To the Editor:
There are some reports in the literature pointing out that the progression of the diabetic nephropathy (DN) is slower in patients who take low protein diets.1,2 Macrobiotic diet is an extreme form of vegetarianism that had showed to be useful in the prevention and in the treatment of some tumors. To date it has not been reported that this diet can slow down the progression of the DN.
We present a 58 year-old Caucasian male, with a history of high blood pressure since 1990 regularly controlled with antihypertensives drugs, and of type 2 diabetes mellitus since 1998, treated with insulin and with good metabolic control. He was referred to the Nephrology Department in 2000 because of stage 2 chronic renal failure (CRF) and microalbuminuria secondary to DN. He was being treated with irbesartan 300 mg/day, hydrochlorotiazide 12,5 mg/day, nifedipine 60 mg/day and salicylic acid 100 mg/day. During the follow up the renal function worsened lightly and he had normo-albuminuria. In December of 2005 the following measurements were made: bloodpressure 139/87 mmHg, weight 81 kg, and height 180 cm. The laboratory parameters were urea 61 mg/dL, creatinine 1.7 mg/dL, creatinine clearance 44.37 mL/min, microalbuminuria 11.75 mug/min and hemoglobin A1c 5.5. Other parameters were normal. In January of 2006 the patient began a macrobiotic diet, consisting of wholemeal cereals, like barley and wheat, see algae, and vegetables. He avoided eating meat, milk or milk derivatives. In October of 2006 he had blood pressure 138/82 mmHg and weight 79 Kg. Laboratory findings were urea 46 mg/dL, creatinine 1 mg/dL, creatinine clearance 81.57 mL/min, microalbuminuria 29,31 m/min, hemoglobin A1c 5.9, albumin 4.2 g/dL, total proteins 6.7 g/dL, total cholesterol 150 mg/dL, triglycerides 168 mg/dL, and the other parameters were normal. These findings were similar in further analyses three and six months later. He did not appear malnourished. No changes in the treatment were prescribed and no other cause could be found to explain the improvement in renal function.
Macrobiotic diet is an extreme form of vegetarianism combined with some thoughts derived from Buddhist Zen philosophy. Eating and quality of food are thought to affect the health.3 Macrobioticdiet emphasizes the use of organic products, like cereals, fruits, algae, vegetables, fermented soy, combined according to the principles of the balance between the yin and yang properties.4 Some reports demonstrate the anti-tumoral effect, particularly in breast tumors. Women who make a macrobiotic diet apparently excrete a greater amount of estrogens in stool and urine, have lower blood levels of estradiol and have lower risk of developing a breast carcinoma.5, 6 Some studies about the macrobiotic diet as treatment of different neoplasms, like melanoma or pancreas cancer, have been published. An improvement of the clinical picture and of the quality of life of the patients was observed.6, 7
The effect of macrobiotic diet in diminishing cardiovascular risk has been reported.8, 9 An improvement in total cholesterol, an increase in HDL-cholesterol and an improvement in blood pressure were demonstrated, but no effect on the progression of the DN could be showed.
The potential danger of the diet is that if strictly followed can cause malnourishment, anemia due to vitamin B12 deficiency and scurvy.10
The reported patient presented a - CRF secondary to DN of six years. After 10 months of macrobiotic diet an improvement in renal function was observed, without signs of malnourishment and no other cause could be found to explain this improvement.
