What's worse for us: sugar or fat? To answer the hottest question in nutrition, twin doctors Chris and Xand Van Tulleken go on month-long high-fat and high-sugar diets. The effects on their bodies are shocking and surprising. But they also discover that in the debate about fat and sugar, the real enemy might have been hiding in plain sight.
Horizon investigates a new era of Alzheimer's research, which is bringing hope to millions of sufferers across the world. New scanning and gene technology is allowing scientists to identify the disease at its earliest stages, often 15 years before symptoms appear and the brain cells are destroyed. A series of new drugs trials in Colombia, the USA and Europe are showing startling success in reducing beta amyloid, the protein which is a hallmark of the disease. It is also becoming clear that changes in lifestyle can prevent the development of the disease. A new system inside the brain has been discovered which clears amyloid when we are in deep sleep, but allows it to accumulate if we don't sleep well. The programme reveals that for sufferers in the early stages of the disease, brain connections, or synapses, can be strengthened and even replaced by absorbing enough of the right nutrients. A UK-wide trail helps sufferers in the early stages to concentrate on improving everyday tasks, and in the process not only make their lives easier, but helps to reactivate the planning and organisational parts of the brain. In an ageing world, where the biggest risk of developing Alzheimer's is old age, the scientific breakthroughs in Alzheimer's disease are bringing hope where once there was despair.
Over 62 per cent of adults in the UK are currently overweight or obese and this figure is set to rise. A common attitude is that obese people should be ashamed - it is their fault, they have no will power and if they could just 'eat less and exercise more', the problem would soon be solved. Yet, despite millions of pounds being spent on this simple message, the UK is getting fatter every year. Cambridge geneticist Dr Giles Yeo believes that for many obese people, simply eating less is a lot harder than you might think - and he is taking a road trip around the UK and America to uncover why. He meets the real people behind some of the more shocking newspaper headlines and, through their stories, reveals surprising truths which dispel commonly held myths about obesity. He gains access to scientists and doctors trialling cutting-edge techniques to tackle the crisis - from a 'miracle' hormone injection to a transfusion of faecal matter, and even learns a thing or two about his own size and relationship with food.