Obesity is epidemic in Western societies and constitutes a major public health concern. A study published in the British Journal of Medicine reports that being obese during middle-age can increase the risk of developing dementia later in life (Whitmer et al., 2005). The research is based on data collected from detailed health checks made on 10,276 men and women between 1964 and 1973 (when they were aged 40 to 45). Dementia was diagnosed in seven per cent of participants between 1994 and 2003. Results showed that being obese increased the risk of dementia by a whopping 74 per cent while being overweight increased it by 35 per cent. The link between obesity and dementia in women was stronger than that in men.
This is in agreement with a Swedish study which found that the higher a woman’s body mass index (BMI), the greater the risk of dementia (Gustafson et al., 2003). In this study the relationship between BMI and dementia risk was investigated in 392 Swedish adults who were assessed between the ages of 70 and 88. During the 18-year study, 93 participants were diagnosed as having dementia. Women who developed dementia had a higher average BMI compared to women without dementia. For every one unit increase in BMI at age 70 years, the risk of dementia increased by 36 per cent.
A substantial body of evidence now shows that obesity is a risk factor for dementia. However, it has been argued that current forecasts of dementia fail to take the rising obesity levels into account. A review of studies on the association between midlife obesity and dementia found that, compared to normal weight, being overweight or obese in midlife, increases the risk of dementia later in life by 34 and 91 per cent respectively. It was predicted that dementia levels in the US and China would be nine and 19 per cent higher respectively than previously forecast (Loef et al., 2013). The authors of this review conclude that the increase in midlife obesity levels will contribute significantly to the future prevalence of dementia and suggest that public health measures to reduce midlife obesity should be regarded as also being primary prevention measures to reduce the risk of dementia. This raises very real concerns that the current obesity epidemic could lead to a steep rise in the numbers of people suffering from dementia in the future. The evidence suggests that eating a healthy plant-based diet and leading a healthy lifestyle could help to reduce the risk of dementia (See Overweight and obesity).