|
Study Finds Bison Protein HEALTHIER than Soy Protein
If you're gunning for a heart attack, your doctor probably has already told you to avoid red meats, right? Studies show plant-based protein sources, such as from soy, are better on the plumbing and the ticker than the protein from animal meats. In January of 2000 the U.S. Food and Drug Administration issued only its eleventh health claim, correlating soy protein with decreasing the risk of coronary heart disease.
The National Bison Association helped fund a preliminary study to see if ground bison was healthier than beef as measured by blood cholesterol and atherosclerotic streaks on aortic tissue in hamsters. Predictably, blood cholesterol levels were lower in the 15 hamsters fed soy than in either the bison-fed or beef-fed hamsters. But researchers were confounded when results of the eight-week study showed the bison and beef groups were both actually lower than the soy group when they analyzed the end product of elevated cholesterol, which is fatty streaks in the lining of the aorta.
"The real goal of the study was to show that bison wasn't as bad as beef," says lead researcher Tom Wilson, Ph.D., at the Centre for Chronic Disease Control, Department of Health and Clinical Science, the University of Massachusetts, Lowell.
"We weren't expecting it to be better than the soy protein.
"Bison was in fact better than beef in the measure of blood cholesterol, and not as good as soy. Then they looked at the atherosclerotic streak data and didn't see any difference between the bison and beef groups. This was a matter of some concern because you'd think if bison had lower cholesterol numbers, it would be likely to also mean less fatty streaks in the aorta. The researchers then looked at the atherosclerotic measurements in the soy protein and casein groups.
"That's when we said, "Wow! Wait a minute," says Wilson.
Study results showed the bison group, compared to the beef group, had 14 per- cent lower blood cholesterol levels, 14 percent lower low-density lipoprotein levels (LDL, the "bad" cholesterol), and 14 percent lower high density lipoprotein levels. The bison group also had 25 percent lower blood triglyceride levels compared to beef.
Unexpectedly, the bison group had 50 percent reduced early atherosclerosis compared to soy protein
and 68 percent lower compared to the casein group.
(The beef group had 43 percent and 64 percent less, respectively.)
Elevated LDL and total cholesterol levels are thought to be good indicators of the development of early atherosclerosis. Researchers in this study think that perhaps they are not as good an indicator as previously believed, or perhaps it's just the case with hamsters, which do not necessarily correlate to humans.
DIGGING FOR CLUES
The researchers were confounded as to the results, but offered a few possibilities. One regards the fat or protein composition of the bison and beef. One theory says the composition of the fat may have changed the composition of the LDL particle, making it less likely to cause damage by being oxidized.
Think of oxidation as rusting, or bread going stale. But more than that,
oxidation makes molecules unstable, where they inflict molecular mayhem. You've probably heard the term "antioxidants" thrown around. Well known antioxidants are vitamins C and E. these vitamins neutralize oxidized "free radicals." Once the vitamin molecules neutralize the free radicals, they too are neutralized. However, other such vitamins can come along and recycle the antioxidant vitamin back into action.
And that brings us to another possible way bison and beef may work. Within the fat of bison and beef is conjugated linoleic acid, or CLA. There's more CLA in bison and beef than soy or casein. And CLA is thought to act as an antioxidant similar to vitamin E.
The composition of the amino acids within the protein content of bison and beef may also hold a clue.
"We just don't know," says Wilson. "On the basis of this, though, we got a second study funded, to look at the mechanism of fat to see if bison fat may be more protective than beef fat."
The National Bison Association is helping to sponsor that study as well. So, the bottom line
is, should people at risk of heart disease eat bison as a protein source?
"It may be," says Wilson. "Just due to its protein content and fat and cholesterol content bison is probably a better choice than beef. To me it's a better protein source than beef is."
Source: Smoke Signals, June 2001
|
