Michael Greger prefers baked beans to supplements. By Sophie Morris

newspaper spread with photo of elderly woman in a garden.

Dr Michael Greger grins as he recalls the “firestorm of controversy” he caused delivering the keynote speech to a conference full of anti-ageing professionals. He was speaking to a hall full of incredibly rich American doctors - the race to roll back the years is worth many billions of dollars - organised by the American Academy of Anti- Aging Medicine (A4M). His message to them? Quit selling snake oil and go back to the science, which, he laments, has in some circles become “a dirty word”.

The minutes advises should every “Their whole business model is selling crazy products and services, as that’s where all the money is,” Dr Greger says. “They’re taking advantage of the most vulnerable people in our society, the sick and elderly - preying on our fears of disease and death.”

“People who cannot afford daily necessities are spending ridiculous amounts of money on pills that promise protean benefits but are scams or even worse.”

Dr Greger, 51, is a physician and New York Times bestselling author who lives in Washington DC with his family of rescue dogs. He has a somewhat prosaic message for anyone keen to turn back the clock.The good news? It doesn’t involve any of the esoteric treatments peddled by the anti-ageing industry, such as bee venom, snail serum, sheep placenta or jellyfish protein.

The bad news? Forget pills, potions, needles and treatments, you’ll have to put the work in.

Adapting our diets and lifestyle, Dr Greger says, is the main route to health and longevity. “There’s so much nonsense out there,” he tells me from his London hotel, in the middle of a 100-city speaking tour for his new book, How Not to Age, a 640-page manual on how to slow the ageing process everywhere from our bones and joints to our brains, skin and sight.

“We have tremendous power over our health destiny and longevity, and for the vast majority of people, chronic disease is preventable with the right diet and lifestyle.” Dr Greger’s previous books include How Not to Diet (2019) and How Not to Die (2015) and he points out the crossover between the diet and anti-ageing industries.

“Anyone seeking even basic practical advice about living longer or lighter is faced with this barrage of inscrutable pills and potions. Even with the luxury of being a physician, neck-deep in medical journals, it’s been a challenge to tease out facts from farce. It took me three years to sift through all the science. I’m afraid the casual observer would have no chance.”

How Not To Die investigated the chronic diseases that account for most non-accidental deaths.

“There’s no such thing as dying from old age,” Dr Greger says, explaining that in a study of 42,000 autopsies of centenarians, every single one had died of a disease, usually heart disease, the leading cause of death in the UK, closely followed by other chronic diseases including diabetes and cancer.

He realised the common denominator that linked all disease is ageing and that by turning our attention to ageing, we can delay death, in whatever form it’s approaching. “Even if all cancer was eliminated, we’d only extend life expectancy by a few years,” Dr Greger says. “If one age-related disease doesn’t get us, another will.”

From one perspective, it seems Dr Greger is working within the industry he criticises. How Not to Age is, after all, a product, even if it costs £22 compared to the eye-watering amounts spent by tech billionaires such as 45-year-old Bryan Johnson, who spends $2m a year and takes blood from his son to reverse his own ageing.

Dr Greger insists that his basic and achievable advice - don’t smoke, eat more fruit and veg, walk for 20 minutes, don’t carry excess weight - will get you 80 per cent of the way there. “That’s a decade of lifespan, right there,” he enthuses.

Already hitting these goals? Dr Greger drills down in great detail into hundreds of seemingly tiny lifestyle adjustments in his book, such as examining the so-called Blue Zones, regions with a high proportion of centenarians, and making a DIY anti-ageing elixir of barberries, cumin and hibiscus.

“If you want to tweak the last 20 per cent, I’ve got lots of things you can do,” he says. “But we should not lose sight of the basic foundational things that will improve our health and lifespan.”

We can’t literally arrest ageing, though - can we? “This book is not about immortality but rather how to age with grace and vitality rather than suffering from the ravages of infirmity and decrepitude,” Dr Greger explains. Ageing might not cause death, but it is the single greatest risk factor for all the chronic diseases that do kill us.

