We know a vegan diet is healthy and totally safe - but what about raw vegan?
You may have seen the diet promoted online by YouTuber Fully Raw Kristina, who claims it's the healthiest way to eat.
Even tennis legend Venus Williams reportedly swears by raw, as the best way to prevent and reverse diseases and stay young.
What exactly is a raw food diet?
Raw vegan foodists generally don't eat food that is heated above 118 degrees Fahrenheit or 48 degrees Celcius, in an attempt to preserve the produce's nutritional content.
Basically, in raw vegan parlance, cooking is killing - but is a raw vegan diet unnecessary, harmful, or healthy? What does the research say?
Heat destroyes enzymes in food?
A known claim made by raw vegan dieters is that heat destroys the enzymes in food - this theory is a cornerstone of the diet.
Enzymes, which are proteins that serve as catalysts for specific biochemical reactions in the body, can indeed be damaged by heat.
However, not everyone agrees with the raw foodists on the importance of retaining these enzymes in food by not applying heat.
Plant enzymes are smashed up with other proteins and rendered useless by acids in the stomach - and cooking them will not change that, according to author of 'Bad Medicine', Christopher Wanjek.
They're not even needed for human digestion, he argues; plant enzymes were only there for the plants, helping them grow.
Cooking doesn't destroy nutrients
The common belief is that cooking breaks fiber apart to release nutrients that otherwise would be unavailable from the same raw food.
For instance, cooking tomatoes increases by five-fold the bioavailabilty of the antioxidant lycopene.
Cooking foods with beta-carotene (like squash and sweet potatoes) helps release their nutrients and makes them more absorbable.
Vegetables in the cruciferous vegetables family (kale, broccoli, cauliflower, cabbage, Brussel sprouts) contain goitrogen compounds, which in excess can contribute to hypothyroidism - but they are mostly deactivated by heat.
Kathleen Zelman, MPH, RD says: "Contrary to the claims of many raw food fans, cooking does not make food toxic, but instead makes some foods digestible."
Low bone mass
One study associated a 100 percent raw plant-based diet with a lower bone mass - which is usually a sign of osteoporosis and increased fracture risk.
The study analyzed 18 strict raw food vegans aged 33 to 85, who have been on the diet for an average of 3.6 years. The researchers compared them to people eating a standard American diet and then measured body mass index, bone mass, bone mineral density, markers of bone turnover, and levels of vitamin D.
The participants on the raw diet were found to have significantly lower bone mass.
Removing essential food groups
Since raw foodists remove beans, legumes, and whole grains (and potatoes - who could live without potatoes?) from their diet, they could run the risk of encountering serious nutritional deficiencies.
Some doctors believe a diet composed only of fruits and vegetables would not be capable of providing all the basic essential nutrients.
A study has found that amerorrhea - which is an abnormal absence of menstruation - is a common finding in women following raw vegan diets, as a result of nutrient deficiencies and often under-eating.
The researchers also concluded that the consumption of a raw food diet is associated with a high loss of body weight, and therefore it can't be recommended on a longterm basis.
The same study that found the lower bone mass issue at raw foodists, has also found that they actually have less inflammation in their body, as well as lower levels of IGF-1 - which in high amounts can lead to breast and prostate cancer.
Raw vegan eaters will find that it's easier to consume superfoods in abundance - plus, they can eat a lot of food and feel satisfied, since raw foods are large and so low in calories.
Eating a raw diet is known to be a healing diet: "Raw foods help alkalize the body, reduce acidity, and have less of a chance of fermenting in the gut and causing inflammation/ autoimmune reactions," says Dr. Axe.
Other Benefits can include improved digestion and health health, lower risk of some cancers, high energy, and clearer up the skin.
Eating lots of vegetables and fruits also helps control blood pressure; and since the diet is also low in sodium, it might help lower your chance of stroke, heart failure, stomach cancer, and kidney disease.
There isn't a huge amount of scientific data available about raw vegan diets - it would be helpful to see studies that include greater numbers of participants, for example.
Among the science that is available, there is some debate as to whether a raw vegan diet offers more health benefits or problems.
The anecdotal evidence suggests you may experience increased energy, clear skin, and resistance to infection during the first several months. However, it is possible the diet could lead to health issues later on.
Another thing to consider is a point raised by RD Kathleen Zelman, who argues that a raw vegan diet is a restrictive plan that will be hard to stay on for the longterm.
Hopefully more conclusive data about this diet will come to light in the future.
In the meantime, as ever, if you are considering changing to a raw vegan diet, it is advisable to seek advice from a physician.
PBN is not a doctor. Any information should not be used as a substitute for medical advice