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Seaweeds as Food and Medicine: An Interview with Ryan Drum, PhD

Ryan Drum, PhD, holds a BSc in chemical technology and a PhD in botany (phycology) from Iowa State University. While a NATO scholar, he did postdoctoral studies on cell biology using the electron microscope and microcine at the University of Bonn and the University of Leeds. For 10 years, he taught botany and related subjects at several universities (UMass Amherst, UCLA, and WWU). He is the author of over 30 scientific papers in peer-reviewed journals, as well as the book Electron Microscopy of Diatom Cells (Springer Verlag, 1966).
Dr. Drum studied herbal medicine with Ella Birzneck, president of Dominion Herbal College, for 12 years, and taught at the school’s summer seminars for 35 years. He has been an adjunct faculty member at Bastyr University since 1984, and he lectures at major herbal conferences and herbal schools. For over 40 years, he has lived off the grid in a hilltop cabin he built on a remote island in the Pacific Northwest, where he practiced for many years as a medical herbalist. He continues to work as a medicinal herb wildcrafter and herbal educator, specializing in seaweed therapies and thyroid issues.
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PPNF: Would you begin by telling our readers a little about your lifestyle?
Ryan Drum: I live on the very top of a small island in the San Juans, in the state of Washington. In 1976, after being a professor for 10 years, I went off with the woman who was then my significant other to live in a rustic cabin that we built on this hilltop and to attempt to reinvent civilization one person at a time – creating our own language, medicine, music, religion, and ways of living together. That meant learning an awful lot in a few months and years.
Sarah and I had our children at home and grew our own food, raising goats for their milk. One of the things that we eliminated from our diet was processed salt, which is a major cause of ill health and death, as excessive consumption of it may lead to high blood pressure. Soon, we learned that most of the food traditionally eaten by the indigenous people of this area came from the sea or the edge of the sea. According to the written record, they ate a lot of the easy-to-get seaweeds, particularly sea lettuce. It’s the easiest of all the seaweeds to eat, without any preparation. When it dries, it’s a beautiful bright green color and tastes a bit like the sea, although it has a shelf life of only about three weeks, at the most.
As a botany and phycology professor – that, basically, is a marine botanist – I had a little knowledge about seaweed’s nutritional value, including its high mineral content. So, I said, as long as there’s seaweed and enough fresh water, we shan’t starve.
PPNF: What, in general, are the nutritive benefits of seaweeds?
RD: Seaweeds contain all the essential minerals needed by human beings. Minerals make up 20 to 50 percent of their dry weight, but the single most important element they provide is iodine, which is needed for proper functioning of our thyroid glands and maintenance of our salivary glands, our small intestines, and, in women, the mammary gland ducts. Eating just three to five grams of most dried, unrinsed seaweeds will provide the Recommended Daily Allowance of 150 micrograms of iodine. Seaweeds contain more iodine than any land plant or any animal, and do not seem to accumulate fat-soluble pesticides, as do marine animals.
Adequate mineral supplies in the body are critical for optimal system functioning, and deficiencies can produce both specific and general disease conditions. For example, iodine shortage results in thyroid dysfunction, and poor absorption of dietary calcium can lead to osteoporosis. My personal observations support the notion that nonspecific disease categories such as chronic fatigue, subclinical depression, and depressed immunity are probably due to an inadequate supply of minerals in the diet. Many times, I have seen chronically exhausted patients exhibit complete symptom resolution after several weeks of adding five to ten grams of seaweeds to their daily diets.
Most seaweeds are also rich in vitamins, especially the B vitamins, and contain significant amounts of omega-3 fatty acids. The red seaweed nori is high in vitamins A and C. In addition, all seaweeds contain a large proportion (25 to 40 percent, dry weight) of mucopolysaccharides known as phycopolymers, and many of these are of therapeutic value. Brown seaweeds, for example, contain algin, which is a heavy metal detoxifying agent; and fucoidan, which has antiviral properties and seems to reduce the intensity of the inflammatory response.