Dr Greger says he has tweaked his own diet through researching How Not to Age, adding wheatgerm (to fight dementia) and berries (the healthiest fruit overall, and packed with antioxidants and antiinflammatories) for example. He eats the “Daily Dozen”, a list of food groups including beans, flaxseed, cruciferous veg, whole grains and a B12 supplement, which is especially recommended for the over-50s.

Apart from B12 and Vitamin D in the winter, he is highly critical of most supplements. The majority aren’t even what they say on the packet, says Dr Greger.

He works with a team of 22 and had to edit the original 1,200- page manuscript for How Not to Age down to 600, which are supplemented with a wealth of free material, including thousands of videos available at his website nutritionfacts.org.

I wonder if he has a favourite anecdote from his research into living well at old age, but he isn’t interested in stories and hearsay. “The media loves stories of centenarians who attribute their longevity to lard, vodka and a favourite brand of cigarette, but how do they really eat and live? We actually have the data.”

For those of us in the UK, the data are a mixed blessing. Dr Greger says unequivocally that the leading cause of death and disability in this country is poor diet.

But he has high praise for the English breakfast he’s just enjoyed in his hotel.

“It’s difficult to eat healthily when you’re travelling, but I had mushrooms, beans and tomatoes this morning. It’s fantastic. When I talk around the world, I say: ‘Everyone should eat like the Brits, and have beans for breakfast.’”

‘How Not To Age: The Scientific Approach to Getting Healthier as You Get Older’ by Dr Michael Greger is out now, £22

Eight diet tips Dr Greger’s anti-ageing advice for longevity and vitality

1. NUTS Of all of the food groups, nothing beats nuts (inset) for reducing the associated risk of dying before one’s time. Nut consumption is associated with a lower risk of dying from stroke, heart disease, respiratory disease, infections, diabetes and even cancer.

2. GREENS Green leafy vegetables match nuts for their potential to decrease the risk of premature death. Eating greens can boost immunity, slow the metabolism and protect our bodies from the effects of air pollution.

3. BERRIES People who eat berries tend to live significantly longer than those who do not. Berries have benefits for cognition, immunity and eyesight - plus they taste great.

4. GETTING FIVE A DAY, OR MORE What doesn’t kill plants makes us stronger. Plants have biological processes that allow them to thrive, and we can harness these powers by eating them.

“Mild stresses like exercise can trigger a protective response that leads to strengthened defences in the long run,” Greger writes in How Not to Age. Plants are going through this stress-repair response constantly, and it makes them stronger. If we eat them, we can share the benefits.

MicroRNAs - only discovered this century - act as the messengers for our DNA. They can regulate what our genes are doing, and we can modulate them via diet. It is believed, for example, they could be the key to preventing cognitive decline and Alzheimer’s.

5. PREBIOTICS AND POSTBIOTICS The bacteria in our gut can boost the immune system, make vitamins for us, improve digestion, and balance hormones. When we feed our gut bacteria with foods they love, we benefit. Vegetables, beans and legumes - even baked beans - are great for gut health.

6. CALORIC RESTRICTION Carefully reducing calorie intake and occasional fasting can free up our cells to do anti-ageing work such as combating free radicals and inflammation.

7. PROTEIN RESTRICTION Reducing protein in our diet can give us access to the same longevity benefits as calorie restriction and may be even easier to do. Dr Greger clarifies that he means cutting protein down to recommended levels of around 50g a day, and switching to more plant proteins because methionine, an essential amino acid found in animal products, is associated with a shorter lifespan. Fish and chicken contain much higher levels of methionine than red meat, dairy and eggs.

8. THE MAGIC MOLECULE By adjusting our diet to restore youthful levels of one of the most abundant molecules in our body, we can delay or even reverse age-related disorders.

NAD+ is an essential molecule and while the evidence is complex, boosting it as we age could fight all kinds of ageing - and foods such as purple sweet potatoes or corn, dark berries, parsley, turmeric and green tea might help.