When you walk through your local grocery, you may note that there are a couple of aisles dedicated to fruits and vegetables at the outside border of the store and a great many aisles dedicated to food in bags, boxes, bottles and cans that fill the middle aisles. Some people spend more time and money at the edge of the store, and some spend more in the middle. For those with fructose intolerance, danger, or at least discomfort, lurks throughout the store.
Fructose intolerance, sometimes referred to as hereditary fructose intolerance, is an inherited condition marked by the inability to digest fructose, which is the sugar in fruit. Those with this condition must be careful about what they eat, as fructose or fructose-like sweeteners are added to thousands of processed foods in the form of fructose, crystalline fructose, honey or sorbitol, according to the University of Virginia. While the usual dietary remedy for many conditions is “eat vegetables,” for those with fructose intolerance even vegetables pose risk, because vegetables, too, contain fructose, and some vegetables contain sufficient fructose to create problems for the intolerant.
People with fructose intolerance either lack or are deficient in the enzyme fructose-1-phosphate aldolase, which normally breaks down fructose into bio-usable glucose. Consequently, fructose-1-phospate accumulates in their liver, kidneys and small intestine. Problems can occur quickly after consuming fructose, but problems also develop as fructose-1-phosphate accumulates in the body. The fructose intolerant person must monitor her consumption of fructose from all food sources, including vegetables, to ensure that she does not overload.
Symptoms can include bloating, diarrhea, vomiting, dehydration, severe abdominal pain due to gas, excessive urination, sweating, extreme thirst and confusion due to low blood sugar. Accumulative effects can be worsened by eating or drinking anything that contains high amounts of fructose. Left untreated, fructose intolerance can lead to loss of nutrition, such as calcium and iron, coma or death.
Vegetable Serving Size
For those with intolerance, the amount of vegetables consumed in one sitting should be limited, depending on the severity of the intolerance. Generally, the serving size for vegetables is ¼ to ½ cup, with one cup allowed for leafy green vegetables. The recommended daily levels of low fructose vegetables range from one and a half to two cups per day, according to the University of Virginia Health System.
Low-fructose vegetables that can be eaten up to four times daily contain 0 to .2 g of fructose. Recommended daily vegetables, according to University of Iowa Healthcare, include broad beans, celery, chives, dandelion greens, endive, escarole, mushrooms, mustard greens, immature pea pods, potatoes, shallots, spinach, Swiss chard and turnip greens.
Medium-low fructose vegetables contain .3 to .6 g of fructose. Fructose intolerant individuals can eat up to two servings per week of these vegetables, including asparagus, broccoli, Brussels sprouts, raw, white cabbage, cauliflower, raw cucumber, raw green peppers, cooked leeks, iceberg lettuce, raw radishes, summer squash, watercress and zucchini.
- “Prescription for Nutritional Healing;” Phyllis Balch; 2006
- University of Iowa Health Care: Dietary Fructose Intolerance (DFI)
- University of Virginia Health System: Low Fructose Diet