Thursday, November 5, 2009
Paleo Diet Q & A - 11.5.09
More Q & A from the Paleo Diet community:
Q: I believe in the Paleo Diet and want to introduce it into my lifestyle but I have a chronic renal condition (IgA nephropathy) which is still mild. Can I still follow this diet but eating moderate protein instead of high? Or do you have any other suggestions to how I can go about it? The doctors never advised me to restrict my protein intake but I have read many articles that says that restricting protein intake benefits renal disease sufferers.
A: Circumstantial data from the Inuit people, before westernization, suggests that they ate high protein diets for a lifetime, and likely had normal kidney function. The available human data suggests that the kidney responds to a higher protein diet by increasing the glomerular filtration rate (GFR). This response is not pathological, but rather a healthful response as the effective GFR remains constant as kidney mass increases. The analogy is like a muscle that responds to lifting more weight - it hypertrophies (gets larger) to adapt to the increased load.
Yes, people with pre-existing kidney disease will worsen on a higher protein diet. My recommendation for these people would be to reduce the glycemic load of their diet (e.g. get rid of most processed food) first and carefully monitor kidney function until it begins to improve. Ironically, it is likely a high glycemic load diet that worsens kidney function in the first place.
Q: I am not yet on the Paleo diet, though I would really like to be. I do not doubt the validity of the science or the biology that leads to the Paleolithic diet being so successful. However, living in the Western world means that just about everything has dairy and grains in it, along with unhealthy refined carbohydrates and trans fatty acids, therefore the most logical and reliable way to get a healthy Paleo diet is to buy the basic organic ingredients and make meals from them oneself.
Unfortunately, I don't know what the correct proportions of the food groups for a well-balanced Paleo diet are; i.e. how much fruit and vegetables compared with lean meat compared with nuts and seeds compared with fish, etc?
I also wanted to ask about the sorts of foods that should be eaten instead of grains and dairy. Although I am aware that calcium uptake is based on many factors besides just calcium intake, what is the source of calcium in the diet? Fish bones and the like? For grains, what should we eat instead for those meals: I know it has been said that vegetables of some kind (or fruit) should be eaten with every meal, but what does that make breakfast and lunch besides a pile of vegetables?
What else do we eat with them?
With this increase in fruit and veg consumption (about how many portions per day do you recommend?), how do we prevent ourselves getting massive diarrhoea? I personally had one point in my life where I was eating over 30 portions of fruit and five portions of veg per day. Is this too much, perhaps even to the point of being unhealthy?
Furthermore, with this increase in meat and seafood consumption, even with the reduction in grain and dairy production, will not an increased percentage of Paleo dieters hasten the trends of soil erosion and landscape damage due to the increase quantity of land required for farming to feed people?
Finally, with increased individual meat consumption, would not the risk of things like gout increase? Would it not at least potentially be risking the same health problems and complications of the Atkin's Diet?
Thank you for your help.
A: Regarding the optimal proportion of fruits, vegetables, lean meats and seafood there's not a consensus. Some studies made by Dr. Cordain et al. have shown plant to animal ratio ranges from 35:65 to 65:35 percent. This depends on latitude, season, climate, culture, etc. However, all ancestral diets shared key characteristics. Food sources were limited to unprocessed plants for ages, and unprocessed land and marine animals hunted from the proximate environment. We believe that the most common pattern was 30-35% protein (40% is the toxic ceiling), 30% fats and 40% carbohidrates. This means that lunch and dinner are based on lean meats or seafood and vegetables. Breakfast could be an opportunity to eat fruits, nuts, eggs or even vegetables and protein (turkey breast), see our newsletter v5_#39. Fruits and nuts are good options for snacks.
Grains and dairy are nutritionally poor when compared to fruits, vegetables, seafood and lean meats. So, grains and dairy have no natural substitute. Milk and grains are usually eaten with breakfast, and I've provided some ideas for breakfast. In our published research section on our website you can download Dr. Cordain's scientific paper regarding grains titled: Cereal grains: humanity's double edged sword.
Broccoli, cauliflower, kale and all green leaves are good calcium sources without the problematic issues that dairy has: they increase metabolic acidity which leads to bone calcium loss.
Yes, too much fruit consumption is not the healthiest choice. High fructose intake is related to many metabolic diseases, especially obesity. Diarrhea is usually associated to fructose intolerance.
So, one doesn't have to precisely count caloric intake from protein, fats and carbohydrates as long as you combine seafood and lean meats with vegetables in meals and use fruits and nuts as breakfast and snack options.
Regarding gout: gout is considered part of a metabolic syndrome and insulin resistance is at the root of gout illness. Along these lines, gout is rare among pre-agricultural populations (Hunter-gatherers). Serum uric acid levels depends on the amount entering the bloodstream and the amount leaving the bloodstream. The amount of uric acid entering the bloodstream depends on the amount of it produced by the liver (1/3 from diet and 2/3 from body turn-over of cells). The amount of uric acid leaving the bloodstream depends on the kidneys' excretion capacity. The metabolic syndrome and insulin resistance induce kidney underexcretion of uric acid. On the other hand, when the kidney is faced with high protein purine-containing foods, serum uric acid levels decrease because the kidney increases uric acid excretion (this is an evolutionary trade-off).
So, the real problem is increased liver production of uric acid and kidney uric acid underexcretion. High glycemic load foods (as found in the typical Western diet and not in The Paleo Diet), and subsequent hyperinsulinemia halts the kidney capacity to excrete uric acid. Regarding liver production of uric acid: fructose--and particularly High Fructose Corn Syrup (HFCS)--decreases inorganic phosphate in the liver, and this increases the production of uric acid from purines.
The Paleo Diet helps to fight gout as it is based on low-glycemic load foods, high protein, and no HCFS foods.
We hope this helps.