From Heart-Healthy Lifestyles to Addressing Vitamin Deficiency, the Latest Research on Reducing Dementia Risk
As recent research shows, a healthy lifestyle can help reduce risk of dementia — even for those already showing signs of it. Photo: Kiyoshi Hijiki
A report released last fall by the World Health Organization (WHO) had a rather sobering prediction: the number of people with dementia is projected to rise 40 per cent — from 55 million to 78 million — by 2030.
And although aging is still the major risk factor, it’s worth noting that the agency reported so-called young-onset dementia — occurring in people under 65 — accounted for around 10 per cent of all dementia cases.
Ominous outlook aside, the WHO did note that developing dementia isn’t inevitable, and risk factors can be reduced by controlling hypertension, diabetes, diet, depression, and the use of alcohol and tobacco.
Here, we look at more interventions, which research since has revealed, that may also help reduce risk.
Researchers say they’ve found a link between vitamin D deficiency and dementia risk.
In a study published this past April by the American Journal of Clinical Nutrition, authors reported that participants (33,000, aged 37 to 73, in the U.K.) who had a genetically higher level of vitamin D (a concentration in the blood of 50 – 75.9 nmol/l) also had a decreased dementia risk, “with the odds of dementia decreasing with higher […] concentrations.”
“In some contexts, where vitamin D deficiency is relatively common, our findings have important implications for dementia risks. Indeed, in this U.K. population we observed that up to 17 per cent of dementia cases might have been avoided by boosting vitamin D levels to be within a normal range,” Elina Hyppönen, senior investigator of the study and director of the Australian Centre for Precision Health at the University of South Australia, said in a press release.
“Most of us are likely to be okay, but for anyone who for whatever reason may not receive enough vitamin D from the sun, modifications to diet may not be enough, and supplementation may well be needed,” she went on to say.
Why that may be of particular interest to Canadians — according to a report from 2013 by Statistics Canada:
- Only just over two-thirds of the population (68 per cent) had blood concentrations of vitamin D over 50 nmol/l — an amount, they note, sufficient to maintain healthy bones
- A minority (34 per cent) took a supplement containing vitamin D, but a larger percentage of those taking supplements were above the 50 nmol/l cut-off (85 per cent), compared with non-supplement users (59 per cent)
Check with your doctor to determine your own levels, and whether you need to supplement. For those under 70, Health Canada’s recommended dietary allowance (RDA) for vitamin D is 600 IU (15 mcg) to a tolerable upper intake level (UL) of 4.000 IU (100 mcg), while the RDA increases to 800 IU for people over the age of 70.
Lucky No. 7
The American Heart Association says scoring well at seven lifestyle factors can decrease risk of cardiovascular disease. They are: managing blood pressure and blood sugar, controlling cholesterol, being active, eating healthily, maintaining a healthy weight and not smoking.
Now, when researchers put these so-called Life’s Simple 7 to the test against dementia they found that the healthy habits may also reduce its risk — even if someone is at the highest risk.
Published this past May in the journal Neurology, a study of more than 11,500 Americans (8,823 people with European ancestry and 2,738 people with African ancestry), followed over 30 years, showed that participants with the highest scores in the seven factors had a lower risk of dementia, including those with the highest genetic risk.
“These healthy habits in the Life’s Simple 7 have been linked to a lower risk of dementia overall, but it is uncertain whether the same applies to people with a high genetic risk,” study author Adrienne Tin of the University of Mississippi Medical Center in Jackson said in a press release. “The good news is that even for people who are at the highest genetic risk, living by this same healthier lifestyle are likely to have a lower risk of dementia.”
Tin says more study is needed to determine if the results would be similar for even more genetic risk groups and in those of other ancestral backgrounds.
Move It or Lose It
“Late-life physical activity is one of the most consistently recommended lifestyle modifications to support brain and cognitive aging,” write authors of a study published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association in January.
They go on to note that physical activity is associated with reduced incidence of Alzheimer’s disease — the most common form of dementia — while inactivity alone may account for as many as 4 million cases of dementia.
But why is physical activity so protective?
The study showed that exercise boosts levels of a protein known to strengthen communication between brain cells via synapses. “All of our thinking and memory occurs as a result of these synaptic communications,” lead author Kaitlin Casaletto, an assistant professor of neurology in the Memory and Aging Center at the University of California San Francisco, told CNN.
“We have described, for the first time in humans, that synaptic functioning may be a pathway through which physical activity promotes brain health,” she added.
Better news still, the study showed that the effect was found even in active older people whose brains showed signs of plaques and other hallmarks of Alzheimer’s and other cognitive diseases.
So how much physical activity do we need for this protective effect?
“We recommend aiming for 150 min/week of physical activity,” said Casaletto, adding. “Prior studies have shown that even walking relates to reduced risk of cognitive decline!”