So far, I am getting results that contradict each other in my research concerning lowering homocysteine levels. On one end, planet-based diets are deficient in B6, B12, and folic acid which incurs a raised level of homocysteine in the blood. Upon hearing this information, I would think a diet somewhat high in meat will be preventable of this condition. Then again, I discovered that red meat contains methionine that converts to homocysteine. At this point, I am now in a conundrum and don't know what exactly to make out of this.
Can anyone shed some knowledge on this issue? Is it a matter of meat/plant balance? Do only some red meats cause this condition?
I was pretty much going to say what Matt said, so I'll just add this study:
"The results of the present 6-mo intervention study clearly show that increasing dietary protein intake from 12% to 22% of total energy, with a corresponding increase in methionine intake, does not increase plasma homocysteine concentrations...A nonsignificant decrease in total plasma homocysteine (≈25%) was observed in the (high protein) group after 3 and 6 mo of the intervention"
According to the paper "Protein sources were primarily dairy and meat products; the latter consisted mainly of beef, pork, poultry, lamb, and fish".
Elevated homocysteine levels mean something is amiss, but lowering them does not necessarily correct underlying problems (or that's what Wikipedia claims).
Homocysteine is an intermediate inbetween cysteine and methionine. Elevated homocystiene suggests deficiency in methyl donors (methyl-B12), methionine can serve as a methyl donor as well, regenerating homocystiene. Wikipedia has all the sexy biochemistry on the cysteine, homocysteine and methionine pages.
What will red meat do? Good levels of B12 (from meat) should drive down homocysteine. Yes, it also contains methionine and cysteine which convert to homocysteine, but assuming all is normal, homocystiene should only exist as an intermediate in low concentration.