In short, seaweeds offer a wide range of therapeutic possibilities. Simply eating them in their unprocessed, dried form can yield many healing benefits. Yet, I believe the most important reason to eat seaweeds is to maintain complete, whole-body mineralization.
PPNF: How did you first start harvesting seaweed?
RD: When I first arrived on the island, I was told by someone who had lived here for 20 or 30 years – and there were only about a dozen such people – that they would gather the bullwhip kelp, Nereocystis luetkeana. They would dry it outdoors in the sunshine or indoors over the woodstove or in little greenhouses. Then, they would just crumble it up, put it in a flour mill, and grind it into a powder. It would keep for a long time in airtight containers.
So, we went out in a little boat and collected a couple of five-gallon buckets of bullwhip kelp, dried it, and powdered it. (You don’t want to gather it when it washes up on the beach because if it rolls in the sand, it gets gritty.) It tasted really good and eliminated our craving for salt. So, we started to put powdered kelp on our eggs. In fact, our kids grew up eating green popcorn, and green eggs and ham. It wasn’t Dr. Seuss – it was just kelp on everything. They had green cookies, green pancakes, and green oatmeal. We didn’t much care for eating big pieces of kelp because it was so salty, mainly due to the high potassium content. However, our neighbors were very explicit that we not rinse it. If you rinse kelp with fresh water, it starts to almost disintegrate and it tastes terrible. We just hung it up to dry, and the seawater – along with much of the salt – dripped right off it.
For those who are unfamiliar with it, bullwhip kelp is a large brown seaweed that grows in the northeastern waters of the Pacific. It has a long stem, or stipe, that can grow up from a depth of 90 feet, and a large, hollow bulb that floats on the surface of the water. Leaves, or lamina, grow out of the bulb, and they are the part that is harvested. Interestingly, the bulb is filled with gas for flotation, and this gas contains quite a bit of carbon monoxide. If you take a bite of it, you will generally inhale a little bit of gas and, if the bulb hasn’t been broken, it will kind of take your breath away. It’s been suggested that this is a defense mechanism of the seaweed to discourage casual browsers.
The big kelps are the most delicious seaweeds for my palate, and I eat powdered kelp every day. If I’m having potatoes, rice, or quinoa, I’ll put a teaspoon of powdered kelp in or on them. I particularly like garlic-flavored olive oil poured onto a thick slice of whole grain, organic bread with enough powdered kelp on top so that it’s almost a green paste. You can also add powdered kelp to soups and stews. I have found that people generally have a hard time eating big pieces of seaweed – except for toasted nori, which has very little salt – and powdering the kelp makes it more accessible.
Kombu (Laminaria groendlandica) is another large brown kelp that I enjoy. It’s a much more substantial form of kelp and just about requires cooking. If you soak dried kombu in water long enough, you can eat it raw, but it may be pretty tough and it tends to be slimy. And unless it’s totally dry, it doesn’t grind very well. So, it’s usually easier to eat when cooked with grains, legumes, or soup. Wakame, which is also a large brown kelp, is often cooked the same way.
Sometimes, people put in a strip of dried kombu when making miso broth and then remove it after a certain amount of time. Although some of them eat that piece of kombu separately, others discard it because they’ve learned that excessive consumption of kombu can suppress thyroid function and lead to goiter.
PPNF: Is that due to the high iodine content of kombu?
RD: Exactly. Although bullwhip kelp has perhaps four or five hundred parts per million of iodine, the large kombus can have up to 8,000 parts per million. That’s 0.8 percent dry weight iodine. But it’s more complex than that, in that several of the large brown seaweeds, such as kombu, Saccharina, and Fucus, also contain significant amounts of thyroid hormones. In the 1920s, the hormones monoiodothyronine (T1) and diiodothyronine (T2) were detected in Fucus, and, more recently, triiodothyronine (T3) and thyroxine (T4) were found in kombu and some other kelps. But long before this, it was observed that people with hypothyroidism could be cured by including seaweeds in their diet.
