Food has always had powerful symbolic associations in Hindu tradition, beginning with the ancient Vedic sacrificial rites. Not until the rise of Jainism and Buddhism, with their emphasis on nonviolence, did vegetarianism become part of mainstream Hindu practice. Brahmins have generally been more careful to observe vegetarian practice than have members of other castes. Among the various denominations, Vaish-navites have paid greater attention to dietary issues. All foods have specific effects on one of the three psycho-spiritual qualities called gunas—light or purity, excitement or energy, darkness or inertia. A traditional Vaishnava diet avoids foods that stir the passions (garlic, red fruits and vegetables) or incline one to negative moods (flesh and intoxicants), while emphasizing those that have a positive effect (dairy products, grains, most fruits and vegetables). Sannyasis of all denominations are usually strict vegetarians. But the majority of Hindus nowadays tend to regard all foods, taken in moderation and as part of a balanced and healthful diet, as religiously acceptable. Most believe that strict vegetarianism is required only in ritual settings and in celebration of specifically religious observances. Some Hindus still refuse to take meals in the presence of members of other castes, whether lower or higher than their own, but this is a social rather than a dietary concern.