The most crucial factor here is preventing obesity. “Obesity means you’re more likely to have high cholesterol, diabetes and high blood pressure,” says Tabet. Over a sustained period, he says, all three things “will start to cause damage to the arteries and cause increased inflammation in the brain”.
“The contents of your blood have been found to go through some of the biggest changes in your 40s and 50s,” with some studies finding that some inflammatory proteins “accelerate the ageing of the brain and predict future cognitive health, sometimes by decades”.
What we eat is essential too, as diets can impact the likes of oxidative stress (the imbalance between free radicals and antioxidants in the body, which can cause organ damage) and inflammation, which has been found to play a key role in the onset and progression of Alzheimer’s (the most common form of dementia).
Two regimes have shown potential cognitive health benefits: the Mediterranean diet, and Mind (a hybrid of the Mediterranean and the dietary approaches to stop hypertension, or Dash). The former prioritises at least three servings of fish a week, legumes, nuts, vegetables and fruits; the latter highlights leafy greens (such as Romaine lettuce and kale) and berries (over other fruits). No specific food, or time at which to eat it, has been conclusively proven to reduce cognitive decline, but blueberries, curcumin (found in turmeric) and leafy greens are thought to have anti-inflammatory properties.