Want to live a longer life? Here's what to eat

Studies in recent years have shown what a healthy diet looks like and how it can help us live longer.

 Buffet of food (photo credit: INGIMAGE)
Buffet of food
(photo credit: INGIMAGE)

From a relatively early age we’re told to eat healthily, but we usually adopt a proper diet only in our thirties, which is a shame. Research has discovered what you need to eat to prolong your life and at what age it’s recommended to start being careful.

Everyone wants to live longer, right? Often, not always, the key to achieving this goal is choosing a healthier lifestyle, like exercising regularly and avoiding smoking and drinking alcohol.

Studies published in recent years have shown that a healthy diet can prolong life expectancy.

The studies

A new study published in the Plos Medicine journal found that a healthy diet can extend life expectancy by six to seven years in middle-aged adults. In young adults, it may extend life expectancy by about 10 years.

Woman doing exercise at home (credit: INGIMAGE)Woman doing exercise at home (credit: INGIMAGE)

Scientists compiled data from many studies examining nutrition and longevity, along with data from the "Global Disease Burden" study, which provides a summary of population health from many countries. Combining these statistics, they assessed how life expectancy has increased vis a vis ongoing changes in consumption of fruits, vegetables, whole grains, nuts, legumes, fish, eggs, dairy products, red meat, processed meats and sugary drinks.

The authors then proposed an optimal diet for longevity, which was compared to a typical Western diet consisting of large amounts of red meat, high-fat dairy products, high-sugar foods and processed foods while eating very few fruits and vegetables.

According to the study, an optimal diet includes more legumes, whole grains and nuts, and less processed red meat. The researchers found that eating an optimal diet from age 20 will increase life expectancy by more than a decade for women and men from the US, China and Europe. They also found that switching from a Western diet to an optimal diet at age 60 might increase life expectancy by eight years; for 80-year-olds, life expectancy could increase by almost three and a half years.

Is there a middle way? 

Obviously, people won't completely change their diet, so researchers took into account what would happen if people switched from a Western diet to a diet that is halfway between the optimal diet and the typical Western diet.

They found that this lifestyle, called the "feasibility approach diet," could still increase the life expectancy of 20-year-olds by just over six years for women, and a little over seven years for men. These results show that long-term dietary changes at any age may have significant benefits for life expectancy but the gains are greatest if these changes begin early in life.

But, there are also some points that the study didn’t take into account. First, to see these benefits, people had to make changes to their diet within a period of ten years. This means that it is uncertain if people still see benefits for their life expectancy if they make dietary changes over a longer period of time.

The study also didn’t account for past diseases and preexisting conditions which can affect life expectancy. This means that the benefits of diet over life expectancy reflect only an average and may differ depending on a variety of other factors, such as persistent health problems, genetics and bad habits such as smoking and excessive drinking.

But the evidence the researchers examined was still strong and drew from many studies on the subject. Their findings are also consistent with previous research showing that modest but long-term improvements in diet and lifestyle can have significant health benefits, including increased longevity.

So how does it work? 

It isn’t yet clear which factors explain why diet can improve life expectancy. But the optimal diet the researchers revealed includes many antioxidant-rich foods and some studies on human cells suggest that these substances may slow or prevent cell damage, which is one cause of aging.

However, research is continuing, so it’s unknown if the antioxidants we consume as part of our diet will have the same effect. Many foods included in this study also have anti-inflammatory properties, which may delay the onset of various diseases and the aging process. Of course, changing your diet from end to end can be difficult. But even adopting some beneficial foods can increase your life expectancy.