Of all the new research, three studies in particular paint a stark picture of the extent to which the quality of our air can determine whether we will age with our minds intact. In one from 2018, researchers followed 130,000 older adults living in London for several years. Those exposed to higher levels of air pollutants, particularly nitrogen dioxide and fine particulate matter released by fossil fuel combustion, were significantly more likely to develop Alzheimer’s disease—the most common kind of dementia—than their otherwise demographically matched peers. In total, Londoners exposed to the highest levels of air pollution were about one and a half times more likely to develop Alzheimer’s across the study period than their neighbors exposed to the lowest levels—a replication of previous findings from Taiwan, where air pollution levels are much higher.
Another, a 2017 study published in the Lancet, followed all adults living in Ontario (roughly 6 and a half million people) for over a decade and found that those who lived closer to major high-traffic roads were significantly more likely to develop Alzheimer’s disease across the study period regardless of their health at baseline or socioeconomic status. Both of these studies estimated that around 6 to 7 percent of all dementia cases in their samples could be attributed to air pollution exposures.
Those studies from Canada and the UK are certainly intriguing. But the most compelling, and least reported on, study comes from the United States. It was also, incidentally, inspired by our previous reporting.
There is no magic shield against Alzheimer’s disease and other dementias. Supplements don’t work. Yet there is evidence that some strategies may help.
Paula Span at the New York Times writes:
Increased physical activity;
Blood pressure management for people with hypertension, particularly in midlife;
And cognitive training.
That last recommendation doesn’t necessarily refer to commercial online brain games, said Dr. Kristine Yaffe, a neuropsychiatrist and epidemiologist at the University of California, San Francisco, who served on the panel.
“It’s really the concept of being mentally active,” she said. “Find something you enjoy where you’re learning something new, challenging and stimulating your brain.”
Though the evidence to date doesn’t establish which mental workouts have the greatest impact or how often people should engage in them, “they’re not expensive and they don’t cause side effects,” Dr. Yaffe pointed out.
The blood pressure recommendation got a boost in January with the latest findings from the Sprint trial, a multisite study stopped early in 2015 when intensive treatment of hypertension (a systolic blood pressure goal of less than 120, compared to the standard 140) was shown to reduce cardiovascular events and deaths.
Dr Wyman concluded, “Apathy at baseline was related to increased risk of conversion accounting for depression severity and treatment, confirming the potential clinical importance of this neuropsychiatric symptom for assessing risk.”
In a seperate study published in the JAMA Psychiatry journal, researchers found apathy to be associated with an increased risk for incident dementia in patients with mild cognitive impairment (MCI).
These findings have high clinical relevance because patients with apathy are likely to withdraw from care. The risk for dementia among patients with apathy appears to be independent of concurrent depression, greater in the short term, and less strong with higher age and greater cognitive impairment. Apathy may be a powerful marker of increased risk for incident dementia.
Although amyloid proteins have always been suspected to play a significant role in Alzheimer’s disease, this study is only the second to find a concrete connection between reduced amyloid buildups and improved cognitive function. It suggests that targeting these proteins may be a good way to combat the disease in future trials.
Amyloid proteins were reduced by as much as 93% in some trial participants, making 81% of participants in the successful group what researchers call “amyloid negative.” Although this doesn’t mean these patients were cured, it’s a big deal. Additionally, the team compared the cognitive decline of this group to those who received the placebo using multiple metrics. They found that participants taking the highest dose of BAN2401 performed 30% better on a new cognition test called ADCOMS than those taking the placebo. ADCOMS is not the typical scale used to assess cognitive decline, but has been shown to be more sensitive (paywall) to changes in cognitive ability. When the group used a more common, longer-standing scale, participants in the highest dosage group performed 47% better than the placebo.
In a study published in the journal Neurology, researchers led by Dr. Zoe Arvanitakis, medical director of the Rush Memory Clinic at Rush Alzheimer’s Disease Center, find more evidence that blood pressure may be one of those risk factors.
A Vancouver-based research team led by Canada’s most cited neuroscientist, Dr. Patrick McGeer, has successfully carried out studies suggesting that, if started early enough, a daily regimen of the non-prescription NSAID (nonsteroidal anti-inflammatory drug) ibuprofen can prevent the onset of Alzheimer’s disease. This means that by taking an over-the-counter medication, people can ward off a disease that, according to Alzheimer’s Disease International’s World Alzheimer Report 2016, affects an estimated 47 million people worldwide, costs health care systems worldwide more than US$818 billion per year and is the fifth leading cause of death in those aged 65 or older.
What these results tell us about the role exercise might play in slowing the development of Alzheimer’s is difficult to nail down. While studies like this suggest that exercising more strengthens the brain against the debilitation leading to severe dementia, definitive answers are still elusive. We don’t know, for example, the amount of exercise that makes a difference, if specific types of exercise are better than others, or whether starting exercise later in life can forestall the progression of dementia.
What we do have are solid indications that we should think of exercise and brain health in a similar way to exercise and heart health. Some of the same benefits exercise provides the heart—like improved blood flow and lower inflammation—also benefit the brain. More evidence along those lines keeps coming, further supporting the case that staying active is a better policy for brain health than the alternative.
James Bullen, Australian Broadcasting Corporation:
It’s not the spice itself that’s key, rather it’s an active compound within turmeric called curcumin. Research has found that curcumin has some anti-oxidant and anti-inflammatory properties.
“Curcumin is a very powerful anti-inflammatory agent,” said Professor Manohar Garg, director of the nutraceuticals research program at the University of Newcastle.
Because inflammation is linked to a range of chronic conditions and diseases, among them arthritis, Alzheimer’s and heart disease, researchers argue curcumin could help reduce the risk of those diseases by limiting inflammation in the body.
“It’s very powerful, the most powerful food I know of, for fighting inflammation in the body,” Professor Garg said.
A longitudinal study, published Thursday in the journal Diabetologia, followed 5,189 people over 10 years and found that people with high blood sugar had a faster rate of cognitive decline than those with normal blood sugar—whether or not their blood-sugar level technically made them diabetic. In other words, the higher the blood sugar, the faster the cognitive decline.
“Dementia is one of the most prevalent psychiatric conditions strongly associated with poor quality of later life,” said the lead author, Wuxiang Xie at Imperial College London, via email. “Currently, dementia is not curable, which makes it very important to study risk factors.”