In fact, the Chinese have known for millennia that seaweed could be used medicinally to treat hypothyroidism, and this information was recorded in the Yellow Emperor’s treatise on internal medicine. In the early twentieth century, however, a curious phenomenon called cretinism had become very prevalent in China. It was estimated that there were up to 200 million iodine-deficient people with compromised physical development and diminished or disrupted brain function, which affected both motor skills and cognition.
A Japanese botanist was hired to find some way to get kombu to grow in the South China Sea, to provide both thyroid hormone and iodine. It took him several years, as the seawater was too warm for wild laminaria to survive in, but he eventually developed strains of Laminaria japonica that would grow in warm water. Now, around a million tons of this brown seaweed are grown in the South China Sea on big ropes, and entire villages are devoted to raising it. As a result, China is able to meet the iodine requirements of about 20 percent of Earth’s human population from farmed kelp.
I should mention that some individuals are extremely sensitive to iodine. If they have a bit too much in their diets, they begin to exhibit hyperthyroid signs and symptoms, such as heart palpitations, sleeplessness, irritability, and even iodine-induced goiter. These rare individuals should avoid consumption of kombu and the other large northern kelps, such as Norwegian kelp (also known as Icelandic kelp), which can contain up to 8,000 parts per million of iodine. Contrary to the belief of some health practitioners, however, nobody has an iodine allergy. Iodine is necessary for life.
People need to be aware that iodine is added to a lot of foods without being mentioned on the nutrition labels. For example, elemental iodine is added to many wheat and other gluten-containing flour products to increase the strength and size of the bubbles in the dough. There is also iodine in milk. I was fortunate to live and practice for over three years in Southern Vermont, and I wanted to check out the dairy industry to find out why that is so. I spent quite a few hours in milking parlors and learned that the cows’ teats were all painted with a 15 percent iodine solution to prevent them from developing mastitis from the use of the stainless steel milkers. Thus, quite a bit of iodine was being dripped into the milk. Unless we live within 70 miles of the ocean, iodine is generally not very abundant in our soil or water, so we tend to have an urge to eat things containing it. Its use in the commercial production of baked goods and dairy products may pose a risk for those who are iodine sensitive.
PPNF: In addition to the possibility of elevated iodine levels from consuming too much seaweed, are there any other cautions that people should be aware of?
RD: Seaweed can become contaminated by sewage or industrial, mining, or agricultural wastes present in the water in which it grows. For this reason, farmed seaweed in relatively clean waters is often the best bet for ensuring safety. Red seaweeds are being grown in the largest aquaculture projects in the world now, and most of those are in the southwest Pacific. Within the last 20 years, some have also been started in the Caribbean. But it’s becoming more and more difficult to find clean seawater in which to farm seaweed.
I should also mention that all seaweeds contain arsenic. However, all seafood also has arsenic in it, and often at much higher levels than is found in seaweeds. Although there was an arsenic scare during the 1980s, there’s probably a greater hazard from eating too many farmed shrimp than from eating farmed seaweed.
PPNF: We understand that the Salish Sea, where you harvest seaweed, is also relatively clean. In addition to the seaweeds that you discussed earlier, do you also gather nori there?
RD: Yes. In the Pacific Northwest, it’s possible to go out to the beach and just pick up a piece of nori at low tide, when it’s exposed. Make sure it’s not covered with sand or, better yet, gather it while you’re knee deep in seawater and the nori is just underwater waving back and forth. If you’re collecting it for later use, you will need to rinse it in fresh water to get rid of all the salt. Nori is only one cell layer thick, and if it has any salt on it, that salt will suck water out of the air and then bacteria will start to devour it.
Although many seaweeds tend to be somewhat slimy, nori is very easy to eat when it’s been toasted a little bit in a dry skillet. It tends to have a sweet, meaty flavor that is pleasant to most palates. I also like the mouth feel of it – it almost explodes into little pieces when I chew it. Nori is also delicious when cooked in soups, re-wetted in salads, deep fat fried and mixed with cooked rolled oats, or used as a food wrap in making sushi. Commercially sold nori sheets, however, are a highly processed industrial product. The nori is toasted, ground up, rinsed three or four times, and then dried on plastic racks on long conveyer belts up to a mile long.
