Scientists take health claims with a pinch of salt

By MAGGIE FOX

BETHESDA - Soy and garlic supplements line the shelves of health food stores and groceries but there is still no proof that the pills, powders and capsules have any health benefits.

Garlic and soy as food may benefit the heart, but a two-day conference of health experts has concluded that it is not entirely clear which constituents are doing the work.

Their findings may be of particular interest to women because of recent studies that show hormone replacement therapy can raise the risk of heart disease and cancer, and soy has been proposed as a non-drug alternative to HRT.

"I have to say that in most of the areas we still have too many questions," Dr Curt Furberg of Wake Forest University in North Carolina told the conference in Bethesda, Maryland.

"I couldn't recommend too strongly any particular supplement."

The researchers said several studies under way might show whether some products work, but these were years away from reporting any results.

A flourishing market has grown for soy protein powders, garlic pills and capsules containing soy isoflavones - supposedly the active ingredients that make soy healthy.

Leading botanical researchers, meeting under the auspices of the National Heart, Lung and Blood Institute, said these products varied greatly in what they contained and some might not even be in a form that the body could use.

"The available clinical trial results are not adequate to answer important questions about the potential cardiovascular benefits of garlic," Christopher Gardner of Stanford University in California told the meeting.

Eric Block of the State University of New York said that as one example, stomach acid and heat might destroy some of the active ingredients in garlic. Like all plants, garlic varies greatly from crop to crop in its make-up.

Dr Furberg said: "We need to precisely define what we are using." "We need to verify that brands contain what they are supposed to contain."

Some studies that suggest soy can lower blood pressure and perhaps cholesterol. But the products vary and studies of them have not made consistent comparisons.

Mr Block said: "Very, very high on the list is the need for standardisation of botanicals to ensure that we know what we are getting."

Dr Gregory Burke of the Wake Forest University School of Medicine said that many soy studies were based on the observation that rates of heart disease and certain cancers such as breast cancer were much lower in China and Japan, where soy was popular.

This may not translate to a commercial supplement, he said.

"When we contrast Asia with the United States, we are comparing people who eat soy over a lifetime and not just a little shake or a little pill.

"I think that if you are talking about dietary soy, increasing soy intake is a good thing.

"If you think of it as another vegetable it's a good thing. But currently, my view is that the data doesn't support the claim that soy and isoflavones are a viable alternative to HRT as a magic bullet."

- REUTERS

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