Food for Thought
Energy - January/February 2004
by Brett Hall, R.D.

Q: I have hypothyroidism and my doctor just told me I should avoid soy products, including soy protein powders and energy bars with soy. He said they’re hard on the thyroid and could make my condition worse. Is this true? If so, do you know of any good energy bars without soy?

A: Ah…the mysteries of the magical bean of soy continue to unfold. As with any mystery sometimes there are unexpected twists and turns. And the effects of soy on the thyroid happens to be one of those twists. Here’s the scoop.

As you may know, soy products contain powerful bioactive chemicals known as isoflavones. These isoflavones have a variety of biological properties which have been shown through research to provide significant health benefits…especially to women. These benefits include everything from control of menopausal hot flashes to protection against breast cancer and heart disease. These beneficial actions are mediated by the potent hormone-like effects of isoflavones. But these hormonal effects have recently been found to be a double-edged sword.

New research conducted by the FDA’s National Center for Toxicological Research shows that two isoflavones found in soy, namely genistein and daidzein, have the ability to inhibit the action of the enzyme (thyroid peroxidase – TPO) in the thyroid gland that catalyzes the reaction necessary for thyroid hormone synthesis. In other words, these isoflavones can block, or significantly slow, thyroid hormone production. And this is definitely not a good thing for someone already struggling with hypothyroidism.

As state by Dr. Mike Fitzpatrick, an environmental scientist and phytoestrogen researcher, "Any inhibition of TPO will clearly work against anyone trying to correct an hypothyroid state."

The end analysis is that consumption of too much soy, especially sources containing high levels of isoflavones (which almost all soy supplements have), will very likely exacerbate an existing thyroid condition. And even a healthy person, if she is a chronic daily consumer of soy supplements, could be put at risk for developing hypothyroidism. According to research as little as 30 mg of soy isoflavones per day is the amount found to have a negative impact on thyroid function. This amount of soy isoflavones is found in just 5-8 ounces of soy milk, or 10-15 grams of concentrated soy protein.

So, yes, I agree strongly with your doctor. You should avoid concentrated soy sources. And for those of you out there who have adopted soy as you manna from heaven and consume it at every meal, you may simply want to moderate a bit.

A few bars I’ve found that are soy free, with a decent nutrient profile, are:



If you’d like further info there are a couple of good websites. For info on soy in general go to www.soyonlineservice.co.nz http://www.soyonlineservice.co.nz/ . And at www.nal.usda.gov/fnic/foodcomp/Data/isoflav/isoflav.html they list the isoflavone content of 128 foods, including foods such as vegetarian hot dogs, soybeans, chickpeas and tofu. This can help you in deciding how much soy to include in your diet.

Q: A friend of mine told me that adding fiber to my diet may help me lose weight. This seems weird. Is it true? If it is how much fiber should I add and what kind?

A: Fiber…it’s one of those words that calls to mind such things as “regularity” and Geritol™. Who would have thought that it would turn out to be one of the easiest, healthiest, cheapest and most effective fat loss supplements ever? Not I. But that it is.

Your friend is absolutely right. The simple act of adding a solid dose of fiber to your daily diet can indeed help you healthfully and painlessly lose fat. There has actually been quite a bit of research done on this. Here is some of what that research shows.

When consuming a fixed number of calories (like on a structured 1,500 calorie diet say) the addition of fiber to the diet:

Increases post meal satiety (feelings of fullness)

Decreases subsequent hunger (you stay fuller longer)

When caloric intake is not controlled (if you’re just eating normally), fiber added to the diet:

Decreases self-selected food and calorie intake by an average of 18%.
Causes an average weight loss of over 5 lb. in a 3.8 month period with no other dietary changes.

In a review of multiple fiber studies it was found that on average “…weight loss was more than three times as great in individuals consuming diets both low in fat and high in fiber compared with diets only low in fat (-7.5 lb. versus -2.2 lb.)”

In a study originally designed to assess the effects of fiber on blood lipids (like cholesterol) it was found that healthy, normal weight adults all spontaneously lost body fat without any other dietary alterations. Average fat loss over 11 weeks was 3.5 lb. No muscle mass was lost. And subjects with the initially lowest level of body fat actually gained muscle (1.3 lb.) while they lost fat mass.

Soluble fiber (pectin in this study) also has been shown to decrease the absorption of both sugar and fat from the intestine.

There is no doubt that fiber is a formidable fat fighting nutrient. But how much of what kind should you take?

First, there are two basic types of fiber – soluble and insoluble. They tend to act a bit differently in the gut, with insoluble fibers soaking up water, creating bulk and a sense of fullness that lasts; while soluble fibers do a bit more of the fat and sugar binding. But as far as fat loss goes it appears that a mixture of the two is optimal. And it has also been recognized that the effects of fiber are not really effected by whether you get it from food or a supplement.

