A study published last week in the British Medical Journal has linked irregular toothbrushing with an increased risk of heart disease: individuals who rarely or never brushed their teeth were found to be at a 70 per cent increased risk of ‘cardiovascular events’ (e.g. heart attacks and strokes) compared to regular brushers . Why? Well, it’s possible that those who do not appear to care much for the dental health might not care so much about the rest of their bodies either, and perhaps have other lifestyle habits that harm the heart and circulatory system. However, the association between irregular toothbrushing and cardiovascular disease was after relevant factors such as smoking, body mass index and history of high blood pressure had been taken into account.
Such adjustments are never perfect, but the results support the idea that it’s something about infrequent teeth-cleaning that might increased disease risk. Looking more deeply, the researchers found that those not so assiduous about their oral hygiene had, generally speaking, higher levels of two substances: C-reactive protein and fibrinogen. C-reactive protein (CRP) is an inflammatory substance, and inflammation has emerged as a key underlying process in the development of cardiovascular disease (as well as other chronic diseases). And higher levels of fibrinogen encourage clotting or ‘stickiness’ in the blood, which would also be expected to increase cardiovascular disease risk.
This study’s findings reminded me of the research which suggests that cholesterol-reduction (either through diet or drugs) is not the life-saver some would have us believe it to be. Many doctors and scientists maintain that we have ‘proof’ that cholesterol is a killer in the form of studies which show that cholesterol-reducing drugs known as statins do reduce heart disease risk. However, this would only hold up if the only thing statins do in the body is to reduce cholesterol levels.
The reality, though, is that statins have several effects in the body which include (but are not limited to) an ability to reduce CRP levels and ‘thin’ the blood.
Interesting, even in people without raised cholesterol levels, statins reduce the risk of cardiovascular disease. However, the benefits have in previous studies been found to be pinned more to a reduction in CRP rather than cholesterol levels. Also, there is other evidence which shows that the degree of clinical benefit from statins does not mirror the extent of cholesterol reduction. For more about this, see here.
Another way to prove the benefit of cholesterol reduction would be to assess the effectiveness of other cholesterol reducing measures. In 2005, some Swiss researchers decided to review the evidence regarding cholesterol-reduction and overall risk of death .
They found that statin use was associated with a reduced risk of death, particularly in those who already had had a heart attack or stroke.
Resin (another cholesterol-reducing agent) use was not found to reduce risk of death, even in high-risk individuals
Fibrate (also a cholesterol-reducing agent) use was not found to reduce risk of death, even in high-risk individuals
In generally low-risk individuals, fibrate use actually increased risk of death (by 25 per cent)
Diets designed to reduce cholesterol did not reduce the risk of death either.
In more recent years, another cholesterol-reducing drug has hit the market by the name of ezetimibe. Yet, there is no good evidence that ezetimibe prevents disease or death. In fact, the reverse may be true. For more on this, see here and here.
Once someone is aware of these facts about cholesterol reduction I generally find they become much more relaxed regarding the role of cholesterol in health and longevity. But, of course, there’s always going to be people who will cling to this theory no matter what the science shows. These may include doctors who are given financial incentives to reduce their patients’ cholesterol levels, as well as doctors and scientists paid by drug companies to remind us all of the miraculous, death-defying benefits of cholesterol reduction.
1. de Oliveira C, et al. Toothbrushing, inflammation, and risk of cardiovascular disease: results from Scottish Health Survey. BMJ 2010;340:c2451
2. Studer M, et al. Effect of different antilipidemic agents and diets on mortality. Archives of Internal Medicine. 2005;165:725-730