Diet-based therapies

DEFINITION: Complementary and alternative therapies using special diets to improve health, increase longevity, and prevent and treat specific health conditions and diseases.

PRINCIPAL PROPOSED USES: Asthma, diabetes, heart disease, high cholesterol, obesity, chronic health conditions, autoimmune disorders, digestive disorders, hormonal and reproductive health, many other medical conditions

OTHER PROPOSED USES: General health, longevity, quality of life, relief of symptoms

Overview

Diet-based therapy, also called medical nutrition therapy, uses specialized dietary regimens to promote wellness and to prevent and treat specific diseases, including cancer, cardiovascular disorders, diabetes, and many other chronic medical conditions. Some low-fat vegetarian diets can help reverse arterial blockages that cause coronary artery disease, and some may help prevent or slow the progression of prostate and other cancers. Persons who follow a specific type of diet have reported cancer remission. It usually takes months or years for benefits to be observed. Diet therapies are more likely to be effective if practiced as a preventive measure against disease or if started early after the onset of the disease.

Some diet-based movements, such as breatharianism, claim that food and even water are not necessary for living. Believers claim that human life can be sustained by a vital force whose energy comes from sunlight and the nutrients of fresh air. Another diet therapy based on religious beliefs is fruitarianism, which involves a diet based solely on consuming fruits, nuts, and seeds. This diet therapy is practiced by people who call themselves fruitarians and believe that fruits are the original diet of humankind, a diet that stems from the time of Adam and Eve. Some followers of this practice will eat only fallen fruits.

However, humans need a balanced diet to be healthy, regardless of philosophical or religious beliefs. People with chronic diseases, various medical conditions, and some types of cancer can enhance their quality of life by improving the quality of their daily meals, shifting or replacing eating habits, and being more aware of calorie intake.

Mechanism of Action

Some studies show that several diets based on fruits can improve lipid profiles and glucose tolerances and stop some people's tendency to gain weight. The intake of nuts, olive oil, and fish can reduce bad cholesterol. Reducing saturated fats in daily meals can reduce triglycerides in the blood. Potassium from fruits can also reduce muscle pain. It is well known that a diet low in salt (sodium) can help to reduce blood pressure.

Uses and Applications

Diets have been used to treat hypertension. One of the most important science based-diets designed to control blood pressure is the Dietary Approaches to Stop Hypertension (DASH) diet, which is promoted by the National Heart, Lung, and Blood Institute, part of the National Institutes of Health (NIH).

The DASH diet is a plan low in saturated fats, cholesterol, and total fat. It emphasizes the intake of fruits, vegetables, fat-free or low-fat milk and milk products, whole grain products, fish, poultry, and nuts. The diet is low in lean red meat, sweets, added sugars, and sugar-containing beverages. It is rich in potassium, magnesium, calcium, protein, and fiber. The DASH diet is very similar to another well-balanced and highly recommended diet, the Mediterranean diet, which has been recognized as an ideal way of eating to prevent the onset of chronic health conditions.

Type 2 diabetes is another chronic disease that can be partially controlled by diet. The ideal diabetic meal consists of a combination of foods, such as bread, products high in fat, dairy items that provide protein, and starchy vegetables. Most of the protein in a diabetic diet comes from chicken, fish, lean beef, or dairy. Servings and portions in diabetic diets depend on a person’s level of physical activity. People with diabetes avoid sugar and processed carbohydrates in their diet.

Cardiovascular diseases can also be prevented and controlled by diet. Histological studies show that vascular injury accumulates from adolescence, making it extremely important to monitor one’s lifestyle and diet from childhood to prevent a heart condition in the future. Any diet designed to control or prevent cardiovascular disease must be low in saturated fats (less than 7 percent of the daily diet) and low in cholesterol (less than 300 milligrams per day for healthy adults and less than 200 milligrams per day for adults with high levels of low-density lipoprotein, or bad, cholesterol).

