Does a vegan diet harm your fitness?

The death of a climber on Everest has sparked a backlash against the regimen. So what is the truth?

Maria Strydom was 15 minutes from the snow-capped tip of Everest, within grasping distance of a pinnacle that had become her sense of purpose. With her husband, Robert Gropel, the 34-year-old had set out to prove that her vegan diet was no barrier to scaling mountains, no impediment to success in life.

A lecturer at Monash University in Australia, Strydom had told the university’s blog how she intended to dispel stereotypes about the dietary approach. “It seems that people have this warped idea of vegans being malnourished and weak,” she said in March. “By climbing the seven summits we want to prove that vegans can do anything and more.”

She came agonisingly close to realising her dream. Over eight years, she had climbed Denali in Alaska, Aconcagua in Argentina, and Kilimanjaro in her continent of birth, Africa, and had reached the final camp below the summit of Everest before succumbing to altitude sickness so severe that it caused a fatal build-up of fluid in her brain.

The tragedy has sparked repercussions of the cruellest nature, with Strydom’s death igniting an anti-veganism crusade. Critics have preoccupied themselves with the potential shortfalls that might come with avoiding all animal products, suggesting that insufficient nutrient intake seems almost certain to have been implicated in the catastrophic event.

Most climbers who die on Everest do so from exhaustion, injuries or the effects of altitude-related illnesses. Above 3,000 metres, more women (22.2 per cent) than men (6.5 per cent) suffer acute altitude sickness. Yet the risk rises as altitude increases, and “as many as 50 per cent of climbers travelling to 4,205-5,500m are said to experience it in some studies”, according to Professor Mike Tipton, director of the extreme environments laboratory at the University of Portsmouth’s department of sport and exercise science.

There is no uniformity of risk — altitude affects different people in different ways. “Some people are more susceptible than others to the mountain sickness,” Tipton says. “If they have a low ventilator response to the air, then carbon dioxide can accumulate in their tissues, which might be responsible for some of the symptoms.”

Maria Strydom with her husband, Robert Gropel, on Everest. The lecturer had been trying to dispel stereotypes about veganismFacebook

A potentially life-threatening build-up of fluid in the lungs occurs in about 2 per cent of people who travel above 3,000m. “It needs to be treated with supplemental oxygen and evacuation to at least 1,000m lower altitude immediately,” Tipton says. “Cerebral oedema, or fluid accumulation in the cranial cavity occupied by the brain, becomes more of a risk at altitudes greater than 4,300m. It’s indistinguishable from mountain sickness in the early stages but causes mental confusion, coma and death in a few hours if not treated straight away.”

Although the causes are not understood fully, there is no evidence that there is a connection with specific foods or a vegan diet. “It’s insensitive and wrong to blame Maria’s vegan diet for what happened,” says Jimmy Pierson, a spokesman for the Vegan Society. “She died from altitude sickness, not because of any lifestyle choice she made.”

Indeed, it’s largely been overlooked that Gropel, who stuck closely to the same vegan diet as his wife, reached the peak and survived. Or that the day before Strydom’s death, Kuntal Joisher, another vegan climber, had become the first to successfully conquer Everest.

Joisher, a 35-year-old software programmer born in Mumbai who works in Los Angeles, took to Instagram and other social media accounts to defend the lifestyle choice. “Firstly, let me tell you that the climber died because of altitude sickness. Altitude sickness doesn’t discriminate based on dietary choices,” he wrote on learning of Strydom’s death. “I am a vegan myself. Been one for 14 years now. I climbed and summited Everest on May 19, the day before Maria attempted. I am here, duly alive and kicking.”

For decades vegans had a reputation of being a pasty-faced, sandal-wearing brigade that adhered to a level of dietary commitment bordering on the obsessive. Rigid rules of the approach mean avoiding all animal products, including meat, fish, cheese, eggs, milk and honey. Yet it’s increasingly seen not as a burden, but as something of a fashionable undertaking. Beyoncé and Jay Z, Joaquin Phoenix and Jessica Simpson are among those who have espoused veganism.

Last month, the biggest poll commissioned by the Vegan Society (carried out by Ipsos MORI) revealed that the number of people shunning animal products has swelled to more than half a million, three and half times as many as in 2006. Google Trends statistics suggest that we are googling “vegan” at higher rates and the UK orders for Peta’s vegan starter kits have more than doubled in the past three years from 14,000 to 35,000. “It is not something that people take lightly,” says Pierson. “Nobody just cuts animal products from their diet. They contemplate it and plan for it which is why ultimately it is a healthy decision.”

