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A Diet That Wards Off Dementia

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Oct 12, 2015

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Most of us can expect to live to a ripe old age in our 80’s or even 90’s, thanks to advances in medicine and technology – according to the World Health Organization, by 2050, the number of people aged 60 or older will represent nearly a quarter of the world’s population.

But this progress also brings increased travails of old age – specifically, diminishing mental faculties. The WHO goes on to state that “the risk of dementia rises sharply with age, with an estimated 25-30% of people aged 85 or older having some degree of cognitive decline.”

To some extent, however, age-related decline in cognitive abilities can be controlled and slowed. The food people consume has long been thought to affect our mental faculties in later life; now, a new study shows that following a specific diet can help counteract age-related effects on our brain.

“Although we are genetically programmed at birth, [this] can be altered by external factors,” says Dr. Raghunandan Nadig, a Bangalore-based neurologist. “Diet and exercise are two factors that have a profound impact on our health and brain.”

The MIND diet – a combination of the Mediterranean diet and DASH (Dietary Approaches to Stop Hypertension) diet – has been shown to keep elderly people who followed it more than seven years younger cognitively than those who didn’t. The observational study, published this year, followed the diet of 900 elderly people over a period of four and a half years while evaluating changes in their cognitive function.

MIND is an acronym of Mediterranean and Intervention for Neurodegenerative Delay. The MIND diet breaks its recommendations into 10 brain-healthy food groups a person should eat and five unhealthy food groups a person should avoid. The brain-healthy food includes whole grains, green leafy vegetables, wine, nuts, and berries – all recommended in the Mediterranean and DASH diets. Where the MIND diet differs, however, is in recommending superfoods like blueberries, kale, chia seeds and quinoa, explains Roopa Sampat, a UK-based dietician. These foods contain key nutrients required for the brain to function normally and optimally: glucose, antioxidants and omega-3 fatty acids. While further studies on the MIND diet are needed, Sampat says, the findings around these nutrients so far are encouraging.

GLUCOSE

The brain needs a lot of energy to function well, and glucose is its fuel. Neurons – that is, brain cells that transmit information – are constantly at work and thus have a high demand for energy; the brain uses about twice as much glucose as the rest of the body. Mental activity drains glucose from the brain, and this drain is more pronounced in older people, impacting their ability to think and remember. Since the brain does not store nutrients, it needs a constant supply of glucose – and older people’s brains require greater amounts. The MIND diet recommends complex carbohydrates – such as wheat, certain varieties of rice, barley, rye and millets – which supply the brain with glucose steadily without spiking your blood sugar.

ANTIOXIDANTS

Due to the brain’s high levels of activity and energy consumption, it is also susceptible to oxidative damage.

“The cells in our body and brain are constantly being built and broken down,” says Dr. Nadig, “and during this process, cells can be damaged or injured. Antioxidants reduce and prevent this damage at molecular level.”

The MIND diet calls for foods rich in antioxidants, which come in a variety of tastes and effects. Alpha lipoic acid, for instance – an antioxidant found in vegetables such as spinach and broccoli – has been shown to improve memory deficits in animal models of Alzheimer’s disease and to reduce cognitive decay in a small group of human Alzheimer’s patients. Foods such as blueberries, olive oil and tuna also contain antioxidants that assist cognition. The same leafy greens and oily fish that provide antioxidants also contain vitamins D and E, which are thought to have similar impact on cognition.

Other foods contain other antioxidants with different effects.

“Red wine, which contains polyphenols, acts as an antioxidant and is known to boost the blood supply to the brain, thereby boosting brain power,” Sampat says.

OMEGA-3 FATTY ACIDS

Omega-3 fatty acids keep brain cell membranes flexible, allowing them to change shape freely to form synapses, or junctions between neurons related to learning and memory. These changes, known as synaptic plasticity, are some of the key neurochemical foundations of cognition, and aging as well as diet can take a toll.

“About 40% of the fatty acid in brain cell membranes is DHA (Docosahexaenoic Acid), one of the omega-3 fatty acids,” says Vasundara Agarwal, a Bangalore-based nutritionist. “Consumption of fish – which are rich in omega-3s – at least three times in a week reduces the risk of Alzheimer’s disease.”

This is why the MIND diet calls for plenty of salmon and walnuts – solid sources of omega-3s that have been shown to improve learning and memory and reduce incidence of depression, mood disorders, and dementia.

FOODS TO AVOID

Finally, the MIND diet also recommends limiting or avoiding certain foods. These include red meat, butter, sweets, pastries, whole-fat cheese and fried foods, which are rich in saturated and trans fat. These types of fat – unlike fatty acids – can clog up blood vessels and reduce the brain’s blood supply, damaging neurons and adversely affecting cognition.

Looking to try the MIND diet for yourself or a loved one? Just keep in mind the following rules:

Eat:

  • Green, leafy vegetables (6 servings / week)
  • Other vegetables (1 / day)
  • Nuts (5 servings / week)
  • Berries (2+ servings / week)
  • Beans (3+ servings / week)
  • Whole grains (3+ servings / day)
  • Fish (1 serving / week)
  • Poultry, such as chicken or turkey (2 servings / week)
  • Olive oil
  • Wine (1 glass / day)

Limit/Avoid:

  • Red meat (4 or fewer servings / week)
  • Butter and margarine (1 tbsp or less / day)
  • Cheese (1 serving / week)
  • Pastries and sweets (5 or fewer / week)
  • Fried or fast food (1 or fewer serving / week)

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Written By Deepa Padmanaban

Deepa is a freelance journalist who writes about health, wellness, science, environment, people and culture. She has published in The Hindu, Mint, The Caravan, Open magazine, India Spend, and international publications such as Quartz, Christian Science Monitor and others. In her previous avatar, she was a biologist at The Indian Institute of Science (Bangalore) and Harvard University. You can follow her work at deepapadmanaban.com or on Twitter @deepa_padma

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