Raw food diets are a visible and ardently promoted alternative to mainstream eating today. But are mostly or fully raw diets better than other strategies for optimal modern nutrition? A recent study of natural human eating patterns by researchers at the Federal University in Brazil, published by the National Academy of Sciences, suggests that our switch to cooked foods may have played a much larger role in our evolutionary development and been far more health-increasing than many of us realize.
Photo Courtesy of Tree of Life
Widely highlighted in the scientific press – see ScienceMag and LiveScience as examples – the new study does more than simply remind us that meat-eating was an integral part of our natural heritage. Using a novel analysis of fossil records, it suggests that the rise of cooked meats and starchy plants was fairly momentous, and even crucial to our brain development and the precipitous advance of our ancestral line in the last million years or more.
In essence, the research team proposes that cooked foods allowed us to consume much more animal proteins and fats, and calories overall, than otherwise would have been possible on the grasslands of Africa. The change is thought to have created an essential precondition for the rapid selection of much larger human brains and more complex behavioral patterns.
Given these new and quite important findings, as well as related prior research on natural human nutrition and key principles from modern dietary science, let’s consider the health-based case for fully and mostly raw diets today.
The Scientific Evidence
Raw food diets can take a number of forms, as outlined in this well-written summary article. Foods are usually considered raw as long as any heating does not exceed temperatures associated with sun-drying (~45C/115F).
Typically, the goal in raw eating is to make uncooked foods at least 80% and as much as 100% of our daily diet. Raw food advocates theorize that this change increases the nutritional quality of the foods we eat, while favorably shifting our diet toward healthier food choices more generally.
Importantly, raw food eating is often combined with veganism – whether to support health or ethical goals – though it needn’t be. In any case, if an adequate protein and calorie intake is pursued, the approach produces a daily diet rich in seeds and tree nuts, sprouted beans and grains, dairy products, and/or raw and dried meats (defined broadly here to include all animal flesh foods).
If we consider the ideas that our natural human diet over the last two million years increasingly included not just meats but cooked meat and starches, and that significant human grain and legume eating did not begin until the agricultural revolution, raw diets cannot be seen as “natural” in an historical sense. But this does not mean they cannot be healthy for modern humans (though raw vegan diets will always lack adequate vitamin B12 without artificial supplementation).
Here is a brief summary of our reading of available research related to the health benefits and limitations of modern raw diets:
+ Healthy raw vegetables & fruits are encouraged – we know via extensive scientific research that diets rich in raw and raw-edible vegetables and fruits are both natural for humans and far healthier than eating practices that lack or marginalize these foods. For this reason, the move toward raw eating can greatly increase dietary quality, notably among people eating industrial diets low in fiber and high in fats, sugars, and salt.
– Excessive grain & legume use is promoted – except where raw or dried meat or dairy products are consumed, raw diets will perpetuate and even increase the relatively new human practice of high grain and bean consumption, if in whole and sprouted rather than processed and cooked forms. Currently the focus of researchers investigating Paleolithic Nutrition, the practice of intensive grain and bean-eating has been shown a relatively recent change to our human dietary patterns and appears to have notable, if still greatly unappreciated negative health effects. These grain and legume-derived effects include elevated blood sugar levels, increased tissue inflammation, and chronic allergic reactions – all a result of the elevated and unnatural carbohydrates, lectins, and other compounds from these newly adoptive foods.
– Low protein, fat & nutrient intake is possible – in both their vegan and non-vegan forms, raw diets can lead to unnaturally low protein and fat consumption, as well as reduced levels of other nutrients, with important health implications. This idea is underscored by the new Federal University research suggesting that not just meats, but more readily consumable cooked meats, may have been essential to our neurological development and past natural fitness. Though the leanness achieved through raw veganism, in particular, is prized and viewed as desirable by many in our time, this outcome represents an unnatural and potentially far from optimal metabolic state. In addition to the potential for reduced essential proteins and fatty acids, other dietary risks from raw eating include chronically low levels of vitamin D, vitamin B12, calcium, iodine, iron, and zinc.
+ Cooked starches are avoided – although it is becoming clear through research that cooked roots and other starchy plants were an increasing part of our diet in nature and an important source of calories after the control of fire, it is not as clear whether this development had as large an impact on our physiological health as it may have on our practical survival potential and general adaptiveness on the African plains. In a way that is analogous to findings about the optimal consumption of red meats, considerable research now suggests that cooked starchy plants, while natural to humans in a strict sense, may be less desirable in large amounts because of their high glycemic effect and potential to promote blood sugar imbalance, obesity, and related diseases.
Our Natural Truth Rating
Given this pattern of evidence, HumanaNatura rates the proposal that raw diets are healthier a 6/10 (Notable Evidence) in our Natural Truth rating system.
We base our rating on two competing considerations. One is the strong evidence that increases in raw vegetable and fruit consumption, and the displacement of common industrial foods, can produce substantial health benefits.
But we temper this important finding with other research suggesting that raw eating, especially when combined with veganism, can lead to diets that have undesirable excesses of carbohydrates and lectins, as well as potential deficiencies in essential proteins, fats, vitamins, and minerals.
For these reasons, we recommend use of HumanaNatura’s OurPlate healthy eating guide, rather than the goal of raw eating, as a model for optimal modern nutrition. This approach is based on important Natural Eating principles in HumanaNatura’s Personal Health Program, some of which we have touched on here.
In the HumanaNatura OurPlate model, a daily diet based on “salad meals” is encouraged. The approach involves three critical steps: 1) ensuring that 50% of daily food volume comes from raw or raw-edible and thus low-glycemic vegetables, 2) meeting but not exceeding our protein requirements through cooked lean animal protein (and a small amount of seeds and tree nuts), and 3) meeting our remaining calorie needs through raw fruits.
In this way, an optimal post-infancy human diet – one that is about 75% raw by volume and roughly 50% raw by calories – can be easily and enjoyably achieved and maintained throughout our lives. As suggested above, grains, beans, and starchy foods are not included in this approach.
You can click to learn more about our Natural Truth health information campaign and evidence-based 1-10 rating system. And we always welcome your comments and input on this or any other HumanaNatura Natural Truth review.
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