Nori is a red seaweed, and it is the seaweed most widely consumed by human beings. Although it can be gathered wild in areas such as the Salish Sea, 99 percent of the nori in the marketplace is farmed. It’s been farmed for thousands of years in shallow bays in the Japanese Islands.
PPNF: Since the nuclear power plant accident at Fukushima in 2011, we have heard a lot of consumer concerns about potential radiation exposure from seaweeds grown in and around Japan. Should people be worried about this?
RD: When the nuclear reactors exploded at Fukushima, they spewed out huge masses of radioactive isotope-containing clouds, which reached elevations of up to 40,000 feet. Those clouds were picked up by the jet streams and carried, dropping radioactive particles all the way, across the north Pacific to the North American west coast, where the jet streams hit the coast range and were stalled. For three or four days, the entire coast west of the mountains, and the mountains themselves, were dusted with the heaviest load of radioactive isotopes, especially iodine-131, strontium, and cesium, from the Fukushima explosion. That stuff is still in the soil that our crops are grown in, and it washes out to sea where seaweeds have the opportunity to pick it up. The iodine 131 – which is, in my way of thinking, the most hazardous of the radioactive isotopes – has only an eight-day half-life. That means in eight weeks, no biogenic or biological activity remains. However, that’s relying on no more radioactive material being released – and, apparently, there are still small, regular releases going on at the site.
PPNF: Can seaweeds – particularly, kelp tablets – help protect us from the effects of nuclear disasters?
RD: The greatest short-term hazard from nuclear disasters is the risk of poisoning with iodine-131, which will pass right through our skin if we are iodine deficient. However, if we have enough iodine-127, which is the only natural or wild isotope of iodine, we will not take up iodine-131. Kelp tablets work quickly to get iodine-127 into the body. If we take in 150 micrograms of iodine-127 daily, we will most likely be protected from the aggressive uptake of iodine-131. We can do this by eating five to ten grams of seaweed daily. Powdered kelp – or its phycocolloid algin – has even been effectively used to move radioactive and heavy metals out of the body.
However, for immediate protection in the event of a disaster, tincture of potassium iodide is your best bet. Always put potassium iodide on the skin, which will absorb it if your levels are low. Don’t take it internally, as potassium, in excess, is one of the most poisonous metals. The tincture is preferable to potassium iodide tablets, as it works faster, and it’s easy to take too many tablets. Eat iodine-containing foods on a regular basis, so that you don’t find yourself in an emergency situation, acting out of fear. We always tend to overtreat ourselves when we are afraid.
PPNF: Let’s talk about one of the most commonly used seaweed extracts, carrageenan. Would you discuss the issues associated with its use in processed foods?
RD: Carrageenan is a phycopolymer extracted from red seaweeds. When we consume it as part of the whole plant, carrageenan bulks our stool and passes right out of the body. Red seaweeds high in carrageenan can soothe the gastrointestinal tract and help relieve chronic constipation, although they can irritate the bowel lining in patients with irritable bowel syndrome, Crohn’s disease, or ulcerative colitis.
Eventually, people found out that if you add finely powdered carrageenan to ground meat, it will be undetectable and will hold a lot of water, allowing the meat to be sold at a higher price. The chicken served on airplanes these days is nice and moist because carrageenan gel has been injected into it. Both chicken and turkey in the grocery store have often been plumped with carrageenan. However, where it really changed the food industry was in the production of frozen treats. For example, many brands of ice cream contain carrageenan as a thickener and stabilizer. It’s used in other dairy products and non-dairy milks, as well.
