Mary Vance: What health problems do you see in your practice that can be traced back to over-consumption of soy?
Kaayla Daniel: I work mostly with mid-life women, and that is a population likely to eat a lot of soy and drink a lot of soymilk. They’re even taking soy isoflavone supplements because they’ve heard that it’s going to help them through menopause. A lot of these women are very intelligent and educated, and unfortunately they get this idea that if a little of something might be good, then they should do a lot of it. They start doing a whole lot of soy, and they start gaining weight, feeling fatigued, they get lethargic and depressed, and when they go to a regular doctor, they’re told, “Well, what do you expect, you’re getting old,” and that this is typical of menopause. In fact, the symptoms are almost entirely coming from that change in their diet, which had to do with soy.
How much soy does the average person consume in a day?
Someone on a junk food diet is getting soy flour in their fast-food burger bun, soy protein in the burger itself, and soy oil in the fries; soy is in every one of these products because it’s cheap and abundant. You’ll find soy hidden in so many foods, and these small quantities add up.
People often start by drinking a lot of soymilk. If they are doing supplements, they can be getting really high doses and that’s where it starts to get very scary. Even scientists working for the soy industry will say they support soy food but do not support use of soy supplements, so I think that’s something just about everyone has agreed upon. It is so dangerous at such a high level, and it’s harming many people.
Women say [drinking soymilk] makes them feel good. Most soymilks have a lot of sugar, so they might be getting a sugar hit. The other thing that may happen is with the thyroid. Short-term, soy may stimulate the thyroid so they’ll feel better, but the thyroid gets stressed out from extra stimulation and goes long-term into hypothyroidism.
How does marketing affect soy consumption?
It’s very much about marketing. If we look back, the soybean was used in this country for soy oil. They take apart the bean and take out the oil and turn it in into margarines and shortenings and all those liquid vegetable oils. Once the oil is out, what they had left over was a whole lot of protein.
The USDA has spent so much money and many decades researching how to use soy in animal feed so that the animals will stay healthy. Some of the problems they were running into were that the animals were having birth defects; they were having fertility problems; they were dying prematurely on soy feed. The USDA was looking into what vitamins, minerals, or amino acids they needed to add and what is the maximum amount of soy they can use in animal feed before the animals have too many problems. They don’t care that the animals would have thyroid problems and get fat because that’s their objective anyway. Soy is not a natural food for an animal. Only so much soy can be used in animal feeds before there’s big problems. For instance, with poultry feed, it’s 25 percent.
How should people interpret the conflicting information on studies about soy and cancer?
The soy industry has really been running with the recent study where they asked people what they’d been eating during childhood and teenage years; women with the highest soy intake were the ones with the lowest rates of breast cancer. There are a lot of problems with that kind of study. First, if I started to interview you right about what you ate last Tuesday, could you tell me and tell me how much? When people are talking to an interviewer, they like to say what the interviewer wants to hear; there’s a potential for bias. In the latest study, it was only like two servings per week and in all probability it was not things like soy energy bars or shake powders. It was miso soup or tofu. Maybe they were a traditional family eating a lot of foods from scratch. There are other foods and other factors you could get these benefits from.
Is increased soy consumption a reason that girls are hitting puberty as early as eight or nine?
There’s a good reason to think that soy formula is part of that problem, but we also have environmental estrogens and pesticides and plastics and supermarket meats, xenoestrogens. Soy may be the one thing we can completely avoid.
What provoked the Israeli Health Ministry warning on soy foods?
The Israeli Health Ministry issued an advisory that babies should not get soy formula, and that children to age 18 should eat soy no more than once per day, three times per week maximum. Adults should exercise caution due to the adverse effects on fertility and increased breast cancer risk. It’s a pretty strong statement and a good start.
Were they seeing problems or was it a precautionary measure?
Both. It started a few years ago when several babies were hospitalized with severe beriberi and brain damage because of a soy infant formula that was deficient in vitamin B1. The manufacturer had gotten the idea that why should they add extra B vitamins if soy is such a perfect food, already high in B vitamins? They didn’t understand that babies need added B1 and that processing affects vitamins. National alerts were issued, the product recalled, and all the babies on soy formula immediately got injections of B1.
That incident caused the Israeli Health Ministry to start looking into soy formula. They formed a large committee including toxicologists, oncologists, pediatricians, and other experts, reviewed the literature, and decided that there are some risks. The Israeli soy industry has protested mightily and threatened to sue the government, but the health ministry maintained its position.
