HOW AGEING IS STUDIED
We are ageing in a time when science is committed to and compelled by the question “What is ageing?” The science of understanding ageing takes place in laboratories and meeting rooms, at desks and with the help of technology. Study participants may dutifully take medications, try different ways of eating, of moving, of sleeping, or just give up their privacy and answer loads of questions, all so that we can better understand how ageing affects our bodies. The test groups for these studies range in sample size from a hundred people to hundreds of thousands of people. When we see the results of the latest research plastered all over social media or mentioned in a morning news show or even announced in the headlines of newspapers, it’s important to keep in mind that every study varies in terms of how it collects its data. Data can be influenced by how many participants are included, and also by how well a study is designed and the elements for which its researchers are controlling – factors ranging from time and temperature to gender and age may affect a study’s accuracy.
One type of research method is the observational study. Observational studies assess how the choices people make affect their wellness. Some of these studies, like the Framingham heart study (see here), are longitudinal – they track participants over a sustained period of time. Longitudinal studies can last for decades, and they have been very useful in helping us understand ageing.
Observational studies can also examine a cross-section of people and compare them with one another to see how their choices have influenced their health. For example, one cross-sectional study compared older people with similar health profiles to determine the effects of vitamin D deficiency (answer: it can put you in a lousy mood as well as impair your ability to think clearly).
Some studies are less about observing, and are more about getting involved. An interventional study gathers groups of people to study for comparison. Researchers ask one group to implement a specific behaviour in order to observe its impact on health, and use the other group as a control for comparison. For instance, when researchers wanted to understand how the intensity levels of physical activity would affect memory, they organized sixty-two healthy older people into three groups. Over the course of six months, one group performed medium-intensity workouts, one group performed low-intensity workouts, and the other group did not work out at all. The study found that any exercise had great benefits for memory and brain volume, with little difference between the low- and medium-intensity groups.
When researchers study ageing, they don’t only observe humans, they also turn to human cells, animal cells, bacteria, mould, and fungi. They experiment on lab animals (and sometimes wild animals), from sponges and worms to mice and monkeys to naked mole rats. By examining and manipulating genes from other animals, scientists can gain insights into the human ageing process. Although worms look nothing like human beings on the outside, internally, like flies, they have many genes and biological mechanisms in common with us. And just like people, worms and flies age, albeit at a much faster rate. Within a year’s time, many rounds of testing and learning can take place on worms and flies, whereas watching humans age in observational studies takes a human lifetime – more time than one scientist has on her hands.
Comparative biology can also yield important insights. Naked mole rats, which are somewhat terrifying-looking mouse-sized rodents, live seventeen to twenty-eight years, while common mice and rats live only three to five years. Why the disparity? By comparing similar mammals with very different life spans, scientists may be able to identify the specific genes that make some live longer than others.
If one direction of learning shows promise when it comes to increasing the length of life – and the length of a healthy life – scientists will apply and reapply methodologies that are more and more complex, ultimately testing medications or treatments on humans to determine their safety. At each step, they must evaluate the efficacy of their methods. Just because manipulating a certain gene or pathway or hormone makes a fly live longer doesn’t mean it will do the same for a mouse, let alone a human.
And just because it works for a man doesn’t mean it will work for a woman, as we will soon discuss.
IS IT POSSIBLE TO GROW OLD WITH HEALTH?
Life expectancy doesn’t tell us how long a being might live under the best of conditions. It tells us how long a being might live while taking into account the reality of its environment. We can give science a lot of credit for doubling our life span, but we can’t give doctors all the responsibility for keeping us healthy.
Your genes create the basis for your health. The environment you live in and the lifestyle choices you make every day have a massive impact on how you age, what makes you sick, and how your body heals. As we grow older, weakening is inevitable and becoming strong is a choice. Diseases of old age are not necessarily a given for any one of us. I think it’s always more challenging to make new choices or try out new behaviours if you don’t understand the “why” behind them. Advice like “eat healthfully” or “exercise every day” doesn’t really mean anything to me in a vacuum. That’s why the information in this book is so important to me. Without context, how can any of us be expected to understand why we should eat more vegetables or why strength training is a big deal for women? We know from being avid consumers of media that certain things are “good for us”, but we may not fully understand why.
So let’s do our best to learn these things. Let’s try to better understand how our choices influence our health at the cellular level, and how the changes in our cells are what affect our health as a whole and, in particular, our health as we age. We can become better advocates for our own health. It all starts with learning the facts.
FACT: WOMEN LIVE LONGER than men. A baby girl born in the United States in 2010 had a life expectancy of eighty-one; for the baby boy next door, that number was seventy-six. That’s a five-year gap, enough to make a person really curious about why this might be the case, especially when you consider that this is true around the world, too. Country by country, life expectancies vary (due in part to variables like availability of clean water, access to healthcare, and stability of the region), but the world over, the women’s life expectancies are always greater than men’s.
In the United States, over the course of all that longevity, women use more healthcare services and take more prescription drugs than men do. Researchers at the Mayo Clinic made headlines a few years back when they announced that nearly 70 per cent of Americans take at least one prescription drug daily. They also reported that, as a whole, women and older adults receive the most drug prescriptions. As people get older, they are prescribed more pills to take, not fewer, and the quality and accuracy of those medications has a direct impact on health. The more medicines lined up in your bathroom cabinet, the more important it becomes that you are taking the right medications, in the right doses, at the right times.
Health and healthcare are inextricably bound together. Every time you go to the GP surgery, every time you pop a pill, you are relying not only on your doctor and your pharmacist, but also on medical schools, on drug companies, on research labs, on individual scientists – and their assumptions about women, and their awareness of the latest research about women’s