Changing times [PARA]Some experts remain skeptical about the value of trying
to stick closely to what our ancestors ate. [PARA][PARA]"I don't think the
diet back then would hurt us," said Ed Blonz, a nutritional scientist in
Northern California whose column appears in the Food section. "But I don't
know whether it's optimal for the species." [PARA][PARA]Blonz does think
some of our health problems may stem from the change in the types of fat we
eat. [PARA][PARA]The switch from lean wild game to fatty domesticated
animals and from wild greens to grains means we are eating far more omega-6
fats and fewer omega-3 fats than early humans did. While early man may have
had a 1:1 ratio of omega-3 to omega-6 fats, our diets today are tilted
toward omega-6 fats by a ratio that may approach 11 to 1, Blonz noted.
[PARA][PARA]While both fats are necessary, he said, omega-6 fats contribute
to clotting of blood and so may play a role in heart attacks. They may also
encourage tumor growth. Omega-3 fats have the opposite effects.
[PARA][PARA]Ultimately, though, said Blonz, early man survived simply on
what was available to him, and there's much more available to us now.
[PARA][PARA]"The digestive system in the human body is remarkable," Blonz
said. "It's set up for the individual to be an omnivore and to eat just
about everything that comes its way, so to say we didn't evolve to eat dairy
products is a misnomer. We can say we didn't eat dairy products when we were
wearing loin cloths, but our bodies were still set up to handle it.
[PARA][PARA]"I think human animals -- the ones that made it through the
genetic mill -- are the ones that are able to adapt and make use of
everything that's around them." [PARA][PARA]Blonz noted that the conditions
in which we live have changed radically. All that mattered for evolutionary
success was that people survived to reproductive age. Now we are living far
beyond our child-bearing years. [PARA][PARA]"We've come a long way since we
were going around hunting for wild game," he said. "The whole set of
stresses in our life is so much different from the Stone Age. The fact that
we are living so much longer means there may be new nutritional
requirements. I don't want to go back. I want to go forward."
[PARA][PARA]Anthropologist Kuhn also views with skepticism efforts to model
our diets on those of our ancestors. [PARA][PARA]"I think we know enough
about what's healthful for us to eat based on what the things we eat do to
our bodies," he said. "We have much less ability to reconstruct the diets of
our early ancestors, and we're not the same as them anyway." [PARA]Copyright
1998 Union-Tribune Publishing Co.