Nutritional therapy combines science (biochemistry and nutrition) with naturopathy (natural, drug-free medicine) in order to maintain or return oneself to a state of good health. Nutritional therapy is wholistic because it is designed to treat the body as a whole – curing the causes of problems, not just the symptoms as is too often the case in conventional medicine. Good nutrition means that all the essential nutrients, vitamins, minerals, carbohydrates, fats and water are supplied and utilized in adequate balance to maintain optimal health and well-being. Nutritional deficiencies will occur when inadequate amounts of these essential nutrients are provided to the tissues, thus resulting in illness and disease. The key is a balance of foods that should be consumed based on the five food groups, which are:
- Bread, cereals and potatoes.
- Fruit and vegetables.
- Milk and dairy.
- Meat, fish and alternatives.
- Foods containing fat; foods and drinks containing sugar.
Five or more portions of fruit and vegetables a day are recommended as well as an increased amount of bread, other cereals and potatoes than people normally consume. Wholemeal, wholegrain, brown or high fibre versions are preferable and a wide variety of fruit and vegetables. Also one should aim to eat at least one portion of oily fish such as sardines and salmon each week.
Lower fat milk and dairy versions such as semi-skimmed or skimmed milk, low fat (0.1% fat) yoghurts or fromage frais, and lower fat cheeses are preferable. Although fat will be eaten every day, it should be kept to small amounts that include margarine and butter, other spreading fats (including low fat spreads), cooking oils, oil-based salad dressings and mayonnaise.
Nutritional supplements related to CAM include herbal medicines (also called botanicals), vitamins, minerals, and probiotics . These types of natural products are becoming more and more popular with a reported 17.7% of American adults using herbal medicines in a recent study.
Probiotics are live microorganisms, usually bacteria, that are similar to beneficial microorganisms found in the human gut. The most common types of these “good bacteria,” Lactobacilli and Bifidobacteria, are available to consumers in the form of dietary supplements and foods (such as yogurt). Little evidence supports the claim that probiotics help prevent colds. However, strong evidence supports the use of probiotics to slow the growth of certain cancerous tumors. A study of 10 colorectal cancer patients and 20 healthy persons showed that colorectal patients have deteriorated intestinal environments compared to the healthy controls, but that intestinal conditions improved when probiotics were taken, suggesting that probiotics may prevent colorectal cancer. A different study showed that pigs given vaccines and probiotics have better immune systems than pigs given only vaccines. This knowledge helps researchers understand how to offer safer and more effective rotavirus vaccines in humans. However, both studies noted that more research on the mechanisms behind the health effects of probiotics must be conducted.
Omega-3 fatty acids are naturally found in fish, plant, and nut oils, and have also been made into dietary supplements. Fish oil contains both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which have been proven to lower triglycerides, slow the buildup of atherosclerotic plaques (hardening of the artery walls), lower blood pressure, and reduce risk of death, heart attack, and dangerous abnormal heart beats due to cardiovascular disease. More specifically, an analysis of 17 clinical studies of the use of fish oil supplements showed that taking three or more grams of fish oil daily significantly reduces blood pressure for people with untreated hypertension. One clinical study found that overweight, mildly hyperlipidemic men who took four grams of purified DHA per day had lower blood pressure (BP) than did those who took the placebo, olive oil capsules. The study concluded: “Relative to the placebo group, 24-hour BP fell 5.8/3.3 (systolic/diastolic) mm Hg and daytime BP fell 3.5/2.0 mm Hg with DHA.” Furthermore, fish oil is effective in reducing high triglyceride levels by 20 to 50%. One fish oil supplement, Lovaza, is now FDA-approved for use to lower triglycerides.
Echinacea is a flower found in the Midwestern region of North America and is widely used to treat, prevent, or shorten the duration of colds and to stimulate the immune system to fight infections. The parts of the Echinacea flower that grow above ground can be used fresh or dried to make teas, juice, and extracts. Health effects of Echinacea are uncertain. Two NCCAM-funded studies did not find any health benefits from Echinacea (either as Echinacea purpurea in a fresh-pressed juice or a mixture of Echinacea angustifolia root and Echinacea purpurea root and herb). Other studies have shown that Echinacea may help treat upper respiratory infections. Different results have been observed because each study uses different methods of preparation. Therefore, Medline rates Echinacea as “possibly effective” for treating the common cold (but not effective in preventing it).
Acai is a palm tree found in the northern regions of South America. The acai palm tree produces reddish-purple berries that are commonly used as medicine. Acai is now widely marketed in America as a “superfood,” because it is claimed to have weight-loss and anti-aging properties. However, no definitive evidence from clinical trials shows human health benefits of acai berries. Laboratory studies of acai berries do support their antioxidant properties (antioxidants are substances that protect cells from damaging effects of chemical reactions with oxygen). A 2008 study showed that antioxidants in a juice blend (MonaVie Active) that contains acai as a primary ingredient protected cells from oxidative damage. Still, no published studies support claims that acai supplements alone promote weight loss.
Soy, a plant in the pea family, is also marketed as a “superfood,” because it is reputed to lower cholesterol levels. According to the FDA, 25 grams per day of soy protein, in addition to a diet low in saturated fat and cholesterol, may reduce the risk of heart disease by lowering levels of LDL (“bad” cholesterol). A 2006 study found that in the majority of 22 randomized trials, isolated soy protein with isoflavones decreased LDL concentrations.
Green tea is a product made from the Camellia sinensis plant and can be prepared as a beverage or as a medicine. Green tea is used to increase mental alertness, due to its caffeine content, and is purported to facilitate weight loss, though no evidence supports this claim. Green tea is, however, rated as “possibly effective” at preventing certain types of cancer, including bladder, esophageal, ovarian, and pancreatic cancer. One study reported that women who drank more than two cups of green tea daily had a 46% lower risk of developing ovarian cancer compared to women who did not drink green tea.