Daycare centers have been told to cut back on soy foods. They were [serving soy products] every day and now they’re doing it three times a week. I would say that’s still a little too much for children, but it’s a big start.
How much soy should people consume, if at all?
I’ll use the numbers the Israelis used. But of course some people are allergic to soy; some are sensitive to soy; some have thyroid problems already. Those people probably should avoid it. Then there’s the issue of what types of soy are we talking about. I still enjoy miso soup.
Which soy product is the worst?
The biggest problem is soymilk. Those with lactose intolerance are thinking that soymilk is a great alternative, and they’re drinking a lot and getting a huge dose of isoflavones. If you’re drinking soymilk, you’re going to have a problem, or most people will sooner or later. We’re all different—some people will start having problems in a day, and some people will think they’re fine and a year later things will start to go downhill.
Drinking just one glass a day of soymilk will give someone the level of plant estrogens that has hurt the thyroids of healthy Japanese men and women. Most people are doing several glasses, plus the soy protein energy bars and the bags of edamame.
If people are worried about calcium, they could try coconut milk, which has the calcium, magnesium, and potassium they’ll get from cow’s milk and is a wonderful tonic. I don’t recommend rice milk due to the sugar content. It’s still a heavily processed food. Many lactose-intolerant people find they can tolerate raw milk that hasn’t been pasteurized, which kills the enzymes needed for digestion.
Before they started using soy protein isolate they used soy flour, and that gave babies very bad gas. Once they started using soy protein isolate they were having fewer problems in terms of gas and overall digestability. Babies in the short term seemed to be doing better. The problems with hydrolyzed plant protein include that the processing creates MSG and other excitotoxins, and we get that with soy protein isolate as well.
Also, the protein is unstable when soybeans are cooked a long time. It’s a very tricky thing to not cook them too long or to cook them long enough—it varies from bean to bean. Some of the USDA studies were going on for years: how to do that processing to make it work. Then they finally gave up. What’s happened is some of the things they tried to get rid of they’re now marketing as things that can prevent cancer or prevent problems. They take something that’s bad and turn it into something that’s good. Every time they remove a component of soy, they have another thing they can sell.
In Kenya, the soy industry is talking to bakers, teaching them to use soy flour in baked goods, and down in Johannesburg they’re working on using soy protein shake powders to help AIDS patients. When the tsunami hit, the soy industry was right there giving people assistance and free soy products. Rather than help the people pick up the pieces and get their small farms back together, they’re replacing the local foods with something that’s global.
WhiteWave Foods, which makes Silk Soymilk, started out as a small company in Boulder, but it is now owned by Dean Foods. You see it in supermarkets everywhere. And Dean Foods—you don’t have to look very far to see what kind of products they’re selling. Kellogg and Dean and Con-Agra—all these big companies own what used to be small-time companies. New standards for organics means quality assurance goes down. We need to be looking at buying locally. Transportation alone has a very serious toll on the environment.
Do you think we should have a warning label here in the US?
That’s the next step to take. I will be involved with three petitions to the FDA. The first will be to remove the current health claim that soy prevents heart disease. It’s been on foods since November 1999, and in fact, soy food sales went from less than a billion to $4 billion between 1999 and 2004. They had planned to get a “soy prevents cancer” claim but we put a stop to that. Last year, the American Heart Association retracted its position on soy. They’re now saying soy does not prevent heart disease or lower cholesterol. Secondly we’re going to petition the FDA to remove the GRAS status for soy protein isolate. The third will have to do with putting warning labels on soy foods.
Do you think that labeling will be a reality in the US?
We’re hopeful our petitions work but the other part is that we’re bringing attention to the issues. What amazes me is that so many vegetarians and vegans will say that the FDA would never have approved a “soy prevents heart disease” claim unless there was good strong evidence. Hello! This is the same FDA that gave us Vioxx and aspartame!
I’m sure in Berkeley in the ’60s there were little companies that made tofu and soymilk, and people still believe soy is that kind of food. What they’re not getting is that we have Big Pharma and now we have Big Soy. It is a global industry. The industry is whining because growth has slowed. They’re hoping for the next big product. They had high hopes that soy protein sales would go from four to eight billion by 2007 with the “soy prevents cancer” health claim, but we killed that for them.