We’re never too ancient to improve our eating habits.
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We’re living longer, which sounds good, but given age is a risk factor for so many chronic diseases, can we positively influence the way we age? And how old is too old to do that?
It’s often said we should choose our parents wisely, but studies with identical twins suggest our genes may not be the source of most chronic disease. Cardiovascular diseases, cancers, chronic respiratory diseases and type 2 diabetes share common risk factors we can change, namely an unhealthy diet, lack of physical activity and, of course, tobacco use.
The National Institutes of Health in the US estimates that nearly 80% of cancers are diagnosed after the age of 55. A man’s risk of invasive cancer at age 70 is 27 times higher than it was at age 39 and, for a woman, it’s 13 times. Despite this, the American Institute for Cancer Research recently launched a campaign called “It’s never too late to lower your cancer risk”. Aimed at Americans over the age of 50, it was responding to research that found many people didn’t understand they could still protect themselves, delaying or even preventing cancers through lifestyle changes. Its focus is a more plant-based diet and regular physical activity.
Risk factors for chronic diseases are modifiable at all stages of life. As we age, we need less energy in our diets but the recommendations for nutrients are either the same or more. This means a nutrient-rich diet becomes even more important. Vegetables are nutrient-rich, high in fibre and potassium and low in energy and sodium. If we were to make just one change in our diets, eating more vegetables might be a good place to start.
Many people, including older people, don’t get five serves of vegetables and fruit each day, which could be considered a minimum. Modelling using New Zealand data showed just one more serving of vegetables and fruit a day could, through their effects on blood pressure and total cholesterol, lower risk of coronary heart disease by around 5-8%, lower risk of ischaemic stroke by about 4%, and reduce risk for various cancers by up to 5% in the over 65s. The numbers may seem small, but that’s just one small change. The effects are greater if we start younger.
Recommended daily intakes (RDIs) for specific nutrients not only suggest levels to prevent deficiency but, for nutrients such as antioxidants, dietary fibre and omega-3 fats, intake guidance is also given to minimise the risk of chronic disease. Scientists love to isolate the individual constituents of foods to see what they do to lab rats, but it seems the combined effects of whole foods offer the most benefit. Good amounts of vegetables, fruits, legumes, whole grains and fatty fish in our diets will ensure we reach these targets.
A body mass index (BMI) between 25-29.9kg/m2, although classified as overweight by the World Health Organisation, may pose increased mortality risk for younger folk, but for the over-fifties with no other risk factors, maintaining weight seems to be the way to go. For people over 65 a little extra weight to come and go on is not a bad thing, as they’re more susceptible to weight loss as a result of illness and can also take longer to regain weight than younger people.
However, people in their fifties with a BMI of 30 or more would do well to trim down now: not only is obesity strongly linked with cancers, cardiovascular and other diseases, it can also affect physical abilities even more as we age.
The great thing about exercise is that it doesn’t take long to feel the benefits and those outward signs would likely be backed up by clinical measures of improved health. Although the long-term benefits are well known, a number of studies have highlighted short-term metabolic benefits of exercise. In one study a dozen older sedentary people with impaired glucose tolerance, a precursor to type 2 diabetes, undertook aerobic exercise for one hour each day for seven days.
Rather than killing them, this improved their insulin resistance. This demonstrates one benefit of exercise, not that an hour each day is what’s needed. Getting off the couch is the take-home message.