THE LANCET, 23/1/99 Bovine somatotropin---who's crying over spilt milk?

[Guest guest]

Dear All,

FYI - some clues to government appointees with " conflicted intersts " !!

Cheers, Lynette.

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http://www.thelancet.com/newlancet/reg/issues/vol353no9149/news_pp304.html#

THE LANCET, Volume 353, Number 9149 23 January 1999

Bovine somatotropin---who's crying over spilt milk?

A hormone used to increase milk yield in cows--recombinant bovine

somatotropin (rbST)--is proving to be one of the most controversial drugs

of the decade.

Since the 1980s there have been fears over the safety of milk from

rbST-treated cows, and last year, a leaked internal report by Health Canada

scientists identified numerous gaps in the safety data on human and animal

safety. Last week, Health Canada announced that, unlike many other

agencies, it would not approve the drug. US consumer groups now want the

drug withdrawn.

rbST was first approved by the US FDA in November, 1993. At that time, the

European regulatory authority also gave a positive opinion, but the EU

banned rbST until the end of 1999 for socioeconomic reasons.

In Canada, approval of the drug is opposed by, among others, the National

Farmers Union (NFU). The debate concerns not just animal and human health

but also the socioeconomic impact of the drug, says Lloyd (NFU).

After more than 8 years of review, Health Canada asked two external panels

to review the animal and human safety last year. Rejection of

rbST was partly based on the animal-health panel's report of adverse

effects in cows, including lameness, mastitis, and reduced lifespan. The

human-safety panel found, with one exception, " no biologically plausible

reason for concern " . But the findings of the leaked Canadian Gaps Analysis

and testimony by several scientists to last year's Canadian Senate hearings

on rbST

indicate that the human-health debate seems set to continue.

Critics of the hormone suggest that both rbST and its mediator,

insulin-like growth factor-1 (IGF-1), are found at higher concentrations in

milk from treated cows. IGF-1 has been linked with cellularity changes in

the human gut, and tentatively with human cancer. And, IGF-1 is not wholly

destroyed in the gut, particularly in the presence of casein. The Gaps

Analysis concluded that long-term toxicity and oral absorption had not been

fully studied. The longest toxicology study--a 90-day rat study submitted

by manufacturer Monsanto--indicated that rbST was absorbed intact from the

gut at high doses and elicited " a primary antigenic response " . The external

panel concluded that this possible hypersensitivity reaction " deserves

further study " . The Gaps Analysis also notes that the full significance of

human exposure to rbST and IGF-1 is unknown, particularly in the neonate,

" the subpopulation at greatest risk " (http://www.nfu.ca ).

The FDA and most other agencies interpret the data differently. For

example, JECFA--the Joint Food and Agriculture Organization (FAO)/WHO

Expert Committee on Food Additives--concluded last year that rbST " does not

represent a hazard to human health " . Somatotropin and IGF-1 occur naturally

in milk, and, says FDA, " milk composition of supplemented cows appears to

be well within the normal variation observed " . Further, JECFA states that

" any increase of IGF-1 in milk from rbST-treated cows is orders of

magnitude lower than the physiological amounts produced in the

gastrointestinal tract as well as in other parts of the body . . .

Consequently, the potential for IGF-1 to promote tumour growth will not

increase when milk from rbST-treated cows is consumed " .

The FDA did not consider the 90-day rat study pivotal, says spokesman

Lawrence Bachorik, and further toxicology testing is not warranted.

Barton of Monsanto says such tests would be toxicology studies of natural

milk components. " There is no test anywhere that can find any distinction

between milk from treated cows and untreated cows . . . What are you

testing, that

milk is bad? " But, the Senate Committee heard scientists testify for and

against further study. Verrall, member of the UK Food Ethics Council,

told the hearings that, given the uncertainty, any approval of the hormone

shows " a total disregard for the precautionary principle " .

The Canadian decision may have far-reaching consequences. The US Center for

Food Safety (CFS) and about two dozen other consumer groups have already

petitioned the FDA to reverse its 1993 decision. CFS says it will sue the

FDA if rbST is not taken off the market. Eyes are now turned to the

international food standards agency, Codex Alimentarius, which meets this

summer to consider approval of rbST. If Codex, which is advised by JECFA,

concludes that the hormone is safe, " Canada may find itself unable under

international trade law to refuse using a drug it has proven to be unsafe " ,

notes Jo Dufay of the citizen's group Council of Canadians (CoC).

Scientific debate remains hampered by secrecy surrounding regulatory

reviews, which has also left several bodies open to allegations of bias.

CoC has " serious questions about the objectivity " of the external panels.

" Both panels have chairs and a number of members who have worked closely

with related industries. " For example, CoC alleges that human-safety

panellist Rejeanne Gougeon has been a consultant for Monsanto on rbST since

1993.

International agencies are also under fire. One case cited is that of

Margaret , a rapporteur at the JECFA meeting who was previously

employed by Monsanto, though she was cleared of a conflict of interest for

her involvement with rbST at FDA. Senator Eugene Whelan told the Senate

hearings that he would not be impressed by any testimony quoting WHO, FAO, or

Codex because " The big companies sit behind them, and tell them what to

do " . Lloyd believes that this possibility of undue influence is one of the

" dangers of moving to global homogeneous regulatory agreements. Canada's

experience shows that we need more, not less, review. "

" What is most important to remember " , says Verrall, is that rbST is not a

therapeutic drug to which the public has limited exposure " . Yet, regulatory

agencies apply the same standards of safety and efficacy to therapeutic and

non-therapeutic agents, regardless of the potential population exposed;

other factors that might be in the public's interest are not within their

remit.

rbST--one of the first biotechnology products licensed solely for economic

purposes--has challenged this thinking.