Can diet protect our long-term mental health and prevent Alzheimer’s disease? There have been many claims but even though important, it’s not something that often comes up in the pub or over a family dinner. I had a look at the scientific research and it turns out, it’s not that complicated! The research all points in the same direction.
We know that diet influences our nervous system in the long term and has been linked to dementia, Alzheimer’s disease and other conditions. All the foods linked to an array of other diseases – such as foods rich in saturated fats (dairy and meat products), processed meats, fat and sugar laden snacks and desserts – are also linked to a higher chance of cognitive decline. A vegan diet that’s naturally high in antioxidants, fibre and low in saturated fats helps protect your cognitive health and can lower your risk of some neurodegenerative diseases.
When examining the link between diet and cognitive function, one study found that people whose mid-life diets were characterised as healthy (high in plant-based foods, low in saturated fats etc) had a lower risk of dementia and Alzheimer’s disease later in life compared with people with unhealthy diets rich in meat and dairy foods. The difference was staggering – people who ate the healthiest had an 86-90 per cent decreased risk of dementia and a 90-92 per cent decreased risk of Alzheimer’s disease compared with people whose diet was the least healthy.
Another long-term study with a similar design followed participants for 20-30 years. The results revealed that people with higher cholesterol levels in mid-life had a 50 per cent higher risk of Alzheimer’s disease and dementia later in life.
Research shows that apart from genetic and age-related factors, the risk of Alzheimer’s disease is increased by elevated blood lipids (cholesterol and other fats in the blood), blood pressure and diabetes. At the International Conference on Nutrition and the Brain in Washington (USA) in 2013, experts in the field were asked to draw and comment on evidence-based guidelines for the prevention of Alzheimer’s disease. They agreed on the following guidelines:
1. Minimise your intake of saturated fats and trans fats. Saturated fat is found primarily in dairy products, meats and certain oils (coconut and palm oils). Trans (or hydrogenated) fats are found in many processed foods.
2. Vegetables, pulses (beans, peas and lentils), fruits and wholegrains should replace meats and dairy products as primary staples of the diet.
3. Vitamin E should come from foods, rather than supplements. Healthy food sources of vitamin E include seeds, nuts, green leafy vegetables and wholegrains.
4. A reliable source of vitamin B12, such as fortified foods or a supplement, should be part of your daily diet. Many factors, including age, may impair absorption so this is very important.
5. If using multiple vitamins, choose those without iron and copper and consume iron supplements only when directed by your physician (to avoid dangerously high iron intake).
6. Although aluminium’s role in Alzheimer’s disease remains unclear, those who want to minimise their exposure can do so by avoiding the use of cookware, antacids, baking powder or other products that contain aluminium.
7. Include aerobic exercise in your routine, equivalent to 40 minutes of brisk walking, three times per week.
To add a special boost to protect your delicate nervous system – berries (blueberries, raspberries, strawberries) in particular have been shown to have a protective effect due to their high flavonoid content. Flavonoids are a group of natural compounds found only in plants and research indicates they might be neuroprotective. In one study, nearly 130,000 people were followed for over 20 years. At the end of the study, scientists found that those who consumed the most berries had a significantly lower risk of developing Parkinson’s disease. The results of another long-term study that followed over 16,000 people, analysed their diets and measured cognitive function showed that high intake of flavonoids, especially from berries, slowed down cognitive decline.
Although we don’t know the precise mechanisms of how the nervous system is affected by diet, we do know that a vegan diet can be protective and reduce the risk of neurodegenerative diseases.
To find out more, see the studies mentioned above and learn what else can a vegan diet do for you, see Viva! Health’s The Incredible Vegan Health Report.