All you need to know about diets and fats

Is there any credible anti-ageing advice? Which diet and fats either kill us or make us live longer?

If Charles Dickens were a time traveller and a health nut, he might describe today as both the best and worst of times for an anti-ageing consumer. Our access to information is limitless, but a lot of it is more muddling than enlightening. Who isn’t receiving daily emails about miracle weight-loss diets, superfoods and life-prolonging antioxidants?

To counter these exuberant claims, with mind-disturbing regularity we seem to be assaulted by new studies that rail against existing notions of salubrious behaviours, challenging the very notion that there is even such a thing as a healthy diet, an entirely beneficial food substance or an antioxidant worth taking. We might as well wolf down as many profiteroles as our digestive systems can tolerate, prepare ourselves for Armageddon and start smoking, a practice commenced by Jean Calment — a French centenarian who lived to the age of 122 years and 164 days, the longest confirmed human lifespan in history — on her 115th birthday. This remarkable milestone was achieved without any death-defying diet or supernatural supplement.

Diet

Most diets are about weight loss and honing the perfectly sculpted body. If you’re wanting to back a sure-fire winner, just step inside the 24-hour gymnasium or go to your local trendy eatery and discover which diet the body obsessives hope will give them the physique of their dreams. The high-protein low-carbohydrate diet, enthusiastically endorsed by gym junkies and the Paleo CrossFit movement, might invigorate your reproductive hormones, build muscle and assist with weight loss, but if you’re a mouse it’s bad for your heart and shortens your life. The primary culprit might be branched-chain amino acids, substances that body builders use to pump up their muscles. Mice fed low-protein high-carbohydrate diets were more rotund but lived longer. The amino-acid-rich diet helped the rats to be toned and procreate but at the expense of their lifespan.

It’s enough to make any Sylvester Stallone wannabe with just a little foresight sit up and weep — and it’s very bad news for all those who advocate a Paleo-style diet, the kind supposedly followed by our hunter-gatherer ancestors, with its emphasis on consuming proteins and fats while limiting grain carbohydrates. Protein and fats are essential nutrients for manufacturing and repairing muscle and giving birth to vital sex hormones that allow for the perpetuation of the species but, beyond this point, eating these in abundance may undermine our health and speed up our demise.

According to Professor Steve Simpson — who helms the Charles Perkins Centre at the University of Sydney and devotes himself to research targeting the scourge of obesity, diabetes and heart disease — because protein is essential to our survival, significantly reducing its intake is also going to be counterproductive, as we will be compelled to eat more fats and carbohydrates to generate the proteins we are lacking.

The blueprint for a healthy lifespan would seem to demand that we eat the right amount of protein that prepares us for successful procreation, thereafter cutting back on our consumption if we want to extend our lives. Curbing our appetite for animal protein and replacing it with the plant variety might also be beneficial as well as do our much beleaguered planet huge favours at the same time. With global warming escalating at an alarming rate, pretty soon public health policy might compel us to fill our plates with more vegetable than animal protein.

The fats

What about fats, specifically saturated fat found in meat, butter, milk and eggs, a substance we thought clogged up our arteries? It’s the demon that’s supposed to raise cholesterol, especially LDL, the cholesterol that’s spectacularly bad for our hearts. A review examining a number of studies that have attempted to link saturated fats with heart disease has failed to demonstrate such a connection.

As it turns out, saturated fats can execute the kinds of good deeds hitherto thought to be unimaginable, like increase HDL, the protective cholesterol, and reduce triglycerides, another fat associated with heart disease risk. These revelations have had heart specialists seeking refuge in the recesses of their medical journals where saturated fats retain villain status. Tune into them on newsfeeds and you’ll still hear cardiologists demonising fats and telling us we should avoid them.

Still, that’s not entirely bad counsel. There’s a whole bunch of other ways in which these multitasking sheep in wolves’ clothing can kill us. Saturated fat increases the risk of colon and prostate cancer. Saturated fat can also undermine the function of insulin, the primary hormone responsible for lowering blood sugar. There’s a number of studies demonstrating that a high saturated fat diet increases blood sugar or glucose levels. In those who already have type 2 diabetes, which is often but not always associated with being overweight, saturated fat can substantially increase the likelihood of having a heart attack.

Dr Michael Elstein is an anti-ageing physician and writer based in Sydney, Australia. He is the author of three books including his latest, The Wellness Guide to Preventing the Diseases of Ageing. He has also designed the app The Diet Guide to Ageing Prevention.