In a world where the average person is living a longer (if not necessarily healthier) life, Alzheimer's disease has become a hot-button health topic. The search for a way to prevent, cure or effectively treat the disease that affects over five million Americans and their families has also ramped up in recent years.

At this week's Alzheimer's Association International Conference in Copenhagen, Denmark, the results of several important Alzheimer's studies were presented. Here are some of the key findings about one of the most most fear-inducing ailments of the modern age:

Having a strong sense of smell can be bad if you're sitting next to someone who didn't have time to take a shower this morning. But an unusual decline in your schnoz's scent-sensing power could indicate a decline in the health of your brain, according to two new studies, one from Harvard University, the other from Columbia University.

Each investigation used the University of Pennsylvania Smell Identification Test (UPSIT)—a 40-question "scratch and sniff" test—to determine whether a correlation between cognitive decline and sense of smell existed in a population of aging adults who didn't have dementia at the beginning of the study. Over the course of each investigation, some participants did develop dementia, while others didn't. By the end of the two studies, there was one, clear conclusion: a decreased sense of smell and cognitive decline seem to go hand-in-hand.

The University of Columbia study, led by professor of psychiatry, Dr. Davangere Devanand, tested more than 750 adults with an average age of 80 years. Devanand's team determined that scoring just one point less on the UPSIT test equated to a 10 percent increase in a person's risk for developing Alzheimer's. This finding held true, even after accounting for external factors, such as the natural decrease in scenting ability that tends to occur as we age.

In his conference presentation, Devanand admits that the results need to be duplicated on a larger scale in order to have a real-world impact, but says such findings could lead to a more efficient way to detecting cognitive decline; "…a relatively inexpensive test such as odor identification may be able to identify subjects at increased risk of dementia and Alzheimer's disease at a very early stage, and may be useful in identifying people at increased risk of cognitive decline more broadly."

Check out Blogger and longtime dementia caregiver, Marlis Powers' take on the notion of using your nose to sniff out cognitive decline in: "The Peanut Butter Sniff Test for Alzheimer's."

In addition to being "the windows to the soul," a person's eyes could also hold the key to a more efficient method of Alzheimer's detection.

Beta-amyloid—a protein-based plaque that builds up in a person's brain and is thought to be a major contributor to the development of Alzheimer's—also apparently accumulates in the retinas of the eye.

Using a curcumin-containing supplement to visibly highlight the beta-amyloid and a special retinal scanning technique to spot the pesky plaque, researchers from the Commonwealth Scientific and Industrial Research Organization were able to correctly identify people with Alzheimer's 100 percent of the time, and correctly weed out people who didn't have Alzheimer's 80 percent of the time.

The study's lead author, Shaun Frost, says his team sees the retinal scanning technique working alongside other, pre-existing methods for detecting and tracking Alzheimer's progression (e.g. MRI brain scans, brain PET imaging and clinical evaluations). "If further research shows that our initial findings are correct, it could potentially be delivered as part of an individual's regular eye check-up," he says.

Consuming a healthy diet full of fruits and vegetables, engaging in regular exercise and remaining mentally and socially engaged are increasingly cited as actionable tips for staving off cognitive decline in old age. Multiple studies have led clout to these claims, but some of the most promising findings on this topic were presented this week by Dr. Miia Kivipelto, professor at the Karolinska Institutet in Sweden.

Under Kivipelto's guidance, researchers split more than 1,200 aging adults with risk factors for cognitive decline into two groups. One group was given generic health information and guidance from their doctors, while the other group received specific strategies targeted at optimizing their physical wellness, nutritional health, social engagement and cognitive fitness.

The groups stuck with their respective regimens for two years, undergoing regular cognitive screening tests throughout. When the participants were subjected to the mental evaluations, those who took advantage of the targeted lifestyle interventions had memories that were not only faster, but more accurate. These individuals were also better at performing complex planning and problem-solving tasks than their counterparts who received more generic counsel form their health care providers.

"These results highlight the value of addressing multiple risk factors in improving performance in several cognitive domains," says Kivipelto, whose team is planning a longer follow-up study to cement their findings. It's important to note that the participants in these investigations had pre-existing risk factors, including poor health habits and less-than-optimal vascular health, which study authors say created a special "window of opportunity for prevention."

The good news is that this window appears to exist no matter how old a person is. Indeed, other studies have shown that individuals in their 70s and 80s can derive cognitive benefits by making healthy lifestyle changes. Engaging in regular exercise can even help people with Alzheimer's perform everyday tasks.

Alzheimer's advances continue to be made, albeit a bit too slowly to offer much benefit to those already dealing with the disease. But each incremental improvement sheds additional light on this highly-complex condition.