Great sources of insoluble fiber are things like wheat bran, psyllium husk, and any other whole grain foods and fibrous veggies. While soluble fibers can be found in abundance in all types of beans and fruits. A couple fiber supplements I would recommend, if you choose to go that route, are “Pro-Fiber” (soluble) and “Fiber-psyll” (insoluble).

The current fiber intake of the average American is 15 g per day. The American Heart Association recommends 25 to 30 g per day. Personally, for fat loss purposes, I’d like to see you shoot for 40 g a day. Include 5 to 10 grams with each meal. But only use a few grams with your pre-workout meal, or your stomach could get a bit disturbed. Make sure to drink plenty of water with your meals, and between, as you increase your fiber intake. It tends to soak up water and can cause some dehydration and “back up” issues with too little water intake.

Q: I stopped taking all of my supplements while I was pregnant. Now I am breastfeeding my son and I would like to know if you think it would be safe to start taking some supplements again.

A: For starters let me say that I recommend the same supplement usage precautions be taken when you are breastfeeding as when you are pregnant. It is well known that many of the nutrients you consume will pass through into your breast milk. So you still want to be careful about the types of supplements you choose to use. But yes, there are some that I feel are quite safe, which can help support both you and your babies health.

I base my assessment of what is safe to use and what is not first by what is known about the nutrients overall safety profile. If any research shows that there is even the slightest chance of undesirable side effects with a supplement in adults, it is excluded immediately. Secondly, I look at what is known about the effects of the supplement nutrients on an infant. There are some that will have very differing effects in the developing physiology of a child versus an adult.

Using these criteria, virtually ALL herbal supplement are a no-no. There is simply not enough known about their effects on developing systems and too many with known side effects in adults.

Next, you should steer clear of all stimulant products like caffeine, green tea, etc. Due to their very water soluble nature they will pass easily into breast milk. And the last thing you want is your infant wired on caffeine in the wee hours of the morning.

The products I would feel comfortable recommending are as follows:
· A Multivitamin and Mineral with very moderate levels of all nutrients in the formula. Avoid any with mega doses of B-vitamins and / or with herbal “support” nutrients.

· An Essential Fatty Acid (EFA) product. EFAs are quite innocuous in their biological actions, and they can offer great benefits. Finding an EFA product including DHA would be great. Good research shows that DHA helps support healthy development of the infant and fetal brain.

· A quality protein product. I would suggest sticking with a milk protein (such as casein or whey) or an egg protein, and avoiding too much soy. They phyto-hormonal effects of soy may interfere with the delicate hormonal balance in your body at this time.

And that’s about it. As a final reminder, please make sure to check with your doctor to see if he has input as well. Take even the supplements listed above in cautious moderation. And see if there is any change in your babies behavior when you start taking them. Happy feeding!


Peanut Butter Comes of Age

Not long ago research from Harvard School of Public Health demonstrated that adding 2 Tbsp. of peanut butter to your daily diet may help you stick with a fat loss diet plan more effectively, and maintain your weight loss longer. This was good news for those of us who are peanut butter addicts (myself included), but who have deprived ourselves for so long because we thought it was fattening. And now this good news is getting even better.

A brand new peanut butter product, which has literally just landed in select GNC stores within the past 30 days, has taken peanut butter to a whole new level. Simply named Peanut Power Butter, this potent new peanut paste packs a powerful protein punch. Whereas normal peanut butter contains about 15 grams of protein per 2 ounce serving, Power Butter boasts an impressive 32 grams. And this isn’t just a low quality plant protein of some kind, this is from pure pasteurized egg whites. Good stuff.

But the Power Butter folks didn’t stop there. They also found a way to both lower the overall fat content of the peanut butter and enhance the fatty acid profile. By first de-fatting natural peanut butter, then adding flaxseed oil and whole roasted flax seeds back into the mix, they took the normal 75% of fat calories in peanut butter down to just 50%. And whereas normal peanut butter is almost exclusively monounsaturated fat, Power Butter contains hefty doses of omega-3 and omega-6 essential fatty acids.

But does it taste good? Amazingly it does. Being a peanut butter addict for more than 30 years now I count myself somewhat of a connoisseur of the paste of the peanut. And this my friend is good peanut butter.
So, if you looking to prop up your protein intake, increase your EFA consumption…or just want another good reason to eat peanut butter straight from the jar, try a bit of this pasty pooch, I think you’ll be pleasantly surprised. You can get more info or even order online at www.powerbutter.com