A new study by Chinese scientists has shown that, compared with meat eaters, people who do not eat eggs and meat have health benefits: lower body mass index, lower blood pressure, lower triglycerides, total cholesterol, bad cholesterol, less free radicals, etc.
However, if a plant-based person is not getting enough vitamin B12, blood levels of arterial-damaging homocysteine can rise and outweigh some of the benefits of a healthy diet. One group of Taiwanese researchers found that the arteries of vegetarians were similarly stiff, with the same level of thickening in the carotid artery, probably due to elevated levels of homocysteine.
The researchers concluded: “The negative results of these studies should not be considered as neutral cardiovascular effects of vegetarianism, they only indicate the need to supplement the vegan diet with vitamin B12 supplements. B12 deficiency can be a very serious problem and can eventually lead to anemia, neuropsychiatric disorders, permanent nerve damage and high levels of homocysteine in the blood. Prudent vegans should include sources of B12 in their diet.”
One study of B12-deficient vegetarians found that their arteries were even more rigid and dysfunctional than those of meat eaters. Why do we think it’s B12? Because as soon as they were given B12, there was an improvement. The arteries narrowed again and began to function normally.
Without B12 supplementation, vegan meat eaters developed a vitamin deficiency. Yes, it takes blood levels to drop to 150 pmol/L for the classic signs of B12 deficiency to develop, such as anemia or spinal cord degeneration, but long before that, we may have an increased risk of cognitive decline, stroke, depression, and nerve and bone damage. An increase in homocysteine levels may reduce the positive effect of a vegetarian diet on vascular and heart health. The researchers concluded that although a vegetarian diet has a positive effect on cholesterol and blood sugar levels, the lack of vitamin B12 in a vegetarian diet should not be underestimated. Be healthy!
Dr. Michael Greger