The problem is that, as you micronize carrageenan, making it into smaller and smaller particles, these particles will not form a solid per se. When they enter the food stream, they seem to have a tendency to settle out in the microvilli crypts of the small intestine, which play a role in digestion. These canyons between the microvilli can get plugged with masses of red seaweed gel and can become so impacted that little or no digestion takes place there. So, I see the addition of carrageenan to food as both dishonest – we’re paying for extra water weight – and a health hazard.
PPNF: Yet we understand that seaweed gel can also be used in the treatment of chronic disease. What are some of the mechanisms of this?
RD: Red seaweed gel – usually carrageenan or agar – is made by cooking dried seaweed bodies until you have an extract that resembles thin Jello. Those gel particles that don’t clog up your microvilli crypts can make their way to your sinuses and lungs. When you lie down to sleep, you may collect a lot of mucus in your lungs – particularly, if you have chronic obstructive pulmonary disease – and you will need to cough it up and spit it out in the morning. This gel improves the quality of the respiratory mucus, making it easier to expel, and helps to clear waste and toxins out of the respiratory apparatus.
In addition, seaweed gels, when they reach the intestines, will chelate toxins, including heavy metals, and assist in their elimination. Seaweeds – and, especially, brown seaweed gels, such as algin and sometimes fucoidan – can capture large metallic ions in our waste streams and carry them out of the body. Otherwise, these toxic metals will remain in the system and can contribute to the development of stomach or colon cancer – particularly, as I see it, when their presence is accompanied by stool retention for more than 18 hours.
Oats and figs, which contain a lot of indigestible fiber, can facilitate the process of elimination. So, the perfect combination would be seaweeds, figs, and oatmeal, with a little bit of cinnamon for palatability. Eat this every day to avoid stool retention and help move metallic ions and other toxins, including complex organic molecules, out of your body. When it was discovered that polychlorinated biphenyls (PCBs) and dioxins would bind to red and, sometimes, brown seaweed gel and pass out of the body in the stool, that was great news, especially for our veterans who were sprayed with toxic chemicals. They should start increasing the amount of seaweed gel in their diet. Keep in mind, though, that if a person takes too much seaweed gel, it will have a tendency to loosen the stool. In fact, some people get diarrhea just from eating a very small amount of seaweed.
PPNF: Another issue we hear about is the danger of overharvesting seaweeds. Are they currently being threatened?
RD: Yes. The overharvesting we are referring to here is done by machine. As an example, let’s talk about kelp, which grows in cold seawater. It’s a lot of work gathering it by hand, so little vacuum harvesters were developed to clean all the kelp off the beach – and they were too efficient. Beaches were being stripped bare, especially on the seacoasts of Nova Scotia, Newfoundland, and Labrador. Harvesting was banned for five years in the Gulf of Maine because the rocks were stripped of seaweed – including the breeding population, so there were no spores. If you don’t have any parents, there will be no children.
The large kelps that are mostly submerged – such as the big curtain kelp, the macrocystis – are fairly well protected against overharvesting. Although bullwhip kelp has its reproductive bodies in its surface lamina, which can be overharvested, it can recolonize easily if conditions are right, because its spores travel.
PPNF: Would you provide some guidance for people who want to sustainably gather seaweed for their own use?
RD: In most places now, you need a permit to harvest seaweed for personal use. In the state of Washington, that costs $7.50 to $17.40 for state residents, and more for nonresidents. You’re allowed to harvest up to ten wet pounds of seaweed a day, which dries down to about one pound. If you were to harvest every day, you would get 365 pounds annually. But harvest only as much as you can actually process, and keep in mind that some seaweeds don’t keep for more than a year, at the most. Greed is not good when you’re working with seaweed, although it’s easy to be greedy because the seaweed is so beautiful.
When you are gathering seaweed, shake it up and down in seawater to remove any big animals, and then bring it back in uncovered containers. Seaweeds need to breathe, and if you put them in closed containers, they will die right away and start to putrefy. Then, separate out the different varieties. I try to keep each species in its own container. If I have something like bladderwrack or Sargassum, both of which are brown seaweeds, I’ll rinse it with vigorous up-and-down movements in fresh water to get all the salt and snails off, and then let it drain. If it is a species that should not be rinsed in fresh water, such as kelp, I’ll just start hanging it up outside on stainless steel trawling wire.
