Targeting risk factors could cut Alzheimer’s by a quarter. Barnes & Yaffe (2011) Lancet Neurol.
If some of the known risk factors in Alzheimer’s disease were modified to a relatively modest degree, millions could avoid this disease
Alzheimer’s disease, like most degenerative conditions is largely preventable. Who gets it and who doesn’t comes down to risk factors – factors which increase or decrease your risk of developing the condition. Some risk factors such as age and genes are not modifiable – there’s nothing you can do about them – but these contribute only a very small part to your overall risk. Most other risk factors are modifiable, meaning you can change them. This study looked at the evidence regarding seven modifiable risk factors for Alzheimer’s. They calculated that about half of the 33 million cases worldwide could be prevented (that’s 17 mllion!) and calculated that if these risk factors were to be modified to only a ‘relatively modest degree’, specifically by 10-25% as many as 1 – 3 million cases of the current 33 million worldwide could have been prevented.
The risk factors they considered were diabetes, midlife high blood pressure (hypertension), midlife obesity, smoking, depression, cognitive inactivity or low educational attainment, and physical inactivity.A major shortcoming of this report is that they didn’t consider dietary and lifestyle factors such as increasing B vitamins / reducing homocysteine, increasing essential fats and vitamin D, adopting a Mediterranean diet. Given that lowering homocysteine with B vitamins has the most proven clinical evidence this is a major oversight.
Let’s look at the seven risk factors that were considered:
- Diabetes (let’s assume we’re talking about Type II diabetes which makes up the vast majority of cases) is a preventable disease so in theory you can reduce this risk factor by 100% by eating a low GL diet and exercising regularly;
- Midlife hypertension (hypertension in late life doesn’t carry the same risk) – again, largely preventable, with a low GL, low salt, high fruit and vegetable, magnesium and potassium rich diet and exercise;
- Midlife obesity (similarly to hypertension, late life obesity doesn’t carry the same risk) – preventable by following a low GL diet and moderate exercise;
- Smoking – preventable;
- Depression has many causes, some of which cannot be avoided, but your risk of this is reduced by eating a healthy diet (low GL) including plenty of oily fish (see below), B vitamins, fruits and vegetables;
- Cognitive inactivity or low educational attainment – even if you missed opportunities for education earlier in life, there is nothing stopping you continuing to learn and be cognitively stimulated as you get older – take a course, join a group, volunteer at a community project, but whatever you do, don’t spend your days watching daytime television! And finally,
- Physical activity – whether its gardening, walking or keep fit classes, make sure you are active every day.