A person does not need meat to be a successful athlete

Perhaps the most surprising surge has occurred among the seriously fitness-minded. Russ Best is a researcher in physiology and nutrition at Teesside University who advises top athletes on their diets. He says it’s perfectly possible to follow a meat-free diet and compete at the highest level in sport. “A lot of athletes are very fit, but not that healthy,” Best says. “At best they eat chicken and rice all the time. I tend to recommend that they have two or three days a week on a vegetarian or vegan diet to get more variety in the form of tofu, lentils, pulses and chickpeas as protein, for instance.”

Some find it works and stick with it full-time. One of the first to speak publicly about the benefits of cutting out animal products was the former track and field star Carl Lewis, who switched from a vegetarian to vegan diet in preparation for the 1991 World Athletics Championships in Tokyo. Lewis, who has said that “most athletes have the worst diet in the world and compete in spite of it”, went on to win the men’s 100m race in world-record time. He later added another three Olympic gold medals to the six he had already won. “I’ve found that a person does not need protein from meat to be a successful athlete,” he said. “In fact, my best year of track competition was the first year I ate a vegan diet.”

While it remains an extremely uncommon dietary regime for professional sportsmen and women, some notable high-profile athletes have embraced it, including Venus Williams. Although the tennis player adopted a mostly raw vegan diet after being diagnosed with the autoimmune disease Sjögren’s Syndrome in 2012, she calls herself a “cheagan”, or “cheat’s vegan”, because she sometimes indulges in chicken or fish. She also persuaded her sister Serena to take the plunge during the tennis season.

Meanwhile Novak Djokovic — who describes his diet as “vegan with eating a little bit of fish here and there” — recently opened a vegan restaurant with his wife in Monte Carlo, where they live. David Haye, the British former heavyweight boxing champion, became vegan two years ago, initially for ethical reasons but discovering in the process that it helped his attempt at a comeback. In recent interviews, Haye has described how cutting out animal products “made me feel immediately better and stronger than ever”.

Venus and Serena Williams have embraced the dietary approachGraham Denholm/Getty Images

Even the world of football, renowned for serving burgers and meat pies on the terraces, is becoming more open-minded. Last October, Forest Green Rovers FC in Gloucestershire became the world’s first vegan club after chairman Dale Vince removed red meat from the menu and replaced it with locally sourced plant-based food. Even the beer and cider on sale at their ground is completely vegan. And in March, the Norwich City FC captain Russell Martin went vegan to relieve the symptoms of ulcerative colitis. He hasn’t had a flare-up since and says: “I recover quicker after games now and feel good. I can’t think of one negative thing on my game”.

Best says that such popularity among the hard-bodied has spurned a wave of new products aimed at the gym market. “It used to be very tricky to find vegan sports supplements,” he says, “but now you can get pea protein, hemp protein and a range of other products.” Add natural muscle-building protein from plant-based protein sources, such as split peas, sprouted quinoa and brown rice, beans, nuts and lentils, rather than the whey-based supplements and meat or dairy traditionally used by athletes, and you have a perfectly balanced dietary intake.

All of which bolsters the vegan cause. “There’s plenty of documented evidence that plant-based diets protect against certain diseases and lower obesity rates,” says Pierson, “but there are so many anecdotal claims for other benefits such as people feeling fitter, recovering faster after a workout and having better endurance after adopting a vegan diet.”

Stephanie Davis, one of the world’s leading female climbers, is a case in point. “I started eating vegan because I noticed that it made me feel better and perform better,” the 42-year-old explained on her blog in 2012. “I’ve been vegan for ten years now, and there’s nothing in my life that hasn’t become better as a result, from climbing and athletics to mental and spiritual wellbeing.”

For Joisher there were never doubts that his diet would fail to fuel his Everest attempt. Two years ago he braved strong winds and white-out conditions to conquer Mount Elbrus in Russia. “I was able to adjust to all of these severe conditions while eating healthy vegan food such as raw vegetables and fruits, buckwheat, rice porridges, wheat breads, and dried fruits and nuts,” he wrote in his blog for the Huffington Post.

What most troubled him was not his nutrition, but sourcing vegan-friendly alternatives to the gear needed at the highest altitudes — specifically a bodysuit that wasn’t stuffed with goose feathers. “Imagine,” he said, “if you summited holding a vegan flag, wearing a down-filled suit.”

Please wait...

Sign up to get

My Best Means Worldwide e-book