I try to dry as much of my seaweed outside as I can, preferably in full sunlight for four to ten hours. If this is not possible, I hang it indoors on nongalvanized nails set into the exposed rafters of my house – I have somewhere between 1,000 and 1,500 nails there – and dry it at 80-100 degrees F using wood heat. In the past, when we were harvesting commercially and had a lot of seaweed production, we used three or four 12-volt muffin fans for air circulation. The seaweed hanging inside would form its own little moisture cloud, so at the highest part of the house, which has a peaked roof, we had little openings where the cold, wet air would be vented. Today, we sometimes have two or three kinds of seaweed, as well as half a dozen different herbs, drying. As soon as the seaweed is completely dry, I place it in airtight, opaque containers – I use square, four-gallon food-grade buckets – for storage.
I also keep fresh green seaweed, of which there are about a dozen different species, packed in salt and brine, for seaweed salad. To make it, you just rinse off the salt in fresh water, so the seaweeds are semi-sweet, and serve it up. It’s tender and delicious – just wonderful. You can use green seaweeds such as sea lettuce and codium, and red seaweed as well. You can also just add seaweed to any salad. The large kombus will be tough unless you steam them just a little, and bladderwrack is pretty tough as well. Sargassum and hijiki are more tender and delicate.
There is a seaweed that doesn’t grow around here, to my knowledge, called seaweed spaghetti. It’s very common in Ireland and England. When it dries, it resembles spoiled noodles, but if you steam or boil it for 10 to 15 minutes, it swells up and looks just like spaghetti. It has the same texture as spaghetti and even tastes somewhat like it.
PPNF: What advice would you give to beginners who have never tried seaweed before?
RD: Kombu and wakame are among the easiest to digest, so they could start with just eating little pieces of those raw. But some people do not like the slippery consistency of seaweed micropolymers, so they might want to prepare their seaweed in such a way that they don’t have to confront it frontally. When people are adverse to the tastes, smells, or textures of seaweed, I urge them to add it as small pieces or a powder to foods strongly flavored with vinegar or spices, such as cayenne, fried onions, raw garlic, chili powder, or curry.
When a person first eats seaweed, most of it will pass through their digestive system unchanged because their bacteria don’t recognize it as food and don’t make the enzymes needed to digest it. The key to bacterial dietary adaptation is continual exposure to the new food material. Although most of us can adapt in four to six weeks, the digestive flora may take up to four months to produce the dedicated enzymes needed to thoroughly digest seaweeds. So, I suggest eating a little bit of seaweed every day – four or five grams, which is between an eighth and a quarter of an ounce – to train the digestive flora. That comes out to three to four pounds per year. I generally recommend eating both brown and red seaweeds daily, in a 2:1 ratio. I eat about ten to twelve pounds of seaweed per year, including three to five pounds of powdered kelp and about a pound of toasted nori.
People should also be aware that it’s important to store their seaweeds in airtight, waterproof containers. Seaweeds are hygroscopic and if not stored correctly, will draw water out of the air, leading to a distinct deterioration in their odor and taste. However, many seaweeds, when carefully stored and kept out of direct sunlight, have a very long shelf life.
PPNF: How can consumers find high-quality seaweed products to purchase?
RD: I list a number of recommended seaweed suppliers on my website, ryandrum.com. They can be found at the end of two of my seaweed papers, titled “Medicinal Uses of Seaweeds” and “Sea Vegetables for Food and Medicine.” People can also buy seaweed directly from BC Kelp, a small family business in British Columbia, using the order form on my website.
About Ryan Drum, PhD
For more information about Ryan Drum, PhD, see his website, ryandrum.com. He may be contacted via email at: ryandrum2020@gmail.com.
Published in the Price-Pottenger Journal of Health & Healing
Fall 2017 | Volume 41, Number 3
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