MARIKA SBOROS: Modifying risk factors and adopting healthier habits may ward off dementia

If you had to choose, would you prefer to die from cancer or dementia? That can seem like Hobson’s choice.

Yet many claim to “prefer” a cancer death over the “long, slow death from dementia”. They describe dementia as “a death that slowly erases you”, that “strips away your living self, bit by bit”.

Others call a cancer death “heroic” compared with the progressive loss of memory, ability to think rationally, to plan and perform basic functions that result from dementia.

Research shows that dementia disease, the most common and well-known of which is Alzheimer’s, is a growing, global crisis. UK specialists recently called dementia “the biggest health crisis of our time”.

SA is not immune to the crisis. And with no cure on the horizon, despite decades of research and drugs that haven’t lived up to expectations, the focus is back on prevention.

Studies highlight general lifestyle habits (no smoking, little alcohol, exercising the brain and body regularly, staying socially active) and, particularly, diet for prevention. But just how effective are these to keep dementia at bay?

That depends on who you talk to.

And while diet remains controversial and divisive, the most exciting research puts all other dementia interventions in the scientific shade. It is on the use of ketones (by-products of the body’s fat-metabolism processes) and ketogenic diets (very high-fat, very low-carbohydrate) to offset the effects of brain ageing and atrophy that leads to dementia.

It doesn’t mean we should all be on ketogenic diets to protect ourselves from dementia. “Keto diets”, as they are popularly known, are not new or a “fad”. However, as US physician scientist and keto specialist, Prof Stephen Phinney, chief medical officer and co-founder of Virta Health, once told me, keto diets “are very difficult to get right, very easy to get wrong”.

However, with ageing as one of the biggest risk factors, there is still a pervasive sense of doom and inevitability about dementia, compounded by genetics and ageing populations.

Researchers in a multicentre study published in Jama (Journal of the American Medical Association) in August claim to deliver “a really important message” undermining a “fatalistic view of dementia”. The UK, US and Australian researchers say their data show that a healthy lifestyle may help to offset the genetic risk of dementia.

That builds on studies showing that major risk factors for cardiovascular disease (heart disease and stroke), hypertension (raised blood pressure), obesity, diabetes and smoking are also risk factors for dementia. And modifying these risk factors can reduce dementia risk about 30%.

Doctors, dietitians and Alzheimer’s associations worldwide still regularly advise a low-fat diet for heart health, obesity and diabetes, and reduced risk of dementia. The Alzheimer’s Association of SA recommends “balanced” eating, including fresh fruit, vegetables, fish, wholegrains, nuts, olive oil, moderate poultry, eggs, dairy, and red meat and red wine “sparingly”.

Others have a radically different approach though all appear to agree that excess sugar and processed foods should be avoided.

Harvard-trained psychiatrist and nutrition specialist Dr Georgia Ede says that multiple lines of high-quality, scientific evidence now indicate that insulin resistance is “a primary driver behind most cases of Alzheimer’s disease”.

The evidence has grown “so compelling”, that many researchers now refer to Alzheimer’s disease as “type three diabetes”, Ede says.

Good and bad news flow from the research, she says.

The bad news is that insulin resistance (IR) has reached “epidemic proportions in many countries about the world”. (Data suggest SA firmly among those countries.) That means many people already have some degree of insulin resistance, she says.

The good news is that IR is “a largely preventable, treatable condition rooted squarely in our modern lifestyle”, Ede says.

She defines IR as “a metabolic disorder characterised by gradually rising blood insulin levels and worsening carbohydrate tolerance”. Diets too high in refined carbohydrates, such as sugars, flours, juices, and processed cereals, worsen insulin resistance.

These ingredients generate “unnaturally steep blood-sugar spikes and insulin levels that damage metabolism over time”. They do so in the body, which can lead to type two diabetes and many other chronic diseases, but also in the brain.

This “lays the groundwork for Alzheimer’s disease”.

“For the minority with healthy metabolism, simply eating a whole-foods diet free of processed carbohydrates and other risky ingredients, and engaging in regular physical activity may go a long way toward maintaining healthy metabolism and preventing this modern scourge,” Ede says.

For the majority with already damaged carbohydrate metabolism, a low-carbohydrate diet may be “the wisest strategy” as it is one of the easiest, most effective ways to normalise glucose and insulin levels”, Ede says

She sees a glimmer of hope in clinical trials exploring low-carb and ketogenic diets in the treatment of mild cognitive impairment (pre-Alzheimer’s) and early Alzheimer’s disease.

“But when it comes to this serious, neurodegenerative condition that gradually starves and shrinks the brain over decades, prevention is the best medicine.”

US nutrition specialist and researcher Amy Berger, author of The Alzheimer’s Antidote (Chelsea Green Publishing, 2017), says the  most compelling evidence suggests that there won’t be a “magic pill” or  “silver bullet” treatment for dementia. “But if dementia is from a metabolic problem, it needs a metabolic solution rooted in diet.”

It might also need other synergistic and complementary strategies to address this from “multiple angles”. But the medical literature is “overflowing with research identifying impaired cerebral glucose metabolism as the fundamental problem in [Alzheimer’s]”, Berger says.

“First and foremost, if the brain is essentially starving, feed it,” Berger says.

Neurons in affected brain regions lose the capacity to metabolise glucose effectively. This, essentially, creates a “fuel shortage or energy crisis in the brain”, she says. That’s known as “metabolic-cognitive syndrome” because of the strong links between Alzheimer’s and metabolic syndrome (also known as chronic hyperinsulinemia).

“It’s everywhere in the scientific literature, hiding in plain sight, as they say. Yet no one was talking about it.”

If the fundamental problem in the Alzheimer’s brain is neurons unable to harness energy from glucose effectively, the most important aid is an alternative fuel source that they can metabolise, Berger says.

“Ketones fit this description.”

While an Alzheimer-ravaged brain cannot use glucose effectively, it still takes up and metabolises ketones, Berger says. The “stellar work” of Prof Stephen Cunnane and colleagues at Canada’s Sherbrooke University has firmly established this, she says.

Cunnane holds the research chair on brain metabolism and cognition in ageing at the university’s medical faculty.

The research may not always mean a ketogenic diet. It most likely means “eating and living in ways as to remain metabolically healthy into older age”, Berger says.

“Some people will be able to tolerate a liberal carbohydrate intake, others will do best remaining low-carb,” she says.

Petra du Toit, Alzheimer’s Association of SA executive director, says there are ways to deal with dementia diseases that help people living with them to live well.

“Your heart and your brain are the most important organs.

“What is good for your heart is also good for your brain,” Du Toit says.

Dementia in SA:

• Dementia is a “progressive decline in cognitive function due to brain damage or disease beyond what might be expected from normal ageing”.
• The most common forms of dementia in SA are: Alzheimer’s; vascular dementia; HIV/Aids-related dementia, alcohol-related (Korsakoff’s) dementia; and dementia with Lewy bodies.
• An abiding myth in SA is that Alzheimer’s is a white man’s disease. Alzheimer’s does not respect race, ethnicity, gender, social or economic status.
• Another myth is that dementia is an old man’s disease. It can start forming in the brain as early as in your 30s.

• (Source: Alzheimer’s Association of SA)