“The general view,” says Dr Briffa, “is we need carbohydrates because we need glucose for brain fuel. That’s not strictly true. A lot of carbohydrates, including starchy carbs, are quite disruptive of blood sugar levels so you can have highs of blood sugar and then lows a couple of hours later.” This has a short-term impact on brain function, killing your concentration and motivation. “And with a lot of glucose in the system from all these carbs, you make a lot of insulin, and we’ve got pretty good evidence that insulin resistance is a major underlying factor in cognitive decline.”
Sandwiches for breakfast, pasta for lunch and a pile of potatoes in the evening is generally not so good for brain health — both in the short term and long term. Instead, choose the most nourishing carbs, and choose the ones that are not particularly disruptive to blood sugar. That really means vegetables, advises Dr Briffa. Add healthy wholegrains and legumes to bulk up your meals if needed.