The American Cancer Society recommends that people with cancer not undertake a dietary program as an exclusive or primary means of treatment. Still, a healthy and well-balanced diet can be a helpful complement to traditional cancer treatment. A macrobiotic diet is one of the most common diets followed by cancer patients. It is based on whole cereal grains, especially brown rice, and is low in processed foods. Another diet used in cancer treatment is the Gerson diet, which is part of the Gerson therapy. The Gerson diet is said to cleanse the body, boost the immune system, and stimulate metabolism. The Gerson diet, in general, requires following a strict low-salt, low-fat, vegetarian diet containing a lot of fluids.

The benefits of a healthy and well-balanced diet extend to numerous health conditions. Kidney disease, arthritis, chronic obstructive pulmonary disease (COPD), and osteoporosis can all see improved symptoms and slowed progression with careful dietary management. Diet-based therapies can also be valuable in addressing autoimmune and inflammatory diseases such as irritable bowel disease and celiac disease, as well as managing food intolerances and allergies. Women struggling with premenstrual syndrome (PMS) or menopausal symptoms may find relief through dietary adjustments. Similarly, regulating one's diet can help manage symptoms of polycystic ovary syndrome (PCOS). The extensive list of health conditions that can be partially controlled, and often prevented, through diet-based therapies underscores the critical role of a well-balanced and nutritious diet in overall well-being.

Scientific Evidence

NIH studies have demonstrated that a low level of salt combined with the DASH diet is effective at lowering blood pressure. The effect of this combination (at a sodium level of 1,500 milligrams per day) was an average blood pressure reduction of 8.9/4.5 millimeters of mercury (systolic/diastolic) in normal subjects. Persons in the studies who were hypertensive experienced an average reduction of 11.5/5.7 millimeters of mercury.

A low intake of saturated fats will reduce triglycerides in the blood. Studies have claimed that some diets designed for persons with cancer dramatically increase life expectancy, but many physicians counter this claim, saying that a lack of control groups means that there is insufficient scientific evidence to support those observations. Although making claims that diet can cure or greatly relieve the symptoms of a health condition is dangerous and controversial, medical experts agree and endless studies have shown the importance of a healthy and well-balanced diet.

Choosing a Practitioner

A nutritionist is the recommended professional advisor for the selection of a diet for a specific chronic condition. For persons with cancer, diets must be chosen and recommended by an oncologist.

Safety Issues

When beginning a therapeutic diet that involves a dramatically different way of eating, people should receive expert supervision so that they can avoid nutritional deficiencies. The human body, which needs carbohydrates, fats, and proteins for healthy function, burns its own reserves of energy in the absence of calorie intake. Intermittent fasting may offer health benefits for people trying to control their blood sugar, but fasting for extended periods leads to starvation, dehydration, and eventual death.

Diets based on one type of food, such as those based solely on fruits, can cause protein deficiencies, which inhibit growth and development in children. Fruit-based diets can also cause deficiencies in vitamin D, vitamin B₁₂, calcium, iron, zinc, and essential fatty acids.

Bibliography

The DASH Diet for Healthy Weight Loss, Lower Blood Pressure and Cholesterol, www.dashdiet.org. Accessed 13 Sept. 2024.

"Gerson Therapy." National Cancer Institute, 7 Jan. 2015, www.cancer.gov/about-cancer/treatment/cam/patient/gerson-pdq#section/all. Accessed 13 Sept. 2024.

Rouse, Veronica, and Laura O'Hara. "DASH Diet vs. Mediterranean Diet: Which One is Best for You?" ArchWell Health, 17 May 2024, archwellhealth.com/news/dash-diet-vs-mediterranean-diet-which-one-is-best-for-you. Accessed 13 Sept. 2024.

Warwick, Kathy W., and Jillian Kubala. "Medical Nutrition Therapy: How It Works, Conditions, and More." Healthline, 18 Feb. 2020, www.healthline.com/nutrition/nutrition-therapy#how-it-works. Accessed 13 Sept. 2024.

Zandile, June-Rosa. "Diet Therapy and Public Health." Environmental Research & Public Health, vol. 19, no. 14, p.8312, 7 July 2022, doi.org/10.3390/ijerph19148312. Accessed 14 Dec. 2022.