 Low back pain became one of the biggest problems for public health systems in the Western world during the second half of the 20th century. The lifetime prevalence of low back pain is reported to be as high as 84%, and chronic low back pain currently affects about 1 in 5, with 1 in 10 being disabled. It's an epidemic. Are people just lifting more heavy stuff? No. Mechanical factors such as lifting, caring probably do not play a major role in the disease. Well, then what causes it? I've touched on it before. Atherosclerosis can obstruct the arteries that feed the spine, and this diminished blood flow can result in various back problems. This can be seen on angiography, showing normal arteries on the left and clogged on the right, or on autopsy, where you can see the openings to the spinal arteries can get squeezed shut by these cholesterol-filled plaques on the right. Obviously because back pain may predict fatal heart disease. Just like clogs in the penile arteries, erectile dysfunction, can proceed heart attacks because it's the same disease, clogged crippled arteries throughout our body. Now we have MRI imaging that can show the occlusion of spinal arteries in people with back pain and the degeneration of their discs. Normal blood flow in someone without back pain versus constricted blood flow in someone with. They show that patients with long-term lower back pain had these kinds of arterial clogs, and those with high cholesterol appeared to suffer more severe symptoms. Those with narrowed arteries appear about 8.5 times more likely to have suffered from chronic back pain. This makes sense. The discs in our lower back are the largest avascular tissue in the body, meaning our discs don't have any blood vessels. Thus its nutrition just kind of diffuses in from the margins, making it especially vulnerable to deprivation. Using MRIs, you can measure the effects of impaired blood flow on that diffusion, and see how this can turn into that. Although disc degeneration has multiple causal factors, with genetic, occupational, and mechanical influences, alteration in nutrition has been proposed as the final common pathway. By age 49, 97% of the discs of those eating the standard American diet show at least grade 2 degradation. Cholesterol plaques in the walls of the aorta can obliterate the orifices, the lumbar and middle sacral arteries, and make decreased blood flow of the lumbar spine and surrounding structures. Structures with precarious nutrient supply, such as the inter-rotebral discs, may suffer and gradually degenerate from this lack of blood flow, as well as herniate. Not only is there a link between cholesterol levels and disc degeneration, there's association between cholesterol levels and disc herniation as well. This compromised blood flow may also damage the nerve roots that come off the spine, causing sciatica. Sciatica is back pain that radiates down the legs, causing additional pain, numbness or weakness, and prolonged disability, and may affect as many as 1 in 20 people. And independent of weight, some other factors, clinical sciatica may be associated with cholesterol as well. See the nerve roots, which are most commonly associated with sciatic pain, are supplied by some of the arteries most vulnerable to atherosclerotic plaque formation. Obliteration of these arteries by cholesterol buildup results in compromised nutrient supply to the nerve itself, and that lack of oxygen to the nerve may be playing a role in sciatica pain. Reduced blood flow also hampers the removal waste products, such as lactic acid, which can in turn irritate the nerve endings, causing pain and deterioration. Because of this vulnerability, discs degenerate far earlier than do other musculoskeletal tissues. The first unequivocal findings of degeneration in the discs of the lower spine can be seen starting around age 11. By the early teen years, you can already see the discs starting to degenerate. And this makes sense, as I've talked about before, nearly all kids have the beginnings of atherosclerosis by age 10. And sadly, low back pain is now common in children and adolescents as well, as it's becoming a real public health concern. And it's getting worse. It's like kids now getting disorders like adult onset diabetes. Teenagers starting their lives out with a chronic disease. That's why it's never too early to start eating healthier.