The tang of fresh grapefruit (GI 25) will not only start your day with zest, just half a medium-sized one will deliver around 70% of your daily dose of vitamin C. Canned grapefruit segments (GI 47) and commercial grapefruit juice (GI 48) are easy year-round options when fresh fruit isn’t available, but as you can see they have higher GI values. In fact, fresh grapefruit has the lowest GI value of all fruit tested so far. It’s not just the acid that has a blood glucose-lowering effect, it’s also the pectin (a type of soluble fibre).
Grapefruit can play a smart part in helping you to reach your weight-loss goals as part of an overall healthy balanced diet being a nutrient-rich food that’s low in calories and high in volume (they are very juicy). A 2006 study in the Journal of Medicinal Food found that ‘half of a fresh grapefruit eaten before meals was associated with significant weight loss (an average of 1.6kg [3½lb] over twelve weeks).’ Insulin resistance also improved.
Writing in the Journal of Agricultural and Food Chemistry Israeli researchers report that a heart-healthy diet supplemented with fresh red grapefruit was effective in lowering triglycerides, a blood fat that’s a risk factor for heart disease. They divided 57 post-operative bypass patients with atherosclerosis (not taking statins) into three groups who were served a standard diet for 30 days with either a single serving of fresh red grapefruit, or a single serving of fresh white grapefruit, or no grapefruit (the control group). The men and women who consumed fresh red or white grapefruit had significant decreases in total and LDL cholesterol levels compared with the control group.
Grapefruit and medication: Grapefruit and grapefruit juice can interact with a number of medications, either making them work too strongly or causing unpleasant side effects. Mayo Clinic nutritionist Katherine Zeratsky, R.D. says: ‘If you're concerned about the effect grapefruit juice may have on your medications, talk to your doctor or pharmacist.’
- Toss segments in salads with chickpeas; or fennel and rocket/arugula; smoked salmon and avocado; prawn and avocado; or witlof, radicchio, beets and avocado; or simply add to Asian greens with a citrus dressing.
- Whip up a winter fruit salad with grapefruit and orange segments, a sprinkle of raisins and a drizzle of honey.
- Spritz tangy grapefruit juice and soda for a fresh and fruit drink with fewer calories.