of the minerals and fiber in seaweed, however trigger and impact can’t be confirmed with this type of research. Maybe different elements of the eating regimen that went together with seaweed consuming that made the distinction.
It’s even tougher to do these sorts of research on adults, since so many individuals are on hypertension medicines. College of Tokyo researchers took an revolutionary method by evaluating the diets of individuals on completely different intensities of remedy: low-dose of a single blood strain drug, high-dose of a single drug, and a number of medicine. And, though all of them had artificially normalized blood strain “on account of efficient remedy,” those that ate probably 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 attention-grabbing discovering, however why not simply put it to the check?
A double-blind, crossover trial discovered that seaweed fiber lowered blood strain, apparently by pulling sodium out of the system. Actual seaweed couldn’t be used within the research, as a result of the themes wouldn’t have the ability to be fooled with a placebo, however why not simply put entire powdered seaweed into capsules? That was lastly tried ten years later. In comparison with doing nothing, topics receiving a day by day dose of dried wakame powder in capsules had stunning drops in blood strain. 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 consuming seaweed salad is definitely going to assist with blood strain. What we want is a randomized, managed trial with plain, straight seaweed. Nobody 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 strain, particularly in those that began out with excessive strain. The topics skilled solely minor unintended effects and ones that could possibly be anticipated with growing fiber consumption. A pleasant factor about whole-food, plant-based interventions is that we generally get good unintended 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 would possibly assist with hypertension? See:
For extra on stopping and treating hypertension, considered one of our main killers, see:
Need extra on seaweed and iodine? Take a look at:
My video Salt of the Earth: Sodium and Plant-Based mostly Diets additional addresses the sodium query.
In well being,
Michael Greger, M.D.
PS: In case you haven’t but, you’ll be able to subscribe to my free movies right here and watch my stay, year-in-review displays: