Alzheimer’s update: How we can all reduce our risk
Latest research shows a disturbing link between what we eat and harmful changes in the brain which may increase the risk of Alzheimer’s.
How it happens
Dementia occurs when protein plaques (abnormal clusters) and tangles (twisted strands) develop in the brain tissue, which block cell signals and lead to the death of brain cells. Early symptoms are confusion and disorientation, memory loss and language problems.
The diet-brain link
Most of us know that a high-fat diet is bad for our heart as well as our weight. But did you know that a poor diet may also increase our risk of dementia?
There’s growing evidence suggesting that the same unhealthy habits that lead to obesity, high blood pressure and type 2 diabetes may also increase the risk of developing Alzheimer’s and vascular dementia (the second most common form of dementia).
In a recent study, the brains of elderly people were scanned. Scientists found that those with hardened arteries and high blood pressure were more likely to exhibit changes in the brain that are associated with Alzheimer’s.
“It’s pretty clear that untreated high blood pressure in our 30s, 40s and 50s has a major impact on the risk of developing dementia,” says John Watkins, CEO of Alzheimer’s Australia.
“We’re never going to get a cure in one tablet because there are so many types of dementia. But more and more we’re looking at the preventable issues,” he says.
Fats bring it on
According to a 2006 study, a moderate intake of saturated fat in mid-life (45–60 years) was enough to double the risk of dementia. Trans fats (industrially produced fats used in foods such as biscuits and pastry) are even more damaging. In a diet high in trans fats, the cell membranes in your brain become less permeable. This makes it more difficult for the cells to dispose of waste. This triggers inflammation in the brain, blocking signals and resulting in Alzheimer’s symptoms.
The insulin link
A connection between Alzheimer’s disease and type 2 diabetes is also being explored.
Following a meal, insulin is released from the pancreas, whisking glucose out of the bloodstream and into the body’s cells. But in people with type 2 diabetes, the cells don’t accept the glucose (because of their insulin resistance). So, over time, the glucose in the bloodstream just accumulates.
Their levels of insulin also increase, as the body pumps out more of it in an attempt to whisk away the glucose in the blood. This is how a person develops type 2 diabetes.
Recent research has found the brain cells of people with Alzheimer’s are frequently insulin resistant.
“Type 2 diabetes and Alzheimer’s share a common mechanism,” says Watson. As insulin promotes the healthy functioning of brain cells, scientists think insulin resistance may play a key role in the way the disease develops. This might explain why people with type 2 diabetes are more predisposed to dementia.
Your food plan
Rethink your diet to give your brain a fighting chance.
The good news is you can slash your chances of developing dementia by following a healthy diet. Research shows that people who are overweight in mid-life are 71 per cent more likely to develop dementia than those of a normal weight. To lose weight and enjoy a brain boost, follow these tips:
1. Fill up on fruit and veg
Fresh fruit and veg could help lower your risk. This may be due partly to the antioxidants found in brightly coloured fruits and vegies, which help protect healthy cells. To get your five serves a day, add fruit or veg into every meal: for breakfast, slide a tomato or some spinach onto eggs on toast; at lunch, stack your sandwich with crunchy salad; and at dinner, plate up your veg to fill half the plate.
2. Include omega-3
Although more research is needed, there’s evidence that omega-3 fats play a role in maintaining brain health. The best source is oily fish, such as salmon, tuna, sardines and trout. Aim for two to three servings a week. Unsaturated fats, such as those found in avocado, olive oil and nuts, have also been found to reduce the risk of developing dementia by about half.
3. Focus on fibre
Research shows that a high-fibre diet reduces cholesterol and your risk of heart disease and type 2 diabetes. It keeps your brain healthy, too. To reach your daily target of 25–30g of fibre, opt for wholegrain versions of bread, cereal, pasta and rice.
Get into the exercise habit
Perhaps the most encouraging news is the extent to which exercise can play a role in preventing dementia.
Researchers found that people who followed any four of the five healthy lifestyle habits (see below) experienced a 60 per cent decline in the onset of dementia (as well as 70 per cent fewer instances of heart disease, stroke and diabetes), compared to those who followed none — and exercise was the most significant.
“Physical activity comes up again and again as THE critical issue,” says Watkins. “It improves your weight, it reduces hypertension and improves blood flow around the brain and the body.
“Physical activity also improves brain plasticity [which governs our ability to learn and think]. It also reduces ‘risky’ stress hormones, which is important because stress is also a risk factor for dementia.”
HFG tip: Exercise may also help those who already have Alzheimer’s. A recent Cochrane Collaboration review found that being active improved patients’ cognitive skills and their ability to get out of a chair.
Easy ways to get active
Exercise is key — but that doesn’t have to mean hitting the gym or taking up a new sport (unless you want to, of course). Experts advise you fit in at least 150 minutes of moderate-intensity activity every week — which is five sessions of 30 minutes each.
There are plenty of ways you can hit this target, such as swimming, cycling or taking an aerobics class. But for most of us, walking is the easy option. To get the maximum benefits, make sure you walk briskly — so talking at the same time is a little hard.
Or consider taking a long walk at lunchtime. Or leave your car further from the office or station and add those steps into your commute.
As a general rule, we should aim to walk 10,000 steps a day. A fitness tracker can be helpful for reaching this goal.
Five ways to cut your risk
Results from a 35-year study have identified these five healthy lifestyle habits in preventing dementia:
Maintain a healthy weight
Follow a healthy diet
Keep alcohol intake low
Did you know? In Australia, more than 353,800 Australians live with dementia. By the age of 65, almost one in 10 of us will have it, and after the age of 85 our risk rises to an alarming one in three. There are also more than 25,000 people under the age of 65 currently with dementia, some sadly as young as 30. There is currently no cure and dementia is now the second leading cause of death in Australia.