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Diet Therapy

By

Denise Millstine

, MD, Mayo Clinic

Last full review/revision Oct 2021
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  • Treat or prevent a specific disorder (eg, cancer, cardiovascular disorders)

  • Generally promote wellness

  • Detoxify the body (ie, neutralize or eliminate toxins from the body)

Some diets (eg, Mediterranean diet) are widely accepted and encouraged in conventional and integrative medicine. Many other diets have been proposed as ways to promote health, with varying degrees of supportive evidence. They often make similar recommendations (eg, limiting less healthful fats and refined carbohydrates, substituting with plant-based and whole foods).

Intermittent fasting causes a switch from using glucose from the liver to ketones stored in fat (1 References Diet therapy, a biologically based practice, uses specialized dietary regimens (eg, Gerson therapy, macrobiotic diets, Pritikin diet) to Treat or prevent a specific disorder (eg, cancer, cardiovascular... read more ). It has been shown to have favorable metabolic effects (eg, increased insulin sensitivity and autophagy, possibly increased life span) in animal studies. Human studies have not shown as robust evidence for health benefits.

Diet therapy effects may occur slowly and are inherently difficult to study.

Ornish Diet

This very low-fat vegetarian diet aims to help reverse arterial blockages that cause coronary artery disease and may help prevent or slow the progression of prostate and other cancers. It focuses on plant-based foods and avoidance of fat, refined carbohydrates, and animal protein. As a component of an intensive lifestyle program for participants with symptomatic coronary artery disease, the Ornish diet is effective and cost saving. However, it is not clear what benefits result from the specific food restrictions of the diet. Similar benefits may result from other diets that limit less healthful fats and refined carbohydrates but do not limit more healthful fats (eg, olive oil).

Macrobiotic Diet

This diet consists mainly of vegetables, whole grains, fruits, and cereals. Some proponents claim that this diet can prevent and treat cancer and other chronic disorders; however, no evidence supports efficacy of a macrobiotic diet for treatment of cancer. The macrobiotic diet has also been investigated in patients with metabolic syndrome, prediabetes, and diabetes without conclusive evidence of efficacy.

Paleo Diet

This diet consists of types of food allegedly consumed during the Paleolithic era, when food was hunted or gathered (ie, animals and wild plants). Thus, the diet includes

  • Increased protein intake

  • Decreased carbohydrate intake (with intake consisting mainly of nonstarchy fresh fruits and vegetables)

  • A moderate to higher fat intake (with intake mainly of monounsaturated and polyunsaturated fats)

Foods thought not to be available during the Paleolithic era (eg, dairy products, grains, legumes, processed oils, refined sugar, salt, coffee) are avoided. Proponents claim that human metabolism has not adapted to handle many of these foods.

Paleo diet is thought to treat or reduce the risk of coronary artery disease, metabolic syndrome, type 2 diabetes, and many chronic degenerative disorders (3 References Diet therapy, a biologically based practice, uses specialized dietary regimens (eg, Gerson therapy, macrobiotic diets, Pritikin diet) to Treat or prevent a specific disorder (eg, cancer, cardiovascular... read more , 4 References Diet therapy, a biologically based practice, uses specialized dietary regimens (eg, Gerson therapy, macrobiotic diets, Pritikin diet) to Treat or prevent a specific disorder (eg, cancer, cardiovascular... read more ). The paleo diet also potentially promotes weight loss, improves athletic performance, enhances sleep, and improves mental function. However, there is limited evidence concerning the efficacy of this diet.

Risks include inadequate nutrition (due to decreased intake of whole grains and dairy).

Knowledge of what was eaten in the Paleolithic era is limited; however, some evidence suggests that the diet of the Paleolithic era was not as limited as the modern paleo diet.

References

  • 1. de Cabo R, Mattson MP: Effects of intermittent fasting on health, aging, and disease. N Engl J Med. 381(26):2541-2551, 2019. doi: 10.1056/NEJMra1905136. Erratum in: N Engl J Med. 2020 Jan 16;382(3):298. Erratum in: N Engl J Med. 382(10):978, 2020. PMID: 31881139.

  • 2. Harmon BE, Carter M, Hurley TG, et al: Nutrient composition and anti-inflammatory potential of a prescribed macrobiotic diet. Nutr Cancer. 67(6):933-40, 2015. doi: 10.1080/01635581.2015.1055369

  • 3. Manheimer EW, van Zuuren EJ, Fedorowicz Z, et al: Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis. Am J Clin Nutr102(4):922-32, 2015. doi: 10.3945/ajcn.115.113613

  • 4. Whalen KA, Judd S, McCullough ML, et al: Paleolithic and Mediterranean diet pattern scores are inversely associated with all-cause and cause-specific mortality in adults. J Nutr 147(4):612-620, 2017. doi: 10.3945/jn.116.241919

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